KDirWatch Class

Class for watching directory and file changes. More...

• Header: #include <KDirWatch>
• CMake: find_package(KF6 REQUIRED COMPONENTS CoreAddons)
target_link_libraries(mytarget PRIVATE KF6::CoreAddons)
• Inherits: QObject

List of all members, including inherited members

#Public Types

• enum KDirWatch::Method
• enum KDirWatch::WatchMode

#Public Functions

• KDirWatch(QObject *parent = nullptr)
• ~KDirWatch()
• void addDir(const QString &path, KDirWatch::WatchModes watchModes = WatchDirOnly)
• void addFile(const QString &file)
• bool contains(const QString &path) const
• QDateTime ctime(const QString &path) const
• KDirWatch::Method internalMethod() const
• bool isStopped()
• void removeDir(const QString &path)
• void removeFile(const QString &file)
• bool restartDirScan(const QString &path)
• void startScan(bool notify = false, bool skippedToo = false)
• bool stopDirScan(const QString &path)
• void stopScan()

#Public Slots

• void setCreated(const QString &path)
• void setDeleted(const QString &path)
• void setDirty(const QString &path)

#Signals

• void created(const QString &path)
• void deleted(const QString &path)
• void dirty(const QString &path)

#Static Public Members

• bool exists()
• KDirWatch *self()

#Detailed Description

Watch directories and files for changes. The watched directories or files don't have to exist yet.

When a watched directory is changed, i.e. when files therein are created or deleted, KDirWatch will emit the signal dirty().

When a watched, but previously not existing directory gets created, KDirWatch will emit the signal created().

When a watched directory gets deleted, KDirWatch will emit the signal deleted(). The directory is still watched for new creation.

When a watched file is changed, i.e. attributes changed or written to, KDirWatch will emit the signal dirty().

Scanning of particular directories or files can be stopped temporarily and restarted. The whole class can be stopped and restarted. Directories and files can be added/removed from the list in any state.

The implementation uses the INOTIFY functionality on LINUX. As a last resort, a regular polling for change of modification times is done; the polling interval is a global config option: DirWatch/PollInterval and DirWatch/NFSPollInterval for NFS mounted directories. The choice of implementation can be adjusted by the user, with the key [DirWatch] PreferredMethod={Stat|QFSWatch|inotify}

#Member Type Documentation

#enum KDirWatch::Method

#enum KDirWatch::WatchMode

flags KDirWatch::WatchModes

Available watch modes for directory monitoring

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

#Member Function Documentation

#[explicit] KDirWatch::KDirWatch(QObject *parent = nullptr)

Constructor.

Scanning begins immediately when a dir/file watch is added.

parent the parent of the QObject (or nullptr for parent-less KDataTools)

#[override virtual noexcept] KDirWatch::~KDirWatch()

Destructor.

Stops scanning and cleans up.

#void KDirWatch::addDir(const QString &path, KDirWatch::WatchModes watchModes = WatchDirOnly)

Adds a directory to be watched.

The directory does not have to exist. When watchModes is set to WatchDirOnly (the default), the signals dirty(), created(), deleted() can be emitted, all for the watched directory. When watchModes is set to WatchFiles, all files in the watched directory are watched for changes, too. Thus, the signals dirty(), created(), deleted() can be emitted. When watchModes is set to WatchSubDirs, all subdirs are watched using the same flags specified in watchModes (symlinks aren't followed). If the path points to a symlink to a directory, the target directory is watched instead. If you want to watch the link, use addFile().

path the path to watch

watchModes watch modes

See also KDirWatch::WatchMode

#void KDirWatch::addFile(const QString &file)

Adds a file to be watched. If it's a symlink to a directory, it watches the symlink itself.

file the file to watch

#bool KDirWatch::contains(const QString &path) const

Check if a directory is being watched by this KDirWatch instance path the directory to check Returns true if the directory is being watched

#[signal] void KDirWatch::created(const QString &path)

Emitted when a file or directory (being watched explicitly) is created. This is not emitted when creating a file is created in a watched directory.

path the path of the file or directory

See also setCreated()

#QDateTime KDirWatch::ctime(const QString &path) const

Returns the time the directory/file was last changed.

path the file to check

Returns the date of the last modification

#[signal] void KDirWatch::deleted(const QString &path)

Emitted when a file or directory is deleted.

The object is still watched for new creation.

path the path of the file or directory

See also setDeleted()

#[signal] void KDirWatch::dirty(const QString &path)

Emitted when a watched object is changed. For a directory this signal is emitted when files therein are created or deleted. For a file this signal is emitted when its size or attributes change.

When you watch a directory, changes in the size or attributes of contained files may or may not trigger this signal to be emitted depending on which backend is used by KDirWatch.

The new ctime is set before the signal is emitted.

path the path of the file or directory

See also setDirty()

#[static] bool KDirWatch::exists()

Returns true if there is an instance of KDirWatch.

See also KDirWatch::self()

#KDirWatch::Method KDirWatch::internalMethod() const

Returns the preferred internal method to watch for changes.

#bool KDirWatch::isStopped()

Is scanning stopped? After creation of a KDirWatch instance, this is false. Returns true when scanning stopped

#void KDirWatch::removeDir(const QString &path)

Removes a directory from the list of scanned directories.

If specified path is not in the list this does nothing.

path the path of the dir to be removed from the list

#void KDirWatch::removeFile(const QString &file)

Removes a file from the list of watched files.

If specified path is not in the list this does nothing.

file the file to be removed from the list

#bool KDirWatch::restartDirScan(const QString &path)

Restarts scanning for specified path.

It doesn't notify about the changes (by emitting a signal). The ctime value is reset.

Call it when you are finished with big operations on that path, and when you have refreshed that path.

path the path to restart scanning

Returns true if the path is being watched, otherwise false

See also stopDirScan()

#[static] KDirWatch *KDirWatch::self()

The KDirWatch instance usually globally used in an application. It is automatically deleted when the application exits.

However, you can create an arbitrary number of KDirWatch instances aside from this one - for those you have to take care of memory management.

This function returns an instance of KDirWatch. If there is none, it will be created.

Returns a KDirWatch instance

#[slot] void KDirWatch::setCreated(const QString &path)

Emits created().

path the path of the file or directory

See also created()

#[slot] void KDirWatch::setDeleted(const QString &path)

Emits deleted().

path the path of the file or directory

See also deleted()

#[slot] void KDirWatch::setDirty(const QString &path)

Emits dirty().

path the path of the file or directory

See also dirty()

#void KDirWatch::startScan(bool notify = false, bool skippedToo = false)

Starts scanning of all dirs in list.

notify If true, all changed directories (since stopScan() call) will be notified for refresh. If notify is false, all ctimes will be reset (except those who are stopped, but only if skippedToo is false) and changed dirs won't be notified. You can start scanning even if the list is empty. First call should be called with false or else all directories in list will be notified.

skippedToo if true, the skipped directories (scanning of which was stopped with stopDirScan() ) will be reset and notified for change. Otherwise, stopped directories will continue to be unnotified.

#bool KDirWatch::stopDirScan(const QString &path)

Stops scanning the specified path.

The path is not deleted from the internal list, it is just skipped. Call this function when you perform an huge operation on this directory (copy/move big files or many files). When finished, call restartDirScan(path).

path the path to skip

Returns true if the path is being watched, otherwise false

See also restartDirScan()

#void KDirWatch::stopScan()

Stops scanning of all directories in internal list.

The timer is stopped, but the list is not cleared.

#Related Non-Members

#QDebug operator<<(QDebug debug, const KDirWatch &watch)

Dump debug information about the KDirWatch::self() instance. This checks for consistency, too.