This class tracks map layers that are currently loaded and provides a means to fetch a pointer to a map layer and delete it. More...

#include <qgsmaplayerregistry.h>

Collaboration diagram for QgsMapLayerRegistry:

[legend]

List of all members.

Signals
void	layersWillBeRemoved (QStringList theLayerIds)
	Emitted when one or more layers are removed from the registry.
void	layerWillBeRemoved (QString theLayerId)
	emitted when a layer is removed from the registry connected to main map canvas and overview map canvas remove()
void	layersAdded (QList< QgsMapLayer * > theMapLayers)
	Emitted when one or more layers are added to the registry.
void	layerWasAdded (QgsMapLayer *theMapLayer)
	emitted when a layer is added to the registry connected to main map canvas and overview map canvas addLayer()
void	removedAll ()
	emitted when ALL layers are removed at once This could have been implemented by iteratively signalling layerWillBeRemoved() for each layer as it is removed.
Public Member Functions
int	count ()
	~QgsMapLayerRegistry ()
QgsMapLayer *	mapLayer (QString theLayerId)
	Retrieve a pointer to a loaded layer by id.
QMap< QString, QgsMapLayer * > &	mapLayers ()
	Retrieve the mapLayers collection (mainly intended for use by projectio)
Q_DECL_DEPRECATED QgsMapLayer *	addMapLayer (QgsMapLayer *theMapLayer, bool theEmitSignal=true)
	Add a layer to the map of loaded layers.
QList< QgsMapLayer * >	addMapLayers (QList< QgsMapLayer * > theMapLayers, bool theEmitSignal=true)
	Add a list of layers to the map of loaded layers.
Q_DECL_DEPRECATED void	removeMapLayer (QString theLayerId, bool theEmitSignal=true)
	Remove a layer from qgis.
void	removeMapLayers (QStringList theLayerIds, bool theEmitSignal=true)
	Remove a set of layers from qgis.
void	removeAllMapLayers ()
	Remove all registered layers.
void	clearAllLayerCaches ()
void	reloadAllLayers ()
	Reload all provider data caches (currently used for WFS and WMS providers)
Static Public Member Functions
static QgsMapLayerRegistry *	instance ()
	Returns the instance pointer, creating the object on the first call.
Protected Member Functions
	QgsMapLayerRegistry (QObject *parent=0)
	protected constructor
Private Member Functions
void	connectNotify (const char *signal)
	debugging member invoked when a connect() is made to this object
Private Attributes
QMap< QString, QgsMapLayer * >	mMapLayers
Static Private Attributes
static QgsMapLayerRegistry *	mInstance = 0

Detailed Description

This class tracks map layers that are currently loaded and provides a means to fetch a pointer to a map layer and delete it.

Definition at line 32 of file qgsmaplayerregistry.h.

Constructor & Destructor Documentation

QgsMapLayerRegistry::~QgsMapLayerRegistry ( )

Definition at line 44 of file qgsmaplayerregistry.cpp.

References removeAllMapLayers().

QgsMapLayerRegistry::QgsMapLayerRegistry ( QObject * parent = 0 ) [protected]

protected constructor

Definition at line 39 of file qgsmaplayerregistry.cpp.

Referenced by instance().

Member Function Documentation

QgsMapLayer * QgsMapLayerRegistry::addMapLayer	(	QgsMapLayer *	theMapLayer,
		bool	theEmitSignal = `true`
	)

Add a layer to the map of loaded layers.

Returns:: NULL if unable to add layer, otherwise pointer to newly added layer

Note:

As a side-effect QgsProject is made dirty.

Emits signal that layer has been added only if theEmitSignal is true (by default).

Not emitting signal is useful when you want to use registry for layers on a different canvas and don't want them added to the main canvas automatically.

Note:: This method is deprecated since QGIS 1.8, you should use addMapLayers rather.

Definition at line 96 of file qgsmaplayerregistry.cpp.

References addMapLayers().

QList< QgsMapLayer * > QgsMapLayerRegistry::addMapLayers	(	QList< QgsMapLayer * >	theMapLayers,
		bool	theEmitSignal = `true`
	)

Add a list of layers to the map of loaded layers.

Returns:: QList<QgsMapLayer *> - a list of the map layers that were added successfully. If a layer is invalid, or already exists in the registry, it will not be part of the returned QList.

Note:: added in QGIS 1.8

As a side-effect QgsProject is made dirty.

If theEmitSignal is true (by default), a layersAdded( QList<QgsMapLayer *>) signal will be emitted indicating that a batch of layers were added. Not emitting signal is useful when you want to use registry for layers on a different canvas and don't want them added to the main canvas automatically.

Definition at line 61 of file qgsmaplayerregistry.cpp.

References QgsMapLayer::id(), QgsMapLayer::isValid(), layersAdded(), layerWasAdded(), mMapLayers, and QgsDebugMsg.

Referenced by addMapLayer().

void QgsMapLayerRegistry::clearAllLayerCaches ( )

Definition at line 150 of file qgsmaplayerregistry.cpp.

References mMapLayers.

Referenced by QgsMapRenderer::render().

void QgsMapLayerRegistry::connectNotify ( const char * signal ) [private]

debugging member invoked when a connect() is made to this object

Definition at line 180 of file qgsmaplayerregistry.cpp.

int QgsMapLayerRegistry::count ( )

Return the number of registered layers.

Definition at line 50 of file qgsmaplayerregistry.cpp.

References mMapLayers.

QgsMapLayerRegistry * QgsMapLayerRegistry::instance ( ) [static]

Returns the instance pointer, creating the object on the first call.

Definition at line 26 of file qgsmaplayerregistry.cpp.

References mInstance, and QgsMapLayerRegistry().

Referenced by QgsVectorLayerJoinBuffer::addJoinedFeatureAttributes(), QgsVectorLayer::addJoinedFeatureAttributes(), QgsGeometry::avoidIntersections(), QgsVectorLayerJoinBuffer::cacheJoinLayer(), QgsComposerMap::connectUpdateSlot(), QgsComposerMap::containsWMSLayer(), QgsAttributeEditor::createAttributeEditor(), QgsComposerLegend::drawLayerItem(), QgsApplication::exitQgis(), QgsApplication::initQgis(), QgsVectorLayerJoinBuffer::joinForFieldIndex(), QgsMapCanvas::layer(), QgsMapCanvas::layers(), QgsVectorLayer::maximumValue(), QgsVectorLayer::minimumValue(), QgsQuickPrint::printMap(), QgsComposerAttributeTable::QgsComposerAttributeTable(), QgsLegendModel::QgsLegendModel(), QgsVectorLayer::QgsVectorLayer(), QgsFormAnnotationItem::readXML(), QgsComposerAttributeTable::readXML(), QgsComposerSymbolItem::readXML(), QgsVectorLayer::readXml(), QgsVectorLayerJoinBuffer::removeJoin(), QgsMapRenderer::render(), QgsQuickPrint::scalePointSymbols(), QgsQuickPrint::scaleTextLabels(), QgsVectorLayerJoinBuffer::select(), QgsLegendModel::setAutoUpdate(), QgsVectorLayer::setDataProvider(), QgsLegendModel::setLayerSet(), QgsMapCanvasSnapper::snapToBackgroundLayers(), QgsComposerMap::syncLayerSet(), QgsVectorLayer::uniqueValues(), QgsVectorLayerJoinBuffer::updateFeatureAttributes(), QgsVectorLayerJoinBuffer::updateFieldMap(), QgsMapRenderer::updateFullExtent(), and QgsLegendModel::updateLayer().

void QgsMapLayerRegistry::layersAdded ( QList< QgsMapLayer * > theMapLayers ) [signal]

Emitted when one or more layers are added to the registry.

Note:: intended to replace layerWasAdded in QGIS 1.8

Referenced by addMapLayers().

void QgsMapLayerRegistry::layersWillBeRemoved ( QStringList theLayerIds ) [signal]

Emitted when one or more layers are removed from the registry.

Note:: intended to replace layerWillBeRemoved in QGIS 1.8

Referenced by removeMapLayers().

void QgsMapLayerRegistry::layerWasAdded ( QgsMapLayer * theMapLayer ) [signal]

emitted when a layer is added to the registry connected to main map canvas and overview map canvas addLayer()

Note:: we should deprecate this at some stage

Referenced by addMapLayers().

void QgsMapLayerRegistry::layerWillBeRemoved ( QString theLayerId ) [signal]

emitted when a layer is removed from the registry connected to main map canvas and overview map canvas remove()

Note:: we should deprecate this at some stage

Referenced by removeMapLayers().

QgsMapLayer * QgsMapLayerRegistry::mapLayer ( QString theLayerId )

Retrieve a pointer to a loaded layer by id.

Definition at line 55 of file qgsmaplayerregistry.cpp.

References mMapLayers.

Referenced by QgsVectorLayerJoinBuffer::addJoinedFeatureAttributes(), QgsVectorLayer::addJoinedFeatureAttributes(), QgsGeometry::avoidIntersections(), QgsVectorLayerJoinBuffer::cacheJoinLayer(), QgsComposerMap::containsWMSLayer(), QgsAttributeEditor::createAttributeEditor(), QgsComposerLegend::drawLayerItem(), QgsVectorLayerJoinBuffer::joinForFieldIndex(), QgsMapCanvas::layer(), QgsMapCanvas::layers(), QgsVectorLayer::maximumValue(), QgsVectorLayer::minimumValue(), QgsQuickPrint::printMap(), QgsFormAnnotationItem::readXML(), QgsComposerAttributeTable::readXML(), QgsComposerSymbolItem::readXML(), QgsVectorLayerJoinBuffer::removeJoin(), QgsMapRenderer::render(), QgsQuickPrint::scalePointSymbols(), QgsQuickPrint::scaleTextLabels(), QgsVectorLayerJoinBuffer::select(), QgsLegendModel::setLayerSet(), QgsMapCanvasSnapper::snapToBackgroundLayers(), QgsVectorLayer::uniqueValues(), QgsVectorLayerJoinBuffer::updateFeatureAttributes(), QgsVectorLayerJoinBuffer::updateFieldMap(), QgsMapRenderer::updateFullExtent(), and QgsLegendModel::updateLayer().

QMap< QString, QgsMapLayer * > & QgsMapLayerRegistry::mapLayers ( )

Retrieve the mapLayers collection (mainly intended for use by projectio)

Definition at line 173 of file qgsmaplayerregistry.cpp.

References mMapLayers.

Referenced by QgsComposerAttributeTable::QgsComposerAttributeTable(), QgsVectorLayer::setDataProvider(), and QgsComposerMap::syncLayerSet().

void QgsMapLayerRegistry::reloadAllLayers ( )

Reload all provider data caches (currently used for WFS and WMS providers)

Note:: : this method was added in QGIS 1.6

Definition at line 160 of file qgsmaplayerregistry.cpp.

References mMapLayers, and QgsMapLayer::reload().

void QgsMapLayerRegistry::removeAllMapLayers ( )

Remove all registered layers.

Note:: raises removedAll() As a side-effect QgsProject is made dirty.; The layers are deleted as the registry is cleared!

Definition at line 131 of file qgsmaplayerregistry.cpp.

References mMapLayers, removedAll(), and removeMapLayers().

Referenced by ~QgsMapLayerRegistry().

void QgsMapLayerRegistry::removedAll ( ) [signal]

emitted when ALL layers are removed at once This could have been implemented by iteratively signalling layerWillBeRemoved() for each layer as it is removed.

However, this generally causes a cascade of effects that are unnecessary if we're ultimately removing all layers. E.g., removing the legend item corresponding to the layer. Why bother doing that when you're just going to clear everything anyway?

Referenced by removeAllMapLayers().

void QgsMapLayerRegistry::removeMapLayer	(	QString	theLayerId,
		bool	theEmitSignal = `true`
	)

Remove a layer from qgis.

Note:: As a side-effect QgsProject is made dirty. Any canvases using that layer will need to remove it

If theEmitSignal is true (by default), a layerWillBeRemoved( QString theId ) signal will be emitted indicating to any listeners that the layer is being removed.

The layer being removed is deleted as well as the registry table entry.

Note:: This method is deprecated since QGIS 1.8, you should use removeMapLayers rather.

Definition at line 123 of file qgsmaplayerregistry.cpp.

References removeMapLayers().

void QgsMapLayerRegistry::removeMapLayers	(	QStringList	theLayerIds,
		bool	theEmitSignal = `true`
	)

Remove a set of layers from qgis.

Note:: As a side-effect QgsProject is made dirty. Any canvases using the affected layers will need to remove them

If theEmitSignal is true (by default), a layersRemoved( QStringList theLayerIds ) signal will be emitted indicating to any listeners that the layers are being removed.

The layer being removed is deleted as well as the registry table entry.

Definition at line 106 of file qgsmaplayerregistry.cpp.

References layersWillBeRemoved(), layerWillBeRemoved(), and mMapLayers.

Referenced by removeAllMapLayers(), and removeMapLayer().