Fix #11474 (cannot move layers in layer tree anymore)

I have managed to break that with implementation of #11369.
Obviously it is a bad idea to change selection in a slot connected to model's rowsInserted signals
because the drag'n'drop does not work properly anymore. Now registry bridge will emit a signal after
new layers have been added, so the selection change at that point should be safe.

python/core/layertree/qgslayertreeregistrybridge.sip

@@ -29,4 +29,9 @@ class QgsLayerTreeRegistryBridge : QObject
     //! By default it is root group with zero index.
     void setLayerInsertionPoint( QgsLayerTreeGroup* parentGroup, int index );
 
+  signals:
+    //! Tell others we have just added layers to the tree (used in QGIS to auto-select first newly added layer)
+    //! @note added in 2.6
+    void addedLayersToLayerTree( QList<QgsMapLayer*> layers );
+
 };

python/gui/layertree/qgslayertreeview.sip

@@ -63,13 +63,6 @@ class QgsLayerTreeView : QTreeView
     //! Get list of selected layers
     QList<QgsMapLayer*> selectedLayers() const;
 
-    //! if enabled, current selection will be automatically changed to the newly added layer node.
-    //! This is purely for user's convenience so they do not need to click on the layer explicitly.
-    //! @note added in 2.6
-    void setAutoSelectAddedLayers( bool enabled );
-    //! @note added in 2.6
-    bool autoSelectAddedLayers() const;
-
   public slots:
     //! Force refresh of layer symbology. Normally not needed as the changes of layer's renderer are monitored by the model
     void refreshLayerSymbology( const QString& layerId );

src/app/qgisapp.cpp

@@ -2315,13 +2315,14 @@ void QgisApp::initLayerTreeView()
 
   mLayerTreeView->setModel( model );
   mLayerTreeView->setMenuProvider( new QgsAppLayerTreeViewMenuProvider( mLayerTreeView, mMapCanvas ) );
-  mLayerTreeView->setAutoSelectAddedLayers( true );
 
   setupLayerTreeViewFromSettings();
 
   connect( mLayerTreeView, SIGNAL( doubleClicked( QModelIndex ) ), this, SLOT( layerTreeViewDoubleClicked( QModelIndex ) ) );
   connect( mLayerTreeView, SIGNAL( currentLayerChanged( QgsMapLayer* ) ), this, SLOT( activeLayerChanged( QgsMapLayer* ) ) );
   connect( mLayerTreeView->selectionModel(), SIGNAL( currentChanged( QModelIndex, QModelIndex ) ), this, SLOT( updateNewLayerInsertionPoint() ) );
+  connect( QgsProject::instance()->layerTreeRegistryBridge(), SIGNAL( addedLayersToLayerTree( QList<QgsMapLayer*> ) ),
+           this, SLOT( autoSelectAddedLayer( QList<QgsMapLayer*> ) ) );
 
   // add group tool button
   QToolButton* btnAddGroup = new QToolButton;
@@ -2447,6 +2448,15 @@ void QgisApp::updateNewLayerInsertionPoint()
   QgsProject::instance()->layerTreeRegistryBridge()->setLayerInsertionPoint( parentGroup, index );
 }
 
+void QgisApp::autoSelectAddedLayer( QList<QgsMapLayer*> layers )
+{
+  if ( layers.count() )
+  {
+    QgsLayerTreeLayer* nodeLayer = QgsProject::instance()->layerTreeRoot()->findLayer( layers[0]->id() );
+    QModelIndex index = mLayerTreeView->layerTreeModel()->node2index( nodeLayer );
+    mLayerTreeView->setCurrentIndex( index );
+  }
+}
 
 void QgisApp::createMapTips()
 {
@@ -3782,7 +3792,6 @@ void QgisApp::enableProjectMacros()
   QgsPythonRunner::run( "qgis.utils.reloadProjectMacros()" );
 }
 
-
 /**
   adds a saved project to qgis, usually called on startup by specifying a
   project file on the command line
@@ -3798,11 +3807,6 @@ bool QgisApp::addProject( QString projectFile )
   // close the previous opened project if any
   closeProject();
 
-  // temporarily disable auto-select for project loading
-  // (having it on all the time would give inconsistent results,
-  // e.g. we select the first node if it is a layer, but not if it is a group)
-  mLayerTreeView->setAutoSelectAddedLayers( false );
-
   if ( ! QgsProject::instance()->read( projectFile ) )
   {
     QApplication::restoreOverrideCursor();
@@ -3818,8 +3822,6 @@ bool QgisApp::addProject( QString projectFile )
     return false;
   }
 
-  mLayerTreeView->setAutoSelectAddedLayers( true );
-
   setTitleBarText_( *this );
   int  myRedInt = QgsProject::instance()->readNumEntry( "Gui", "/CanvasColorRedPart", 255 );
   int  myGreenInt = QgsProject::instance()->readNumEntry( "Gui", "/CanvasColorGreenPart", 255 );

src/app/qgisapp.h

@@ -477,6 +477,8 @@ class APP_EXPORT QgisApp : public QMainWindow, private Ui::MainWindow
     void layerTreeViewDoubleClicked( const QModelIndex& index );
     //! Make sure the insertion point for new layers is up-to-date with the current item in layer tree view
     void updateNewLayerInsertionPoint();
+    //! connected to layer tree registry bridge, selects first of the newly added map layers
+    void autoSelectAddedLayer( QList<QgsMapLayer*> layers );
     void activeLayerChanged( QgsMapLayer* layer );
     //! Zoom to full extent
     void zoomFull();

src/core/layertree/qgslayertreeregistrybridge.cpp

@@ -68,6 +68,9 @@ void QgsLayerTreeRegistryBridge::layersAdded( QList<QgsMapLayer*> layers )
 
   // add new layers to the right place
   mInsertionPointGroup->insertChildNodes( mInsertionPointIndex, nodes );
+
+  // tell other components that layers have been added - this signal is used in QGIS to auto-select the first layer
+  emit addedLayersToLayerTree( layers );
 }
 
 void QgsLayerTreeRegistryBridge::layersWillBeRemoved( QStringList layerIds )

src/core/layertree/qgslayertreeregistrybridge.h

@@ -53,6 +53,9 @@ class CORE_EXPORT QgsLayerTreeRegistryBridge : public QObject
     void setLayerInsertionPoint( QgsLayerTreeGroup* parentGroup, int index );
 
   signals:
+    //! Tell others we have just added layers to the tree (used in QGIS to auto-select first newly added layer)
+    //! @note added in 2.6
+    void addedLayersToLayerTree( QList<QgsMapLayer*> layers );
 
   protected slots:
     void layersAdded( QList<QgsMapLayer*> layers );

src/gui/layertree/qgslayertreeview.cpp

@@ -28,7 +28,6 @@ QgsLayerTreeView::QgsLayerTreeView( QWidget *parent )
     : QTreeView( parent )
     , mDefaultActions( 0 )
     , mMenuProvider( 0 )
-    , mAutoSelectAddedLayers( false )
 {
   setHeaderHidden( true );
 
@@ -138,10 +137,6 @@ void QgsLayerTreeView::modelRowsInserted( QModelIndex index, int start, int end
     updateExpandedStateFromNode( children[i] );
   }
 
-  // make newly added layer active (if auto-select is enabled)
-  if ( mAutoSelectAddedLayers && QgsLayerTree::isLayer( children[start] ) )
-    setCurrentIndex( layerTreeModel()->node2index( children[start] ) );
-
   // make sure we still have correct current layer
   onCurrentChanged();
 }

src/gui/layertree/qgslayertreeview.h

@@ -81,13 +81,6 @@ class GUI_EXPORT QgsLayerTreeView : public QTreeView
     //! Get list of selected layers
     QList<QgsMapLayer*> selectedLayers() const;
 
-    //! if enabled, current selection will be automatically changed to the newly added layer node.
-    //! This is purely for user's convenience so they do not need to click on the layer explicitly.
-    //! @note added in 2.6
-    void setAutoSelectAddedLayers( bool enabled ) { mAutoSelectAddedLayers = enabled; }
-    //! @note added in 2.6
-    bool autoSelectAddedLayers() const { return mAutoSelectAddedLayers; }
-
   public slots:
     //! Force refresh of layer symbology. Normally not needed as the changes of layer's renderer are monitored by the model
     void refreshLayerSymbology( const QString& layerId );
@@ -121,8 +114,6 @@ class GUI_EXPORT QgsLayerTreeView : public QTreeView
     QgsLayerTreeViewMenuProvider* mMenuProvider;
     //! Keeps track of current layer ID (to check when to emit signal about change of current layer)
     QString mCurrentLayerID;
-    //! Indicates whether the view should select newly added layers when they are added to the model
-    bool mAutoSelectAddedLayers;
 };