Fix #10339 (crash when reordering layers)

wonder-sk · wonder-sk · commit 2c51dcb7e90d · 2014-05-25T23:17:42.000+07:00
This was caused by the recent addition of currentNode handling in model.
Changed to use persistent indices which are auto-updated when model changes.
diff --git a/src/gui/layertree/qgslayertreemodel.cpp b/src/gui/layertree/qgslayertreemodel.cpp
@@ -32,7 +32,6 @@ QgsLayerTreeModel::QgsLayerTreeModel( QgsLayerTreeGroup* rootNode, QObject *pare
     : QAbstractItemModel( parent )
     , mRootNode( rootNode )
     , mFlags( ShowSymbology )
-    , mCurrentNode( 0 )
 {
   Q_ASSERT( mRootNode );
 
@@ -242,7 +241,7 @@ QVariant QgsLayerTreeModel::data( const QModelIndex &index, int role ) const
       f.setItalic( true );
     if ( QgsLayerTree::isLayer( node ) )
       f.setBold( true );
-    if ( node == mCurrentNode )
+    if ( index == mCurrentIndex )
       f.setUnderline( true );
     return f;
   }
@@ -402,21 +401,15 @@ void QgsLayerTreeModel::refreshLayerSymbology( QgsLayerTreeLayer* nodeLayer )
   addSymbologyToLayer( nodeLayer );
 }
 
-void QgsLayerTreeModel::setCurrentNode( QgsLayerTreeNode* currentNode )
+void QgsLayerTreeModel::setCurrentIndex( const QModelIndex& currentIndex )
 {
-  if ( mCurrentNode )
-  {
-    QModelIndex idx = node2index( mCurrentNode );
-    emit dataChanged( idx, idx );
-  }
-
-  mCurrentNode = currentNode;
+  QModelIndex oldIndex = mCurrentIndex;
+  mCurrentIndex = currentIndex;
 
-  if ( mCurrentNode )
-  {
-    QModelIndex idx = node2index( mCurrentNode );
-    emit dataChanged( idx, idx );
-  }
+  if ( oldIndex.isValid() )
+    emit dataChanged( oldIndex, oldIndex );
+  if ( currentIndex.isValid() )
+    emit dataChanged( currentIndex, currentIndex );
 }
 
 void QgsLayerTreeModel::nodeWillAddChildren( QgsLayerTreeNode* node, int indexFrom, int indexTo )
diff --git a/src/gui/layertree/qgslayertreemodel.h b/src/gui/layertree/qgslayertreemodel.h
@@ -96,8 +96,8 @@ class GUI_EXPORT QgsLayerTreeModel : public QAbstractItemModel
 
     void refreshLayerSymbology( QgsLayerTreeLayer* nodeLayer );
 
-    QgsLayerTreeNode* currentNode() const { return mCurrentNode; }
-    void setCurrentNode( QgsLayerTreeNode* currentNode );
+    QModelIndex currentIndex() const { return mCurrentIndex; }
+    void setCurrentIndex( const QModelIndex& currentIndex );
 
   signals:
 
@@ -132,7 +132,7 @@ class GUI_EXPORT QgsLayerTreeModel : public QAbstractItemModel
 
     QMap<QgsLayerTreeLayer*, QList<QgsLayerTreeModelSymbologyNode*> > mSymbologyNodes;
 
-    QgsLayerTreeNode* mCurrentNode;
+    QPersistentModelIndex mCurrentIndex;
 };
 
 Q_DECLARE_OPERATORS_FOR_FLAGS( QgsLayerTreeModel::Flags )
diff --git a/src/gui/layertree/qgslayertreeview.cpp b/src/gui/layertree/qgslayertreeview.cpp
@@ -53,10 +53,11 @@ void QgsLayerTreeView::setModel( QAbstractItemModel* model )
     return;
 
   connect( model, SIGNAL( rowsInserted( QModelIndex, int, int ) ), this, SLOT( modelRowsInserted( QModelIndex, int, int ) ) );
+  connect( model, SIGNAL( rowsRemoved( QModelIndex, int, int ) ), this, SLOT( modelRowsRemoved( QModelIndex, int, int ) ) );
 
   QTreeView::setModel( model );
 
-  connect( selectionModel(), SIGNAL( currentChanged( QModelIndex, QModelIndex ) ), this, SLOT( onCurrentChanged( QModelIndex, QModelIndex ) ) );
+  connect( selectionModel(), SIGNAL( currentChanged( QModelIndex, QModelIndex ) ), this, SLOT( onCurrentChanged() ) );
 
   updateExpandedStateFromNode( layerTreeModel()->rootGroup() );
 }
@@ -123,6 +124,15 @@ void QgsLayerTreeView::modelRowsInserted( QModelIndex index, int start, int end
   {
     updateExpandedStateFromNode( parentNode->children()[i] );
   }
+
+  // make sure we still have correct current layer
+  onCurrentChanged();
+}
+
+void QgsLayerTreeView::modelRowsRemoved()
+{
+  // make sure we still have correct current layer
+  onCurrentChanged();
 }
 
 void QgsLayerTreeView::updateExpandedStateToNode( QModelIndex index )
@@ -134,19 +144,16 @@ void QgsLayerTreeView::updateExpandedStateToNode( QModelIndex index )
   node->setExpanded( isExpanded( index ) );
 }
 
-void QgsLayerTreeView::onCurrentChanged( QModelIndex current, QModelIndex previous )
+void QgsLayerTreeView::onCurrentChanged()
 {
-  QgsMapLayer* layerPrevious = layerForIndex( previous );
-  QgsMapLayer* layerCurrent = layerForIndex( current );
-
-  if ( layerPrevious == layerCurrent )
+  QgsMapLayer* layerCurrent = layerForIndex( currentIndex() );
+  QModelIndex layerCurrentIndex = layerCurrent ? layerTreeModel()->node2index( layerTreeModel()->rootGroup()->findLayer( layerCurrent->id() ) ) : QModelIndex();
+  if ( mCurrentIndex == layerCurrentIndex )
     return;
 
-  if ( layerCurrent )
-    layerTreeModel()->setCurrentNode( layerTreeModel()->rootGroup()->findLayer( layerCurrent->id() ) );
-  else
-    layerTreeModel()->setCurrentNode( 0 );
+  layerTreeModel()->setCurrentIndex( layerCurrentIndex );
 
+  mCurrentIndex = layerCurrentIndex;
   emit currentLayerChanged( layerCurrent );
 }
 
diff --git a/src/gui/layertree/qgslayertreeview.h b/src/gui/layertree/qgslayertreeview.h
@@ -70,14 +70,16 @@ class GUI_EXPORT QgsLayerTreeView : public QTreeView
   protected slots:
 
     void modelRowsInserted( QModelIndex index, int start, int end );
+    void modelRowsRemoved();
 
     void updateExpandedStateToNode( QModelIndex index );
 
-    void onCurrentChanged( QModelIndex current, QModelIndex previous );
+    void onCurrentChanged();
 
   protected:
     QgsLayerTreeViewDefaultActions* mDefaultActions;
     QgsLayerTreeViewMenuProvider* mMenuProvider;
+    QPersistentModelIndex mCurrentIndex;
 };
 
 /** interface to allow custom menus */
