[FEATURE] Add duplicate button to symbol properties

Allows easy duplication of a symbol layer

python/gui/symbology-ng/qgssymbolv2selectordialog.sip

@@ -67,6 +67,10 @@ class QgsSymbolV2SelectorDialog : QDialog
     void saveSymbol();
     void lockLayer();
 
+    //! Duplicates the current symbol layer and places the duplicated layer above the current symbol layer
+    //! @note added in QGIS 2.14
+    void duplicateLayer();
+
     void layerChanged();
 
     void updateLayerPreview();

src/gui/symbology-ng/qgssymbolv2selectordialog.cpp

@@ -240,6 +240,7 @@ QgsSymbolV2SelectorDialog::QgsSymbolV2SelectorDialog( QgsSymbolV2* symbol, QgsSt
   iconLock.addFile( QgsApplication::iconPath( "locked.svg" ), QSize(), QIcon::Normal, QIcon::On );
   iconLock.addFile( QgsApplication::iconPath( "unlocked.svg" ), QSize(), QIcon::Normal, QIcon::Off );
   btnLock->setIcon( iconLock );
+  btnDuplicate->setIcon( QIcon( QgsApplication::iconPath( "mActionDuplicateLayer.svg" ) ) );
   btnUp->setIcon( QIcon( QgsApplication::iconPath( "symbologyUp.svg" ) ) );
   btnDown->setIcon( QIcon( QgsApplication::iconPath( "symbologyDown.svg" ) ) );
 
@@ -259,6 +260,7 @@ QgsSymbolV2SelectorDialog::QgsSymbolV2SelectorDialog( QgsSymbolV2* symbol, QgsSt
   connect( btnAddLayer, SIGNAL( clicked() ), this, SLOT( addLayer() ) );
   connect( btnRemoveLayer, SIGNAL( clicked() ), this, SLOT( removeLayer() ) );
   connect( btnLock, SIGNAL( clicked() ), this, SLOT( lockLayer() ) );
+  connect( btnDuplicate, SIGNAL( clicked() ), this, SLOT( duplicateLayer() ) );
   connect( btnSaveSymbol, SIGNAL( clicked() ), this, SLOT( saveSymbol() ) );
 
   updateUi();
@@ -362,6 +364,7 @@ void QgsSymbolV2SelectorDialog::updateUi()
     btnDown->setEnabled( false );
     btnRemoveLayer->setEnabled( false );
     btnLock->setEnabled( false );
+    btnDuplicate->setEnabled( false );
     return;
   }
 
@@ -372,6 +375,7 @@ void QgsSymbolV2SelectorDialog::updateUi()
   btnDown->setEnabled( currentRow < rowCount - 1 );
   btnRemoveLayer->setEnabled( rowCount > 1 );
   btnLock->setEnabled( true );
+  btnDuplicate->setEnabled( true );
 }
 
 void QgsSymbolV2SelectorDialog::updatePreview()
@@ -617,6 +621,43 @@ void QgsSymbolV2SelectorDialog::lockLayer()
   layer->setLocked( btnLock->isChecked() );
 }
 
+void QgsSymbolV2SelectorDialog::duplicateLayer()
+{
+  QModelIndex idx = layersTree->currentIndex();
+  if ( !idx.isValid() )
+    return;
+
+  SymbolLayerItem *item = static_cast<SymbolLayerItem*>( model->itemFromIndex( idx ) );
+  if ( !item->isLayer() )
+    return;
+
+  QgsSymbolLayerV2* source = item->layer();
+
+  int insertIdx = item->row();
+  item = static_cast<SymbolLayerItem*>( item->parent() );
+
+  QgsSymbolV2* parentSymbol = item->symbol();
+
+  QgsSymbolLayerV2* newLayer = source->clone();
+  if ( insertIdx == -1 )
+    parentSymbol->appendSymbolLayer( newLayer );
+  else
+    parentSymbol->insertSymbolLayer( item->rowCount() - insertIdx, newLayer );
+
+  SymbolLayerItem *newLayerItem = new SymbolLayerItem( newLayer );
+  item->insertRow( insertIdx == -1 ? 0 : insertIdx, newLayerItem );
+  if ( newLayer->subSymbol() )
+  {
+    loadSymbol( newLayer->subSymbol(), newLayerItem );
+    layersTree->setExpanded( newLayerItem->index(), true );
+  }
+  item->updatePreview();
+
+  layersTree->setCurrentIndex( model->indexFromItem( newLayerItem ) );
+  updateUi();
+  updatePreview();
+}
+
 void QgsSymbolV2SelectorDialog::saveSymbol()
 {
   bool ok;

src/gui/symbology-ng/qgssymbolv2selectordialog.h

@@ -139,6 +139,10 @@ class GUI_EXPORT QgsSymbolV2SelectorDialog : public QDialog, private Ui::QgsSymb
     void saveSymbol();
     void lockLayer();
 
+    //! Duplicates the current symbol layer and places the duplicated layer above the current symbol layer
+    //! @note added in QGIS 2.14
+    void duplicateLayer();
+
     void layerChanged();
 
     void updateLayerPreview();

src/ui/qgssymbolv2selectordialogbase.ui

@@ -6,7 +6,7 @@
    <rect>
     <x>0</x>
     <y>0</y>
-    <width>436</width>
+    <width>670</width>
     <height>359</height>
    </rect>
   </property>
@@ -104,6 +104,22 @@
          </property>
         </widget>
        </item>
+       <item>
+        <widget class="QPushButton" name="btnDuplicate">
+         <property name="maximumSize">
+          <size>
+           <width>50</width>
+           <height>16777215</height>
+          </size>
+         </property>
+         <property name="toolTip">
+          <string>Duplicates the current layer</string>
+         </property>
+         <property name="text">
+          <string/>
+         </property>
+        </widget>
+       </item>
        <item>
         <widget class="QPushButton" name="btnUp">
          <property name="maximumSize">