Merge pull request #4054 from nyalldawson/fix_2738

[composer] Restore legend customisation from composer templates (Fix #2738)
qgis · Mar 22, 2017 · 616868e · 616868e
2 parents e8deab2 + 75b20ca
commit 616868e
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Showing 11 changed files with 327 additions and 24 deletions.
diff --git a/python/core/layertree/qgslayertreegroup.sip b/python/core/layertree/qgslayertreegroup.sip
@@ -55,12 +55,23 @@ class QgsLayerTreeGroup : QgsLayerTreeNode
     //! Find group node with specified name. Searches recursively the whole sub-tree.
     QgsLayerTreeGroup* findGroup( const QString& name );
 
-    //! Read group (tree) from XML element <layer-tree-group> and return the newly created group (or null on error)
-    static QgsLayerTreeGroup* readXML( QDomElement& element ) /Factory/;
+    /**
+     * Read group (tree) from XML element <layer-tree-group> and return the newly
+     * created group (or null on error). If the looseMatch
+     * parameter is true then child legend layers will use looser matching criteria,
+     * eg testing layer source instead of layer IDs.
+     */
+    static QgsLayerTreeGroup* readXML( QDomElement& element, bool looseMatch = false ) /Factory/;
+
     //! Write group (tree) as XML element <layer-tree-group> and add it to the given parent element
     virtual void writeXML( QDomElement& parentElement );
-    //! Read children from XML and append them to the group.
-    void readChildrenFromXML( QDomElement& element );
+
+    /**
+     * Read children from XML and append them to the group. If the looseMatch
+     * parameter is true then legend layers will use looser matching criteria,
+     * eg testing layer source instead of layer IDs.
+     */
+    void readChildrenFromXML( QDomElement& element, bool looseMatch = false );
 
     //! Return text representation of the tree. For debugging purposes only.
     virtual QString dump() const;

diff --git a/python/core/layertree/qgslayertreelayer.sip b/python/core/layertree/qgslayertreelayer.sip
@@ -21,10 +21,30 @@ class QgsLayerTreeLayer : QgsLayerTreeNode
 %TypeHeaderCode
 #include <qgslayertreelayer.h>
 %End
+  public:
+
+    //! Parameters for loose layer matching
+    struct LayerMatchParams
+    {
+      //! Layer public source
+      QString source;
+      //! Layer name
+      QString name;
+      //! Provider
+      QString providerKey;
+    };
 
   public:
     explicit QgsLayerTreeLayer( QgsMapLayer* layer );
 
+    /**
+     * Creates a layer node which will attach to a layer with matching
+     * parameters. This can be used for "looser" layer matching,
+     * avoiding the usual layer id check in favour of attaching to any layer
+     * with an equal source/name/provider.
+     */
+    static QgsLayerTreeLayer* createLayerFromParams( const LayerMatchParams& source ) /Factory/;
+
     explicit QgsLayerTreeLayer( const QString& layerId, const QString& name = QString() );
 
     QString layerId() const;
@@ -38,13 +58,27 @@ class QgsLayerTreeLayer : QgsLayerTreeNode
     //! @note added in 2.18.1
     void setName( const QString& n );
 
+    /**
+     * Attempts to attach this layer node to a layer with a matching
+     * QgsMapLayer::publicSource(). This can be used for "looser" layer matching,
+     * avoiding the usual layer id check in favour of attaching to any layer
+     * with an equal source.
+     */
+    void attachToSource( const LayerMatchParams &source );
+
     QString layerName() const;
     void setLayerName( const QString& n );
 
     Qt::CheckState isVisible() const;
     void setVisible( Qt::CheckState visible );
 
-    static QgsLayerTreeLayer* readXML( QDomElement& element ) /Factory/;
+    /**
+     * Creates a new layer from an XML definition. If the looseMatch
+     * parameter is true then legend layers will use looser matching criteria,
+     * eg testing layer source instead of layer IDs.
+     */
+    static QgsLayerTreeLayer* readXML( QDomElement& element, bool looseMatch = false ) /Factory/;
+
     virtual void writeXML( QDomElement& parentElement );
 
     virtual QString dump() const;

diff --git a/python/core/layertree/qgslayertreenode.sip b/python/core/layertree/qgslayertreenode.sip
@@ -83,8 +83,13 @@ class QgsLayerTreeNode : QObject
     //! @note added in 2.18.1
     virtual void setName( const QString& name ) = 0;
 
-    //! Read layer tree from XML. Returns new instance
-    static QgsLayerTreeNode *readXML( QDomElement &element );
+    /**
+     * Read layer tree from XML. Returns new instance. If the looseMatch
+     * parameter is true then child legend layers will use looser matching criteria,
+     * eg testing layer source instead of layer IDs.
+     */
+    static QgsLayerTreeNode *readXML( QDomElement &element, bool looseMatch = false ) /Factory/;
+
     //! Write layer tree to XML
     virtual void writeXML( QDomElement &parentElement ) = 0;
 

diff --git a/src/core/composer/qgscomposerlegend.cpp b/src/core/composer/qgscomposerlegend.cpp
@@ -535,7 +535,7 @@ bool QgsComposerLegend::readXML( const QDomElement& itemElem, const QDomDocument
   {
     // QGIS >= 2.6
     QDomElement layerTreeElem = itemElem.firstChildElement( "layer-tree-group" );
-    setCustomLayerTree( QgsLayerTreeGroup::readXML( layerTreeElem ) );
+    setCustomLayerTree( QgsLayerTreeGroup::readXML( layerTreeElem, true ) );
   }
 
   //restore general composer item properties

diff --git a/src/core/layertree/qgslayertreegroup.cpp b/src/core/layertree/qgslayertreegroup.cpp
@@ -254,7 +254,7 @@ QgsLayerTreeGroup* QgsLayerTreeGroup::findGroup( const QString& name )
   return nullptr;
 }
 
-QgsLayerTreeGroup* QgsLayerTreeGroup::readXML( QDomElement& element )
+QgsLayerTreeGroup* QgsLayerTreeGroup::readXML( QDomElement& element, bool looseMatch )
 {
   if ( element.tagName() != "layer-tree-group" )
     return nullptr;
@@ -270,7 +270,7 @@ QgsLayerTreeGroup* QgsLayerTreeGroup::readXML( QDomElement& element )
 
   groupNode->readCommonXML( element );
 
-  groupNode->readChildrenFromXML( element );
+  groupNode->readChildrenFromXML( element, looseMatch );
 
   groupNode->setIsMutuallyExclusive( isMutuallyExclusive, mutuallyExclusiveChildIndex );
 
@@ -298,13 +298,13 @@ void QgsLayerTreeGroup::writeXML( QDomElement& parentElement )
   parentElement.appendChild( elem );
 }
 
-void QgsLayerTreeGroup::readChildrenFromXML( QDomElement& element )
+void QgsLayerTreeGroup::readChildrenFromXML( QDomElement& element, bool looseMatch )
 {
   QList<QgsLayerTreeNode*> nodes;
   QDomElement childElem = element.firstChildElement();
   while ( !childElem.isNull() )
   {
-    QgsLayerTreeNode* newNode = QgsLayerTreeNode::readXML( childElem );
+    QgsLayerTreeNode* newNode = QgsLayerTreeNode::readXML( childElem, looseMatch );
     if ( newNode )
       nodes << newNode;
 

diff --git a/src/core/layertree/qgslayertreegroup.h b/src/core/layertree/qgslayertreegroup.h
@@ -76,12 +76,22 @@ class CORE_EXPORT QgsLayerTreeGroup : public QgsLayerTreeNode
     //! Find group node with specified name. Searches recursively the whole sub-tree.
     QgsLayerTreeGroup* findGroup( const QString& name );
 
-    //! Read group (tree) from XML element <layer-tree-group> and return the newly created group (or null on error)
-    static QgsLayerTreeGroup* readXML( QDomElement& element );
+    /**
+     * Read group (tree) from XML element <layer-tree-group> and return the newly
+     * created group (or null on error). If the looseMatch
+     * parameter is true then child legend layers will use looser matching criteria,
+     * eg testing layer source instead of layer IDs.
+     */
+    static QgsLayerTreeGroup* readXML( QDomElement& element, bool looseMatch = false );
+
     //! Write group (tree) as XML element <layer-tree-group> and add it to the given parent element
     virtual void writeXML( QDomElement& parentElement ) override;
-    //! Read children from XML and append them to the group.
-    void readChildrenFromXML( QDomElement& element );
+    /**
+     * Read children from XML and append them to the group. If the looseMatch
+     * parameter is true then legend layers will use looser matching criteria,
+     * eg testing layer source instead of layer IDs.
+     */
+    void readChildrenFromXML( QDomElement& element, bool looseMatch = false );
 
     //! Return text representation of the tree. For debugging purposes only.
     virtual QString dump() const override;

diff --git a/src/core/layertree/qgslayertreelayer.cpp b/src/core/layertree/qgslayertreelayer.cpp
@@ -18,7 +18,10 @@
 #include "qgslayertreeutils.h"
 #include "qgsmaplayer.h"
 #include "qgsmaplayerregistry.h"
-
+#include "qgsvectorlayer.h"
+#include "qgsrasterlayer.h"
+#include "qgsvectordataprovider.h"
+#include "qgsrasterdataprovider.h"
 
 QgsLayerTreeLayer::QgsLayerTreeLayer( QgsMapLayer *layer )
     : QgsLayerTreeNode( NodeLayer )
@@ -50,6 +53,13 @@ QgsLayerTreeLayer::QgsLayerTreeLayer( const QgsLayerTreeLayer& other )
   attachToLayer();
 }
 
+QgsLayerTreeLayer *QgsLayerTreeLayer::createLayerFromParams( const LayerMatchParams &source )
+{
+  QgsLayerTreeLayer* l = new QgsLayerTreeLayer( QString() );
+  l->attachToSource( source );
+  return l;
+}
+
 void QgsLayerTreeLayer::attachToLayer()
 {
   // layer is not necessarily already loaded
@@ -71,6 +81,35 @@ void QgsLayerTreeLayer::attachToLayer()
   }
 }
 
+bool QgsLayerTreeLayer::layerMatchesSource( QgsMapLayer* layer, const QgsLayerTreeLayer::LayerMatchParams &params ) const
+{
+  if ( layer->publicSource() != params.source ||
+       layer->name() != params.name )
+    return false;
+
+  switch ( layer->type() )
+  {
+    case QgsMapLayer::VectorLayer:
+    {
+      QgsVectorLayer* vl = qobject_cast< QgsVectorLayer* >( layer );
+      if ( vl->dataProvider()->name() != params.providerKey )
+        return false;
+      break;
+    }
+    case QgsMapLayer::RasterLayer:
+    {
+      QgsRasterLayer* rl = qobject_cast< QgsRasterLayer* >( layer );
+      if ( rl->dataProvider()->name() != params.providerKey )
+        return false;
+      break;
+    }
+    case QgsMapLayer::PluginLayer:
+      break;
+
+  }
+  return true;
+}
+
 QString QgsLayerTreeLayer::name() const
 {
   return layerName();
@@ -81,6 +120,29 @@ void QgsLayerTreeLayer::setName( const QString& n )
   setLayerName( n );
 }
 
+void QgsLayerTreeLayer::attachToSource( const LayerMatchParams &source )
+{
+  // check if matching source already open
+  bool foundMatch = false;
+  Q_FOREACH ( QgsMapLayer* layer, QgsMapLayerRegistry::instance()->mapLayers() )
+  {
+    if ( layerMatchesSource( layer, source ) )
+    {
+      // found a source! need to disconnect from layersAdded signal as original attachToLayer call
+      // will have set this up
+      disconnect( QgsMapLayerRegistry::instance(), SIGNAL( layersAdded( QList<QgsMapLayer*> ) ), this, SLOT( registryLayersAdded( QList<QgsMapLayer*> ) ) );
+      mLayerId = layer->id();
+      attachToLayer();
+      emit layerLoaded();
+      foundMatch = true;
+      break;
+    }
+  }
+
+  if ( !foundMatch )
+    mLooseMatchParams = source; // no need to store source if match already made
+}
+
 QString QgsLayerTreeLayer::layerName() const
 {
   return mLayer ? mLayer->name() : mLayerName;
@@ -113,13 +175,17 @@ void QgsLayerTreeLayer::setVisible( Qt::CheckState state )
   emit visibilityChanged( this, state );
 }
 
-QgsLayerTreeLayer* QgsLayerTreeLayer::readXML( QDomElement& element )
+QgsLayerTreeLayer* QgsLayerTreeLayer::readXML( QDomElement& element , bool looseMatch )
 {
   if ( element.tagName() != "layer-tree-layer" )
     return nullptr;
 
   QString layerID = element.attribute( "id" );
   QString layerName = element.attribute( "name" );
+
+  QString source = element.attribute( "source" );
+  QString providerKey = element.attribute( "providerKey" );
+
   Qt::CheckState checked = QgsLayerTreeUtils::checkStateFromXml( element.attribute( "checked" ) );
   bool isExpanded = ( element.attribute( "expanded", "1" ) == "1" );
 
@@ -129,6 +195,14 @@ QgsLayerTreeLayer* QgsLayerTreeLayer::readXML( QDomElement& element )
 
   if ( layer )
     nodeLayer = new QgsLayerTreeLayer( layer );
+  else if ( looseMatch && !source.isEmpty() )
+  {
+    LayerMatchParams params;
+    params.name = layerName;
+    params.source = source;
+    params.providerKey = providerKey;
+    nodeLayer = QgsLayerTreeLayer::createLayerFromParams( params );
+  }
   else
     nodeLayer = new QgsLayerTreeLayer( layerID, layerName );
 
@@ -144,6 +218,31 @@ void QgsLayerTreeLayer::writeXML( QDomElement& parentElement )
   QDomDocument doc = parentElement.ownerDocument();
   QDomElement elem = doc.createElement( "layer-tree-layer" );
   elem.setAttribute( "id", mLayerId );
+  if ( mLayer )
+  {
+    elem.setAttribute( "source", mLayer->publicSource() );
+
+    QString providerKey;
+    switch ( mLayer->type() )
+    {
+      case QgsMapLayer::VectorLayer:
+      {
+        QgsVectorLayer* vl = qobject_cast< QgsVectorLayer* >( mLayer );
+        providerKey = vl->dataProvider()->name();
+        break;
+      }
+      case QgsMapLayer::RasterLayer:
+      {
+        QgsRasterLayer* rl = qobject_cast< QgsRasterLayer* >( mLayer );
+        providerKey = rl->dataProvider()->name();
+        break;
+      }
+      case QgsMapLayer::PluginLayer:
+        break;
+    }
+    elem.setAttribute( "providerKey", providerKey );
+  }
+
   elem.setAttribute( "name", layerName() );
   elem.setAttribute( "checked", QgsLayerTreeUtils::checkStateToXml( mVisible ) );
   elem.setAttribute( "expanded", mExpanded ? "1" : "0" );
@@ -167,6 +266,12 @@ void QgsLayerTreeLayer::registryLayersAdded( const QList<QgsMapLayer*>& layers )
 {
   Q_FOREACH ( QgsMapLayer* l, layers )
   {
+    if ( !mLooseMatchParams.source.isEmpty() && layerMatchesSource( l, mLooseMatchParams ) )
+    {
+      // we are loosely matching, and found a layer with a matching source.
+      // Attach to this!
+      mLayerId = l->id();
+    }
     if ( l->id() == mLayerId )
     {
       disconnect( QgsMapLayerRegistry::instance(), SIGNAL( layersAdded( QList<QgsMapLayer*> ) ), this, SLOT( registryLayersAdded( QList<QgsMapLayer*> ) ) );