The QIcon class provides scalable icons in different modes and states. More...

Public Types
enum	Mode

enum	State

Public Methods
	QIcon ()

	QIcon (const QIcon &other)

	QIcon (const QPixmap &pixmap)

	QIcon (const QString &fileName)

	QIcon (QIcon &&other)

	QIcon (QIconEngine *engine)

	~QIcon ()

QSize	actualSize (const QSize &size, Mode mode=Normal, State state=Off) const

QSize	actualSize (QWindow *window, const QSize &size, Mode mode=Normal, State state=Off) const

void	addFile (const QString &fileName, const QSize &size=QSize (), Mode mode=Normal, State state=Off)

void	addPixmap (const QPixmap &pixmap, Mode mode=Normal, State state=Off)

QList< QSize >	availableSizes (Mode mode=Normal, State state=Off) const

qint64	cacheKey () const

bool	isMask () const

bool	isNull () const

QString	name () const

	operator QVariant () const

QIcon &	operator= (const QIcon &other)

QIcon &	operator= (QIcon &&other)

void	paint (QPainter *painter, const QRect &rect, Qt::Alignment alignment=Qt::AlignCenter, Mode mode=Normal, State state=Off) const

void	paint (QPainter *painter, int x, int y, int w, int h, Qt::Alignment alignment=Qt::AlignCenter, Mode mode=Normal, State state=Off) const

QPixmap	pixmap (const QSize &size, Mode mode=Normal, State state=Off) const

QPixmap	pixmap (int extent, Mode mode=Normal, State state=Off) const

QPixmap	pixmap (int w, int h, Mode mode=Normal, State state=Off) const

QPixmap	pixmap (QWindow *window, const QSize &size, Mode mode=Normal, State state=Off) const

void	setIsMask (bool isMask)

void	swap (QIcon &other)

Static Public Methods
static QIcon	fromTheme (const QString &name, const QIcon &fallback=QIcon ())

static bool	hasThemeIcon (const QString &name)

static void	setThemeName (const QString &theme)

static void	setThemeSearchPaths (const QStringList &paths)

static QString	themeName ()

static QStringList	themeSearchPaths ()

Friends
QDataStream &	operator<< (QDataStream &stream, const QIcon &icon)

QDataStream &	operator>> (QDataStream &stream, QIcon &icon)

Detailed Description

The QIcon class provides scalable icons in different modes and states. A QIcon can generate smaller, larger, active, and disabled pixmaps from the set of pixmaps it is given. Such pixmaps are used by CopperSpice widgets to show an icon representing a particular action.

The simplest use of QIcon is to create one from a QPixmap file or resource, and then use it, allowing CopperSpice to work out all the required icon styles and sizes.

QToolButton *button = new QToolButton;

button->setIcon(QIcon("open.xpm"));

To undo a QIcon, simply set a null icon in its place:

button->setIcon(QIcon());

Use the QImageReader::supportedImageFormats() and QImageWriter::supportedImageFormats() functions to retrieve a complete list of the supported file formats.

When you retrieve a pixmap using pixmap(QSize, Mode, State), and no pixmap for this given size, mode and state has been added with addFile() or addPixmap(), then QIcon will generate one on the fly. This pixmap generation happens in a QIconEngine. The default engine scales pixmaps down if required, but never up, and it uses the current style to calculate a disabled appearance. By using custom icon engines, you can customize every aspect of generated icons. With QIconEnginePlugin it is possible to register different icon engines for different file suffixes, making it possible for third parties to provide additional icon engines to those included with CopperSpice.

Making Classes that Use QIcon

If you write your own widgets that have an option to set a small pixmap, consider allowing a QIcon to be set for that pixmap. The CopperSpice class QToolButton is an example of such a widget.

Provide a method to set a QIcon, and when you draw the icon, choose whichever pixmap is appropriate for the current state of your widget.

void MyWidget::drawIcon(QPainter *painter, QPoint pos) {
   QPixmap pixmap = icon.pixmap(QSize(22, 22),
         isEnabled() ? QIcon::Normal : QIcon::Disabled, isChecked() ? QIcon::On : QIcon::Off);
 
   painter->drawPixmap(pos, pixmap);
 }

You might also make use of the Active mode, perhaps making your widget Active when the mouse is over the widget (see QWidget::enterEvent()), while the mouse is pressed pending the release that will activate the function, or when it is the currently selected item. If the widget can be toggled, the "On" mode might be used to draw a different icon.

See also: pixmap(), paint()

Member Enumeration Documentation

enum QIcon::Mode

This enum type describes the mode for which a pixmap is intended to be used. The currently defined modes are:

Constant	Value	Description
`QIcon::Normal`	`0`	Display the pixmap when the user is not interacting with the icon, but the functionality represented by the icon is available.
`QIcon::Disabled`	`1`	Display the pixmap when the functionality represented by the icon is not available.
`QIcon::Active`	`2`	Display the pixmap when the functionality represented by the icon is available and the user is interacting with the icon, for example, moving the mouse over it or clicking it.
`QIcon::Selected`	`3`	Display the pixmap when the item represented by the icon is selected.

enum QIcon::State

This enum describes the state for which a pixmap is intended to be used. The state can be:

Constant	Value	Description
`QIcon::Off`	`1`	Display the pixmap when the widget is in an "off" state
`QIcon::On`	`0`	Display the pixmap when the widget is in an "on" state

Constructor & Destructor Documentation

QIcon::QIcon ( )

Constructs a null icon.

QIcon::QIcon ( const QPixmap & pixmap )

Constructs an icon from a pixmap.

QIcon::QIcon ( const QIcon & other )

Copy constructs a new QIcon from other.

QIcon::QIcon ( QIcon && other )

inline

Move constructs a new QIcon from other.

QIcon::QIcon ( const QString & fileName )

explicit

Constructs an icon from the file with the given fileName. The file will be loaded on demand. If fileName contains a relative path (e.g. the filename only) the relevant file must be found relative to the runtime working directory.

The file name can be either refer to an actual file on disk or to one of the application's embedded resources. Refer to the Resource System overview for details on how to embed images and other resource files in the application's executable.

Use the QImageReader::supportedImageFormats() and QImageWriter::supportedImageFormats() functions to retrieve a complete list of the supported file formats.

QIcon::QIcon ( QIconEngine * engine )

explicit

Creates an icon with a specific icon engine. The icon takes ownership of the engine.

QIcon::~QIcon ( )

Destroys the icon.

Method Documentation

QSize QIcon::actualSize	(	const QSize &	size,
		Mode	mode = `Normal`,
		State	state = `Off`
	)		const

Returns the actual size of the icon for the requested size, mode, and state. The result might be smaller than requested, but never larger.

See also: pixmap(), paint()

QSize QIcon::actualSize	(	QWindow *	window,
		const QSize &	size,
		Mode	mode = `Normal`,
		State	state = `Off`
	)		const

Returns the actual size of the icon for the requested window, size, mode, and state. The pixmap can be smaller than the requested size. The returned size is in device independent pixels. This is relevant for high DPI pixmaps.

See also: actualSize(), pixmap(), paint()

void QIcon::addFile	(	const QString &	fileName,
		const QSize &	size = `QSize()`,
		Mode	mode = `Normal`,
		State	state = `Off`
	)

Adds an image from the file with the given fileName to the icon, as a specialization for size, mode and state. The file will be loaded on demand. Note: custom icon engines are free to ignore additionally added pixmaps.

If fileName contains a relative path (e.g. the filename only) the relevant file must be found relative to the runtime working directory. The file name can be either refer to an actual file on disk or to one of the application's embedded resources. Refer to the Resource System overview for details on how to embed images and other resource files in the application's executable.

Use the QImageReader::supportedImageFormats() and QImageWriter::supportedImageFormats() functions to retrieve a complete list of the supported file formats. When you add a non-empty filename to a QIcon, the icon becomes non-null, even if the file does not exist or points to a corrupt file.

See also: addPixmap()

void QIcon::addPixmap	(	const QPixmap &	pixmap,
		Mode	mode = `Normal`,
		State	state = `Off`
	)

Adds pixmap to the icon, as a specialization for mode and state. Custom icon engines are free to ignore additionally added pixmaps.

See also: addFile()

QList< QSize > QIcon::availableSizes	(	Mode	mode = `Normal`,
		State	state = `Off`
	)		const

Returns a list of available icon sizes for the specified mode and state.

qint64 QIcon::cacheKey ( ) const

Returns a number that identifies the contents of this QIcon object. Distinct QIcon objects can have the same key if they refer to the same contents. The cacheKey() will change when the icon is altered via addPixmap() or addFile(). Cache keys are mostly useful in conjunction with caching.

See also: QPixmap::cacheKey()

QIcon QIcon::fromTheme	(	const QString &	name,
		const QIcon &	fallback = `QIcon()`
	)

static

Returns the QIcon corresponding to name in the current icon theme. If no such icon is found in the current theme fallback is returned instead. The following example fetches an icon from the current theme.

QIcon undoicon = QIcon::fromTheme("edit-undo");

If you want to provide a fallback for platforms which do not support theme icons specify the second argument.

QIcon undoicon = QIcon::fromTheme("edit-undo", QIcon(":/undo.png"));

The latest version of the freedesktop icon specification and naming specification can be obtained on the following websites.

http://standards.freedesktop.org/icon-theme-spec/icon-theme-spec-latest.html

http://standards.freedesktop.org/icon-naming-spec/icon-naming-spec-latest.html

See also: themeName(), setThemeName(), themeSearchPaths()

bool QIcon::hasThemeIcon ( const QString & name )

static

Returns true if there is an icon available for name in the current icon theme, otherwise returns false.

See also: themeSearchPaths(), fromTheme(), setThemeName()

bool QIcon::isMask ( ) const

Returns true if the current icon has been marked as a mask image. Certain platforms render mask icons differently.

See also: setIsMask()

bool QIcon::isNull ( ) const

Returns true if the icon is empty, otherwise returns false. An icon is empty if it has neither a pixmap nor a filename.

It is worth noting, a non-null icon might not be able to create valid pixmaps. For example, if the file does not exist or can not be read.

QString QIcon::name ( ) const

Returns the name used to create the icon if it is available. Depending on the way the icon was created, it may have an associated name. This is the case for icons created with fromTheme() or icons using a QIconEngine which supports the QIconEngine::IconNameHook.

See also: fromTheme(), QIconEngine

QIcon::operator QVariant ( ) const

Returns the icon as a QVariant.

QIcon & QIcon::operator= ( const QIcon & other )

Copy assigns from other and returns a reference to this object.

QIcon & QIcon::operator= ( QIcon && other )

inline

Move assigns from other and returns a reference to this object.

void QIcon::paint	(	QPainter *	painter,
		const QRect &	rect,
		Qt::Alignment	alignment = `Qt::AlignCenter`,
		Mode	mode = `Normal`,
		State	state = `Off`
	)		const

Uses the given painter to render the icon with specified alignment, required mode, and state into the given rect.

See also: actualSize(), pixmap()

void QIcon::paint	(	QPainter *	painter,
		int	x,
		int	y,
		int	w,
		int	h,
		Qt::Alignment	alignment = `Qt::AlignCenter`,
		Mode	mode = `Normal`,
		State	state = `Off`
	)		const

inline

Paints the icon into the rectangle QRect(x, y, w, h).

QPixmap QIcon::pixmap	(	const QSize &	size,
		Mode	mode = `Normal`,
		State	state = `Off`
	)		const

Returns a pixmap with the requested size, mode, and state, generating one if necessary. The pixmap might be smaller than requested, but never larger.

See also: actualSize(), paint()

QPixmap QIcon::pixmap	(	int	extent,
		Mode	mode = `Normal`,
		State	state = `Off`
	)		const

inline

Returns a pixmap of size QSize(extent, extent). The pixmap might be smaller than requested, but never larger.

QPixmap QIcon::pixmap	(	int	w,
		int	h,
		Mode	mode = `Normal`,
		State	state = `Off`
	)		const

inline

Returns a pixmap of size QSize(w, h). The pixmap might be smaller than requested, but never larger.

QPixmap QIcon::pixmap	(	QWindow *	window,
		const QSize &	size,
		Mode	mode = `Normal`,
		State	state = `Off`
	)		const

Returns a pixmap with the requested window, size, mode, and state, creating a QPixmap if necessary. The pixmap can be smaller than the requested size. If window is on a high DPI display the pixmap can be larger. In this case it will have a devicePixelRatio larger than 1.

See also: actualSize(), paint()

void QIcon::setIsMask ( bool isMask )

If isMask is true this indicates the current icon is a mask image.

See also: isMask()

void QIcon::setThemeName ( const QString & theme )

static

Sets the current icon to theme. The theme should correspond to a directory in the themeSearchPath(). The directory must contain an index.theme file.

See also: themeSearchPaths(), themeName()

void QIcon::setThemeSearchPaths ( const QStringList & paths )

static

Sets the search paths for icon themes to paths.

See also: themeSearchPaths(), fromTheme(), setThemeName()

void QIcon::swap ( QIcon & other )

inline

Swaps icon other with this icon. This operation is very fast and never fails.

QString QIcon::themeName ( )

static

Returns the name of the current icon theme. On X11, the current icon theme depends on your desktop settings. On other platforms it is not set by default.

See also: setThemeName(), themeSearchPaths(), fromTheme(), hasThemeIcon()

QStringList QIcon::themeSearchPaths ( )

static

Returns the search paths for icon themes. The default value will depend on the platform. On X11 the search path will use the XDG_DATA_DIRS environment variable if available.

By default all platforms will have the resource directory :\icons as a fallback. You can use "rcc -project" to generate a resource file from your icon theme.

See also: setThemeSearchPaths(), fromTheme(), setThemeName()

Friends And Related Function Documentation

QDataStream & operator<<	(	QDataStream &	stream,
		const QIcon &	icon
	)

friend

Writes the given icon to the given stream as a PNG image. If the icon contains more than one image, all images will be written to the stream. Writing the stream to a file will not produce a valid image file.

QDataStream & operator>>	(	QDataStream &	stream,
		QIcon &	icon
	)

friend

Reads an image, or a set of images, from the given stream into the given icon.

Public Types

Public Methods

Static Public Methods

Friends

Detailed Description

Making Classes that Use QIcon

Member Enumeration Documentation

Constructor & Destructor Documentation

Method Documentation

Friends And Related Function Documentation