CopperSpice API  1.7.2
QFileSystemWatcher Class Reference

Provides an interface for monitoring files and directories for modifications. More...

Inheritance diagram for QFileSystemWatcher:
QObject

Public Signals

void directoryChanged (const QString &path)
 
void fileChanged (const QString &path)
 
- Public Signals inherited from QObject
void destroyed (QObject *obj=nullptr)
 
void objectNameChanged (const QString &objectName)
 

Public Methods

 QFileSystemWatcher (const QStringList &pathList, QObject *parent=nullptr)
 
 QFileSystemWatcher (QObject *parent=nullptr)
 
 ~QFileSystemWatcher ()
 
void addPath (const QString &path)
 
void addPaths (const QStringList &pathList)
 
QStringList directories () const
 
QStringList files () const
 
void removePath (const QString &path)
 
void removePaths (const QStringList &pathList)
 
- 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
 

Additional Inherited Members

- Public Slots inherited from QObject
void deleteLater ()
 
- 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 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)
 
- Properties inherited from QObject
 objectName
 

Detailed Description

The QFileSystemWatcher class provides an interface for monitoring files and directories for modifications. QFileSystemWatcher monitors the file system for changes to files and directories by watching a list of specified path locations.

Call addPath() to watch a particular file or directory. Multiple paths can be added using the addPaths() method. Existing paths can be removed by using the removePath() and removePaths() methods. QFileSystemWatcher examines each path added to it. Files that have been added to the QFileSystemWatcher can be accessed using the files() method, and directories using the directories() method.

The fileChanged() signal is emitted when a file has been modified, renamed or removed from disk. Similarly, the directoryChanged() signal is emitted when a directory or its contents is modified or removed. Note that QFileSystemWatcher stops monitoring files once they have been renamed or removed from disk, and directories once they have been removed from disk.

On systems running Linux without inotify support, file systems that contain watched paths can not be unmounted.

Monitoring files and directories for modifications consumes system resources. This implies there is a limit to the number of files and directories your process can monitor simultaneously. On some platforms an open file descriptor is required for each monitored file. Some system limits the number of open file descriptors to 256 by default. This means that addPath() and addPaths() will fail if your process tries to add more than 256 files or directories to the file system monitor. Also note that your process may have other file descriptors open in addition to the ones for files being monitored, and these other open descriptors also count in the total.

See also
QFile, QDir

Constructor & Destructor Documentation

QFileSystemWatcher::QFileSystemWatcher ( QObject parent = nullptr)

Constructs a new file system watcher object with the given parent.

QFileSystemWatcher::QFileSystemWatcher ( const QStringList pathList,
QObject parent = nullptr 
)

Constructs a new file system watcher object with the given parent which monitors the specified pathList.

QFileSystemWatcher::~QFileSystemWatcher ( )

Destroys the file system watcher.

Method Documentation

void QFileSystemWatcher::addPath ( const QString path)

Adds path to the file system watcher if it exists. The path is not added if it does not exist, or if it is already being monitored by the file system watcher. If path specifies a directory, the directoryChanged() signal will be emitted when path is modified or removed from disk, otherwise the fileChanged() signal is emitted when path is modified, renamed or removed.

Note
There is a system dependent limit to the number of files and directories that can be monitored simultaneously. If this limit has been reached, path will not be added to the file system watcher, and a warning message will be printed to stderr.
See also
addPaths(), removePath()
void QFileSystemWatcher::addPaths ( const QStringList pathList)

Adds each path in pathList to the file system watcher. Paths are not added if they not exist, or if they are already being monitored by the file system watcher. If a path specifies a directory, the directoryChanged() signal will be emitted when the path is modified or removed from disk, otherwise the fileChanged() signal is emitted when the path is modified, renamed, or removed.

Note
There is a system dependent limit to the number of files and directories that can be monitored simultaneously. If this limit has been reached, the excess pathList will not be added to the file system watcher, and a warning message will be printed to stderr for each path that could not be added.
See also
addPath(), removePaths()
QStringList QFileSystemWatcher::directories ( ) const

Returns a list of paths to directories that are being watched.

See also
files()
void QFileSystemWatcher::directoryChanged ( const QString path)
signal

This signal is emitted when the directory at a specified path, is modified (e.g., when a file is added, modified or deleted) or removed from disk. Note that if there are several changes during a short period of time, some of the changes might not emit this signal. However, the last change in the sequence of changes will always generate this signal.

See also
fileChanged()
void QFileSystemWatcher::fileChanged ( const QString path)
signal

This signal is emitted when the file at the specified path is modified, renamed or removed from disk.

See also
directoryChanged()
QStringList QFileSystemWatcher::files ( ) const

Returns a list of paths to files that are being watched.

See also
directories()
void QFileSystemWatcher::removePath ( const QString path)

Removes the specified path from the file system watcher.

See also
removePaths(), addPath()
void QFileSystemWatcher::removePaths ( const QStringList pathList)

Removes the specified pathList from the file system watcher.

See also
removePath(), addPaths()