This class is responsible for keeping cache of rendered images of individual layers. More...

#include <qgsmaprenderercache.h>

Inheritance diagram for QgsMapRendererCache:

Public Member Functions
	QgsMapRendererCache ()

QImage	cacheImage (const QString &layerId)
	get cached image for the specified layer ID. Returns null image if it is not cached. More...

void	clear ()
	invalidate the cache contents More...

void	clearCacheImage (const QString &layerId)
	remove layer from the cache More...

bool	init (const QgsRectangle &extent, double scale)
	initialize cache: set new parameters and erase cache if parameters have changed More...

void	setCacheImage (const QString &layerId, const QImage &img)
	set cached image for the specified layer ID More...

Public Member Functions inherited from QObject
	QObject (QObject *parent)

	QObject (QObject parent, const char name)

virtual	~QObject ()

bool	blockSignals (bool block)

QObject *	child (const char objName, const char inheritsClass, bool recursiveSearch) const

const QObjectList &	children () const

const char *	className () const

bool	connect (const QObject sender, const char signal, const char *method, Qt::ConnectionType type) const

void	deleteLater ()

void	destroyed (QObject *obj)

bool	disconnect (const QObject receiver, const char method)

bool	disconnect (const char signal, const QObject receiver, const char *method)

void	dumpObjectInfo ()

void	dumpObjectTree ()

QList< QByteArray >	dynamicPropertyNames () const

virtual bool	event (QEvent *e)

virtual bool	eventFilter (QObject watched, QEvent event)

T	findChild (const QString &name) const

QList< T >	findChildren (const QRegExp &regExp) const

QList< T >	findChildren (const QString &name) const

bool	inherits (const char *className) const

void	insertChild (QObject *object)

void	installEventFilter (QObject *filterObj)

bool	isA (const char *className) const

bool	isWidgetType () const

void	killTimer (int id)

virtual const QMetaObject *	metaObject () const

void	moveToThread (QThread *targetThread)

const char *	name () const

const char *	name (const char *defaultName) const

QString	objectName () const

QObject *	parent () const

QVariant	property (const char *name) const

void	removeChild (QObject *object)

void	removeEventFilter (QObject *obj)

void	setName (const char *name)

void	setObjectName (const QString &name)

void	setParent (QObject *parent)

bool	setProperty (const char *name, const QVariant &value)

bool	signalsBlocked () const

int	startTimer (int interval)

QThread *	thread () const

Protected Slots
void	layerRequestedRepaint ()
	remove layer (that emitted the signal) from the cache More...

Protected Member Functions
void	clearInternal ()
	invalidate cache contents (without locking) More...

Protected Member Functions inherited from QObject
bool	checkConnectArgs (const char signal, const QObject object, const char *method)

virtual void	childEvent (QChildEvent *event)

virtual void	connectNotify (const char *signal)

virtual void	customEvent (QEvent *event)

virtual void	disconnectNotify (const char *signal)

int	receivers (const char *signal) const

QObject *	sender () const

int	senderSignalIndex () const

virtual void	timerEvent (QTimerEvent *event)

Protected Attributes
QMap< QString, QImage >	mCachedImages

QgsRectangle	mExtent

QMutex	mMutex

double	mScale

Additional Inherited Members
Static Public Member Functions inherited from QObject
bool	connect (const QObject sender, const char signal, const QObject receiver, const char method, Qt::ConnectionType type)

bool	connect (const QObject sender, const QMetaMethod &signal, const QObject receiver, const QMetaMethod &method, Qt::ConnectionType type)

bool	disconnect (const QObject sender, const char signal, const QObject receiver, const char method)

bool	disconnect (const QObject sender, const QMetaMethod &signal, const QObject receiver, const QMetaMethod &method)

QString	tr (const char sourceText, const char disambiguation, int n)

QString	trUtf8 (const char sourceText, const char disambiguation, int n)

Static Protected Member Functions inherited from QObject
QByteArray	normalizeSignalSlot (const char *signalSlot)

Properties inherited from QObject
	objectName

Detailed Description

This class is responsible for keeping cache of rendered images of individual layers.

Once a layer has rendered image stored in the cache (using setCacheImage(...)), the cache listens to repaintRequested() signals from layer. If triggered, the cache removes the rendered image (and disconnects from the layer).

The class is thread-safe (multiple classes can access the same instance safely).

Note: added in 2.4

Definition at line 37 of file qgsmaprenderercache.h.

Constructor & Destructor Documentation

◆ QgsMapRendererCache()

QgsMapRendererCache::QgsMapRendererCache ( )

Definition at line 21 of file qgsmaprenderercache.cpp.

Member Function Documentation

◆ cacheImage()

QImage QgsMapRendererCache::cacheImage ( const QString & layerId )

get cached image for the specified layer ID. Returns null image if it is not cached.

Definition at line 81 of file qgsmaprenderercache.cpp.

◆ clear()

void QgsMapRendererCache::clear ( )

invalidate the cache contents

Definition at line 26 of file qgsmaprenderercache.cpp.

◆ clearCacheImage()

void QgsMapRendererCache::clearCacheImage ( const QString & layerId )

remove layer from the cache

Definition at line 94 of file qgsmaprenderercache.cpp.

◆ clearInternal()

void QgsMapRendererCache::clearInternal ( )

protected

invalidate cache contents (without locking)

Definition at line 32 of file qgsmaprenderercache.cpp.

◆ init()

bool QgsMapRendererCache::init	(	const QgsRectangle &	extent,
		double	scale
	)

initialize cache: set new parameters and erase cache if parameters have changed

Returns: flag whether the parameters are the same as last time

Definition at line 50 of file qgsmaprenderercache.cpp.

◆ layerRequestedRepaint

void QgsMapRendererCache::layerRequestedRepaint ( )

protectedslot

remove layer (that emitted the signal) from the cache

Definition at line 87 of file qgsmaprenderercache.cpp.

◆ setCacheImage()

void QgsMapRendererCache::setCacheImage	(	const QString &	layerId,
		const QImage &	img
	)

set cached image for the specified layer ID

Definition at line 68 of file qgsmaprenderercache.cpp.

Member Data Documentation

◆ mCachedImages

QMap<QString, QImage> QgsMapRendererCache::mCachedImages

protected

Definition at line 72 of file qgsmaprenderercache.h.

◆ mExtent

QgsRectangle QgsMapRendererCache::mExtent

protected

Definition at line 70 of file qgsmaprenderercache.h.

◆ mMutex

QMutex QgsMapRendererCache::mMutex

protected

Definition at line 69 of file qgsmaprenderercache.h.

◆ mScale

double QgsMapRendererCache::mScale

protected

Definition at line 71 of file qgsmaprenderercache.h.

The documentation for this class was generated from the following files:

/tmp/buildd/qgis-2.18.21+99unstable/src/core/qgsmaprenderercache.h
/tmp/buildd/qgis-2.18.21+99unstable/src/core/qgsmaprenderercache.cpp

Public Member Functions

Protected Slots

Protected Member Functions

Protected Attributes

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ QgsMapRendererCache()

Member Function Documentation

◆ cacheImage()

◆ clear()

◆ clearCacheImage()

◆ clearInternal()

◆ init()

◆ layerRequestedRepaint

◆ setCacheImage()

Member Data Documentation

◆ mCachedImages

◆ mExtent

◆ mMutex

◆ mScale