Merge pull request #4368 from nyalldawson/composer_map_layer_ref

More use of weak layer references in composer templates
qgis · Apr 18, 2017 · e6aa44f · e6aa44f
2 parents 6bb3fa6 + f413963
commit e6aa44f
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Showing 11 changed files with 441 additions and 76 deletions.
diff --git a/src/core/composer/qgscomposerattributetablev2.cpp b/src/core/composer/qgscomposerattributetablev2.cpp
@@ -51,7 +51,6 @@ bool QgsComposerAttributeTableCompareV2::operator()( const QgsComposerTableRow &
 QgsComposerAttributeTableV2::QgsComposerAttributeTableV2( QgsComposition *composition, bool createUndoCommands )
   : QgsComposerTableV2( composition, createUndoCommands )
   , mSource( LayerAttributes )
-  , mVectorLayer( nullptr )
   , mCurrentAtlasLayer( nullptr )
   , mComposerMap( nullptr )
   , mMaximumNumberOfFeatures( 30 )
@@ -69,15 +68,15 @@ QgsComposerAttributeTableV2::QgsComposerAttributeTableV2( QgsComposition *compos
     QgsVectorLayer *vl = dynamic_cast<QgsVectorLayer *>( mapIt.value() );
     if ( vl )
     {
-      mVectorLayer = vl;
+      mVectorLayer.setLayer( vl );
       break;
     }
   }
   if ( mVectorLayer )
   {
     resetColumns();
     //listen for modifications to layer and refresh table when they occur
-    connect( mVectorLayer, &QgsVectorLayer::layerModified, this, &QgsComposerTableV2::refreshAttributes );
+    connect( mVectorLayer.get(), &QgsVectorLayer::layerModified, this, &QgsComposerTableV2::refreshAttributes );
   }
 
   if ( mComposition )
@@ -103,14 +102,14 @@ QString QgsComposerAttributeTableV2::displayName() const
 
 void QgsComposerAttributeTableV2::setVectorLayer( QgsVectorLayer *layer )
 {
-  if ( layer == mVectorLayer )
+  if ( layer == mVectorLayer.get() )
   {
     //no change
     return;
   }
 
   QgsVectorLayer *prevLayer = sourceLayer();
-  mVectorLayer = layer;
+  mVectorLayer.setLayer( layer );
 
   if ( mSource == QgsComposerAttributeTableV2::LayerAttributes && layer != prevLayer )
   {
@@ -124,7 +123,7 @@ void QgsComposerAttributeTableV2::setVectorLayer( QgsVectorLayer *layer )
     resetColumns();
 
     //listen for modifications to layer and refresh table when they occur
-    connect( mVectorLayer, &QgsVectorLayer::layerModified, this, &QgsComposerTableV2::refreshAttributes );
+    connect( mVectorLayer.get(), &QgsVectorLayer::layerModified, this, &QgsComposerTableV2::refreshAttributes );
   }
 
   refreshAttributes();
@@ -539,7 +538,7 @@ QgsExpressionContext QgsComposerAttributeTableV2::createExpressionContext() cons
 
   if ( mSource == LayerAttributes )
   {
-    context.appendScope( QgsExpressionContextUtils::layerScope( mVectorLayer ) );
+    context.appendScope( QgsExpressionContextUtils::layerScope( mVectorLayer.get() ) );
   }
 
   return context;
@@ -563,7 +562,7 @@ QgsVectorLayer *QgsComposerAttributeTableV2::sourceLayer()
     case QgsComposerAttributeTableV2::AtlasFeature:
       return mComposition->atlasComposition().coverageLayer();
     case QgsComposerAttributeTableV2::LayerAttributes:
-      return mVectorLayer;
+      return mVectorLayer.get();
     case QgsComposerAttributeTableV2::RelationChildren:
     {
       QgsRelation relation = mComposition->project()->relationManager()->relation( mRelationId );
@@ -579,7 +578,7 @@ void QgsComposerAttributeTableV2::removeLayer( const QString &layerId )
   {
     if ( layerId == mVectorLayer->id() )
     {
-      mVectorLayer = nullptr;
+      mVectorLayer.setLayer( nullptr );
       //remove existing columns
       qDeleteAll( mColumns );
       mColumns.clear();
@@ -657,7 +656,10 @@ bool QgsComposerAttributeTableV2::writeXml( QDomElement &elem, QDomDocument &doc
   }
   if ( mVectorLayer )
   {
-    composerTableElem.setAttribute( QStringLiteral( "vectorLayer" ), mVectorLayer->id() );
+    composerTableElem.setAttribute( QStringLiteral( "vectorLayer" ), mVectorLayer.layerId );
+    composerTableElem.setAttribute( QStringLiteral( "vectorLayerName" ), mVectorLayer.name );
+    composerTableElem.setAttribute( QStringLiteral( "vectorLayerSource" ), mVectorLayer.source );
+    composerTableElem.setAttribute( QStringLiteral( "vectorLayerProvider" ), mVectorLayer.provider );
   }
 
   bool ok = QgsComposerTableV2::writeXml( composerTableElem, doc, ignoreFrames );
@@ -726,19 +728,12 @@ bool QgsComposerAttributeTableV2::readXml( const QDomElement &itemElem, const QD
   }
 
   //vector layer
-  QString layerId = itemElem.attribute( QStringLiteral( "vectorLayer" ), QStringLiteral( "not_existing" ) );
-  if ( layerId == QLatin1String( "not_existing" ) )
-  {
-    mVectorLayer = nullptr;
-  }
-  else
-  {
-    QgsMapLayer *ml = mComposition->project()->mapLayer( layerId );
-    if ( ml )
-    {
-      mVectorLayer = dynamic_cast<QgsVectorLayer *>( ml );
-    }
-  }
+  QString layerId = itemElem.attribute( QStringLiteral( "vectorLayer" ) );
+  QString layerName = itemElem.attribute( QStringLiteral( "vectorLayerName" ) );
+  QString layerSource = itemElem.attribute( QStringLiteral( "vectorLayerSource" ) );
+  QString layerProvider = itemElem.attribute( QStringLiteral( "vectorLayerProvider" ) );
+  mVectorLayer = QgsVectorLayerRef( layerId, layerName, layerSource, layerProvider );
+  mVectorLayer.resolveWeakly( mComposition->project() );
 
   //connect to new layer
   connect( sourceLayer(), &QgsVectorLayer::layerModified, this, &QgsComposerTableV2::refreshAttributes );

diff --git a/src/core/composer/qgscomposerattributetablev2.h b/src/core/composer/qgscomposerattributetablev2.h
@@ -20,6 +20,7 @@
 
 #include "qgis_core.h"
 #include "qgscomposertablev2.h"
+#include "qgsvectorlayerref.h"
 
 class QgsComposerMap;
 class QgsVectorLayer;
@@ -119,7 +120,7 @@ class CORE_EXPORT QgsComposerAttributeTableV2: public QgsComposerTableV2
      * \returns attribute table's current vector layer
      * \see setVectorLayer
      */
-    QgsVectorLayer *vectorLayer() const { return mVectorLayer; }
+    QgsVectorLayer *vectorLayer() const { return mVectorLayer.get(); }
 
     /** Sets the relation id from which to display child features
      * \param relationId id for relation to display child features from
@@ -303,7 +304,7 @@ class CORE_EXPORT QgsComposerAttributeTableV2: public QgsComposerTableV2
     //! Attribute source
     ContentSource mSource;
     //! Associated vector layer
-    QgsVectorLayer *mVectorLayer = nullptr;
+    QgsVectorLayerRef mVectorLayer;
     //! Relation id, if in relation children mode
     QString mRelationId;
 

diff --git a/src/core/composer/qgscomposermap.cpp b/src/core/composer/qgscomposermap.cpp
@@ -1190,14 +1190,18 @@ bool QgsComposerMap::writeXml( QDomElement &elem, QDomDocument &doc ) const
 
   //layer set
   QDomElement layerSetElem = doc.createElement( QStringLiteral( "LayerSet" ) );
-  Q_FOREACH ( const QgsWeakMapLayerPointer &layerPtr, mLayers )
+  Q_FOREACH ( const QgsMapLayerRef &layerRef, mLayers )
   {
-    QgsMapLayer *layer = layerPtr.data();
-    if ( !layer )
+    if ( !layerRef )
       continue;
     QDomElement layerElem = doc.createElement( QStringLiteral( "Layer" ) );
-    QDomText layerIdText = doc.createTextNode( layer->id() );
+    QDomText layerIdText = doc.createTextNode( layerRef.layerId );
     layerElem.appendChild( layerIdText );
+
+    layerElem.setAttribute( QStringLiteral( "name" ), layerRef.name );
+    layerElem.setAttribute( QStringLiteral( "source" ), layerRef.source );
+    layerElem.setAttribute( QStringLiteral( "provider" ), layerRef.provider );
+
     layerSetElem.appendChild( layerElem );
   }
   composerMapElem.appendChild( layerSetElem );
@@ -1338,9 +1342,15 @@ bool QgsComposerMap::readXml( const QDomElement &itemElem, const QDomDocument &d
     mLayers.reserve( layerIdNodeList.size() );
     for ( int i = 0; i < layerIdNodeList.size(); ++i )
     {
-      QString layerId = layerIdNodeList.at( i ).toElement().text();
-      if ( QgsMapLayer *ml = mComposition->project()->mapLayer( layerId ) )
-        mLayers << ml;
+      QDomElement layerElem = layerIdNodeList.at( i ).toElement();
+      QString layerId = layerElem.text();
+      QString layerName = layerElem.attribute( QStringLiteral( "name" ) );
+      QString layerSource = layerElem.attribute( QStringLiteral( "source" ) );
+      QString layerProvider = layerElem.attribute( QStringLiteral( "provider" ) );
+
+      QgsMapLayerRef ref( layerId, layerName, layerSource, layerProvider );
+      ref.resolveWeakly( mComposition->project() );
+      mLayers << ref;
     }
   }
 
@@ -1498,12 +1508,12 @@ bool QgsComposerMap::readXml( const QDomElement &itemElem, const QDomDocument &d
 
 QList<QgsMapLayer *> QgsComposerMap::layers() const
 {
-  return _qgis_listQPointerToRaw( mLayers );
+  return _qgis_listRefToRaw( mLayers );
 }
 
 void QgsComposerMap::setLayers( const QList<QgsMapLayer *> &layers )
 {
-  mLayers = _qgis_listRawToQPointer( layers );
+  mLayers = _qgis_listRawToRef( layers );
 }
 
 
@@ -1520,9 +1530,9 @@ void QgsComposerMap::setLayerStyleOverrides( const QMap<QString, QString> &overr
 void QgsComposerMap::storeCurrentLayerStyles()
 {
   mLayerStyleOverrides.clear();
-  Q_FOREACH ( const QgsWeakMapLayerPointer &layerPtr, mLayers )
+  Q_FOREACH ( const QgsMapLayerRef &layerRef, mLayers )
   {
-    if ( QgsMapLayer *layer = layerPtr.data() )
+    if ( QgsMapLayer *layer = layerRef.get() )
     {
       QgsMapLayerStyle style;
       style.readFromLayer( layer );
@@ -1538,8 +1548,8 @@ void QgsComposerMap::layersAboutToBeRemoved( QList< QgsMapLayer * > layers )
     Q_FOREACH ( QgsMapLayer *layer, layers )
     {
       mLayerStyleOverrides.remove( layer->id() );
-      mLayers.removeAll( layer );
     }
+    _qgis_removeLayers( mLayers, layers );
   }
 }
 

diff --git a/src/core/composer/qgscomposermap.h b/src/core/composer/qgscomposermap.h
@@ -24,6 +24,7 @@
 #include "qgscoordinatereferencesystem.h"
 #include "qgsrendercontext.h"
 #include "qgsmaplayer.h"
+#include "qgsmaplayerref.h"
 #include <QFont>
 #include <QGraphicsRectItem>
 
@@ -541,7 +542,7 @@ class CORE_EXPORT QgsComposerMap : public QgsComposerItem
     bool mKeepLayerSet = false;
 
     //! Stored layer list (used if layer live-link mKeepLayerSet is disabled)
-    QgsWeakMapLayerPointerList mLayers;
+    QList< QgsMapLayerRef > mLayers;
 
     bool mKeepLayerStyles = false;
     //! Stored style names (value) to be used with particular layer IDs (key) instead of default style

diff --git a/src/core/layertree/qgslayertreelayer.cpp b/src/core/layertree/qgslayertreelayer.cpp
@@ -45,35 +45,28 @@ QgsLayerTreeLayer::QgsLayerTreeLayer( const QgsLayerTreeLayer &other )
 
 void QgsLayerTreeLayer::resolveReferences( const QgsProject *project, bool looseMatching )
 {
-  if ( mRef.layer )
+  if ( mRef )
     return;  // already assigned
 
-  QgsMapLayer *layer = project->mapLayer( mRef.layerId );
-
-  if ( !layer && looseMatching && !mRef.name.isEmpty() )
+  if ( !looseMatching )
+  {
+    mRef.resolve( project );
+  }
+  else
   {
-    Q_FOREACH ( QgsMapLayer *l, project->mapLayersByName( mRef.name ) )
-    {
-      if ( mRef.layerMatchesSource( l ) )
-      {
-        layer = l;
-        break;
-      }
-    }
+    mRef.resolveWeakly( project );
   }
 
-  if ( !layer )
+  if ( !mRef )
     return;
 
-  mRef.layer = layer;
-  mRef.layerId = layer->id();
   attachToLayer();
   emit layerLoaded();
 }
 
 void QgsLayerTreeLayer::attachToLayer()
 {
-  if ( !mRef.layer )
+  if ( !mRef )
     return;
 
   connect( mRef.layer, &QgsMapLayer::nameChanged, this, &QgsLayerTreeLayer::layerNameChanged );
@@ -83,16 +76,16 @@ void QgsLayerTreeLayer::attachToLayer()
 
 QString QgsLayerTreeLayer::name() const
 {
-  return mRef.layer ? mRef.layer->name() : mLayerName;
+  return mRef ? mRef->name() : mLayerName;
 }
 
 void QgsLayerTreeLayer::setName( const QString &n )
 {
-  if ( mRef.layer )
+  if ( mRef )
   {
-    if ( mRef.layer->name() == n )
+    if ( mRef->name() == n )
       return;
-    mRef.layer->setName( n );
+    mRef->setName( n );
     // no need to emit signal: we will be notified from layer's nameChanged() signal
   }
   else
@@ -143,10 +136,10 @@ void QgsLayerTreeLayer::writeXml( QDomElement &parentElement )
   elem.setAttribute( QStringLiteral( "id" ), layerId() );
   elem.setAttribute( QStringLiteral( "name" ), name() );
 
-  if ( mRef.layer )
+  if ( mRef )
   {
-    elem.setAttribute( "source", mRef.layer->publicSource() );
-    elem.setAttribute( "providerKey", mRef.layer->dataProvider() ? mRef.layer->dataProvider()->name() : QString() );
+    elem.setAttribute( "source", mRef->publicSource() );
+    elem.setAttribute( "providerKey", mRef->dataProvider() ? mRef->dataProvider()->name() : QString() );
   }
 
   elem.setAttribute( QStringLiteral( "checked" ), mChecked ? QStringLiteral( "Qt::Checked" ) : QStringLiteral( "Qt::Unchecked" ) );
@@ -169,9 +162,9 @@ QgsLayerTreeLayer *QgsLayerTreeLayer::clone() const
 
 void QgsLayerTreeLayer::layerWillBeDeleted()
 {
-  Q_ASSERT( mRef.layer );
+  Q_ASSERT( mRef );
 
-  mLayerName = mRef.layer->name();
+  mLayerName = mRef->name();
   // in theory we do not even need to do this - the weak ref should clear itself
   mRef.layer.clear();
   // layerId stays in the reference
@@ -182,6 +175,6 @@ void QgsLayerTreeLayer::layerWillBeDeleted()
 
 void QgsLayerTreeLayer::layerNameChanged()
 {
-  Q_ASSERT( mRef.layer );
-  emit nameChanged( this, mRef.layer->name() );
+  Q_ASSERT( mRef );
+  emit nameChanged( this, mRef->name() );
 }
diff --git a/src/core/layertree/qgslayertreelayer.h b/src/core/layertree/qgslayertreelayer.h
@@ -54,7 +54,7 @@ class CORE_EXPORT QgsLayerTreeLayer : public QgsLayerTreeNode
 
     QString layerId() const { return mRef.layerId; }
 
-    QgsMapLayer *layer() const { return mRef.layer.data(); }
+    QgsMapLayer *layer() const { return mRef.get(); }
 
     /**
      * Returns the layer's name.

diff --git a/src/core/qgsmaplayerlistutils.h b/src/core/qgsmaplayerlistutils.h
@@ -13,6 +13,7 @@
 #include <QPointer>
 
 #include "qgsmaplayer.h"
+#include "qgsmaplayerref.h"
 
 /// @cond PRIVATE
 
@@ -39,6 +40,40 @@ inline QgsWeakMapLayerPointerList _qgis_listRawToQPointer( const QList<QgsMapLay
   return lst;
 }
 
+inline QList<QgsMapLayer *> _qgis_listRefToRaw( const QList< QgsMapLayerRef > &layers )
+{
+  QList<QgsMapLayer *> lst;
+  lst.reserve( layers.count() );
+  Q_FOREACH ( const QgsMapLayerRef &layer, layers )
+  {
+    if ( layer )
+      lst.append( layer.get() );
+  }
+  return lst;
+}
+
+inline QList< QgsMapLayerRef > _qgis_listRawToRef( const QList<QgsMapLayer *> &layers )
+{
+  QList< QgsMapLayerRef > lst;
+  lst.reserve( layers.count() );
+  Q_FOREACH ( QgsMapLayer *layer, layers )
+  {
+    lst.append( QgsMapLayerRef( layer ) );
+  }
+  return lst;
+}
+
+inline void _qgis_removeLayers( QList< QgsMapLayerRef > &list, QList< QgsMapLayer *> layersToRemove )
+{
+  QMutableListIterator<QgsMapLayerRef> it( list );
+  while ( it.hasNext() )
+  {
+    QgsMapLayerRef &ref = it.next();
+    if ( layersToRemove.contains( ref.get() ) )
+      it.remove();
+  }
+}
+
 inline QStringList _qgis_listQPointerToIDs( const QgsWeakMapLayerPointerList &layers )
 {
   QStringList lst;