CopperSpice API  1.7.2
QWidget Class Reference

Base class fr all user interface controls. More...

Inheritance diagram for QWidget:
QObject QPaintDevice QAbstractButton QAbstractSlider QAbstractSpinBox QCalendarWidget QComboBox QDesktopWidget QDialog QDialogButtonBox QDockWidget QFocusFrame QFrame QGLWidget QGroupBox QKeySequenceEdit QLineEdit QMacCocoaViewContainer QMacNativeWidget QMainWindow QMdiSubWindow QMenu QMenuBar QOpenGLWidget QPrintPreviewWidget QProgressBar QRubberBand QSizeGrip QSplashScreen QSplitterHandle QStatusBar QSvgWidget QTabBar QTabWidget QToolBar QVideoWidget QWebInspector QWebView QWizardPage

Public Types

enum  RenderFlag
 
- Public Types inherited from QPaintDevice
enum  PaintDeviceMetric
 

Public Signals

void customContextMenuRequested (const QPoint &pos)
 
void windowIconChanged (const QIcon &icon)
 
void windowIconTextChanged (const QString &iconText)
 
void windowTitleChanged (const QString &title)
 
- Public Signals inherited from QObject
void destroyed (QObject *obj=nullptr)
 
void objectNameChanged (const QString &objectName)
 

Public Slots

bool close ()
 
void hide ()
 
void lower ()
 
void raise ()
 
void repaint ()
 
void setDisabled (bool disable)
 
void setEnabled (bool enable)
 
void setFocus ()
 
void setHidden (bool hidden)
 
void setStyleSheet (const QString &styleSheet)
 
virtual void setVisible (bool visible)
 
void setWindowModified (bool modified)
 
void setWindowTitle (const QString &title)
 
void show ()
 
void showFullScreen ()
 
void showMaximized ()
 
void showMinimized ()
 
void showNormal ()
 
void update ()
 
- Public Slots inherited from QObject
void deleteLater ()
 

Public Methods

 QWidget (QWidget *parent=nullptr, Qt::WindowFlags flags=Qt::EmptyFlag)
 
 ~QWidget ()
 
bool acceptDrops () const
 
QString accessibleDescription () const
 
QString accessibleName () const
 
QList< QAction * > actions () const
 
void activateWindow ()
 
void addAction (QAction *action)
 
void addActions (const QList< QAction * > &actions)
 
void adjustSize ()
 
bool autoFillBackground () const
 
QPalette::ColorRole backgroundRole () const
 
QBackingStorebackingStore () const
 
QSize baseSize () const
 
QWidget * childAt (const QPoint &position) const
 
QWidget * childAt (int x, int y) const
 
QRect childrenRect () const
 
QRegion childrenRegion () const
 
void clearFocus ()
 
void clearMask ()
 
QMargins contentsMargins () const
 
QRect contentsRect () const
 
Qt::ContextMenuPolicy contextMenuPolicy () const
 
QCursor cursor () const
 
WId effectiveWinId () const
 
void ensurePolished () const
 
Qt::FocusPolicy focusPolicy () const
 
QWidget * focusProxy () const
 
QWidget * focusWidget () const
 
const QFontfont () const
 
QFontInfo fontInfo () const
 
QFontMetrics fontMetrics () const
 
QPalette::ColorRole foregroundRole () const
 
QRect frameGeometry () const
 
QSize frameSize () const
 
const QRectgeometry () const
 
void getContentsMargins (int *left, int *top, int *right, int *bottom) const
 
QPixmap grab (const QRect &rectangle=QRect (QPoint (0, 0), QSize (-1,-1)))
 
void grabGesture (Qt::GestureType gestureType, Qt::GestureFlags flags=Qt::GestureFlags ())
 
void grabKeyboard ()
 
void grabMouse ()
 
void grabMouse (const QCursor &cursor)
 
int grabShortcut (const QKeySequence &key, Qt::ShortcutContext context=Qt::WindowShortcut)
 
QGraphicsEffectgraphicsEffect () const
 
QGraphicsProxyWidgetgraphicsProxyWidget () const
 
bool hasEditFocus () const
 
bool hasFocus () const
 
virtual bool hasHeightForWidth () const
 
bool hasMouseTracking () const
 
int height () const
 
virtual int heightForWidth (int width) const
 
Qt::InputMethodHints inputMethodHints () const
 
virtual QVariant inputMethodQuery (Qt::InputMethodQuery query) const
 
void insertAction (QAction *before, QAction *action)
 
void insertActions (QAction *before, QList< QAction * > actions)
 
bool isActiveWindow () const
 
bool isAncestorOf (const QWidget *child) const
 
bool isEnabled () const
 
bool isEnabledTo (const QWidget *parent) const
 
bool isEnabledToTLW () const
 
bool isFullScreen () const
 
bool isHidden () const
 
bool isMaximized () const
 
bool isMinimized () const
 
bool isModal () const
 
bool isTopLevel () const
 
bool isVisible () const
 
bool isVisibleTo (const QWidget *parent) const
 
bool isWindow () const
 
bool isWindowModified () const
 
QLayoutlayout () const
 
Qt::LayoutDirection layoutDirection () const
 
QLocale locale () const
 
QPoint mapFrom (const QWidget *parent, const QPoint &pos) const
 
QPoint mapFromGlobal (const QPoint &pos) const
 
QPoint mapFromParent (const QPoint &pos) const
 
QPoint mapTo (const QWidget *parent, const QPoint &pos) const
 
QPoint mapToGlobal (const QPoint &pos) const
 
QPoint mapToParent (const QPoint &pos) const
 
QRegion mask () const
 
int maximumHeight () const
 
QSize maximumSize () const
 
int maximumWidth () const
 
int minimumHeight () const
 
QSize minimumSize () const
 
virtual QSize minimumSizeHint () const
 
int minimumWidth () const
 
void move (const QPoint &point)
 
void move (int x, int y)
 
QWidget * nativeParentWidget () const
 
QWidget * nextInFocusChain () const
 
QRect normalGeometry () const
 
void overrideWindowFlags (Qt::WindowFlags flags)
 
QPaintEnginepaintEngine () const override
 
const QPalettepalette () const
 
QWidget * parentWidget () const
 
QPoint pos () const
 
QWidget * previousInFocusChain () const
 
QRect rect () const
 
void releaseKeyboard ()
 
void releaseMouse ()
 
void releaseShortcut (int id)
 
void removeAction (QAction *action)
 
void render (QPaintDevice *target, const QPoint &targetOffset=QPoint (), const QRegion &sourceRegion=QRegion (), RenderFlags renderFlags=RenderFlags (DrawWindowBackground|DrawChildren))
 
void render (QPainter *painter, const QPoint &targetOffset=QPoint (), const QRegion &sourceRegion=QRegion (), RenderFlags renderFlags=RenderFlags (DrawWindowBackground|DrawChildren))
 
void repaint (const QRect &rect)
 
void repaint (const QRegion &region)
 
void repaint (int x, int y, int w, int h)
 
void resize (const QSize &size)
 
void resize (int w, int h)
 
bool restoreGeometry (const QByteArray &geometry)
 
QByteArray saveGeometry () const
 
void scroll (int dx, int dy)
 
void scroll (int dx, int dy, const QRect &rect)
 
void setAcceptDrops (bool on)
 
void setAccessibleDescription (const QString &description)
 
void setAccessibleName (const QString &name)
 
void setAttribute (Qt::WidgetAttribute attribute, bool enable=true)
 
void setAutoFillBackground (bool enable)
 
void setBackgroundRole (QPalette::ColorRole role)
 
void setBaseSize (const QSize &size)
 
void setBaseSize (int basew, int baseh)
 
void setContentsMargins (const QMargins &margins)
 
void setContentsMargins (int left, int top, int right, int bottom)
 
void setContextMenuPolicy (Qt::ContextMenuPolicy policy)
 
void setCursor (const QCursor &cursor)
 
void setEditFocus (bool enable)
 
void setFixedHeight (int h)
 
void setFixedSize (const QSize &size)
 
void setFixedSize (int w, int h)
 
void setFixedWidth (int w)
 
void setFocus (Qt::FocusReason reason)
 
void setFocusPolicy (Qt::FocusPolicy policy)
 
void setFocusProxy (QWidget *widget)
 
void setFont (const QFont &font)
 
void setForegroundRole (QPalette::ColorRole role)
 
void setGeometry (const QRect &rect)
 
void setGeometry (int x, int y, int w, int h)
 
void setGraphicsEffect (QGraphicsEffect *effect)
 
void setInputMethodHints (Qt::InputMethodHints hints)
 
void setLayout (QLayout *layout)
 
void setLayoutDirection (Qt::LayoutDirection direction)
 
void setLocale (const QLocale &locale)
 
void setMask (const QBitmap &bitmap)
 
void setMask (const QRegion &region)
 
void setMaximumHeight (int maxh)
 
void setMaximumSize (const QSize &size)
 
void setMaximumSize (int maxw, int maxh)
 
void setMaximumWidth (int maxw)
 
void setMinimumHeight (int minh)
 
void setMinimumSize (const QSize &size)
 
void setMinimumSize (int minw, int minh)
 
void setMinimumWidth (int minw)
 
void setMouseTracking (bool enable)
 
void setPalette (const QPalette &palette)
 
void setParent (QWidget *parent)
 
void setParent (QWidget *parent, Qt::WindowFlags flags)
 
void setShortcutAutoRepeat (int id, bool enable=true)
 
void setShortcutEnabled (int id, bool enable=true)
 
void setSizeIncrement (const QSize &size)
 
void setSizeIncrement (int w, int h)
 
void setSizePolicy (QSizePolicy policy)
 
void setSizePolicy (QSizePolicy::Policy horizontal, QSizePolicy::Policy vertical)
 
void setStatusTip (const QString &data)
 
void setStyle (QStyle *style)
 
void setToolTip (const QString &data)
 
void setToolTipDuration (int msec)
 
void setUpdatesEnabled (bool enable)
 
void setWhatsThis (const QString &str)
 
void setWindowFilePath (const QString &filePath)
 
void setWindowFlags (Qt::WindowFlags flags)
 
void setWindowIcon (const QIcon &icon)
 
void setWindowModality (Qt::WindowModality windowModality)
 
void setWindowOpacity (qreal level)
 
void setWindowRole (const QString &role)
 
void setWindowState (Qt::WindowStates windowState)
 
QSize size () const
 
virtual QSize sizeHint () const
 
QSize sizeIncrement () const
 
QSizePolicy sizePolicy () const
 
void stackUnder (QWidget *widget)
 
QString statusTip () const
 
QStylestyle () const
 
QString styleSheet () const
 
bool testAttribute (Qt::WidgetAttribute attribute) const
 
QString toolTip () const
 
int toolTipDuration () const
 
QWidget * topLevelWidget () const
 
bool underMouse () const
 
void ungrabGesture (Qt::GestureType gestureType)
 
void unsetCursor ()
 
void unsetLayoutDirection ()
 
void unsetLocale ()
 
void update (const QRect &rect)
 
void update (const QRegion &region)
 
void update (int x, int y, int w, int h)
 
void updateGeometry ()
 
bool updatesEnabled () const
 
QRegion visibleRegion () const
 
QString whatsThis () const
 
int width () const
 
QWidget * window () const
 
QString windowFilePath () const
 
Qt::WindowFlags windowFlags () const
 
QWindowwindowHandle () const
 
QIcon windowIcon () const
 
Qt::WindowModality windowModality () const
 
qreal windowOpacity () const
 
QString windowRole () const
 
Qt::WindowStates windowState () const
 
QString windowTitle () const
 
Qt::WindowType windowType () const
 
WId winId () const
 
int x () const
 
int y () const
 
- Public Methods inherited from QObject
 QObject (QObject *parent=nullptr)
 
 ~QObject ()
 
bool blockSignals (bool block)
 
const QList< QObject * > & children () const
 
bool connect (const QObject *sender, const QString &signalMethod, const QString &location, const QString &slotMethod, Qt::ConnectionType type=Qt::AutoConnection)
 
bool connect (const QObject *sender, const QString &signalMethod, const QString &slotMethod, Qt::ConnectionType type=Qt::AutoConnection)
 
bool disconnect (const QObject *receiver, const QString &slotMethod=QString ()) const
 
bool disconnect (const QString &signalMethod, const QString &location, const QObject *receiver=nullptr, const QString &slotMethod=QString ()) const
 
bool disconnect (const QString &signalMethod=QString (), const QObject *receiver=nullptr, const QString &slotMethod=QString ()) const
 
void dumpObjectInfo ()
 
void dumpObjectTree ()
 
QList< QStringdynamicPropertyNames () const
 
virtual bool event (QEvent *event)
 
virtual bool eventFilter (QObject *watched, QEvent *event)
 
template<typename T >
findChild (const QString &childName=QString ()) const
 
template<class T >
QList< T > findChildren (const QRegularExpression &regExp, Qt::FindChildOptions options=Qt::FindChildrenRecursively) const
 
template<class T >
QList< T > findChildren (const QString &objName=QString (), Qt::FindChildOptions options=Qt::FindChildrenRecursively) const
 
bool inherits (const QString &className) const
 
void installEventFilter (QObject *filterObj)
 
bool isWidgetType () const
 
bool isWindowType () const
 
void killTimer (int id)
 
const QMetaObjectmetaObject () const
 
void moveToThread (QThread *targetThread)
 
QString objectName () const
 
QObject * parent () const
 
template<class T = QVariant>
property (const QString &name) const
 
void removeEventFilter (QObject *obj)
 
void setObjectName (const QString &name)
 
void setParent (QObject *parent)
 
bool setProperty (const QString &name, const QVariant &value)
 
bool signalsBlocked () const
 
int startTimer (int interval, Qt::TimerType timerType=Qt::CoarseTimer)
 
QThreadthread () const
 
- Public Methods inherited from QPaintDevice
virtual ~QPaintDevice ()
 
int colorCount () const
 
int depth () const
 
int devicePixelRatio () const
 
qreal devicePixelRatioF () const
 
int height () const
 
int heightMM () const
 
int logicalDpiX () const
 
int logicalDpiY () const
 
bool paintingActive () const
 
int physicalDpiX () const
 
int physicalDpiY () const
 
int width () const
 
int widthMM () const
 

Static Public Methods

static QWidget * createWindowContainer (QWindow *window, QWidget *parent=nullptr, Qt::WindowFlags flags=Qt::EmptyFlag)
 
static QWidget * find (WId id)
 
static QWidget * keyboardGrabber ()
 
static QWidget * mouseGrabber ()
 
static void setTabOrder (QWidget *firstWidget, QWidget *secondWidget)
 
- Static Public Methods inherited from QObject
static bool connect (const QObject *sender, const QMetaMethod &signalMethod, const QObject *receiver, const QMetaMethod &slotMethod, Qt::ConnectionType type=Qt::AutoConnection)
 
static bool connect (const QObject *sender, const QString &signalMethod, const QObject *receiver, const QString &slotMethod, Qt::ConnectionType type=Qt::AutoConnection, const QString &location=QString ())
 
static bool connect (const QObject *sender, const QString &signalMethod, const QString &location, const QObject *receiver, const QString &slotMethod, Qt::ConnectionType type=Qt::AutoConnection)
 
template<class Sender , class SignalClass , class... SignalArgs, class Receiver , class SlotClass , class... SlotArgs, class SlotReturn >
static bool connect (const Sender *sender, void (SignalClass::*signalMethod)(SignalArgs...), const Receiver *receiver, SlotReturn (SlotClass::*slotMethod)(SlotArgs...), Qt::ConnectionType type=Qt::AutoConnection)
 
template<class Sender , class SignalClass , class... SignalArgs, class Receiver , class T >
static bool connect (const Sender *sender, void (SignalClass::*signalMethod)(SignalArgs...), const Receiver *receiver, T slotLambda, Qt::ConnectionType type=Qt::AutoConnection)
 
static bool disconnect (const QObject *sender, const QMetaMethod &signalMethod, const QObject *receiver, const QMetaMethod &slotMethod)
 
static bool disconnect (const QObject *sender, const QString &signalMethod, const QObject *receiver, const QString &slotMethod)
 
static bool disconnect (const QObject *sender, const QString &signalMethod, const QString &location, const QObject *receiver, const QString &slotMethod)
 
template<class Sender , class SignalClass , class... SignalArgs, class Receiver , class SlotClass , class... SlotArgs, class SlotReturn >
static bool disconnect (const Sender *sender, void (SignalClass::*signalMethod)(SignalArgs...), const Receiver *receiver, SlotReturn (SlotClass::*slotMethod)(SlotArgs...))
 
template<class Sender , class SignalClass , class... SignalArgs, class Receiver >
static bool disconnect (const Sender *sender, void (SignalClass::*signalMethod)(SignalArgs...), const Receiver *receiver, std::nullptr_t slotMethod=nullptr)
 
template<class Sender , class SignalClass , class... SignalArgs, class Receiver , class T >
static bool disconnect (const Sender *sender, void (SignalClass::*signalMethod)(SignalArgs...), const Receiver *receiver, T slotMethod)
 
static QMetaObjectstaticMetaObject ()
 
static QString tr (const char *text, const char *comment=nullptr, std::optional< int > numArg=std::optional< int >())
 

Protected Slots

void updateMicroFocus ()
 

Protected Methods

virtual void actionEvent (QActionEvent *event)
 
virtual void changeEvent (QEvent *event)
 
virtual void closeEvent (QCloseEvent *event)
 
virtual void contextMenuEvent (QContextMenuEvent *event)
 
void create (WId window=0, bool initializeWindow=true, bool destroyOldWindow=true)
 
void destroy (bool destroyWindow=true, bool destroySubWindows=true)
 
virtual void dragEnterEvent (QDragEnterEvent *event)
 
virtual void dragLeaveEvent (QDragLeaveEvent *event)
 
virtual void dragMoveEvent (QDragMoveEvent *event)
 
virtual void dropEvent (QDropEvent *event)
 
virtual void enterEvent (QEvent *event)
 
bool event (QEvent *event) override
 
virtual void focusInEvent (QFocusEvent *event)
 
bool focusNextChild ()
 
virtual bool focusNextPrevChild (bool next)
 
virtual void focusOutEvent (QFocusEvent *event)
 
bool focusPreviousChild ()
 
virtual void hideEvent (QHideEvent *event)
 
void initPainter (QPainter *painter) const override
 
virtual void inputMethodEvent (QInputMethodEvent *event)
 
virtual void keyPressEvent (QKeyEvent *event)
 
virtual void keyReleaseEvent (QKeyEvent *event)
 
virtual void leaveEvent (QEvent *event)
 
int metric (PaintDeviceMetric metric) const override
 
virtual void mouseDoubleClickEvent (QMouseEvent *event)
 
virtual void mouseMoveEvent (QMouseEvent *event)
 
virtual void mousePressEvent (QMouseEvent *event)
 
virtual void mouseReleaseEvent (QMouseEvent *event)
 
virtual void moveEvent (QMoveEvent *event)
 
virtual bool nativeEvent (const QByteArray &eventType, void *message, long *result)
 
virtual void paintEvent (QPaintEvent *event)
 
virtual void resizeEvent (QResizeEvent *event)
 
virtual void showEvent (QShowEvent *event)
 
virtual void tabletEvent (QTabletEvent *event)
 
virtual void wheelEvent (QWheelEvent *event)
 
- Protected Methods inherited from QObject
virtual void childEvent (QChildEvent *event)
 
virtual void connectNotify (const QMetaMethod &signalMethod) const
 
virtual void customEvent (QEvent *event)
 
virtual void disconnectNotify (const QMetaMethod &signalMethod) const
 
bool isSignalConnected (const QMetaMethod &signalMethod) const
 
int receivers (const QString &signal) const
 
QObject * sender () const
 
int senderSignalIndex () const
 
virtual void timerEvent (QTimerEvent *event)
 
- Protected Methods inherited from QPaintDevice
 QPaintDevice ()
 

Properties

 acceptDrops
 
 accessibleDescription
 
 accessibleName
 
 autoFillBackground
 
 baseSize
 
 childrenRect
 
 childrenRegion
 
 contextMenuPolicy
 
 cursor
 
 enabled
 
 focus
 
 focusPolicy
 
 font
 
 frameGeometry
 
 frameSize
 
 fullScreen
 
 geometry
 
 height
 
 inputMethodHints
 
 isActiveWindow
 
 layoutDirection
 
 locale
 
 maximized
 
 maximumHeight
 
 maximumSize
 
 maximumWidth
 
 minimized
 
 minimumHeight
 
 minimumSize
 
 minimumSizeHint
 
 minimumWidth
 
 modal
 
 mouseTracking
 
 normalGeometry
 
 palette
 
 pos
 
 rect
 
 size
 
 sizeHint
 
 sizeIncrement
 
 sizePolicy
 
 statusTip
 
 styleSheet
 
 toolTip
 
 updatesEnabled
 
 visible
 
 whatsThis
 
 width
 
 windowFilePath
 
 windowFlags
 
 windowIcon
 
 windowIconText
 
 windowModality
 
 windowModified
 
 windowOpacity
 
 windowTitle
 
 x
 
 y
 
- Properties inherited from QObject
 objectName
 

Friends

class QAccessibleWidget
 
class QApplication
 
class QFontInfo
 
class QFontMetrics
 
class QGLContext
 
class QGLWidget
 
class QGraphicsProxyWidget
 
class QLayout
 
class QPainter
 
class QPixmap
 
class QWidgetItem
 

Related Functions

These are not member functions

 QWidgetList
 
 WId
 

Detailed Description

The QWidget class is the base class of all user interface controls. A widget is the fundamental building block used to create a user interface. This class receives mouse, keyboard and other events from the windowing system and is responsible for rendering the user interface controls on the screen. The user interface controls such as a push button or a text edit are called widgets. They are sorted in a Z order so the user can press the tab key to transition from one widget to the next.

A widget which does not have a parent is called a window. A window typically has a frame and a title bar although it is possible to create a window without these elements by using window flags. The QMainWindow and the various subclasses of QDialog are the most common window types.

Every constructor for a widget can accept one or two arguments.

QWidget *parent = nullptr
Parent of the new widget. If the parent is a nullptr the new widget will be a window. If a parent is specified the new windows will be a child and it will be constrained by the parent's geometry, unless you specify Qt::Window as a window flag.
Qt::WindowFlags flags = Qt::EmptyFlag
Where available sets the window flags. The default is suitable for almost all widgets but to obtain a window without a window system frame, you must use special flags.

QWidget has numerous methods which are not used directly by this class. For example, the font property is not used internally in QWidget. There are many subclasses which provide implementations which need a font such as QLabel, QPushButton, QListWidget, and QTabWidget.

Top Level and Child Widgets

A widget without a parent widget is always an independent window (top-level widget). For these widgets, setWindowTitle() and setWindowIcon() set the title bar and icon respectively.

Non-window widgets are child widgets, displayed within their parent widgets. Most widgets in CopperSpice are mainly useful as child widgets. For example, it is possible to display a button as a top-level window, but most people prefer to put their buttons inside other widgets, such as QDialog.

The diagram above shows a QGroupBox widget being used to hold various child widgets in a layout provided by QGridLayout. The QLabel child widgets have been outlined to indicate their full sizes.

If you want to use a QWidget to hold child widgets you will usually want to add a layout to the parent QWidget. Refer to Layout Management for more information.

Composite Widgets

When a widget is used as a container to group a number of child widgets, it is known as a composite widget. These can be created by constructing a widget with the required visual properties, like a QFrame for example, and adding child widgets to it, usually managed by a layout. The above diagram shows such a composite widget that was created using Qt Designer.

Composite widgets can also be created by subclassing a standard widget, such as QWidget or QFrame, and adding the necessary layout and child widgets in the constructor of the subclass.

Custom Widgets and Painting

Since QWidget is a subclass of QPaintDevice, subclasses can be used to display custom content that is composed using a series of painting operations with an instance of the QPainter class. This approach contrasts with the canvas-style approach used by the Graphics View System where items are added to a scene by the application and are rendered by CopperSpice itself.

Each widget performs all painting operations from within its paintEvent() method. This is called whenever the widget needs to be redrawn, either as a result of some external change or when requested by the application.

Size Hints and Size Policies

When implementing a new widget, it is almost always useful to reimplement sizeHint() to provide a reasonable default size for the widget and to set the correct size policy with setSizePolicy().

By default, composite widgets which do not provide a size hint will be sized according to the space requirements of their child widgets.

The size policy lets you supply good default behavior for the layout management system, so that other widgets can contain and manage yours easily. The default size policy indicates that the size hint represents the preferred size of the widget, and this is often good enough for many widgets.

Note
The size of top-level widgets are constrained to 2/3 of the desktop's height and width. You can resize() the widget manually if these bounds are inadequate.

Events

Widgets respond to events that are typically caused by user actions. CopperSpice delivers events to widgets by calling specific event handler methods with instances of QEvent subclasses containing information about each event. If your widget only contains child widgets you probably do not need to implement any event handlers. If you want to detect a mouse click in a child widget call the child's underMouse() method inside the widget's mousePressEvent().

You will need to supply the behavior and content for your own widgets. The following is a an overview of the events that are relevant to QWidget.

paintEvent()
Called when the widget needs to be repainted. Every widget displaying custom content must implement it. Painting using a QPainter can only take place in a paintEvent() or a method called by a paintEvent().
resizeEvent()
Called when the widget has been resized.
mousePressEvent()
Called when a mouse button is pressed while the mouse cursor is inside the widget, or when the widget has grabbed the mouse using grabMouse(). Pressing the mouse without releasing it is effectively the same as calling grabMouse().
mouseReleaseEvent()
Called when a mouse button is released. A widget receives mouse release events when it has received the corresponding mouse press event. This means that if the user presses the mouse inside your widget, then drags the mouse somewhere else before releasing the mouse button, your widget receives the release event. There is one exception, if a popup menu appears while the mouse button is held down, this popup immediately steals the mouse events.
mouseDoubleClickEvent()
Called when the user double-clicks in the widget. If the user double-clicks, the widget receives a mouse press event, a mouse release event and finally this event instead of a second mouse press event. Some mouse move events may also be received if the mouse is not held steady during this operation.) It is not possible to distinguish a click from a double-click until the second click arrives.

Widgets that accept keyboard input need to reimplement additional more event handlers.

keyPressEvent()
Called whenever a key is pressed, and again when a key has been held down long enough for it to auto-repeat. The Tab and Shift+Tab keys are only passed to the widget if they are not used by the focus change mechanisms. To force those keys to be processed by your widget, you must reimplement QWidget::event().
focusInEvent()
Called when the widget gains keyboard focus.
focusOutEvent()
Called when the widget loses keyboard focus.

You may be required to also reimplement some of the less common event handlers as listed below.

mouseMoveEvent()
Called when the mouse moves while a mouse button is held down. This can be useful during drag and drop operations. If you call setMouseTracking(true) you get mouse move events even when no buttons are held down. Refer to the Drag and Drop documentation.
keyReleaseEvent()
Called whenever a key is released and while it is held down (if the key is auto-repeating). In that case, the widget will receive a pair of key release and key press event for every repeat. The Tab and Shift+Tab keys are only passed to the widget if they are not used by the focus-change mechanisms. To force those keys to be processed by your widget, you must reimplement QWidget::event().
wheelEvent()
Called whenever the user turns the mouse wheel while the widget has the focus.
enterEvent()
Called when the mouse enters the widget's screen space, this excludes screen space owned by any of the widget's children.
leaveEvent()
Called when the mouse leaves the widget's screen space. If the mouse enters a child widget it will not cause a leaveEvent().
moveEvent()
Called when the widget has been moved relative to its parent.
closeEvent()
Called when the user closes the widget or when close() is called.

There are also some rather obscure events described in the documentation for QEvent::Type. To handle these events, you need to reimplement event() directly. The default implementation of event() handles Tab and Shift+Tab (to move the keyboard focus), and passes on most of the other events to one of the more specialized handlers above.

Events and the mechanism used to deliver them are covered in The Event System.

Groups of Functions and Properties

ContextFunctions and Properties
Window methodsshow(), hide(), raise(), lower(), close()
Top-level windowswindowModified, windowTitle, windowIcon, windowIconText, isActiveWindow, activateWindow(), minimized, showMinimized(), maximized, showMaximized(), fullScreen, showFullScreen(), showNormal()
Window contentsupdate(), repaint(), scroll()
Geometrypos, x(), y(), rect, size, width(), height(), move(), resize(), sizePolicy, sizeHint(), minimumSizeHint(), updateGeometry(), layout(), frameGeometry, geometry, childrenRect, childrenRegion, adjustSize(), mapFromGlobal(), mapToGlobal(), mapFromParent(), mapToParent(), maximumSize, minimumSize, sizeIncrement, baseSize, setFixedSize()
Modevisible, isVisibleTo(), enabled, isEnabledTo(), modal, isWindow(), mouseTracking, updatesEnabled, visibleRegion()
Look and feelstyle(), setStyle(), styleSheet, cursor, font, palette, backgroundRole(), setBackgroundRole(), fontInfo(), fontMetrics()
Keyboard focus methodsfocus, focusPolicy, setFocus(), clearFocus(), setTabOrder(), setFocusProxy(), focusNextChild(), focusPreviousChild()
Mouse & keyboard grabbinggrabMouse(), releaseMouse(), grabKeyboard(), releaseKeyboard(), mouseGrabber(), keyboardGrabber()
Event handlersevent(), mousePressEvent(), mouseReleaseEvent(), mouseDoubleClickEvent(), mouseMoveEvent(), keyPressEvent(), keyReleaseEvent(), focusInEvent(), focusOutEvent(), wheelEvent(), enterEvent(), leaveEvent(), paintEvent(), moveEvent(), resizeEvent(), closeEvent(), dragEnterEvent(), dragMoveEvent(), dragLeaveEvent(), dropEvent(), childEvent(), showEvent(), hideEvent(), customEvent(). changeEvent()
System methodsparentWidget(), window(), setParent(), winId(), find(), metric()
Interactive helpsetToolTip(), setWhatsThis()

Widget Style Sheets

In addition to the standard widget styles for each platform, widgets can also be styled according to rules specified in a style sheet. This feature enables you to customize the appearance of specific widgets to provide visual cues to users about their purpose. For example, a button could be styled in a particular way to indicate that it performs a destructive action.

The use of widget style sheets is described in more detail in CopperSpice Style Sheets.

Transparency and Double Buffering

QWidget automatically double-buffers its painting, so there is no need to write double-buffering code in paintEvent() to avoid flicker.

The Qt::WA_ContentsPropagated widget attribute has been deprecated. Instead, the contents of parent widgets are propagated by default to each of their children as long as Qt::WA_PaintOnScreen is not set. Custom widgets can be written to take advantage of this feature by updating irregular regions (to create non-rectangular child widgets), or painting with colors that have less than full alpha component. The following diagram shows how attributes and properties of a custom widget can be fine-tuned to achieve different effects.

In the above diagram, a semi-transparent rectangular child widget with an area removed is constructed and added to a parent widget (a QLabel showing a pixmap). Then, different properties and widget attributes are set to achieve different effects:

  • The left widget has no additional properties or widget attributes set. This default state suits most custom widgets using transparency, are irregularly-shaped, or do not paint over their entire area with an opaque brush.
  • The center widget has the autoFillBackground property set. This property is used with custom widgets that rely on the widget to supply a default background, and do not paint over their entire area with an opaque brush.
  • The right widget has the Qt::WA_OpaquePaintEvent widget attribute set. This indicates that the widget will paint over its entire area with opaque colors. The widget's area will initially be uninitialized, represented in the diagram with a red diagonal grid pattern that shines through the overpainted area. The Qt::WA_OpaquePaintArea attribute is useful for widgets that need to paint their own specialized contents quickly and do not need a default filled background.

To rapidly update custom widgets with simple background colors, such as real-time plotting or graphing widgets, it is better to define a suitable background color (using setBackgroundRole() with the QPalette::Window role), set the autoFillBackground property, and only implement the necessary drawing functionality in the widget's paintEvent().

To rapidly update custom widgets that constantly paint over their entire areas with opaque content, e.g., video streaming widgets, it is better to set the widget's Qt::WA_OpaquePaintEvent, avoiding any unnecessary overhead associated with repainting the widget's background.

If a widget has both the Qt::WA_OpaquePaintEvent widget attribute and the autoFillBackground property set, the Qt::WA_OpaquePaintEvent attribute takes precedence. Depending on your requirements, you should choose either one of them.

The contents of parent widgets are also propagated to standard CopperSpice widgets. This can lead to some unexpected results if the parent widget is decorated in a non-standard way, as shown in the diagram below.

The scope for customizing the painting behavior of standard CopperSpice widgets, without resorting to subclassing, is slightly less than that possible for custom widgets. Usually, the desired appearance of a standard widget can be achieved by setting its autoFillBackground property.

Creating Translucent Windows

It is possible to create windows with translucent regions on window systems that support compositing.

To enable this feature in a top-level widget, set its Qt::WA_TranslucentBackground attribute with setAttribute() and ensure that its background is painted with non-opaque colors in the regions you want to be partially transparent.

Platform notes:

  • X11: This feature relies on the use of an X server that supports ARGB visuals and a compositing window manager.
  • Windows: The widget needs to have the Qt::FramelessWindowHint window flag set for the translucency to work.

Native Widgets vs Alien Widgets

Alien widgets are widgets unknown to the windowing system. They do not have a native window handle associated with them. This feature significantly speeds up widget painting, resizing, and removes flicker.

Should you require the old behavior with native windows, you can choose one of the following options:

  1. Use the QT_USE_NATIVE_WINDOWS=1 in your environment.
  2. Set the Qt::AA_NativeWindows attribute on your application. All widgets will be native widgets.
  3. Set the Qt::WA_NativeWindow attribute on widgets: The widget itself and all of its ancestors will become native (unless Qt::WA_DontCreateNativeAncestors is set).
  4. Call QWidget::winId to enforce a native window (this implies 3).
  5. Set the Qt::WA_PaintOnScreen attribute to enforce a native window (this implies 3).
See also
QEvent, QPainter, QGridLayout, QBoxLayout, addAction(), QAction, QMenuBar

Member Enumeration Documentation

This enum describes how to render the widget when calling QWidget::render().

ConstantValueDescription
QWidget::DrawWindowBackground 0x1 If you enable this option, the widget's background is rendered into the target even if autoFillBackground is not set. By default, this option is enabled.
QWidget::DrawChildren 0x2 If you enable this option, the widget's children are rendered recursively into the target. By default, this option is enabled.
QWidget::IgnoreMask 0x4 If you enable this option, the widget's QWidget::mask() is ignored when rendering into the target. By default, this option is disabled.

The RenderFlags type is a typedef for QFlags<RenderFlag>. It stores an OR combination of RenderFlag values.

Constructor & Destructor Documentation

QWidget::QWidget ( QWidget *  parent = nullptr,
Qt::WindowFlags  flags = Qt::EmptyFlag 
)
explicit

Constructs a widget which is a child of parent, with widget flags set to flags. If parent is nullptr the new widget becomes a window. If parent is another widget, this widget becomes a child window inside parent. The new widget is deleted when its parent is deleted.

The widget flags argument f is normally 0, but it can be set to customize the frame of a window (i.e. parent must be nullptr). To customize the frame use a value composed from the bitwise OR of any of the window flags.

If you add a child widget to an already visible widget you must explicitly show the child to make it visible.

The X11 version of CopperSpice may not be able to deliver all combinations of style flags on all systems. This occurs because CopperSpice can only ask the window manager and the window manager can override the application's settings.

On Windows, CopperSpice can set whatever flags you want.

See also
windowFlags
QWidget::~QWidget ( )

Destroys the widget.

All this widget's children are deleted first. The application exits if this widget is the main widget.

Method Documentation

bool QWidget::acceptDrops ( ) const

Returns the value of the acceptDrops property.

QString QWidget::accessibleDescription ( ) const

Returns the value of the accessibleDescription property.

QString QWidget::accessibleName ( ) const

Returns the value of the accessibleName property.

void QWidget::actionEvent ( QActionEvent event)
protectedvirtual

This event handler is called with the given event whenever the widget's actions are changed.

See also
addAction(), insertAction(), removeAction(), actions(), QActionEvent

Reimplemented in QMenu, QToolBar, QToolButton, and QMenuBar.

QList< QAction * > QWidget::actions ( ) const

Returns the (possibly empty) list of this widget's actions.

See also
contextMenuPolicy, insertAction(), removeAction()
void QWidget::activateWindow ( )

Sets the top-level widget containing this widget to be the active window. An active window is a visible top-level window that has the keyboard input focus.

This method performs the same operation as clicking the mouse on the title bar of a top-level window. On X11, the result depends on the Window Manager. If you want to ensure that the window is stacked on top as well you should also call raise(). Note, the window must be visible otherwise activateWindow() has no effect.

On Windows, if you are calling this when the application is not currently the active one then it will not make it the active window. It will change the color of the taskbar entry to indicate that the window has changed in some way. This is because Microsoft does not allow an application to interrupt what the user is currently doing in another application.

See also
isActiveWindow(), window(), show()
void QWidget::addAction ( QAction action)

Appends action to the list of existing actions available for this widget. A QAction list is typically used to create a context QMenu, however it can be represented in different ways depending on the widget.

A QWidget should only have one of each action. Adding an action which already exists will not cause the same action to be in the widget multiple times. The ownership of action is not transferred to this QWidget.

See also
removeAction(), insertAction(), actions(), QMenu
void QWidget::addActions ( const QList< QAction * > &  actions)

Appends the actions actions to this widget's list of actions.

See also
removeAction(), QMenu, addAction()
void QWidget::adjustSize ( )

Adjusts the size of the widget to fit its contents.

This method uses sizeHint() if it is valid, for example the size hint's width and height are >= 0. Otherwise, it sets the size to the children rectangle that covers all child widgets (the union of all child widget rectangles).

For windows, the screen size is also taken into account. If the sizeHint() is less than (200, 100) and the size policy is expanding, the window will be at least (200, 100). The maximum size of a window is 2/3 of the screen's width and height.

See also
sizeHint(), childrenRect()
bool QWidget::autoFillBackground ( ) const

Returns the value of the autoFillBackground property.

QPalette::ColorRole QWidget::backgroundRole ( ) const

Returns the background role of the widget. The background role defines the brush from the widget's palette that is used to render the background.

If no explicit background role is set the widget inherits its parent widget's background role.

See also
setBackgroundRole(), foregroundRole()
QBackingStore * QWidget::backingStore ( ) const

Returns the QBackingStore this widget will be drawn into.

QSize QWidget::baseSize ( ) const

Returns the value of the baseSize property.

void QWidget::changeEvent ( QEvent event)
protectedvirtual

This event handler can be reimplemented to handle state changes. The state being changed in this event can be retrieved through the event supplied.

Reimplemented in QTextEdit, QPlainTextEdit, QFileDialog, QMessageBox, QComboBox, QLineEdit, QTabBar, QMenu, QToolBar, QTabWidget, QAbstractSpinBox, QAbstractSlider, QLabel, QAbstractButton, QDialogButtonBox, QProgressDialog, QDockWidget, QToolButton, QFrame, QSplitter, QMenuBar, QColorDialog, QToolBox, QFontDialog, QGroupBox, QRubberBand, QErrorMessage, QMdiSubWindow, and QWebView.

QWidget * QWidget::childAt ( const QPoint position) const

Returns the visible child widget at point position in the widget's own coordinate system.

QWidget * QWidget::childAt ( int  x,
int  y 
) const
inline

Returns the visible child widget at the position (x, y) in the widget's coordinate system. If there is no visible child widget at the specified position the method returns nullptr.

QRect QWidget::childrenRect ( ) const

Returns the value of the childrenRect property.

QRegion QWidget::childrenRegion ( ) const

Returns the value of the childrenRegion property.

void QWidget::clearFocus ( )

Removes keyboard input focus from the widget. If the widget has focus then a focusOutEvent is sent to the widget.

See also
hasFocus(), setFocus(), focusInEvent(), focusOutEvent(), setFocusPolicy(), QApplication::focusWidget()
void QWidget::clearMask ( )

Removes any mask set by setMask().

See also
setMask()
bool QWidget::close ( )
slot

Closes this widget. Returns true if the widget was closed, otherwise returns false.

First it sends the widget a QCloseEvent. The widget is hidden if it accepts the close event. If it ignores the event, nothing happens. The default implementation of QWidget::closeEvent() accepts the close event.

If the widget has the Qt::WA_DeleteOnClose flag, the widget is also deleted. A close events is delivered to the widget no matter if the widget is visible or not.

The QApplication::lastWindowClosed() signal is emitted when the last visible primary window (i.e. window with no parent) with the Qt::WA_QuitOnClose attribute set is closed. By default this attribute is set for all widgets except transient windows such as splash screens, tool windows, and popup menus.

void QWidget::closeEvent ( QCloseEvent event)
protectedvirtual

This event handler is called with the given event when CopperSpice receives a window close request for a top-level widget from the window system.

By default, the event is accepted and the widget is closed. You can reimplement this method to change the way the widget responds to window close requests. For example, you can prevent the window from closing by calling ignore() on all events.

Main window applications typically use reimplementations of this method to check whether the user's work has been saved and ask for permission before closing.

See also
event(), hide(), close(), QCloseEvent

Reimplemented in QMessageBox, QAbstractSpinBox, QProgressDialog, QDockWidget, QDialog, QWebInspector, and QMdiSubWindow.

QMargins QWidget::contentsMargins ( ) const

The contentsMargins method returns the widget's contents margins.

See also
getContentsMargins(), setContentsMargins(), contentsRect()
QRect QWidget::contentsRect ( ) const

Returns the area inside the widget's margins.

See also
setContentsMargins(), getContentsMargins()
void QWidget::contextMenuEvent ( QContextMenuEvent event)
protectedvirtual

This event handler, for event event, can be reimplemented in a subclass to receive widget context menu events. The handler is called when the widget's contextMenuPolicy is Qt::DefaultContextMenu.

The default implementation ignores the context event.

See also
event(), customContextMenuRequested(), QContextMenuEvent

Reimplemented in QTextEdit, QPlainTextEdit, QComboBox, QLineEdit, QGraphicsView, QMainWindow, QAbstractSpinBox, QLabel, QAbstractScrollArea, QDialog, QScrollBar, QMdiSubWindow, and QWebView.

Qt::ContextMenuPolicy QWidget::contextMenuPolicy ( ) const

Returns the value of the contextMenuPolicy property.

void QWidget::create ( WId  window = 0,
bool  initializeWindow = true,
bool  destroyOldWindow = true 
)
protected

Creates a new widget window if window is 0, otherwise sets the widget's window to window.

Initializes the window (sets the geometry etc.) if initializeWindow is true. If initializeWindow is false, no initialization is performed. This parameter only makes sense if window is a valid window.

Destroys the old window if destroyOldWindow is true. If destroyOldWindow is false, you are responsible for destroying the window yourself (using platform native code).

The QWidget constructor calls create(0,true,true) to create a window for this widget.

QWidget * QWidget::createWindowContainer ( QWindow window,
QWidget *  parent = nullptr,
Qt::WindowFlags  flags = Qt::EmptyFlag 
)
static

Property documentation pending.

QCursor QWidget::cursor ( ) const

Returns the value of the cursor property.

void QWidget::customContextMenuRequested ( const QPoint pos)
signal

This signal is emitted when the widget's contextMenuPolicy is Qt::CustomContextMenu, and the user has requested a context menu on the widget. The position pos is the position of the context menu event that the widget receives. Normally this is in widget coordinates. The exception to this rule is QAbstractScrollArea and its subclasses that map the context menu event to coordinates of the viewport() .

See also
mapToGlobal(), QMenu, contextMenuPolicy
void QWidget::destroy ( bool  destroyWindow = true,
bool  destroySubWindows = true 
)
protected

Frees up window system resources. Destroys the widget window if destroyWindow is true.

This method () calls itself recursively for all the child widgets, passing destroySubWindows for the destroyWindow parameter. To have more control over destruction of subwidgets, destroy subwidgets selectively first.

This method is usually called from the QWidget destructor.

void QWidget::dragEnterEvent ( QDragEnterEvent event)
protectedvirtual

This event handler is called when a drag is in progress and the mouse enters this widget. The event is passed in the event parameter. If the event is ignored, the widget will not receive any drag move events.

Refer to the Drag and Drop documentation for an overview of how to provide drag and drop in your application.

See also
QDrag, QDragEnterEvent

Reimplemented in QAbstractItemView, QTextEdit, QPlainTextEdit, QGraphicsView, QLineEdit, QAbstractScrollArea, and QWebView.

void QWidget::dragLeaveEvent ( QDragLeaveEvent event)
protectedvirtual

This event handler is called when a drag is in progress and the mouse leaves this widget. The event is passed in the event parameter.

Refer to the Drag and Drop documentation for an overview of how to provide drag and drop in your application.

See also
QDrag, QDragLeaveEvent

Reimplemented in QAbstractItemView, QTextEdit, QPlainTextEdit, QGraphicsView, QLineEdit, QListView, QAbstractScrollArea, and QWebView.

void QWidget::dragMoveEvent ( QDragMoveEvent event)
protectedvirtual

This event handler is called if a drag is in progress, and when any of the following conditions occur: the cursor enters this widget, the cursor moves within this widget, or a modifier key is pressed on the keyboard while this widget has the focus. The event is passed in the event parameter.

Refer to the Drag and Drop documentation for an overview of how to provide drag and drop in your application.

See also
QDrag, QDragMoveEvent

Reimplemented in QAbstractItemView, QTextEdit, QPlainTextEdit, QGraphicsView, QLineEdit, QTreeView, QListView, QAbstractScrollArea, and QWebView.

void QWidget::dropEvent ( QDropEvent event)
protectedvirtual

This event handler is called when the drag is dropped on this widget. The event is passed in the event parameter.

Refer to the Drag and Drop documentation for an overview of how to provide drag and drop in your application.

See also
QDrag, QDropEvent

Reimplemented in QTreeWidget, QAbstractItemView, QTableWidget, QTextEdit, QListWidget, QPlainTextEdit, QGraphicsView, QLineEdit, QListView, QAbstractScrollArea, and QWebView.

WId QWidget::effectiveWinId ( ) const

Returns the effective window system identifier of the widget. For example, the native parent's window system identifier.

If the widget is native, this method returns the native widget ID. Otherwise, the window ID of the first native parent widget, the top-level widget that contains this widget, is returned.

See also
nativeParentWidget()
void QWidget::ensurePolished ( ) const

Ensures that the widget has been polished by QStyle and has a proper font and palette.

QWidget calls this method after it has been fully constructed but before it is shown the very first time. You can call this method if you want to ensure that the widget is polished before doing an operation, e.g., the correct font size might be needed in the widget's sizeHint() reimplementation. Note, this method is called from the default implementation of sizeHint().

Polishing is useful for final initialization that must happen after all constructors (from base classes as well as from subclasses) have been called.

If you need to change some settings when a widget is polished, reimplement event() and handle the QEvent::Polish event type.

Note
The method is declared const so that it can be called from other const functions (for example sizeHint()).
See also
event()
void QWidget::enterEvent ( QEvent event)
protectedvirtual

This event handler can be reimplemented in a subclass to receive widget enter events which are passed in the event parameter. An event is sent to the widget when the mouse cursor enters the widget.

See also
leaveEvent(), mouseMoveEvent(), event()

Reimplemented in QMenu, and QToolButton.

bool QWidget::event ( QEvent event)
overrideprotected

This is the main event handler and it handles event event. You can reimplement this method in a subclass, but we recommend using one of the specialized event handlers instead.

Key press and release events are treated differently from other events. event() checks for Tab and Shift+Tab and tries to move the focus appropriately. If there is no widget to move the focus to (or the key press is not Tab or Shift+Tab), event() calls keyPressEvent().

Mouse and tablet event handling is also slightly special: only when the widget is enabled, event() will call the specialized handlers such as mousePressEvent(), otherwise it will discard the event.

This method returns true if the event was recognized, otherwise it returns false. If the recognized event was accepted (see QEvent::accepted), any further processing such as event propagation to the parent widget stops.

See also
closeEvent(), focusInEvent(), focusOutEvent(), enterEvent(), keyPressEvent(), keyReleaseEvent(), leaveEvent(), mouseDoubleClickEvent(), mouseMoveEvent(), mousePressEvent(), mouseReleaseEvent(), moveEvent(), paintEvent(), resizeEvent(), QObject::event(), QObject::timerEvent()
QWidget * QWidget::find ( WId  id)
static

Returns a pointer to the widget with a window identifier or handle matching id.

The window identifier type depends on the underlying window system, see qwindowdefs.h for the actual definition. If there is no widget with this identifier then nullptr is returned.

void QWidget::focusInEvent ( QFocusEvent event)
protectedvirtual

This event handler can be reimplemented in a subclass to receive keyboard focus events for the widget. The default implementation updates the widget if a focusPolicy() is specified. The event is passed in the event parameter.

A widget normally must the setFocusPolicy() to something other than Qt::NoFocus in order to receive focus events.

See also
focusOutEvent(), setFocusPolicy(), keyPressEvent(), keyReleaseEvent(), event(), QFocusEvent

Reimplemented in QMdiSubWindow, QAbstractItemView, QTextEdit, QPlainTextEdit, QGraphicsView, QComboBox, QLineEdit, QDateTimeEdit, QAbstractSpinBox, QLabel, QAbstractButton, QMenuBar, QGroupBox, QPushButton, and QWebView.

bool QWidget::focusNextChild ( )
inlineprotected

Move keyboard focus to the next widget and returns true if it can find a widget or false if it can not.

See also
focusPreviousChild()
bool QWidget::focusNextPrevChild ( bool  next)
protectedvirtual

Finds a new widget to give the keyboard focus to, as appropriate for Tab and Shift+Tab, and returns true if it can find a new widget, or false if it can not.

If next is true this method searches forward, if next is false it searches backward.

You may want to reimplement this method. For example, a web browser might reimplement it to move its "current active link" forward or backward, and call focusNextPrevChild() only when it reaches the last or first link on the "page".

Child widgets call focusNextPrevChild() on their parent widgets, but only the window that contains the child widgets decides where to redirect focus. By reimplementing this method for an object, you thus gain control of focus traversal for all child widgets.

See also
focusNextChild(), focusPreviousChild()

Reimplemented in QAbstractItemView, QTextEdit, QPlainTextEdit, QGraphicsView, QMenu, QDateTimeEdit, QWebView, QLabel, QTextBrowser, and QScrollArea.

void QWidget::focusOutEvent ( QFocusEvent event)
protectedvirtual

This event handler can be reimplemented in a subclass to receive keyboard focus events for the widget. The default implementation updates the widget if a focusPolicy() is specified. The events is passed in the event parameter.

A widget normally must setFocusPolicy() to something other than Qt::NoFocus in order to receive focus events.

See also
focusInEvent(), setFocusPolicy(), keyPressEvent(), keyReleaseEvent(), event(), QFocusEvent

Reimplemented in QMdiSubWindow, QAbstractItemView, QTextEdit, QPlainTextEdit, QGraphicsView, QComboBox, QLineEdit, QAbstractSpinBox, QLabel, QAbstractButton, QTextBrowser, QMenuBar, QPushButton, and QWebView.

Qt::FocusPolicy QWidget::focusPolicy ( ) const

Returns the value of the focusPolicy property.

bool QWidget::focusPreviousChild ( )
inlineprotected

Move keyboard focus to the previous widget and returns true if it can find a widget or false if it can not.

See also
focusNextChild()
QWidget * QWidget::focusProxy ( ) const

Returns the focus proxy or nullptr if there is no focus proxy.

See also
setFocusProxy()
QWidget * QWidget::focusWidget ( ) const

Returns the last child of this widget that setFocus had been called on. For top level widgets this is the widget that will get focus in case this window gets activated.

This is not the same as QApplication::focusWidget(), which returns the focus widget in the currently active window.

const QFont & QWidget::font ( ) const
inline

Returns the value of the font property.

QFontInfo QWidget::fontInfo ( ) const
inline

Returns the font info for the widget's current font. Equivalent to calling QFontInto(widget->font()).

See also
font(), fontMetrics(), setFont()
QFontMetrics QWidget::fontMetrics ( ) const
inline

Returns the font metrics for the widget's current font. Equivalent to calling QFontMetrics(widget->font()).

See also
font(), fontInfo(), setFont()
QPalette::ColorRole QWidget::foregroundRole ( ) const

Returns the foreground role. The foreground role defines the color from the widget's palette that is used to draw the foreground.

If no explicit foreground role is set, the method returns a role that contrasts with the background role.

See also
setForegroundRole(), backgroundRole()
QRect QWidget::frameGeometry ( ) const

Returns the value of the frameGeometry property.

QSize QWidget::frameSize ( ) const

Returns the value of the frameSize property.

const QRect & QWidget::geometry ( ) const
inline

Returns the value of the geometry property.

void QWidget::getContentsMargins ( int *  left,
int *  top,
int *  right,
int *  bottom 
) const

Returns the widget's contents margins for left, top, right, and bottom.

See also
setContentsMargins(), contentsRect()
QPixmap QWidget::grab ( const QRect rectangle = QRect(QPoint(0, 0), QSize(-1, -1)))

Renders the widget into a pixmap restricted by the given rectangle. If the widget has any children, then they are also painted in the appropriate positions.

If a rectangle with an invalid size is specified (the default), the entire widget is painted.

See also
render(), QPixmap
void QWidget::grabGesture ( Qt::GestureType  gestureType,
Qt::GestureFlags  flags = Qt::GestureFlags() 
)

Subscribes the widget to a given gestureType with specific flags.

See also
ungrabGesture(), QGestureEvent
void QWidget::grabKeyboard ( )

Grabs the keyboard input.

This widget will receive all keyboard events until releaseKeyboard() is called. No other widgets will receive any keyboard events. Mouse events are not affected by this call. Use grabMouse() to grab mouse events.

The focus widget is not affected except that it does not receive any keyboard events. The setFocus() method moves the focus as usual, but the new focus widget receives keyboard events only after releaseKeyboard() is called.

If a different widget is currently grabbing keyboard input, that widget's grab is released first.

See also
releaseKeyboard(), grabMouse(), releaseMouse(), focusWidget()
void QWidget::grabMouse ( )

Grabs the mouse input. This widget receives all mouse events until releaseMouse() is called; other widgets get no mouse events at all. Keyboard events are not affected. Use grabKeyboard() if you want to grab that.

Problems in applications which grab the mouse can make the computer unresponsive. This method should be used with extreme caution.

It is almost never necessary to grab the mouse. CopperSpice grabs the mouse when a mouse button is pressed and keeps it until the last button is released. Only visible widgets can grab mouse input. If isVisible() returns false for a widget, that widget can not call grabMouse().

Note
Mac OS X developers using Cocoa and calling grabMouse() on a widget only works when the mouse is inside the frame of that widget. For Carbon it works outside the widget's frame as well, similar to Windows and X11.
See also
releaseMouse(), grabKeyboard(), releaseKeyboard()
void QWidget::grabMouse ( const QCursor cursor)

Grabs the mouse input and changes the cursor shape. The cursor will assume shape cursor and this widget will be the only one to receive mouse events until releaseMouse() is called().

See also
releaseMouse(), grabKeyboard(), releaseKeyboard(), setCursor()
int QWidget::grabShortcut ( const QKeySequence key,
Qt::ShortcutContext  context = Qt::WindowShortcut 
)

Adds a shortcut to the CopperSpice shortcut system that watches for the given key sequence in the given context. If the context is Qt::ApplicationShortcut< the shortcut applies to the application as a whole. Otherwise, it is either local to this widget, Qt::WidgetShortcut, or to the window itself, Qt::WindowShortcut.

If the same key sequence has been grabbed by several widgets when the key sequence is pressed, a QEvent::Shortcut event is sent to all the widgets in a non-deterministic order. The QShortcutEvent::isAmbiguous() method will return true for this event.

Warning
This method is normally not required. Instead, create QActions with the shortcut key sequences you require (if you also want equivalent menu options and toolbar buttons), or create QShortcuts if you just need key sequences. Both QAction and QShortcut handle all the event filtering for you, and provide signals which are triggered when the user triggers the key sequence, so are much easier to use than this low-level function.
See also
releaseShortcut(), setShortcutEnabled()
QGraphicsEffect * QWidget::graphicsEffect ( ) const

The graphicsEffect function returns a pointer to the widget's graphics effect. If the widget has no graphics effect, a nullptr is returned.

See also
setGraphicsEffect()
QGraphicsProxyWidget * QWidget::graphicsProxyWidget ( ) const

Returns the proxy widget for the corresponding embedded widget in a graphics view, otherwise returns a nullptr.

See also
QGraphicsProxyWidget::createProxyForChildWidget(), QGraphicsScene::addWidget()
bool QWidget::hasEditFocus ( ) const

Returns true if this widget currently has edit focus, otherwise false.

See also
setEditFocus(), QApplication::keypadNavigationEnabled()
bool QWidget::hasFocus ( ) const

Returns the value of the hasFocus property.

bool QWidget::hasHeightForWidth ( ) const
virtual

Returns true if the widget's preferred height depends on its width, otherwise returns false.

Reimplemented in QTabWidget.

bool QWidget::hasMouseTracking ( ) const
inline

Returns the value of the mouseTracking property.

int QWidget::height ( ) const
inline

Returns the value of the height property.

int QWidget::heightForWidth ( int  width) const
virtual

Returns the preferred height for this widget, given the width width.

If this widget has a layout, the default implementation returns the layout's preferred height. if there is no layout, the default implementation returns -1 indicating that the preferred height does not depend on the width.

Reimplemented in QTabWidget, QLabel, QMenuBar, and QCommandLinkButton.

void QWidget::hide ( )
slot

Hides the widget. This method is equivalent to calling setVisible(false).

Note
If you are working with QDialog or its subclasses and you invoke show() after this method, the dialog will be displayed in its original position.
See also
hideEvent(), isHidden(), show(), setVisible(), isVisible(), close()
void QWidget::hideEvent ( QHideEvent event)
protectedvirtual

This event handler can be reimplemented in a subclass to receive widget hide events. The event is passed in the event parameter. Hide events are sent to widgets immediately after they have been hidden.

Note: A widget receives spontaneous show and hide events when its mapping status is changed by the window system, e.g. a spontaneous hide event when the user minimizes the window, and a spontaneous show event when the window is restored again. After receiving a spontaneous hide event, a widget is still considered visible in the sense of isVisible().

See also
visible, event(), QHideEvent

Reimplemented in QMdiSubWindow, QComboBox, QMenu, QTabBar, QAbstractSpinBox, QScrollBar, QSizeGrip, and QWebInspector.

void QWidget::initPainter ( QPainter painter) const
overrideprotectedvirtual

Initializes the painter pen, background and font to the same as the given widget's. This method is called automatically when the painter is opened on a QWidget.

Reimplemented from QPaintDevice.

void QWidget::inputMethodEvent ( QInputMethodEvent event)
protectedvirtual

This event handler, for event event, can be reimplemented in a subclass to receive Input Method composition events. This handler is called when the state of the input method changes.

Note that when creating custom text editing widgets, the Qt::WA_InputMethodEnabled window attribute must be set explicitly (using the setAttribute() function) in order to receive input method events.

The default implementation calls event->ignore(), which rejects the Input Method event.

See also
event(), QInputMethodEvent

Reimplemented in QAbstractItemView, QTextEdit, QPlainTextEdit, QGraphicsView, QComboBox, QLineEdit, and QWebView.

Qt::InputMethodHints QWidget::inputMethodHints ( ) const

Property documentation pending.

QVariant QWidget::inputMethodQuery ( Qt::InputMethodQuery  query) const
virtual

This method is only relevant for input widgets. It is used by the input method to query a set of properties of the widget to be able to support complex input method operations as support for surrounding text and reconversions.

The given query specifies which property is queried.

See also
inputMethodEvent(), QInputMethodEvent, inputMethodHints

Reimplemented in QLineEdit, QAbstractSpinBox, QAbstractItemView, QGraphicsView, QComboBox, QTextEdit, QPlainTextEdit, and QWebView.

void QWidget::insertAction ( QAction before,
QAction action 
)

Inserts the action action to this widget's list of actions, before the action before. It appends the action if before is 0 or before is not a valid action for this widget.

A QWidget should only have one of each action.

See also
removeAction(), addAction(), QMenu, contextMenuPolicy, actions()
void QWidget::insertActions ( QAction before,
QList< QAction * >  actions 
)

Inserts the actions actions to this widget's list of actions, before the action before. It appends the action if before is 0 or before is not a valid action for this widget.

A QWidget can have at most one of each action.

See also
removeAction(), QMenu, insertAction(), contextMenuPolicy
bool QWidget::isActiveWindow ( ) const

Returns the value of the isActiveWindow property.

bool QWidget::isAncestorOf ( const QWidget *  child) const

Returns true if this widget is a parent, (or grandparent and so on to any level), of the given child, and both widgets are within the same window, otherwise returns false.

bool QWidget::isEnabled ( ) const
inline

Returns the value of the enabled property.

bool QWidget::isEnabledTo ( const QWidget *  parent) const

Returns true if this widget would become enabled if parent is enabled, otherwise returns false. This is the case if neither the widget itself nor every parent up to but excluding ancestor has been explicitly disabled.

Calling isEnabledTo(0) is equivalent to calling isEnabled().

See also
setEnabled(), enabled
bool QWidget::isEnabledToTLW ( ) const
inlinedeprecated
Deprecated:
This function is deprecated. It is equivalent to isEnabled().
bool QWidget::isFullScreen ( ) const

Returns the value of the fullScreen property.

bool QWidget::isHidden ( ) const
inline

Returns true if the widget is hidden, otherwise returns false. A hidden widget will only become visible when show() is called on it. It will not be automatically shown when the parent is shown. To check visibility, use ! isVisible() instead (notice the exclamation mark).

isHidden() implies !isVisible(), but a widget can be not visible and not hidden at the same time. This is the case for widgets that are children of widgets that are not visible.

Widgets are hidden if:

  • they were created as independent windows,
  • they were created as children of visible widgets,
  • hide() or setVisible(false) was called.
bool QWidget::isMaximized ( ) const

Returns the value of the maximized property.

bool QWidget::isMinimized ( ) const

Returns the value of the minimized property.

bool QWidget::isModal ( ) const
inline

Returns the value of the modal property.

bool QWidget::isTopLevel ( ) const
inlinedeprecated
Deprecated:
Use isWindow() instead.
bool QWidget::isVisible ( ) const
inline

Returns the value of the visible property.

bool QWidget::isVisibleTo ( const QWidget *  parent) const

Returns true if this widget would become visible if parent is shown, otherwise returns false. The true case occurs if neither the widget itself nor any parent up to but excluding ancestor has been explicitly hidden.

This method will still return true if the widget is obscured by other windows on the screen, but could be physically visible if it or they were to be moved.

isVisibleTo(0) is identical to isVisible().

See also
show(), hide(), isVisible()
bool QWidget::isWindow ( ) const
inline

Returns true if the widget is an independent window, otherwise returns false.

A window is a widget that is not visually the child of any other widget and that usually has a frame and a window title.

A window can have a parent widget. It will then be grouped with its parent and deleted when the parent is deleted, minimized when the parent is minimized etc. If supported by the window manager, it will also have a common taskbar entry with its parent.

QDialog and QMainWindow widgets are by default windows, even if a parent widget is specified in the constructor. This behavior is specified by the Qt::Window flag.

See also
window(), isModal(), parentWidget()
bool QWidget::isWindowModified ( ) const

Returns the value of the windowModified property.

QWidget * QWidget::keyboardGrabber ( )
static

Returns the widget that is currently grabbing the keyboard input.

If no widget in this application is currently grabbing the keyboard, 0 is returned.

See also
grabMouse(), mouseGrabber()
void QWidget::keyPressEvent ( QKeyEvent event)
protectedvirtual

The event handler for event event can be reimplemented in a subclass to receive key press events for the widget. A widget must call setFocusPolicy() to accept focus initially and have focus in order to receive a key press event.

If you reimplement this handler it is very important to call the base class implementation if you do not act upon the key. A QKeyEvent starts with isAccepted() set to true so you do not need to call QKeyEvent::accept(). Do not call the base class implementation if you consume the key event.

The default implementation closes popup widgets if the user presses Esc, otherwise the event is ignored and the widget's parent can react to it.

See also
keyReleaseEvent(), setFocusPolicy(), focusInEvent(), focusOutEvent(), event(), QKeyEvent

Reimplemented in QMdiSubWindow, QAbstractItemView, QTextEdit, QGraphicsView, QComboBox, QPlainTextEdit, QMessageBox, QLineEdit, QTabBar, QMenu, QTreeView, QCalendarWidget, QDateTimeEdit, QTabWidget, QAbstractSpinBox, QLabel, QAbstractSlider, QAbstractButton, QTextBrowser, QAbstractScrollArea, QDialog, QMenuBar, QPushButton, QKeySequenceEdit, and QWebView.

void QWidget::keyReleaseEvent ( QKeyEvent event)
protectedvirtual

The event handler for event event can be reimplemented in a subclass to receive key release events for the widget. A widget must call setFocusPolicy() to accept focus initially and have focus in order to receive a key release event.

If you reimplement this handler it is very important to call the base class implementation if you do not act upon the key. A QKeyEvent starts with isAccepted() set to true so you do not need to call QKeyEvent::accept(). Do not call the base class implementation if you consume the key event.

The default implementation closes popup widgets if the user presses Esc. Otherwise the event is ignored and the widget's parent can react to it.

See also
keyPressEvent(), QKeyEvent::ignore(), setFocusPolicy(), focusInEvent(), focusOutEvent(), event(), QKeyEvent

Reimplemented in QTextEdit, QGraphicsView, QComboBox, QPlainTextEdit, QAbstractSpinBox, QAbstractButton, QKeySequenceEdit, and QWebView.

QLayout * QWidget::layout ( ) const

Returns the layout manager that is installed on this widget, or 0 if no layout manager is installed.

The layout manager sets the geometry of the widget's children that have been added to the layout.

See also
setLayout(), sizePolicy(), Layout Management
Qt::LayoutDirection QWidget::layoutDirection ( ) const

Returns the value of the layoutDirection property.

void QWidget::leaveEvent ( QEvent event)
protectedvirtual

This event handler can be reimplemented in a subclass to receive widget leave events which are passed in the event parameter.

A leave event is sent to the widget when the mouse cursor leaves the widget.

See also
enterEvent(), mouseMoveEvent(), event()

Reimplemented in QMdiSubWindow, QMenu, QToolButton, and QMenuBar.

QLocale QWidget::locale ( ) const

Returns the value of the locale property.

void QWidget::lower ( )
slot

Lowers the widget to the bottom of the parent widget's stack.

After this call the widget will be visually behind (and therefore obscured by) any overlapping sibling widgets.

See also
raise(), stackUnder()
QPoint QWidget::mapFrom ( const QWidget *  parent,
const QPoint pos 
) const

Translates the widget coordinate pos from the coordinate system of parent to this widget's coordinate system. The parent must not be 0 and must be a parent of the calling widget.

See also
mapTo(), mapFromParent(), mapFromGlobal(), underMouse()
QPoint QWidget::mapFromGlobal ( const QPoint pos) const

Translates the global screen coordinate pos to widget coordinates.

See also
mapToGlobal(), mapFrom(), mapFromParent()
QPoint QWidget::mapFromParent ( const QPoint pos) const

Translates the parent widget coordinate pos to widget coordinates.

Same as mapFromGlobal() if the widget has no parent.

See also
mapToParent(), mapFrom(), mapFromGlobal(), underMouse()
QPoint QWidget::mapTo ( const QWidget *  parent,
const QPoint pos 
) const

Translates the widget coordinate pos to the coordinate system of parent. The parent must not be 0 and must be a parent of the calling widget.

See also
mapFrom(), mapToParent(), mapToGlobal(), underMouse()
QPoint QWidget::mapToGlobal ( const QPoint pos) const

Translates the widget coordinate pos to global screen coordinates. For example, mapToGlobal(QPoint(0,0)) would give the global coordinates of the top-left pixel of the widget.

See also
mapFromGlobal(), mapTo(), mapToParent()
QPoint QWidget::mapToParent ( const QPoint pos) const

Translates the widget coordinate pos to a coordinate in the parent widget.

Same as mapToGlobal() if the widget has no parent.

See also
mapFromParent(), mapTo(), mapToGlobal(), underMouse()
QRegion QWidget::mask ( ) const

Returns the mask currently set on a widget. If no mask is set the return value will be an empty region.

See also
setMask(), clearMask(), QRegion::isEmpty()
int QWidget::maximumHeight ( ) const
inline

Returns the value of the maximumHeight property.

QSize QWidget::maximumSize ( ) const

Returns the value of the maximumSize property.

int QWidget::maximumWidth ( ) const
inline

Returns the value of the maximumWidth property.

int QWidget::metric ( PaintDeviceMetric  metric) const
overrideprotectedvirtual

Internal implementation of the virtual QPaintDevice::metric() method. The value for metric is the metric to get.

Reimplemented from QPaintDevice.

int QWidget::minimumHeight ( ) const
inline

Returns the value of the minimumHeight property.

QSize QWidget::minimumSize ( ) const

Returns the value of the minimumSize property.

int QWidget::minimumWidth ( ) const
inline

Returns the value of the minimumWidth property.

void QWidget::mouseDoubleClickEvent ( QMouseEvent event)
protectedvirtual

This event handler, for event event, can be reimplemented in a subclass to receive mouse double click events for the widget. The default implementation generates a normal mouse press event.

Note
The widget will also receive mouse press and mouse release events in addition to the double click event. It is up to the developer to ensure that the application interprets these events correctly.
See also
mousePressEvent(), mouseReleaseEvent(), mouseMoveEvent(), event(), QMouseEvent

Reimplemented in QMdiSubWindow, QAbstractItemView, QTextEdit, QPlainTextEdit, QGraphicsView, QLineEdit, QHeaderView, QTreeView, QAbstractScrollArea, and QWebView.

QWidget * QWidget::mouseGrabber ( )
static

Returns the widget that is currently grabbing the mouse input.

If no widget in this application is currently grabbing the mouse, 0 is returned.

See also
grabMouse(), keyboardGrabber()
void QWidget::mouseMoveEvent ( QMouseEvent event)
protectedvirtual

This event handler, for event event, can be reimplemented in a subclass to receive mouse move events for the widget.

If mouse tracking is switched off, mouse move events only occur if a mouse button is pressed while the mouse is being moved. If mouse tracking is switched on, mouse move events occur even if no mouse button is pressed.

QMouseEvent::pos() reports the position of the mouse cursor, relative to this widget. For press and release events, the position is usually the same as the position of the last mouse move event, but it might be different if the user's hand shakes. This is a feature of the underlying window system, not CopperSpice.

If you want to show a tooltip immediately, while the mouse is moving (e.g., to get the mouse coordinates with QMouseEvent::pos() and show them as a tooltip), you must first enable mouse tracking as described above. Then, to ensure that the tooltip is updated immediately, you must call QToolTip::showText() instead of setToolTip() in your implementation of mouseMoveEvent().

See also
setMouseTracking(), mousePressEvent(), mouseReleaseEvent(), mouseDoubleClickEvent(), event(), QMouseEvent

Reimplemented in QMdiSubWindow, QAbstractItemView, QTextEdit, QGraphicsView, QPlainTextEdit, QLineEdit, QHeaderView, QMenu, QTabBar, QTreeView, QAbstractSpinBox, QListView, QLabel, QAbstractButton, QSplitterHandle, QTextBrowser, QMenuBar, QAbstractScrollArea, QGroupBox, QDial, QSlider, QCheckBox, QScrollBar, QRadioButton, QSizeGrip, and QWebView.

void QWidget::mousePressEvent ( QMouseEvent event)
protectedvirtual

This event handler, for event event, can be reimplemented in a subclass to receive mouse press events for the widget.

If you create new widgets in the mousePressEvent() the mouseReleaseEvent() may not end up where you expect, depending on the underlying window system (or X11 window manager), the widgets' location and maybe more.

The default implementation implements the closing of popup widgets when you click outside the window. For other widget types it does nothing.

See also
mouseReleaseEvent(), mouseDoubleClickEvent(), mouseMoveEvent(), event(), QMouseEvent

Reimplemented in QMdiSubWindow, QAbstractItemView, QTextEdit, QGraphicsView, QPlainTextEdit, QComboBox, QLineEdit, QHeaderView, QMenu, QTabBar, QDateTimeEdit, QTreeView, QCalendarWidget, QAbstractSpinBox, QLabel, QAbstractButton, QSplitterHandle, QTextBrowser, QToolButton, QMenuBar, QAbstractScrollArea, QGroupBox, QDial, QSlider, QSplashScreen, QScrollBar, QSizeGrip, and QWebView.

void QWidget::mouseReleaseEvent ( QMouseEvent event)
protectedvirtual
void QWidget::move ( const QPoint point)

Sets the value of the move property to point.

void QWidget::move ( int  x,
int  y 
)
inline

Property documentation pending.

void QWidget::moveEvent ( QMoveEvent event)
protectedvirtual

This event handler can be reimplemented in a subclass to receive widget move events which are passed in the event parameter. When the widget receives this event, it is already at the new position.

The old position is accessible through QMoveEvent::oldPos().

See also
resizeEvent(), event(), move(), QMoveEvent

Reimplemented in QMdiSubWindow, QRubberBand, and QSizeGrip.

bool QWidget::nativeEvent ( const QByteArray eventType,
void *  message,
long *  result 
)
protectedvirtual

This special event handler can be reimplemented in a subclass to receive native platform events identified by eventType which are passed in the message parameter.

In your reimplementation of this method, if you want to stop the event being handled by CopperSpice, return true and set result. If you return false this native event is passed back to CopperSpice, which translates the event into a CopperSpice event and sends it to the widget.

This method supersedes the event filter functions x11Event(), winEvent(), and macEvent().

Note
Events are only delivered to this event handler if the widget is has a native Window handle.
Platform Event Type Identifier Message Type Result Type
Windows "windows_generic_MSG" MSG * LRESULT

Reimplemented in QWizard.

QWidget * QWidget::nativeParentWidget ( ) const

Returns the native parent for this widget. This is the next ancestor widget that has a system identifier or nullptr if it does not have any native parent.

See also
effectiveWinId()
QWidget * QWidget::nextInFocusChain ( ) const

Returns the next widget in this widget's focus chain.

See also
previousInFocusChain()
QRect QWidget::normalGeometry ( ) const

Returns the value of the normalGeometry property.

void QWidget::overrideWindowFlags ( Qt::WindowFlags  flags)

Sets the window flags for the widget to flags, without telling the window system.

See also
setWindowFlags()
QPaintEngine * QWidget::paintEngine ( ) const
overridevirtual

Returns the widget's paint engine.

This method should not be called explicitly by the user, since it is meant for reimplementation purposes only. The method is called by CopperSpice internally, and the default implementation may not always return a valid pointer.

Implements QPaintDevice.

Reimplemented in QGLWidget.

void QWidget::paintEvent ( QPaintEvent event)
protectedvirtual

This event handler can be reimplemented in a subclass to receive paint events passed in event. A paint event is a request to repaint all or part of a widget. It can happen for one of the following reasons.

  • repaint() or update() was invoked
  • widget was obscured and has now been uncovered
  • some other reason

Many widgets can simply repaint their entire surface when asked to, but some slow widgets need to optimize by painting only the requested region: QPaintEvent::region(). This speed optimization does not change the result, as painting is clipped to that region during event processing. QListView and QTableView do this, for example.

CopperSpice also tries to speed up painting by merging multiple paint events into one. When update() is called several times or the window system sends several paint events, CopperSpice merges these events into one event with a larger region (see QRegion::united()). The repaint() function does not permit this optimization, so we suggest using update() whenever possible.

When the paint event occurs, the update region has normally been erased, so you are painting on the widget's background. The background can be set using setBackgroundRole() and setPalette().

QWidget automatically double-buffers its painting, so there is no need to write double-buffering code in paintEvent() to avoid flicker.

For the X11 platform it is possible to toggle global double buffering by calling qt_x11_set_global_double_buffer().

extern void qt_x11_set_global_double_buffer(bool);
qt_x11_set_global_double_buffer(false);

Generally you should refrain from calling update() or repaint() inside a paintEvent(). For example, calling update() or repaint() on children inside a paintevent() results in undefined behavior; the child may or may not get a paint event.

Warning
If you are using a custom paint engine without the CopperSpice backingstore, Qt::WA_PaintOnScreen must be set. Otherwise, QWidget::paintEngine() will never be called; the backingstore will be used instead.
See also
event(), repaint(), update(), QPainter, QPixmap, QPaintEvent

Reimplemented in QMdiArea, QMdiSubWindow, QAbstractButton, QTextEdit, QGraphicsView, QPlainTextEdit, QComboBox, QLineEdit, QMenu, QHeaderView, QTabBar, QDateTimeEdit, QWizard, QTreeView, QToolBar, QListView, QAbstractSpinBox, QTabWidget, QTableView, QLabel, QSplitterHandle, QProgressBar, QTextBrowser, QLCDNumber, QDockWidget, QToolButton, QFrame, QMenuBar, QAbstractScrollArea, QGroupBox, QOpenGLWidget, QPushButton, QDial, QSlider, QStatusBar, QRubberBand, QCheckBox, QSvgWidget, QCommandLinkButton, QScrollBar, QFocusFrame, QRadioButton, QSizeGrip, QGLWidget, and QWebView.

const QPalette & QWidget::palette ( ) const

Returns the value of the palette property.

QWidget * QWidget::parentWidget ( ) const
inline

Returns the parent of this widget or nullptr if it does not have any parent widget.

QPoint QWidget::pos ( ) const

Returns the value of the pos property.

QWidget * QWidget::previousInFocusChain ( ) const

Returns the previous widget in this widget's focus chain.

See also
nextInFocusChain()
void QWidget::raise ( )
slot

Raises this widget to the top of the parent widget's stack. After this call the widget will be visually in front of any overlapping sibling widgets.

When using activateWindow() you can call this method to ensure that the window is stacked on top.

See also
lower(), stackUnder()
QRect QWidget::rect ( ) const
inline

Returns the value of the rect property.

void QWidget::releaseKeyboard ( )

Releases the keyboard grab.

See also
grabKeyboard(), grabMouse(), releaseMouse()
void QWidget::releaseMouse ( )

Releases the mouse grab.

See also
grabMouse(), grabKeyboard(), releaseKeyboard()
void QWidget::releaseShortcut ( int  id)

Removes the shortcut with the given id from the CopperSpice shortcut system. The widget will no longer receive QEvent::Shortcut events for the shortcut's key sequence (unless it has other shortcuts with the same key sequence).

Warning
You should not normally need to use this method since the CopperSpice shortcut system removes shortcuts automatically when their parent widget is destroyed. It is better to use QAction or QShortcut to handle shortcuts, since they are easier to use than this low-level function. This is an expensive operation.
See also
grabShortcut(), setShortcutEnabled()
void QWidget::removeAction ( QAction action)

Removes the action action from this widget's list of actions.

See also
insertAction(), actions(), insertAction()
void QWidget::render ( QPaintDevice target,
const QPoint targetOffset = QPoint(),
const QRegion sourceRegion = QRegion(),
RenderFlags  renderFlags = RenderFlags(DrawWindowBackground | DrawChildren) 
)

Renders the sourceRegion of this widget into the target using renderFlags to determine how to render. Rendering starts at targetOffset in the target.

QPixmap pixmap(widget->size());
widget->render(&pixmap);

If sourceRegion is a null region this method will use QWidget::rect() as the region. Ensure that you call QPainter::end() for the target device's active painter (if any) before rendering.

QPainter painter(this);
painter.end();
myWidget->render(this);
Note
To obtain the contents of an OpenGL widget, use QGLWidget::grabFrameBuffer() or QGLWidget::renderPixmap() instead.
void QWidget::render ( QPainter painter,
const QPoint targetOffset = QPoint(),
const QRegion sourceRegion = QRegion(),
RenderFlags  renderFlags = RenderFlags(DrawWindowBackground | DrawChildren) 
)

Renders the widget into the painter's QPainter::device().

Transformations and settings applied to the painter will be used when rendering.

Note
The painter must be active. On Mac OS X the widget will be rendered into a QPixmap and then drawn by the painter.
See also
QPainter::device()
void QWidget::repaint ( )
slot

Repaints the widget directly by calling paintEvent() immediately, unless updates are disabled or the widget is hidden. We suggest only using repaint() if you need an immediate repaint, for example during animation. In almost all circumstances update() is better, as it permits CopperSpice to optimize for speed and minimize flicker.

Warning
If you call repaint() in a function which may itself be called from paintEvent(), you may get infinite recursion. The update() function never causes recursion.
See also
update(), paintEvent(), setUpdatesEnabled()
void QWidget::repaint ( const QRect rect)

This version repaints a rectangle rect inside the widget.

void QWidget::repaint ( const QRegion region)

This version repaints a region region inside the widget.

void QWidget::repaint ( int  x,
int  y,
int  w,
int  h 
)

This version repaints a rectangle (x, y, w, h) inside the widget.

If w is negative, it is replaced with width() - x, and if h is negative, it is replaced width height() - y.

void QWidget::resize ( const QSize size)

Returns the value of the size property.

void QWidget::resize ( int  w,
int  h 
)
inline

Sets the value of the size property to w, h.

void QWidget::resizeEvent ( QResizeEvent event)
protectedvirtual

This event handler can be reimplemented in a subclass to receive widget resize events which are passed in the event parameter. When resizeEvent() is called, the widget already has its new geometry. The old size is accessible through QResizeEvent::oldSize().

The widget will be erased and receive a paint event immediately after processing the resize event. No drawing need be (or should be) done inside this handler.

See also
moveEvent(), event(), resize(), QResizeEvent, paintEvent()

Reimplemented in QMdiArea, QMdiSubWindow, QAbstractItemView, QTextEdit, QGraphicsView, QPlainTextEdit, QComboBox, QMessageBox, QTabBar, QWizard, QCalendarWidget, QTabWidget, QListView, QAbstractSpinBox, QSplitterHandle, QMenuBar, QSplitter, QDialog, QAbstractScrollArea, QGroupBox, QDesktopWidget, QOpenGLWidget, QColumnView, QDial, QScrollArea, QStatusBar, QRubberBand, QWebInspector, QGLWidget, and QWebView.

bool QWidget::restoreGeometry ( const QByteArray geometry)

Restores the geometry and state top-level widgets stored in the byte array geometry. Returns true on success, otherwise returns false.

If the restored geometry is off-screen, it will be modified to be inside the available screen geometry.

To restore geometry saved using QSettings, you can use code like this:

QSettings settings("MyCompany", "MyApp");
myWidget->restoreGeometry(settings.value("myWidget/geometry").toByteArray());

Refer to Window Geometry documentation for an overview of geometry issues with windows.

Use QMainWindow::restoreState() to restore the geometry and the state of toolbars and dock widgets.

See also
saveGeometry(), QSettings, QMainWindow::saveState(), QMainWindow::restoreState()
QByteArray QWidget::saveGeometry ( ) const

Saves the current geometry and state for top-level widgets. To save the geometry when the window closes, you can implement a close event as shown below.

Use QMainWindow::saveState() to save the geometry and the state of toolbars and dock widgets.

void MyWidget::closeEvent(QCloseEvent *event) {
QSettings settings("MyCompany", "MyApp");
settings.setValue("geometry", saveGeometry());
}

Refer to Window Geometry documentation for an overview of geometry issues with windows.

See also
restoreGeometry(), QMainWindow::saveState(), QMainWindow::restoreState()
void QWidget::scroll ( int  dx,
int  dy 
)

Scrolls the widget including its children dx pixels to the right and dy downward. Both dx and dy may be negative.

After scrolling, the widgets will receive paint events for the areas that need to be repainted. For widgets that CopperSpice knows to be opaque, this is only the newly exposed parts. For example, if an opaque widget is scrolled 8 pixels to the left, only an 8-pixel wide stripe at the right edge needs updating.

Since widgets propagate the contents of their parents by default, you need to set the autoFillBackground property, or use setAttribute() to set the Qt::WA_OpaquePaintEvent attribute, to make a widget opaque.

For widgets that use contents propagation, a scroll will cause an update of the entire scroll area.

See also
Transparency, Double Buffering
void QWidget::scroll ( int  dx,
int  dy,
const QRect rect 
)

This version only scrolls rect and does not move the children of the widget. If rect is empty or invalid the result is undefined.

See also
QScrollArea
void QWidget::setAcceptDrops ( bool  on)

Sets the value of the acceptDrops property to on.

void QWidget::setAccessibleDescription ( const QString description)

Sets the value of the accessibleDescription property to description.

void QWidget::setAccessibleName ( const QString name)

Sets the value of the accessibleName property to name.

void QWidget::setAttribute ( Qt::WidgetAttribute  attribute,
bool  enable = true 
)

Sets the attribute attribute on this widget if enable is true, otherwise clears the attribute.

See also
testAttribute()
void QWidget::setAutoFillBackground ( bool  enable)

Sets the value of the autoFillBackground property to enable.

void QWidget::setBackgroundRole ( QPalette::ColorRole  role)

Sets the background role of the widget to role. The background role defines the brush from the widget's palette that is used to render the background. If role is QPalette::NoRole, then the widget inherits its parent's background role.

Note that styles are free to choose any color from the palette. You can modify the palette or set a style sheet if you do not achieve the result you want with setBackgroundRole().

See also
backgroundRole(), foregroundRole()
void QWidget::setBaseSize ( const QSize size)
inline

Sets the value of the baseSize property to size.

void QWidget::setBaseSize ( int  basew,
int  baseh 
)

This method is equivalent to calling setBaseSize(QSize(basew, baseh)).

void QWidget::setContentsMargins ( const QMargins margins)

The setContentsMargins function sets the margins around the widget's contents.

Sets the margins around the contents of the widget to have the sizes determined by margins. The margins are used by the layout system, and may be used by subclasses to specify the area to draw in (e.g. excluding the frame).

Changing the margins will trigger a resizeEvent().

See also
contentsRect(), getContentsMargins()
void QWidget::setContentsMargins ( int  left,
int  top,
int  right,
int  bottom 
)

Sets the margins around the contents of the widget to have the sizes left, top, right, and bottom. The margins are used by the layout system, and may be used by subclasses to specify the area to draw in (e.g. excluding the frame).

Changing the margins will trigger a resizeEvent().

See also
contentsMargins(), contentsRect(), getContentsMargins()
void QWidget::setContextMenuPolicy ( Qt::ContextMenuPolicy  policy)

Sets the value of the contextMenuPolicy property to policy.

void QWidget::setCursor ( const QCursor cursor)

Sets the value of the cursor property to cursor.

void QWidget::setDisabled ( bool  disable)
slot

Disables widget input events if disable is true, otherwise enables input events.

See also
isEnabledTo(), QKeyEvent, QMouseEvent, changeEvent()
void QWidget::setEditFocus ( bool  enable)

If enable is true, make this widget have edit focus, in which case Qt::Key_Up and Qt::Key_Down will be delivered to the widget normally, otherwise, Qt::Key_Up and Qt::Key_Down are used to change focus.

See also
hasEditFocus(), QApplication::keypadNavigationEnabled()
void QWidget::setEnabled ( bool  enable)
slot

Sets the value of the enabled property to enable.

void QWidget::setFixedHeight ( int  h)

Sets both the minimum and maximum heights of the widget to h without changing the widths. Provided for convenience.

See also
sizeHint(), minimumSize(), maximumSize(), setFixedSize()
void QWidget::setFixedSize ( const QSize size)

Sets both the minimum and maximum sizes of the widget to size, thereby preventing it from ever growing or shrinking. This will override the default size constraints set by QLayout. To remove constraints, set the size to QWIDGETSIZE_MAX.

Alternatively, if you want the widget to have a fixed size based on its contents, you can call QLayout::setSizeConstraint(QLayout::SetFixedSize);

See also
maximumSize, minimumSize
void QWidget::setFixedSize ( int  w,
int  h 
)

Sets the width of the widget to w and the height to h.

void QWidget::setFixedWidth ( int  w)

Sets both the minimum and maximum width of the widget to w without changing the heights. Provided for convenience.

See also
sizeHint(), minimumSize(), maximumSize(), setFixedSize()
void QWidget::setFocus ( )
slot

Gives the keyboard input focus to this widget (or its focus proxy) if this widget or one of its parents is the active window.

void QWidget::setFocus ( Qt::FocusReason  reason)

Gives the keyboard input focus to this widget (or its focus proxy) if this widget or one of its parents is the active window. The reason argument will be passed into any focus event sent from this function, it is used to give an explanation of what caused the widget to get focus. If the window is not active, the widget will be given the focus when the window becomes active.

First, a focus out event is sent to the focus widget (if any) to tell it that it is about to lose the focus. Then a focus in event is sent to this widget to tell it that it just received the focus. (Nothing happens if the focus in and focus out widgets are the same.)

Note
On embedded platforms, setFocus() will not cause an input panel to be opened by the input method. If you want this to happen, you have to send a QEvent::RequestSoftwareInputPanel event to the widget yourself.

This methods gives focus to a widget regardless of its focus policy, but does not clear any keyboard grab (see grabKeyboard()). Be aware that if the widget is hidden, it will not accept focus until it is shown.

Warning
If you call setFocus() in a function which may itself be called from focusOutEvent() or focusInEvent(), you may get an infinite recursion.
See also
hasFocus(), clearFocus(), focusInEvent(), focusOutEvent(), setFocusPolicy(), focusWidget(), QApplication::focusWidget(), grabKeyboard(), grabMouse(), QEvent::RequestSoftwareInputPanel, Keyboard Focus
void QWidget::setFocusPolicy ( Qt::FocusPolicy  policy)

Sets the value of the focusPolicy property to policy.

void QWidget::setFocusProxy ( QWidget *  widget)

Sets the widget's focus proxy to widget. If widget is a nullptr this method resets this QWidget to have no focus proxy.

Some widgets can "have focus" but create a child widget, such as QLineEdit, to actually handle the focus. In this case, the widget can set the line edit to be its focus proxy. This method setFocusProxy() sets the widget which will actually get focus when "this widget" gets it. If there is a focus proxy, setFocus() and hasFocus() operate on the focus proxy.

See also
focusProxy()
void QWidget::setFont ( const QFont font)

Sets the value of the font property to font.

void QWidget::setForegroundRole ( QPalette::ColorRole  role)

Sets the foreground role of the widget to role. The foreground role defines the color from the widget's palette that is used to draw the foreground.

If role is QPalette::NoRole, the widget uses a foreground role that contrasts with the background role.

Note that styles are free to choose any color from the palette. You can modify the palette or set a style sheet if you do not achieve the result you want with setForegroundRole().

See also
foregroundRole(), backgroundRole()
void QWidget::setGeometry ( const QRect rect)

Sets the value of the geometry property to rect.

void QWidget::setGeometry ( int  x,
int  y,
int  w,
int  h 
)
inline

Sets the value of the geometry property to the rectangle x, y, w, h.

void QWidget::setGraphicsEffect ( QGraphicsEffect effect)

The setGraphicsEffect function is for setting the widget's graphics effect. Sets effect as the widget's effect. If there already is an effect installed on this widget, QWidget will delete the existing effect before installing the new effect.

If effect is currently installed on a different widget, setGraphicsEffect() will remove the effect from the widget and install it on this widget. QWidget takes ownership of effect.

This method will apply the effect on itself and all its children. Graphics effects are not supported on Mac, so they will not cause any difference to the rendering of the widget.

See also
graphicsEffect()
void QWidget::setHidden ( bool  hidden)
slot

Equivalent to calling setVisible(! hidden).

See also
isHidden()
void QWidget::setInputMethodHints ( Qt::InputMethodHints  hints)

Property documentation pending.

void QWidget::setLayout ( QLayout layout)

Sets the layout manager for this widget to layout. If there already is a layout manager installed on this widget, QWidget will not let you install another. You must first delete the existing layout manager (returned by layout()) before you can call setLayout() with the new layout.

If layout is the layout manger on a different widget, setLayout() will reparent the layout and make it the layout manager for this widget.

An alternative to calling this function is to pass this widget to the layout's constructor. The QWidget will take ownership of layout.

See also
layout(), Layout Management
void QWidget::setLayoutDirection ( Qt::LayoutDirection  direction)

Sets the value of the layoutDirection property to direction.

void QWidget::setLocale ( const QLocale locale)

Sets the value of the locale property to locale.

void QWidget::setMask ( const QBitmap bitmap)

Causes only the pixels of the widget for which bitmap has a corresponding 1 bit to be visible. If the region includes pixels outside the rect() of the widget, window system controls in that area may or may not be visible, depending on the platform. This effect can be slow if the region is particularly complex.

The following code shows how an image with an alpha channel can be used to generate a mask for a widget. The label shown by this code is masked using the image it contains, giving the appearance that an irregularly-shaped image is being drawn directly onto the screen. Masked widgets receive mouse events only on their visible portions.

QLabel topLevelLabel;
QPixmap pixmap(":/images/tux.png");
topLevelLabel.setPixmap(pixmap);
topLevelLabel.setMask(pixmap.mask());
See also
mask(), clearMask(), windowOpacity()
void QWidget::setMask ( const QRegion region)

Causes only the parts of the widget which overlap region to be visible. If the region includes pixels outside the rect() of the widget, window system controls in that area may or may not be visible, depending on the platform.

Note that this effect can be slow if the region is particularly complex.

See also
windowOpacity
void QWidget::setMaximumHeight ( int  maxh)

Sets the value of the maximumHeight property to maxh.

void QWidget::setMaximumSize ( const QSize size)
inline

Sets the value of the maximumSize property to size.

void QWidget::setMaximumSize ( int  maxw,
int  maxh 
)

This method is equivalent to calling setMaximumSize(QSize(maxw, maxh)).

void QWidget::setMaximumWidth ( int  maxw)

Sets the value of the maximumWidth property to maxw.

void QWidget::setMinimumHeight ( int  minh)

Sets the value of the minimumHeight property to minh.

void QWidget::setMinimumSize ( const QSize size)
inline

Sets the value of the minimumSize property to size.

void QWidget::setMinimumSize ( int  minw,
int  minh 
)

This method is equivalent to calling setMinimumSize(QSize(minw, minh)).

void QWidget::setMinimumWidth ( int  minw)

Sets the value of the minimumWidth property to minw.

void QWidget::setMouseTracking ( bool  enable)
inline

Sets the value of the mouseTracking property to enable.

void QWidget::setPalette ( const QPalette palette)

Sets the value of the palette property to palette.

void QWidget::setParent ( QWidget *  parent)

Sets the parent of the widget to parent and resets the window flags. The widget is moved to position (0, 0) in its new parent.

If the new parent widget is in a different window, the reparented widget and its children are appended to the end of the tab chain of the new parent widget, in the same internal order as before. If one of the moved widgets had keyboard focus, setParent() calls clearFocus() for that widget.

If the new parent widget is in the same window as the old parent, setting the parent does not change the tab order or keyboard focus.

If the "new" parent widget is the old parent widget, this function does nothing.

Note
The widget becomes invisible as part of changing its parent, even if it was previously visible. You must call show() to make the widget visible again.
Warning
It is very unlikely that you will ever need this method. If you have a widget that changes its content dynamically, it is far easier to use QStackedWidget.
See also
setWindowFlags()
void QWidget::setParent ( QWidget *  parent,
Qt::WindowFlags  flags 
)

This method also takes widget flags flags as an argument.

void QWidget::setShortcutAutoRepeat ( int  id,
bool  enable = true 
)

If enable is true, auto repeat of the shortcut with the given id is enabled, otherwise it is disabled.

See also
grabShortcut(), releaseShortcut()
void QWidget::setShortcutEnabled ( int  id,
bool  enable = true 
)

If enable is true, the shortcut with the given id is enabled, otherwise the shortcut is disabled.

Warning
You should not normally need to use this function since the CopperSpice shortcut system enables/disables shortcuts automatically as widgets become hidden/visible and gain or lose focus. It is best to use QAction or QShortcut to handle shortcuts, since they are easier to use than this low-level function.
See also
grabShortcut(), releaseShortcut()
void QWidget::setSizeIncrement ( const QSize size)
inline

Sets the value of the sizeIncrement property to size.

void QWidget::setSizeIncrement ( int  w,
int  h 
)

Sets the x (width) size increment to w and the y (height) size increment to h.

void QWidget::setSizePolicy ( QSizePolicy  policy)

Property documentation pending.

void QWidget::setSizePolicy ( QSizePolicy::Policy  horizontal,
QSizePolicy::Policy  vertical 
)
inline

Sets the value of the sizePolicy property to horizontal, vertical.

void QWidget::setStatusTip ( const QString data)

Sets the value of the statusTip property to data.

void QWidget::setStyle ( QStyle style)

Sets the widget's GUI style to style. The ownership of the style object is not transferred.

If no style is set, the widget uses the application's style, QApplication::style() instead.

Setting a widget's style has no effect on existing or future child widgets.

Warning
This function is particularly useful for demonstration purposes, where you want to show the CopperSpice styling capabilities. Real applications should avoid it and use one consistent GUI style instead.
CopperSpice style sheets are currently not supported for custom QStyle subclasses. We plan to address this in some future release.
See also
style(), QStyle, QApplication::style(), QApplication::setStyle()
void QWidget::setStyleSheet ( const QString styleSheet)
slot

Sets the value of the styleSheet property to styleSheet.

void QWidget::setTabOrder ( QWidget *  firstWidget,
QWidget *  secondWidget 
)
static

Puts the second widget after the first widget in the focus order. If first or second has a focus proxy, setTabOrder() correctly substitutes the proxy. Since the tab order of the second widget has changed use code like the following to set a focus chain.

setTabOrder(a, b); // a to b
setTabOrder(b, c); // a to b to c
setTabOrder(c, d); // a to b to c to d

The following code will not produce the desired result.

// INCORRECT
setTabOrder(c, d); // c to d
setTabOrder(a, b); // a to b AND c to d
setTabOrder(b, c); // a to b to c, but not c to d
See also
setFocusPolicy(), setFocusProxy(), Keyboard Focus
void QWidget::setToolTip ( const QString data)

Sets the value of the toolTip property to data.

void QWidget::setToolTipDuration ( int  msec)

Sets the value of the statusTip property to msec.

void QWidget::setUpdatesEnabled ( bool  enable)

Sets the value of the updatesEnabled property to enable.

void QWidget::setVisible ( bool  visible)
slot

Sets the value of the visible property to visible.

void QWidget::setWhatsThis ( const QString str)

Sets the value of the whatsThis property to str.

void QWidget::setWindowFilePath ( const QString filePath)

Sets the value of the windowFilePath property to filePath.

void QWidget::setWindowFlags ( Qt::WindowFlags  flags)

Sets the value of the windowFlags property to flags.

void QWidget::setWindowIcon ( const QIcon icon)

Sets the value of the windowIcon property to icon.

void QWidget::setWindowModality ( Qt::WindowModality  windowModality)

Sets the value of the windowModality property to windowModality.

void QWidget::setWindowModified ( bool  modified)
slot

Sets the value of the windowModified property to modified.

void QWidget::setWindowOpacity ( qreal  level)

Sets the value of the windowOpacity property to level.

void QWidget::setWindowRole ( const QString role)

Sets the window's role to role. This only makes sense for windows on X11.

See also
windowRole()
void QWidget::setWindowState ( Qt::WindowStates  windowState)

Sets the window state to windowState. The window state is a OR'ed combination of Qt::WindowState, Qt::WindowMinimized, Qt::WindowMaximized, Qt::WindowFullScreen, and Qt::WindowActive.

If the window is not visible (i.e. isVisible() returns false), the window state will take effect when show() is called. For visible windows, the change is immediate. For example, to toggle between full-screen and normal mode, use the following code.

w->setWindowState(w->windowState() ^ Qt::WindowFullScreen);

In order to restore and activate a minimized window, while preserving its maximized and/or full-screen state, use code similar to the following.

w->setWindowState(w->windowState() & ~Qt::WindowMinimized | Qt::WindowActive);

Calling this method will hide the widget. You must call show() to make the widget visible again. On some window systems Qt::WindowActive is not immediate and may be ignored in certain cases. When the window state changes, the widget receives a changeEvent() of type QEvent::WindowStateChange.

See also
Qt::WindowState, windowState()
void QWidget::setWindowTitle ( const QString title)
slot

Sets the value of the windowTitle property to title.

void QWidget::show ( )
slot

Shows the widget and its child widgets. This method is equivalent to calling setVisible(true).

See also
raise(), showEvent(), hide(), setVisible(), showMinimized(), showMaximized(), showNormal(), isVisible()
void QWidget::showEvent ( QShowEvent event)
protectedvirtual

This event handler can be reimplemented in a subclass to receive widget show events which are passed in the event parameter. Non-spontaneous show events are sent to widgets immediately before they are shown. The spontaneous show events of windows are delivered afterwards.

A widget receives spontaneous show and hide events when its mapping status is changed by the window system, e.g. a spontaneous hide event when the user minimizes the window, and a spontaneous show event when the window is restored again. After receiving a spontaneous hide event, a widget is still considered visible in the sense of isVisible().

See also
visible, event(), QShowEvent

Reimplemented in QMdiArea, QMdiSubWindow, QTextEdit, QPlainTextEdit, QGraphicsView, QComboBox, QMessageBox, QTabBar, QAbstractSpinBox, QTabWidget, QProgressDialog, QDialog, QToolBox, QStatusBar, QRubberBand, QSizeGrip, and QWebInspector.

void QWidget::showFullScreen ( )
slot

Shows the widget in full-screen mode. Calling this method only affects windows. To return from full-screen mode call showNormal().

Full-screen mode works fine under Windows, but has certain problems under X. These problems are due to limitations of the ICCCM protocol that specifies the communication between X11 clients and the window manager. ICCCM simply does not understand the concept of non-decorated full-screen windows. Therefore, the best we can do is to request a borderless window and place and resize it to fill the entire screen. Depending on the window manager, this may or may not work. The borderless window is requested using MOTIF hints, which are at least partially supported by virtually all modern window managers.

An alternative would be to bypass the window manager entirely and create a window with the Qt::X11BypassWindowManagerHint flag. This has other severe problems though, like totally broken keyboard focus and very strange effects on desktop changes or when the user raises other windows.

X11 window managers that follow modern post-ICCCM specifications support full-screen mode properly.

See also
showNormal(), showMaximized(), show(), hide(), isVisible()
void QWidget::showMaximized ( )
slot

Shows the widget maximized.

On X11, this method may not work properly with certain window managers. Refer to Window Geometry documentation for an explanation.

See also
setWindowState(), showNormal(), showMinimized(), show(), hide(), isVisible()
void QWidget::showMinimized ( )
slot

Shows the widget minimized as an icon.

See also
showNormal(), showMaximized(), show(), hide(), isVisible(), isMinimized()
void QWidget::showNormal ( )
slot

Restores the widget after it has been maximized or minimized.

Calling this function only affects windows.

See also
setWindowState(), showMinimized(), showMaximized(), show(), hide(), isVisible()
QSize QWidget::size ( ) const
inline

Returns the value of the size property.

QSize QWidget::sizeIncrement ( ) const

Returns the value of the sizeIncrement property.

QSizePolicy QWidget::sizePolicy ( ) const

Returns the value of the sizePolicy property.

void QWidget::stackUnder ( QWidget *  widget)

Places the widget under widget in the parent widget's stack. To make this work, the QWidget and widget must be siblings.

See also
raise(), lower()
QString QWidget::statusTip ( ) const

Returns the value of the statusTip property.

QString QWidget::styleSheet ( ) const

Returns the value of the styleSheet property.

void QWidget::tabletEvent ( QTabletEvent event)
protectedvirtual

This event handler, for event event, can be reimplemented in a subclass to receive tablet events for the widget.

If you reimplement this handler, it is very important that you ignore() the event if you do not handle it, so that the widget's parent can interpret it.

The default implementation ignores the event.

See also
QTabletEvent::ignore(), QTabletEvent::accept(), event(), QTabletEvent
bool QWidget::testAttribute ( Qt::WidgetAttribute  attribute) const
inline

Returns true if attribute attribute is set on this widget, otherwise returns false.

See also
setAttribute()
QString QWidget::toolTip ( ) const

Returns the value of the toolTip property.

int QWidget::toolTipDuration ( ) const

Returns the value of the toolTipDuration property.

QWidget * QWidget::topLevelWidget ( ) const
inlinedeprecated
Deprecated:
Use window() instead.
bool QWidget::underMouse ( ) const
inline

Returns true if the widget is under the mouse cursor, otherwise returns false. This value is not updated properly during drag and drop operations.

See also
enterEvent(), leaveEvent()
void QWidget::ungrabGesture ( Qt::GestureType  gestureType)

Unsubscribes the widget from a given gestureType type

See also
grabGesture(), QGestureEvent
void QWidget::unsetCursor ( )

Sets the value of the cursor property to the default value.

void QWidget::unsetLayoutDirection ( )

Sets the value of the layoutDirection property to the default value.

void QWidget::unsetLocale ( )

Sets the value of the locale property to the default value.

void QWidget::update ( )
slot

Updates the widget unless updates are disabled or the widget is hidden.

This function does not cause an immediate repaint, instead it schedules a paint event for processing when CopperSpice returns to the main event loop. This permits CopperSpice to optimize for more speed and less flicker than a call to repaint() does.

Calling update() several times normally results in just one paintEvent() call.

CopperSpice normally erases the widget's area before the paintEvent() call. If the Qt::WA_OpaquePaintEvent> widget attribute is set, the widget is responsible for painting all its pixels with an opaque color.

See also
repaint(), paintEvent(), setUpdatesEnabled()
void QWidget::update ( const QRect rect)

This version updates a rectangle rect inside the widget.

void QWidget::update ( const QRegion region)

This version repaints a region inside the widget.

void QWidget::update ( int  x,
int  y,
int  w,
int  h 
)
inline

This version updates a rectangle (x, y, w, h) inside the widget.

void QWidget::updateGeometry ( )

Notifies the layout system that this widget has changed and may need to change geometry. Call this method if either the sizeHint() or sizePolicy() have changed.

For explicitly hidden widgets, updateGeometry() is a no-op. The layout system will be notified as soon as the widget is shown.

void QWidget::updateMicroFocus ( )
protectedslot

Updates the widget's micro focus.

bool QWidget::updatesEnabled ( ) const
inline

Returns the value of the updatesEnabled property.

QRegion QWidget::visibleRegion ( ) const

Returns the unobscured region where paint events can occur. For visible widgets, this is an approximation of the area not covered by other widgets, otherwise this is an empty region.

The repaint() method calls this method if necessary, so in general you do not need to call it.

QString QWidget::whatsThis ( ) const

Returns the value of the whatsThis property.

void QWidget::wheelEvent ( QWheelEvent event)
protectedvirtual

This event handler, for event event, can be reimplemented in a subclass to receive wheel events for the widget. If you reimplement this handler, it is very important that you ignore() the event if you do not handle it, so that the widget's parent can interpret it.

The default implementation ignores the event.

See also
QWheelEvent::ignore(), QWheelEvent::accept(), event(), QWheelEvent

Reimplemented in QTextEdit, QPlainTextEdit, QGraphicsView, QComboBox, QMenu, QTabBar, QDateTimeEdit, QListView, QAbstractSpinBox, QAbstractSlider, QAbstractScrollArea, QScrollBar, and QWebView.

int QWidget::width ( ) const
inline

Returns the value of the width property.

QWidget * QWidget::window ( ) const

Returns the window for this widget, i.e. the next ancestor widget that has (or could have) a window-system frame. If the widget is a window, the widget itself is returned.

Typical usage is changing the window title:

aWidget->window()->setWindowTitle("New Window Title");
See also
isWindow()
QString QWidget::windowFilePath ( ) const

Returns the value of the windowFilePath property.

Qt::WindowFlags QWidget::windowFlags ( ) const
inline

Returns the value of the windowFlags property.

QWindow * QWidget::windowHandle ( ) const

If this is a native widget returns the associated QWindow, otherwise it returns a nullptr. Native widgets include toplevel widgets, QGLWidget, and child widgets on which winId() was called.

See also
winId()
QIcon QWidget::windowIcon ( ) const

Returns the value of the windowIcon property.

void QWidget::windowIconChanged ( const QIcon icon)
signal

Property documentation pending.

void QWidget::windowIconTextChanged ( const QString iconText)
signal

Property documentation pending.

Qt::WindowModality QWidget::windowModality ( ) const

Returns the value of the windowModality property.

qreal QWidget::windowOpacity ( ) const

Returns the value of the windowOpacity property.

QString QWidget::windowRole ( ) const

Returns the window's role, or an empty string.

See also
setWindowRole(), QWidget::windowIcon, QWidget::windowTitle
Qt::WindowStates QWidget::windowState ( ) const

Returns the current window state. The window state is a OR'ed combination of Qt::WindowState, Qt::WindowMinimized, Qt::WindowMaximized, Qt::WindowFullScreen, and Qt::WindowActive.

See also
Qt::WindowState, setWindowState()
QString QWidget::windowTitle ( ) const

Returns the value of the windowTitle property.

void QWidget::windowTitleChanged ( const QString title)
signal

Property documentation pending.

Qt::WindowType QWidget::windowType ( ) const
inline

Returns the window type of this widget. This is identical to windowFlags() & Qt::WindowType_Mask.

See also
windowFlags
WId QWidget::winId ( ) const

Returns the window system identifier of the widget. This method is supported on all platforms however the return value is only useful when calling platform specific functions.

If a widget is non-native (alien) and winId() is invoked on it, that widget will be provided a native handle. This value may change at run time. An event with type QEvent::WinIdChange will be sent to the widget following a change in window system identifier.

On Mac OS X the type returned depends on which framework was used. If CopperSpice is linked with Carbon the {WId} is actually an HIViewRef. If CopperSpice is linked with Cocoa, {WId} is a pointer to an NSView.

See also
find()
int QWidget::x ( ) const

Returns the value of the x property.

int QWidget::y ( ) const

Returns the value of the y property.

Friends And Related Function Documentation

QWidgetList ( )
related

Synonym for QList<QWidget *>.

WId ( )
related

Platform dependent window identifier.

Property Documentation

QWidget::acceptDrops

This property holds whether drop events are enabled for this widget. Setting this property to true announces to the system that this widget may be able to accept drop events. By default this property is false.

If the widget is the desktop (windowType() == Qt::Desktop), this may fail if another application is using the desktop, you can call acceptDrops() to test if this occurs.

Warning
Do not modify this property in a drag and drop event handler.
See also
Drag and Drop
PropertiesClass Methods
read acceptDrops
write setAcceptDrops
QWidget::accessibleDescription

This property holds the widget's description as seen by assistive technologies. By default this property contains an empty string.

See also
QAccessibleInterface::text()
PropertiesClass Methods
read accessibleDescription
write setAccessibleDescription
QWidget::accessibleName

This property holds the widget's name as seen by assistive technologies. By default this property contains an empty string.

This property is used by accessible clients to identify, find, or announce the widget for accessible clients.

See also
QAccessibleInterface::text()
PropertiesClass Methods
write setAccessibleName
QWidget::autoFillBackground

This property holds whether the widget background is filled automatically.

If enabled, this property will cause CopperSpice to fill the background of the widget before invoking the paint event. The color used is defined by the QPalette::Window color role from the widget's palette.

In addition, Windows are always filled with QPalette::Window, unless the WA_OpaquePaintEvent or WA_NoSystemBackground attributes are set.

This property can not be turned off (i.e., set to false) if a widget's parent has a static gradient for its background.

Warning
Use this property with caution in conjunction with CopperSpice Style Sheets. When a widget has a style sheet with a valid background or a border-image, this property is automatically disabled.

By default, this property is false.

See also
Qt::WA_OpaquePaintEvent, Qt::WA_NoSystemBackground, Transparency, Double Buffering
PropertiesClass Methods
read autoFillBackground
write setAutoFillBackground
QWidget::baseSize

This property holds the base size of the widget.

The base size is used to calculate a proper widget size if the widget defines sizeIncrement().

By default, for a newly-created widget, this property contains a size with zero width and height.

See also
setSizeIncrement()
PropertiesClass Methods
read baseSize
write cs_setBaseSize
QWidget::childrenRect

This property holds the bounding rectangle of the widget's children.

Hidden children are excluded.

By default, for a widget with no children, this property contains a rectangle with zero width and height located at the origin.

See also
childrenRegion(), geometry()
PropertiesClass Methods
read childrenRect
QWidget::childrenRegion

This property holds the combined region occupied by the widget's children.

Hidden children are excluded.

By default, for a widget with no children, this property contains an empty region.

See also
childrenRect(), geometry(), mask()
PropertiesClass Methods
read childrenRegion
QWidget::contextMenuPolicy

This property holds how the widget shows a context menu.

The default value of this property is Qt::DefaultContextMenu, which means the contextMenuEvent() handler is called. Other values are Qt::NoContextMenu, Qt::PreventContextMenu, Qt::ActionsContextMenu, and Qt::CustomContextMenu. With Qt::CustomContextMenu, the signal customContextMenuRequested() is emitted.

See also
contextMenuEvent(), customContextMenuRequested(), actions()
PropertiesClass Methods
read contextMenuPolicy
write setContextMenuPolicy
QWidget::cursor

This property holds the cursor shape for this widget. The mouse cursor will assume this shape when it is over this widget. If no cursor has been set, or after a call to unsetCursor(), the parent's cursor is used. By default, this property contains a cursor with the Qt::ArrowCursor shape.

Refer to the list of predefined cursor objects for a range of useful shapes. For example, an editor widget might use an I-beam cursor.

setCursor(Qt::IBeamCursor);

Some underlying window implementations will reset the cursor if it leaves a widget even if the mouse is grabbed. If you want to have a cursor set for all widgets, even when outside the window, consider QApplication::setOverrideCursor().

See also
QApplication::setOverrideCursor()
PropertiesClass Methods
read cursor
write setCursor
reset unsetCursor
QWidget::enabled

This property holds whether the widget is enabled. In general an enabled widget handles keyboard and mouse event, a disabled widget does not. Disabling a widget implicitly disables all its children. Enabling respectively enables all child widgets unless they have been explicitly disabled.

Some widgets display themselves differently when they are disabled. For example a button might draw its label grayed out. If your widget needs to know when it becomes enabled or disabled, you can use the changeEvent() with type QEvent::EnabledChange.

By default, this property is true.

See also
isEnabledTo(), QKeyEvent, QMouseEvent, changeEvent()
PropertiesClass Methods
read isEnabled
write setEnabled
QWidget::focus

This property holds whether this widget (or its focus proxy) has the keyboard input focus. By default this property is false.

Note
Obtaining the value of this property for a widget is equivalent to checking whether QApplication::focusWidget() refers to the widget.
See also
setFocus(), clearFocus(), setFocusPolicy(), QApplication::focusWidget()
PropertiesClass Methods
read hasFocus
QWidget::focusPolicy

This property holds the way the widget accepts keyboard focus.

The policy is Qt::TabFocus if the widget accepts keyboard focus by tabbing, Qt::ClickFocus if the widget accepts focus by clicking, Qt::StrongFocus if it accepts both, and Qt::NoFocus (the default) if it does not accept focus at all.

You must enable keyboard focus for a widget if it processes keyboard events. This is normally done from the widget's constructor. For instance, the QLineEdit constructor calls setFocusPolicy(Qt::StrongFocus).

If the widget has a focus proxy then the focus policy will be propagated to it.

See also
focusInEvent(), focusOutEvent(), keyPressEvent(), keyReleaseEvent(), enabled
PropertiesClass Methods
read focusPolicy
write setFocusPolicy
QWidget::font

This property holds the font currently set for the widget.

This property describes the widget's requested font. The font is used by the widget's style when rendering standard components, and is available as a means to ensure that custom widgets can maintain consistency with the native platform's look and feel. It's common that different platforms, or different styles, define different fonts for an application.

When you assign a new font to a widget, the properties from this font are combined with the widget's default font to form the widget's final font. You can call fontInfo() to get a copy of the widget's final font. The final font is also used to initialize QPainter's font.

The default depends on the system environment. QApplication maintains a system/theme font which serves as a default for all widgets. There may also be special font defaults for certain types of widgets. You can also define default fonts for widgets yourself by passing a custom font and the name of a widget to QApplication::setFont(). Finally, the font is matched against the CopperSpice font database to find the best match.

QWidget propagates explicit font properties from parent to child. If you change a specific property on a font and assign that font to a widget, that property will propagate to all the widget's children, overriding any system defaults for that property. Note that fonts by default do not propagate to windows (see isWindow()) unless the Qt::WA_WindowPropagation attribute is enabled.

QWidget's font propagation is similar to its palette propagation.

The current style, which is used to render the content of all standard CopperSpice widgets, is free to choose to use the widget font, or in some cases, to ignore it (partially, or completely). In particular, certain styles like GTK style, Mac style, Windows XP, and Vista style, apply special modifications to the widget font to match the platform's native look and feel. Because of this, assigning properties to a widget's font is not guaranteed to change the appearance of the widget. Instead, you may choose to apply a styleSheet.

Note
If CopperSpice Style Sheets are used on the same widget as setFont(), style sheets will take precedence if the settings conflict.
See also
fontInfo(), fontMetrics()
PropertiesClass Methods
read font
write setFont
QWidget::frameGeometry

This property holds geometry of the widget relative to its parent including any window frame. By default this property contains a value that depends on the user's platform and screen geometry.

Refer to Window Geometry documentation for an overview of geometry issues with windows.

See also
geometry(), x(), y(), pos()
PropertiesClass Methods
read frameGeometry
QWidget::frameSize

This property holds the size of the widget including any window frame. By default this property contains a value that depends on the user's platform and screen geometry.

PropertiesClass Methods
read frameSize
QWidget::fullScreen

This property holds whether the widget is shown in full screen mode. By default this property is false.

A widget in full screen mode occupies the whole screen area and does not display window decorations, such as a title bar.

See also
windowState(), minimized, maximized
PropertiesClass Methods
read isFullScreen
QWidget::geometry

This property holds the geometry of the widget relative to its parent and excluding the window frame. By default this property contains a value that depends on the user's platform and screen geometry.

When changing the geometry, the widget, if visible, receives a move event (moveEvent()) and/or a resize event (resizeEvent()) immediately. If the widget is not currently visible, it is guaranteed to receive appropriate events before it is shown.

The size component is adjusted if it lies outside the range defined by minimumSize() and maximumSize().

Refer to Window Geometry documentation for an overview of geometry issues with windows.

Warning
Calling setGeometry() inside resizeEvent() or moveEvent() can lead to infinite recursion.
See also
geometry, setGeometry, frameGeometry(), rect(), move(), resize(), moveEvent(), resizeEvent(), minimumSize(), maximumSize()
PropertiesClass Methods
read geometry
write cs_setGeometry
QWidget::height

This property holds the height of the widget excluding any window frame. By default this property contains a value that depends on the user's platform and screen geometry.

Refer to Window Geometry documentation for an overview of geometry issues with windows.

Note
Do not use this function to find the height of a screen on a multiple screen desktop. Read this note for details.
See also
geometry, width, size
PropertiesClass Methods
read height
QWidget::inputMethodHints

This property holds what input method specific hints the widget has. The default value is Qt::ImhNone.

This is only relevant for input widgets. It is used by the input method to retrieve hints as to how the input method should operate. For example, if the Qt::ImhFormattedNumbersOnly flag is set, the input method may change its visual components to reflect that only numbers can be entered.

Note
The flags are only hints, so the particular input method implementation is free to ignore them. If you want to be sure that a certain type of characters are entered, you should also set a QValidator on the widget.
See also
inputMethodQuery()
PropertiesClass Methods
write setInputMethodHints
QWidget::isActiveWindow

This property holds whether this widget's window is the active window. By default this property is false.

The active window is the window that contains the widget that has keyboard focus. The window may still have focus if it has no widgets or none of its widgets accepts keyboard focus. When popup windows are visible, this property is true for both the active window and for the popup.

See also
activateWindow(), QApplication::activeWindow()
PropertiesClass Methods
read isActiveWindow
QWidget::layoutDirection

This property holds the layout direction for this widget. By default this property is set to Qt::LeftToRight.

When the layout direction is set on a widget, it will propagate to the widget's children, but not to a child that is a window and not to a child for which setLayoutDirection() has been explicitly called. Also, child widgets added after setLayoutDirection() has been called for the parent do not inherit the parent's layout direction.

This method no longer affects text layout direction.

See also
QApplication::layoutDirection
PropertiesClass Methods
read layoutDirection
write setLayoutDirection
reset unsetLayoutDirection
QWidget::locale

This property holds the widget's locale.

As long as no special locale has been set, this is either the parent's locale or (if this widget is a top level widget), the default locale. If the widget displays dates or numbers, these should be formatted using the widget's locale.

See also
QLocale, QLocale::setDefault()
PropertiesClass Methods
read locale
write setLocale
reset unsetLocale
QWidget::maximized

This property holds whether this widget is maximized. By default this property is false.

This property is only relevant for windows.

Note
Due to limitations on some window systems, this does not always report the expected results (e.g., if the user on X11 maximizes the window via the window manager, CopperSpice has no way of distinguishing this from any other resize). This is expected to improve as window manager protocols evolve.
See also
windowState(), showMaximized(), visible, show(), hide(), showNormal(), minimized
PropertiesClass Methods
read isMaximized
QWidget::maximumHeight

This property holds the widget's maximum height in pixels. By default this property contains a value of 16777215.

This property corresponds to the height held by the maximumSize property.

Note
The definition of the QWIDGETSIZE_MAX macro limits the maximum size of widgets.
See also
maximumSize, maximumWidth
PropertiesClass Methods
read maximumHeight
write setMaximumHeight
designable true
stored true
QWidget::maximumSize

This property holds the widget's maximum size in pixels. By default this property contains a size in which both width and height have values of 16777215.

The widget can not be resized to a larger size than the maximum widget size.

Note
The definition of the QWIDGETSIZE_MAX macro limits the maximum size of widgets.
See also
maximumWidth, maximumHeight, minimumSize, sizeIncrement
PropertiesClass Methods
read maximumSize
write cs_setMaximumSize
QWidget::maximumWidth

This property holds the widget's maximum width in pixels. By default this property contains a value of 16777215.

This property corresponds to the width held by the maximumSize property.

Note
The definition of the QWIDGETSIZE_MAX macro limits the maximum size of widgets.
See also
maximumSize, maximumHeight
PropertiesClass Methods
read maximumWidth
write setMaximumWidth
designable true
stored true
QWidget::minimized

This property holds whether this widget is minimized (iconified). By default this property is false.

This property is only relevant for windows.

See also
showMinimized(), visible, show(), hide(), showNormal(), maximized
PropertiesClass Methods
read isMinimized
QWidget::minimumHeight

This property holds the widget's minimum height in pixels. By default this property has a value of 0.

This property corresponds to the height held by the minimumSize property.

See also
minimumSize, minimumWidth
PropertiesClass Methods
read minimumHeight
write setMinimumHeight
designable true
stored true
QWidget::minimumSize

This property holds the widget's minimum size. By default this property contains a size with zero width and height.

The widget can not be resized to a smaller size than the minimum widget size. The widget's size is forced to the minimum size if the current size is smaller. The minimum size set by this function will override the minimum size defined by QLayout. In order to unset the minimum size, use a value of QSize(0, 0).

See also
minimumWidth, minimumHeight, maximumSize, sizeIncrement
PropertiesClass Methods
read minimumSize
write cs_setMinimumSize
QWidget::minimumSizeHint

This property holds the recommended minimum size for the widget.

If the value of this property is an invalid size, no minimum size is recommended.

The default implementation of minimumSizeHint() returns an invalid size if there is no layout for this widget, and returns the layout's minimum size otherwise. Most built-in widgets reimplement minimumSizeHint().

QLayout will never resize a widget to a size smaller than the minimum size hint unless minimumSize() is set or the size policy is set to QSizePolicy::Ignore. If minimumSize() is set, the minimum size hint will be ignored.

See also
QSize::isValid(), resize(), setMinimumSize(), sizePolicy()
PropertiesClass Methods
read minimumSizeHint
QWidget::minimumWidth

This property holds the widget's minimum width in pixels. By default this property has a value of 0.

This property corresponds to the width held by the minimumSize property.

See also
minimumSize, minimumHeight
PropertiesClass Methods
read minimumWidth
write setMinimumWidth
designable true
stored true
QWidget::modal

This property holds whether the widget is a modal widget. By default this property is false.

This property only makes sense for windows. A modal widget prevents widgets in all other windows from getting any input.

See also
isWindow(), windowModality, QDialog
PropertiesClass Methods
read isModal
QWidget::mouseTracking

This property holds whether mouse tracking is enabled for the widget.

If mouse tracking is disabled (the default), the widget only receives mouse move events when at least one mouse button is pressed while the mouse is being moved.

If mouse tracking is enabled, the widget receives mouse move events even if no buttons are pressed.

See also
mouseMoveEvent()
PropertiesClass Methods
read hasMouseTracking
write setMouseTracking
QWidget::normalGeometry

This property holds the geometry of the widget as it will appear when shown as a normal (not maximized or full screen) top-level widget. By default this property contains an empty rectangle.

For child widgets this property always holds an empty rectangle.

See also
QWidget::windowState(), QWidget::geometry
PropertiesClass Methods
read normalGeometry
QWidget::palette

This property holds the widget's palette.

This property describes the widget's palette. The palette is used by the widget's style when rendering standard components, and is available as a means to ensure that custom widgets can maintain consistency with the native platform's look and feel. It's common that different platforms, or different styles, have different palettes.

When you assign a new palette to a widget, the color roles from this palette are combined with the widget's default palette to form the widget's final palette. The palette entry for the widget's background role is used to fill the widget's background (see QWidget::autoFillBackground), and the foreground role initializes QPainter's pen.

The default depends on the system environment. QApplication maintains a system/theme palette which serves as a default for all widgets. There may also be special palette defaults for certain types of widgets (e.g., on Windows XP and Vista, all classes that derive from QMenuBar have a special default palette). You can also define default palettes for widgets yourself by passing a custom palette and the name of a widget to QApplication::setPalette(). Finally, the style always has the option of polishing the palette as it's assigned (see QStyle::polish()).

QWidget propagates explicit palette roles from parent to child. If you assign a brush or color to a specific role on a palette and assign that palette to a widget, that role will propagate to all the widget's children, overriding any system defaults for that role. Note that palettes by default do not propagate to windows (see isWindow()) unless the Qt::WA_WindowPropagation attribute is enabled.

QWidget's palette propagation is similar to its font propagation.

The current style, which is used to render the content of all standard CopperSpice widgets, is free to choose colors and brushes from the widget palette, or in some cases, to ignore the palette (partially, or completely). In particular, certain styles like GTK style, Mac style, Windows XP, and Vista style, depend on third party APIs to render the content of widgets, and these styles typically do not follow the palette. Because of this, assigning roles to a widget's palette is not guaranteed to change the appearance of the widget. Instead, you may choose to apply a styleSheet.

Warning
Do not use this function in conjunction with "CopperSpice Style Sheets". When using style sheets, the palette of a widget can be customized using the "color", "background-color", "selection-color", "selection-background-color" and "alternate-background-color".
See also
QApplication::palette(), QWidget::font()
PropertiesClass Methods
read palette
write setPalette
QWidget::pos

This property holds the position of the widget within its parent widget. By default this property contains a position that refers to the origin.

If the widget is a window, the position is that of the widget on the desktop, including its frame. When changing the position, the widget, if visible, receives a move event (moveEvent()) immediately. If the widget is not currently visible, it is guaranteed to receive an event before it is shown.

Warning
Calling move() or setGeometry() inside moveEvent() can lead to infinite recursion.

Refer to Window Geometry documentation for an overview of geometry issues with windows.

See also
frameGeometry, size, x(), y()
PropertiesClass Methods
read pos
write cs_move
designable true
stored true
QWidget::rect

This property holds the internal geometry of the widget excluding any window frame. By default, this property contains a value that depends on the user's platform and screen geometry.

The rect property equals QRect(0, 0, width(), height()).

Refer to Window Geometry documentation for an overview of geometry issues with windows.

See also
size
PropertiesClass Methods
read rect
QWidget::size

This property holds the size of the widget excluding any window frame. By default, this property contains a value that depends on the user's platform and screen geometry.

If the widget is visible when it is being resized, it receives a resize event (resizeEvent()) immediately. If the widget is not currently visible, it is guaranteed to receive an event before it is shown. The size is adjusted if it lies outside the range defined by minimumSize() and maximumSize().

Warning
Calling resize() or setGeometry() inside resizeEvent() can lead to infinite recursion.
Note
Setting the size to QSize(0, 0) will cause the widget to not appear on screen. This also applies to windows.
See also
pos, geometry, minimumSize, maximumSize, resizeEvent(), adjustSize()
PropertiesClass Methods
read size
write cs_resize
designable true
stored true
QWidget::sizeHint

This property holds the recommended size for the widget. The default implementation of sizeHint() returns an invalid size if there is no layout for this widget, and returns the layout's preferred size otherwise. If the value of this property is an invalid size, no size is recommended.

See also
QSize::isValid(), minimumSizeHint(), sizePolicy(), setMinimumSize(), updateGeometry()
PropertiesClass Methods
read sizeHint
QWidget::sizeIncrement

This property holds the size increment of the widget. By default this property contains a size with zero width and height.

When the user resizes the window, the size will move in steps of sizeIncrement().width() pixels horizontally and sizeIncrement.height() pixels vertically, with baseSize() as the basis. Preferred widget sizes are for non-negative integers i and j:

width = baseSize().width() + i * sizeIncrement().width();
height = baseSize().height() + j * sizeIncrement().height();

While you set the size increment for all widgets it only affects windows.

Warning
The size increment has no effect under Windows, and may be disregarded by the window manager on X11.
See also
size, minimumSize, maximumSize
PropertiesClass Methods
read sizeIncrement
write cs_setSizeIncrement
QWidget::sizePolicy

This property holds the default layout behavior of the widget.

If there is a QLayout that manages this widget's children, the size policy specified by that layout is used. If there is no such QLayout, the result of this function is used.

The default policy is Preferred/Preferred, which means that the widget can be freely resized, but prefers to be the size sizeHint() returns. Button-like widgets set the size policy to specify that they may stretch horizontally, but are fixed vertically. The same applies to lineedit controls (such as QLineEdit, QSpinBox or an editable QComboBox) and other horizontally orientated widgets (such as QProgressBar). QToolButton's are normally square, so they allow growth in both directions. Widgets that support different directions (such as QSlider, QScrollBar or QHeader) specify stretching in the respective direction only. Widgets that can provide scroll bars (usually subclasses of QScrollArea) tend to specify that they can use additional space, and that they can make do with less than sizeHint().

See also
sizeHint(), QLayout, QSizePolicy, updateGeometry()
PropertiesClass Methods
read sizePolicy
write cs_setSizePolicy
QWidget::statusTip

This property holds the widget's status tip. By default this property contains an empty string.

See also
toolTip, whatsThis
PropertiesClass Methods
read statusTip
write setStatusTip
QWidget::styleSheet

This property holds the widget's style sheet. The style sheet contains a textual description of customizations to the widget's style, as described in the CopperSpice Style Sheets document.

CopperSpice style sheets fully support Mac OS X.

Warning
CopperSpice style sheets are currently not supported for custom QStyle subclasses.
See also
setStyle(), QApplication::styleSheet, CopperSpice Style Sheets
PropertiesClass Methods
read styleSheet
write setStyleSheet
QWidget::toolTip

This property holds the widget's tooltip. By default this property contains an empty string.

By default tooltips are only shown for widgets that are children of the active window. You can change this behavior by setting the attribute Qt::WA_AlwaysShowToolTips on the window, not on the widget with the tooltip.

If you want to control a tooltip's behavior, you can intercept the event() function and catch the QEvent::ToolTip event (e.g., if you want to customize the area for which the tooltip should be shown).

See also
QToolTip, statusTip, whatsThis
PropertiesClass Methods
read toolTip
write setToolTip
QWidget::updatesEnabled

This property holds whether updates are enabled. By default this property is true.

An updates enabled widget receives paint events and has a system background; a disabled widget does not. This also implies that calling update() and repaint() has no effect if updates are disabled.

setUpdatesEnabled() is normally used to disable updates for a short period of time, for instance to avoid screen flicker during large changes. In CopperSpice, widgets normally do not generate screen flicker, but on X11 the server might erase regions on the screen when widgets get hidden before they can be replaced by other widgets. Disabling updates solves this.

bigVisualChanges();

Disabling a widget implicitly disables all its children. Enabling a widget enables all child widgets except top-level widgets or those that have been explicitly disabled. Re-enabling updates implicitly calls update() on the widget.

See also
paintEvent()
PropertiesClass Methods
read updatesEnabled
write setUpdatesEnabled
designable true
QWidget::visible

This property holds whether the widget is visible.

Calling setVisible(true) or show() sets the widget to visible status if all its parent widgets up to the window are visible. If an ancestor is not visible, the widget will not become visible until all its ancestors are shown. If its size or position has changed, CopperSpice guarantees that a widget gets move and resize events just before it is shown. If the widget has not been resized yet, CopperSpice will adjust the widget's size to a useful default using adjustSize().

Calling setVisible(false) or hide() hides a widget explicitly. An explicitly hidden widget will never become visible, even if all its ancestors become visible, unless you show it.

A widget receives show and hide events when its visibility status changes. Between a hide and a show event, there is no need to waste CPU cycles preparing or displaying information to the user. A video application, for example, might simply stop generating new frames.

A widget that happens to be obscured by other windows on the screen is considered to be visible. The same applies to iconified windows and windows that exist on another virtual desktop (on platforms that support this concept). A widget receives spontaneous show and hide events when its mapping status is changed by the window system, e.g. a spontaneous hide event when the user minimizes the window, and a spontaneous show event when the window is restored again.

You almost never have to reimplement the setVisible() function. If you need to change some settings before a widget is shown, use showEvent() instead. If you need to do some delayed initialization use the Polish event delivered to the event() function.

See also
show(), hide(), isHidden(), isVisibleTo(), isMinimized(), showEvent(), hideEvent()
PropertiesClass Methods
read isVisible
write setVisible
designable true
QWidget::whatsThis

This property holds the widget's What's This help text. By default this property contains an empty string.

See also
QWhatsThis, QWidget::toolTip, QWidget::statusTip
PropertiesClass Methods
read whatsThis
write setWhatsThis
QWidget::width

This property holds the width of the widget excluding any window frame. By default this property contains a value that depends on the user's platform and screen geometry.

Refer to Window Geometry documentation for an overview of geometry issues with windows.

Note
Do not use this method to find the width of a screen on a multiple screen desktop.
See also
geometry, height, size
PropertiesClass Methods
read width
QWidget::windowFilePath

This property holds the file path associated with a widget. By default, this property contains an empty string.

This property only makes sense for windows. It associates a file path with a window. If you set the file path, but have not set the window title, CopperSpice sets the window title to contain a string created using the following components.

On Mac OS X:

On Windows and X11:

  • The file name of the specified path, obtained using QFileInfo::fileName().
  • An optional '*' character, if the windowModified property is set.
  • The 0x2014 unicode character, padded either side by spaces.
  • The application name, obtained from the application's applicationName property.

If the window title is set at any point, then the window title takes precedence and will be shown instead of the file path string. Additionally, on Mac OS X this has an added benefit that it sets the proxy icon for the window, assuming that the file path exists.

If no file path is set this property contains an empty string.

See also
QWidget::windowTitle, QWidget::windowIcon
PropertiesClass Methods
read windowFilePath
write setWindowFilePath
QWidget::windowFlags

Window flags are a combination of a type (e.g. Qt::Dialog) and zero or more hints to the window system (e.g. Qt::FramelessWindowHint).

If the widget had type Qt::Widget or Qt::SubWindow and becomes a window (Qt::Window, Qt::Dialog, etc.), it is put at position (0, 0) on the desktop. If the widget is a window and becomes a Qt::Widget or Qt::SubWindow, it is put at position (0, 0) relative to its parent widget.

Note
This method calls setParent() when changing the flags for a window, causing the widget to be hidden. You must call show() to make the widget visible again.
See also
windowType()
PropertiesClass Methods
read windowFlags
write setWindowFlags
QWidget::windowIcon

This property holds the widget's icon. This property only makes sense for windows. If no icon has been set, windowIcon() returns the application icon (QApplication::windowIcon()).

See also
QWidget::windowIconText, QWidget::windowTitle
PropertiesClass Methods
write setWindowIcon
notify windowIconChanged
QWidget::windowIconText

This property holds the widget's icon text. This property only makes sense for windows. If no icon text has been set, this functions returns an empty string.

See also
QWidget::windowIcon, QWidget::windowTitle
PropertiesClass Methods
write setWindowIconText
notify windowIconTextChanged
QWidget::windowModality

This property holds which windows are blocked by the modal widget. This property only makes sense for windows. By default this property is Qt::NonModal.

A modal widget prevents widgets in other windows from getting input. The value of this property controls which windows are blocked when the widget is visible. Changing this property while the window is visible has no effect; you must hide() the widget first, then show() it again.

See also
isWindow(), QWidget::modal, QDialog
PropertiesClass Methods
read windowModality
write setWindowModality
QWidget::windowModified

This property holds whether the document shown in the window has unsaved changes.

A modified window is a window whose content has changed but has not been saved to disk. This flag will have different effects varied by the platform. On Mac OS X the close button will have a modified look; on other platforms, the window title will have an '*' (asterisk).

The window title must contain a "[*]" placeholder, which indicates where the '*' should appear. Normally, it should appear right after the file name (e.g., "document1.txt[*] - Text Editor"). If the window is not modified, the placeholder is simply removed.

Note that if a widget is set as modified, all its ancestors will also be set as modified. However, if you call setWindowModified(false) on a widget, this will not propagate to its parent because other children of the parent might have been modified.

See also
windowTitle
PropertiesClass Methods
write setWindowModified
QWidget::windowOpacity

This property holds the level of opacity for the window. The valid range of opacity is from 1.0 (completely opaque) to 0.0 (completely transparent). By default the value of this property is 1.0.

This feature is available on OS X, Windows, and X11 platforms which support the Composite extension.

Under X11, the composite manager and the X11 specific _NET_WM_WINDOW_OPACITY atom needs to be supported by the window manager you are using.

Warning
Changing this property from opaque to transparent might issue a paint event that needs to be processed before the window is displayed correctly. This affects mainly the use of QPixmap::grabWindow(). Also note that semi-transparent windows update and resize significantly slower than opaque windows.
See also
setMask()
PropertiesClass Methods
write setWindowOpacity
QWidget::windowTitle

This property holds the window title. This property only makes sense for top-level widgets, such as windows and dialogs. If no caption has been set, the title is based of the windowFilePath. If neither of these is set, then the title is an empty string.

If you use the windowModified mechanism, the window title must contain a "[*]" placeholder, which indicates where the '*' should appear. Normally, it should appear right after the file name (e.g., "document1.txt[*] - Text Editor"). If the windowModified property is false (the default), the placeholder is simply removed.

See also
QWidget::windowIcon, QWidget::windowIconText, QWidget::windowModified, QWidget::windowFilePath
PropertiesClass Methods
read windowTitle
write setWindowTitle
notify windowTitleChanged
QWidget::x

This property holds the x coordinate of the widget relative to its parent including any window frame. By default this property has a value of 0.

Refer to Window Geometry documentation for an overview of geometry issues with windows.

See also
frameGeometry, y, pos
PropertiesClass Methods
read x
QWidget::y

This property holds the y coordinate of the widget relative to its parent and including any window frame. By default this property has a value of 0.

Refer to Window Geometry documentation for an overview of geometry issues with windows.

See also
frameGeometry, x, pos
PropertiesClass Methods
read y