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>

Inheritance diagram for QgsMapLayerRegistry:

[legend]

Signals
void	layerRemoved (QString theLayerId)
	Emitted after a layer was removed from the registry.
void	layersAdded (QList< QgsMapLayer * > theMapLayers)
	Emitted when one or more layers are added to the registry.
void	layersRemoved (QStringList theLayerIds)
	Emitted after one or more layers were removed from the registry.
void	layersWillBeRemoved (QStringList theLayerIds)
	Emitted when one or more layers are removed from the registry.
void	layerWasAdded (QgsMapLayer *theMapLayer)
	Emitted when a layer is added to the registry.
void	layerWillBeRemoved (QString theLayerId)
	Emitted when a layer is removed from the registry.
void	legendLayersAdded (QList< QgsMapLayer * > theMapLayers)
	Emitted, when a layer is added to the registry and the legend.
void	removeAll ()
	Emitted, when all layers are removed, before layersWillBeRemoved() and layerWillBeRemoved() signals are emitted.

Public Member Functions
	~QgsMapLayerRegistry ()
QgsMapLayer *	addMapLayer (QgsMapLayer *theMapLayer, bool addToLegend=true, bool takeOwnership=true)
	Add a layer to the map of loaded layers.
QList< QgsMapLayer * >	addMapLayers (QList< QgsMapLayer * > theMapLayers, bool addToLegend=true, bool takeOwnership=true)
	Add a list of layers to the map of loaded layers.
Q_DECL_DEPRECATED void	clearAllLayerCaches ()
	Clears all layer caches, resetting them to zero and freeing up any memory they may have been using.
int	count ()
	Return the number of registered layers.
QgsMapLayer *	mapLayer (QString theLayerId)
	Retrieve a pointer to a loaded layer by id.
const QMap< QString, QgsMapLayer * > &	mapLayers ()
	Retrieve the mapLayers collection (mainly intended for use by projection)
QList< QgsMapLayer * >	mapLayersByName (QString layerName)
	Retrieve a pointer to a loaded layer by name.
void	reloadAllLayers ()
	Reload all provider data caches (currently used for WFS and WMS providers)
void	removeAllMapLayers ()
	Remove all registered layers.
void	removeMapLayer (const QString &theLayerId)
	Remove a layer from qgis.
void	removeMapLayers (QStringList theLayerIds)
	Remove a set of layers from the registry.

Friends
class	QgsSingleton< QgsMapLayerRegistry >

Additional Inherited Members
Static Public Member Functions inherited from QgsSingleton< QgsMapLayerRegistry >
static void	cleanup ()
static QgsMapLayerRegistry *	instance ()
Protected Member Functions inherited from QgsSingleton< QgsMapLayerRegistry >
	QgsSingleton ()
virtual	~QgsSingleton ()

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 35 of file qgsmaplayerregistry.h.

Constructor & Destructor Documentation

QgsMapLayerRegistry::~QgsMapLayerRegistry ( )

Definition at line 31 of file qgsmaplayerregistry.cpp.

Member Function Documentation

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

Add a layer to the map of loaded layers.

The layersAdded() and layersWasAdded() signals will be emitted in any case. The legendLayersAdded() signal only if addToLegend is true. If you are adding multiple layers at once, you should use addMapLayers() instead.

Parameters

theMapLayer	A layer to add to the registry
addToLegend	If true (by default), the layer will be added to the legend and to the main canvas. If you have a private you can set this parameter to false to hide it.
takeOwnership	Ownership will be transferred to the layer registry. If you specify false here, you have take care of deleting the layer yourself. Not available in python.

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

See Also: addMapLayers

Note: As a side-effect QgsProject is made dirty.; Use addMapLayers if adding more than one layer at a time; takeOwner not available in python binding - always takes ownership

Definition at line 97 of file qgsmaplayerregistry.cpp.

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

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

The layersAdded() and layersWasAdded() signals will be emitted in any case. The legendLayersAdded() signal only if addToLegend is true.

Parameters

theMapLayers	A list of layer which should be added to the registry
addToLegend	If true (by default), the layers will be added to the legend and to the main canvas. If you have a private layer, you can set this parameter to false to hide it.
takeOwnership	Ownership will be transferred to the layer registry. If you specify false here, you have take care of deleting the layers yourself. Not available in python.

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: As a side-effect QgsProject is made dirty.; takeOwner not available in python binding - always takes ownership

Definition at line 61 of file qgsmaplayerregistry.cpp.

void QgsMapLayerRegistry::clearAllLayerCaches ( )

Clears all layer caches, resetting them to zero and freeing up any memory they may have been using.

Layer caches are used to speed up rendering in certain situations see ticket #1974 for more details.

Deprecated:: since 2.4 - does nothing

Definition at line 141 of file qgsmaplayerregistry.cpp.

int QgsMapLayerRegistry::count ( )

Return the number of registered layers.

Definition at line 37 of file qgsmaplayerregistry.cpp.

void QgsMapLayerRegistry::layerRemoved ( QString theLayerId )

signal

Emitted after a layer was removed from the registry.

Parameters

theLayerId The id of the layer removed

Note: Consider using layersRemoved() instead

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

signal

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

This signal is also emitted for layers added to the registry, but not to the legend and canvas.

Parameters

theMapLayers The layers which have been added

See Also: legendLayersAdded()

void QgsMapLayerRegistry::layersRemoved ( QStringList theLayerIds )

signal

Emitted after one or more layers were removed from the registry.

Parameters

theLayerIds A list of ids of the layers which were removed.

void QgsMapLayerRegistry::layersWillBeRemoved ( QStringList theLayerIds )

signal

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

Parameters

theLayerIds A list of ids of the layers which are removed.

void QgsMapLayerRegistry::layerWasAdded ( QgsMapLayer * theMapLayer )

signal

Emitted when a layer is added to the registry.

Parameters

theMapLayer The id of the layer which has been added

Note: Consider using layersAdded() instead

void QgsMapLayerRegistry::layerWillBeRemoved ( QString theLayerId )

signal

Emitted when a layer is removed from the registry.

Parameters

theLayerId The id of the layer being removed

Note: Consider using layersWillBeRemoved() instead

void QgsMapLayerRegistry::legendLayersAdded ( QList< QgsMapLayer * > theMapLayers )

signal

Emitted, when a layer is added to the registry and the legend.

Plugins are allowed to have private layers, which are signalled by layersAdded() and layerWasAdded() but will not be advertised by this signal.

Parameters

theMapLayers The QgsMapLayers which are added to the legend.

QgsMapLayer * QgsMapLayerRegistry::mapLayer ( QString theLayerId )

Retrieve a pointer to a loaded layer by id.

Definition at line 42 of file qgsmaplayerregistry.cpp.

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

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

Definition at line 158 of file qgsmaplayerregistry.cpp.

QList< QgsMapLayer * > QgsMapLayerRegistry::mapLayersByName ( QString layerName )

Retrieve a pointer to a loaded layer by name.

Definition at line 47 of file qgsmaplayerregistry.cpp.

void QgsMapLayerRegistry::reloadAllLayers ( )

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

Definition at line 145 of file qgsmaplayerregistry.cpp.

void QgsMapLayerRegistry::removeAll ( )

signal

Emitted, when all layers are removed, before layersWillBeRemoved() and layerWillBeRemoved() signals are emitted.

You will still get these signals in any case. You can use this signal to do easy (and fast) cleanup.

void QgsMapLayerRegistry::removeAllMapLayers ( )

Remove all registered layers.

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

Definition at line 132 of file qgsmaplayerregistry.cpp.

void QgsMapLayerRegistry::removeMapLayer ( const QString & theLayerId )

Remove a layer from qgis.

Any canvases using the affected layers will need to remove them

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

Parameters

theLayerId The id of the layer to remove

Note: As a side-effect QgsProject is made dirty.

Definition at line 127 of file qgsmaplayerregistry.cpp.

void QgsMapLayerRegistry::removeMapLayers ( QStringList theLayerIds )

Remove a set of layers from the registry.

Any canvases using the affected layers will need to remove them

The layers being removed are deleted as well as the registry table entries.

Parameters

theLayerIds The ids of the layers to remove

Note: As a side-effect QgsProject is made dirty.

Definition at line 108 of file qgsmaplayerregistry.cpp.

Friends And Related Function Documentation

friend class QgsSingleton< QgsMapLayerRegistry >

friend

Definition at line 246 of file qgsmaplayerregistry.h.

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

/tmp/buildd/qgis-2.8.2+12wheezy/src/core/qgsmaplayerregistry.h
/tmp/buildd/qgis-2.8.2+12wheezy/src/core/qgsmaplayerregistry.cpp

Signals

Public Member Functions

Friends

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Friends And Related Function Documentation