[FEATURE] allow applying the same style to selected layers or to legend group

also fixes #10323

This adds the possibility to paste the style to group or selected layers.

Author: slarosa

src/app/qgisapp.cpp

@@ -7746,7 +7746,33 @@ void QgisApp::legendLayerStretchUsingCurrentExtent()
   }
 }
 
+void QgisApp::applyStyleToGroup()
+{
+  if ( !mLayerTreeView )
+    return;
 
+  Q_FOREACH ( QgsLayerTreeNode* node, mLayerTreeView->selectedNodes() )
+  {
+    if ( QgsLayerTree::isGroup( node ) )
+    {
+      Q_FOREACH ( QgsLayerTreeLayer* nodeLayer, QgsLayerTree::toGroup( node )->findLayers() )
+      {
+        if ( nodeLayer->layer() )
+        {
+          pasteStyle( nodeLayer->layer() );
+        }
+      }
+    }
+    else if ( QgsLayerTree::isLayer( node ) )
+    {
+      QgsLayerTreeLayer* nodeLayer = QgsLayerTree::toLayer( node );
+      if ( nodeLayer->layer() )
+      {
+        pasteStyle( nodeLayer->layer() );
+      }
+    }
+  }
+}
 
 void QgisApp::legendGroupSetCRS()
 {

src/app/qgisapp.h

@@ -748,6 +748,9 @@ class APP_EXPORT QgisApp : public QMainWindow, private Ui::MainWindow
         Only workds on raster layers*/
     void legendLayerStretchUsingCurrentExtent();
 
+    /** Apply the same style to selected layers or to current legend group*/
+    void applyStyleToGroup();
+
     /** Set the CRS of the current legend group*/
     void legendGroupSetCRS();
 

src/app/qgsapplayertreeviewmenuprovider.cpp

@@ -66,6 +66,11 @@ QMenu* QgsAppLayerTreeViewMenuProvider::createContextMenu()
       if ( mView->selectedNodes( true ).count() >= 2 )
         menu->addAction( actions->actionGroupSelected( menu ) );
 
+      if ( QgisApp::instance()->clipboard()->hasFormat( QGSCLIPBOARD_STYLE_MIME ) )
+      {
+        menu->addAction( tr( "Paste Style" ), QgisApp::instance(), SLOT( applyStyleToGroup() ) );
+      }
+
       menu->addAction( tr( "Save As Layer Definition File..." ), QgisApp::instance(), SLOT( saveAsLayerDefinition() ) );
 
       menu->addAction( actions->actionAddGroup( menu ) );
@@ -121,6 +126,13 @@ QMenu* QgsAppLayerTreeViewMenuProvider::createContextMenu()
 
         menu->addMenu( menuStyleManager );
       }
+      else
+      {
+        if ( QgisApp::instance()->clipboard()->hasFormat( QGSCLIPBOARD_STYLE_MIME ) )
+        {
+          menu->addAction( tr( "Paste Style" ), QgisApp::instance(), SLOT( applyStyleToGroup() ) );
+        }
+      }
 
       menu->addSeparator();