Merge pull request #4478 from nyalldawson/layer_store

Split off map layer storage handling from QgsProject to QgsMapLayerStore

python/core/core.sip

@@ -92,6 +92,7 @@
 %Include qgsmaplayermodel.sip
 %Include qgsmaplayerproxymodel.sip
 %Include qgsmaplayerrenderer.sip
+%Include qgsmaplayerstore.sip
 %Include qgsmaplayerstylemanager.sip
 %Include qgsmaprenderercache.sip
 %Include qgsmaprenderercustompainterjob.sip

python/core/processing/qgsprocessingcontext.sip

@@ -75,11 +75,11 @@ class QgsProcessingContext
  Sets the expression ``context``.
 %End
 
-    QgsProject &temporaryLayerStore();
+    QgsMapLayerStore *temporaryLayerStore();
 %Docstring
- Returns a reference to the project used for storing temporary layers during
+ Returns a reference to the layer store used for storing temporary layers during
  algorithm execution.
- :rtype: QgsProject
+ :rtype: QgsMapLayerStore
 %End
 
     QgsFeatureRequest::InvalidGeometryCheck invalidGeometryCheck() const;

python/core/qgsmaplayerstore.sip

@@ -0,0 +1,313 @@
+/************************************************************************
+ * This file has been generated automatically from                      *
+ *                                                                      *
+ * src/core/qgsmaplayerstore.h                                          *
+ *                                                                      *
+ * Do not edit manually ! Edit header and run scripts/sipify.pl again   *
+ ************************************************************************/
+
+
+
+
+
+
+class QgsMapLayerStore : QObject
+{
+%Docstring
+ A storage object for map layers, in which the layers are owned by the
+ store and have their lifetime bound to the store.
+.. versionadded:: 3.0
+%End
+
+%TypeHeaderCode
+#include "qgsmaplayerstore.h"
+%End
+  public:
+
+    explicit QgsMapLayerStore( QObject *parent /TransferThis/ = 0 );
+%Docstring
+ Constructor for QgsMapLayerStore.
+%End
+
+    ~QgsMapLayerStore();
+
+    int count() const;
+%Docstring
+ Returns the number of layers contained in the store.
+ :rtype: int
+%End
+
+
+    int __len__() const;
+%Docstring
+ Returns the number of layers contained in the store.
+ :rtype: int
+%End
+%MethodCode
+    sipRes = sipCpp->count();
+%End
+
+    QgsMapLayer *mapLayer( const QString &id ) const;
+%Docstring
+ Retrieve a pointer to a layer by layer ``id``.
+ \param id ID of layer to retrieve
+ :return: matching layer, or None if no matching layer found
+.. seealso:: mapLayersByName()
+.. seealso:: mapLayers()
+ :rtype: QgsMapLayer
+%End
+
+    QList<QgsMapLayer *> mapLayersByName( const QString &name ) const;
+%Docstring
+ Retrieve a list of matching layers by layer ``name``.
+ \param name name of layers to match
+ :return: list of matching layers
+.. seealso:: mapLayer()
+.. seealso:: mapLayers()
+ :rtype: list of QgsMapLayer
+%End
+
+    QMap<QString, QgsMapLayer *> mapLayers() const;
+%Docstring
+ Returns a map of all layers by layer ID.
+.. seealso:: mapLayer()
+.. seealso:: mapLayersByName()
+.. seealso:: layers()
+ :rtype: QMap<str, QgsMapLayer *>
+%End
+
+
+    QList<QgsMapLayer *> addMapLayers( const QList<QgsMapLayer *> &layers /Transfer/);
+
+%Docstring
+ \brief
+ Add a list of ``layers`` to the store. Ownership of the layers is transferred
+ to the store.
+
+ The layersAdded() and layerWasAdded() signals will always be emitted.
+
+ \param layers A list of layer which should be added to the store.
+ \param takeOwnership Ownership will be transferred to the layer store.
+                      If you specify false here you have take care of deleting
+                      the layers yourself. Not available in Python.
+
+ :return: a list of the map layers that were added
+         successfully. If a layer is invalid, or already exists in the store,
+         it will not be part of the returned list.
+
+.. seealso:: addMapLayer()
+ :rtype: list of QgsMapLayer
+%End
+
+    QgsMapLayer *addMapLayer( QgsMapLayer *layer /Transfer/);
+
+%Docstring
+ \brief
+ Add a ``layer`` to the store. Ownership of the layer is transferred to the
+ store.
+
+ The layersAdded() and layerWasAdded() signals will always be emitted.
+ If you are adding multiple layers at once, you should use
+ addMapLayers() instead.
+
+ \param layer A layer to add to the store
+ \param takeOwnership Ownership will be transferred to the layer store.
+                      If you specify false here you have take care of deleting
+                      the layers yourself. Not available in Python.
+
+ :return: None if unable to add layer, otherwise pointer to newly added layer
+
+.. seealso:: addMapLayers
+
+.. note::
+
+   Use addMapLayers() if adding more than one layer at a time.
+.. seealso:: addMapLayers()
+ :rtype: QgsMapLayer
+%End
+
+    void removeMapLayers( const QStringList &layerIds ) /PyName=removeMapLayersById/;
+%Docstring
+ \brief
+ Remove a set of layers from the store by layer ID.
+
+ The specified layers will be removed from the store.
+ These layers will also be deleted.
+
+ \param layerIds list of IDs of the layers to remove
+
+.. seealso:: takeMapLayer()
+.. seealso:: removeMapLayer()
+.. seealso:: removeAllMapLayers()
+.. note::
+
+   available in Python bindings as removeMapLayersById.
+%End
+
+    void removeMapLayers( const QList<QgsMapLayer *> &layers );
+%Docstring
+ \brief
+ Remove a set of ``layers`` from the store.
+
+ The specified layers will be removed from the store.
+ These layers will also be deleted.
+
+ \param layers A list of layers to remove. Null pointers are ignored.
+
+.. seealso:: takeMapLayer()
+.. seealso:: removeMapLayer()
+.. seealso:: removeAllMapLayers()
+%End
+
+    void removeMapLayer( const QString &id );
+%Docstring
+ \brief
+ Remove a layer from the store by layer ``id``.
+
+ The specified layer will be removed from the store. The layer will also be deleted.
+
+ \param id ID of the layer to remove
+
+.. seealso:: takeMapLayer()
+.. seealso:: removeMapLayers()
+.. seealso:: removeAllMapLayers()
+%End
+
+    void removeMapLayer( QgsMapLayer *layer );
+%Docstring
+ \brief
+ Remove a ``layer`` from the store.
+
+ The specified layer will be removed from the store. The layer will also be deleted.
+
+ \param layer The layer to remove. Null pointers are ignored.
+
+.. seealso:: takeMapLayer()
+.. seealso:: removeMapLayers()
+.. seealso:: removeAllMapLayers()
+%End
+
+    QgsMapLayer *takeMapLayer( QgsMapLayer *layer ) /TransferBack/;
+%Docstring
+ Takes a ``layer`` from the store. If the layer was owned by the store, the
+ layer will be returned without deleting it. The caller takes ownership of
+ the layer and is responsible for deleting it.
+.. seealso:: removeMapLayer()
+ :rtype: QgsMapLayer
+%End
+
+    void removeAllMapLayers();
+%Docstring
+ Removes all registered layers. These layers will also be deleted.
+
+.. note::
+
+   Calling this method will cause the removeAll() signal to
+ be emitted.
+.. seealso:: removeMapLayer()
+.. seealso:: removeMapLayers()
+%End
+
+  signals:
+
+    void layersWillBeRemoved( const QStringList &layerIds );
+%Docstring
+ Emitted when one or more layers are about to be removed from the store.
+
+ \param layerIds A list of IDs for the layers which are to be removed.
+.. seealso:: layerWillBeRemoved()
+.. seealso:: layersRemoved()
+%End
+
+    void layersWillBeRemoved( const QList<QgsMapLayer *> &layers );
+%Docstring
+ Emitted when one or more layers are about to be removed from the store.
+
+ \param layers A list of layers which are to be removed.
+.. seealso:: layerWillBeRemoved()
+.. seealso:: layersRemoved()
+%End
+
+    void layerWillBeRemoved( const QString &layerId );
+%Docstring
+ Emitted when a layer is about to be removed from the store.
+
+ \param layerId The ID of the layer to be removed.
+
+.. note::
+
+   Consider using layersWillBeRemoved() instead.
+.. seealso:: layersWillBeRemoved()
+.. seealso:: layerRemoved()
+%End
+
+    void layerWillBeRemoved( QgsMapLayer *layer );
+%Docstring
+ Emitted when a layer is about to be removed from the store.
+
+ \param layer The layer to be removed.
+
+.. note::
+
+   Consider using layersWillBeRemoved() instead.
+.. seealso:: layersWillBeRemoved()
+.. seealso:: layerRemoved()
+%End
+
+    void layersRemoved( const QStringList &layerIds );
+%Docstring
+ Emitted after one or more layers were removed from the store.
+
+ \param layerIds  A list of IDs of the layers which were removed.
+.. seealso:: layersWillBeRemoved()
+%End
+
+    void layerRemoved( const QString &layerId );
+%Docstring
+ Emitted after a layer was removed from the store.
+
+ \param layerId The ID of the layer removed.
+
+.. note::
+
+   Consider using layersRemoved() instead
+.. seealso:: layerWillBeRemoved()
+%End
+
+    void allLayersRemoved();
+%Docstring
+ Emitted when all layers are removed, before layersWillBeRemoved() and
+ layerWillBeRemoved() signals are emitted. The layersWillBeRemoved() and
+ layerWillBeRemoved() signals will still be emitted following this signal.
+ You can use this signal to do easy (and fast) cleanup.
+%End
+
+    void layersAdded( const QList<QgsMapLayer *> &layers );
+%Docstring
+ Emitted when one or more layers were added to the store.
+
+ \param layers List of layers which have been added.
+
+.. seealso:: legendLayersAdded()
+.. seealso:: layerWasAdded()
+%End
+
+    void layerWasAdded( QgsMapLayer *layer );
+%Docstring
+ Emitted when a ``layer`` was added to the store.
+
+.. note::
+
+   Consider using layersAdded() instead
+.. seealso:: layersAdded()
+%End
+
+};
+
+/************************************************************************
+ * This file has been generated automatically from                      *
+ *                                                                      *
+ * src/core/qgsmaplayerstore.h                                          *
+ *                                                                      *
+ * Do not edit manually ! Edit header and run scripts/sipify.pl again   *
+ ************************************************************************/

python/core/qgsproject.sip

@@ -422,6 +422,8 @@ class QgsProject : QObject, QgsExpressionContextGenerator
      */
     const QgsLabelingEngineSettings &labelingEngineSettings() const;
 
+    QgsMapLayerStore *layerStore();
+
     int count() const;
 
     QgsMapLayer *mapLayer( const QString &layerId ) const;

python/plugins/processing/tools/vector.py

@@ -481,7 +481,7 @@ def createVectorWriter(destination, encoding, fields, geometryType, crs, context
 
         layer = QgsVectorLayer(uri, destination, 'memory')
         sink = layer.dataProvider()
-        context.temporaryLayerStore().addMapLayer(layer, False)
+        context.temporaryLayerStore().addMapLayer(layer)
         destination = layer.id()
     elif destination.startswith(POSTGIS_LAYER_PREFIX):
         uri = QgsDataSourceUri(destination[len(POSTGIS_LAYER_PREFIX):])
@@ -518,7 +518,7 @@ def _runSQL(sql):
 
         layer = QgsVectorLayer(uri.uri(), uri.table(), "postgres")
         sink = layer.dataProvider()
-        context.temporaryLayerStore().addMapLayer(layer, False)
+        context.temporaryLayerStore().addMapLayer(layer)
     elif destination.startswith(SPATIALITE_LAYER_PREFIX):
         uri = QgsDataSourceUri(destination[len(SPATIALITE_LAYER_PREFIX):])
         try:
@@ -548,7 +548,7 @@ def _runSQL(sql):
 
         layer = QgsVectorLayer(uri.uri(), uri.table(), "spatialite")
         sink = layer.dataProvider()
-        context.temporaryLayerStore().addMapLayer(layer, False)
+        context.temporaryLayerStore().addMapLayer(layer)
     else:
         formats = QgsVectorFileWriter.supportedFiltersAndFormats()
         OGRCodes = {}

src/core/CMakeLists.txt

@@ -178,6 +178,7 @@ SET(QGIS_CORE_SRCS
   qgsmaplayerlegend.cpp
   qgsmaplayermodel.cpp
   qgsmaplayerproxymodel.cpp
+  qgsmaplayerstore.cpp
   qgsmaplayerstylemanager.cpp
   qgsmaprenderercache.cpp
   qgsmaprenderercustompainterjob.cpp
@@ -527,6 +528,7 @@ SET(QGIS_CORE_MOC_HDRS
   qgsmaplayerlegend.h
   qgsmaplayermodel.h
   qgsmaplayerproxymodel.h
+  qgsmaplayerstore.h
   qgsmaplayerstylemanager.h
   qgsmaprenderercache.h
   qgsmaprenderercustompainterjob.h