Loading and saving of custom layer order

src/app/qgisapp.cpp

@@ -2227,25 +2227,18 @@ void QgisApp::initLayerTreeView()
   addDockWidget( Qt::LeftDockWidgetArea, mLayerTreeDock );
 
   mLayerTreeCanvasBridge = new QgsLayerTreeMapCanvasBridge( QgsProject::instance()->layerTreeRoot(), mMapCanvas, this );
+  connect( QgsProject::instance(), SIGNAL(writeProject(QDomDocument&)), mLayerTreeCanvasBridge, SLOT(writeProject(QDomDocument&)));
+  connect( QgsProject::instance(), SIGNAL(readProject(QDomDocument)), mLayerTreeCanvasBridge, SLOT(readProject(QDomDocument)));
 
   mMapLayerOrder = new QgsCustomLayerOrderWidget(mLayerTreeCanvasBridge, this);
   mMapLayerOrder->setObjectName("theMapLayerOrder");
 
-  QCheckBox *orderCb = new QCheckBox( tr( "Control rendering order" ) );
-  orderCb->setChecked( false );
-
   mMapLayerOrder->setWhatsThis( tr( "Map layer list that displays all layers in drawing order." ) );
   mLayerOrderDock = new QDockWidget( tr( "Layer order" ), this );
   mLayerOrderDock->setObjectName( "LayerOrder" );
   mLayerOrderDock->setAllowedAreas( Qt::LeftDockWidgetArea | Qt::RightDockWidgetArea );
 
-  QWidget* w = new QWidget( this );
-  QVBoxLayout* l = new QVBoxLayout;
-  l->setMargin( 0 );
-  l->addWidget( mMapLayerOrder );
-  l->addWidget( orderCb );
-  w->setLayout( l );
-  mLayerOrderDock->setWidget( w );
+  mLayerOrderDock->setWidget( mMapLayerOrder );
   addDockWidget( Qt::LeftDockWidgetArea, mLayerOrderDock );
   mLayerOrderDock->hide();
 }
@@ -3263,6 +3256,8 @@ void QgisApp::fileNew( bool thePromptToSaveFlag, bool forceBlank )
   QgsProject* prj = QgsProject::instance();
   prj->clear();
 
+  mLayerTreeCanvasBridge->clear();
+
   //set the color for selections
   //the default can be set in qgisoptions
   //use project properties to override the color on a per project basis

src/gui/layertree/qgslayertreemapcanvasbridge.cpp

@@ -22,6 +22,12 @@ QgsLayerTreeMapCanvasBridge::QgsLayerTreeMapCanvasBridge(QgsLayerTreeGroup *root
   setCanvasLayers();
 }
 
+void QgsLayerTreeMapCanvasBridge::clear()
+{
+  setHasCustomLayerOrder(false);
+  setCustomLayerOrder(defaultLayerOrder());
+}
+
 QStringList QgsLayerTreeMapCanvasBridge::defaultLayerOrder() const
 {
   QStringList order;
@@ -147,6 +153,45 @@ void QgsLayerTreeMapCanvasBridge::setCanvasLayers()
   mPendingCanvasUpdate = false;
 }
 
+void QgsLayerTreeMapCanvasBridge::readProject(const QDomDocument& doc)
+{
+  QDomElement elem = doc.documentElement().firstChildElement("layer-tree-canvas");
+  if (elem.isNull())
+    return;
+
+  QDomElement customOrderElem = elem.firstChildElement("custom-order");
+  if (!customOrderElem.isNull())
+  {
+    QStringList order;
+    QDomElement itemElem = customOrderElem.firstChildElement("item");
+    while (!itemElem.isNull())
+    {
+      order.append(itemElem.text());
+      itemElem = itemElem.nextSiblingElement("item");
+    }
+
+    setHasCustomLayerOrder( customOrderElem.attribute("enabled", 0).toInt() );
+    setCustomLayerOrder(order);
+  }
+}
+
+void QgsLayerTreeMapCanvasBridge::writeProject(QDomDocument& doc)
+{
+  QDomElement elem = doc.createElement("layer-tree-canvas");
+  QDomElement customOrderElem = doc.createElement("custom-order");
+  customOrderElem.setAttribute("enabled", mHasCustomLayerOrder ? 1 : 0);
+
+  foreach (QString layerId, mCustomLayerOrder)
+  {
+    QDomElement itemElem = doc.createElement("item");
+    itemElem.appendChild(doc.createTextNode(layerId));
+    customOrderElem.appendChild(itemElem);
+  }
+  elem.appendChild(customOrderElem);
+
+  doc.documentElement().appendChild(elem);
+}
+
 void QgsLayerTreeMapCanvasBridge::setCanvasLayers(QgsLayerTreeNode *node, QList<QgsMapCanvasLayer> &layers)
 {
   if (QgsLayerTree::isLayer(node))

src/gui/layertree/qgslayertreemapcanvasbridge.h

@@ -17,6 +17,8 @@ class GUI_EXPORT QgsLayerTreeMapCanvasBridge : public QObject
 public:
   QgsLayerTreeMapCanvasBridge(QgsLayerTreeGroup* root, QgsMapCanvas* canvas, QObject* parent = 0);
 
+  void clear();
+
   bool hasCustomLayerOrder() const { return mHasCustomLayerOrder; }
   QStringList customLayerOrder() const { return mCustomLayerOrder; }
 
@@ -39,6 +41,9 @@ public slots:
   //! force update of canvas layers from the layer tree. Normally this should not be needed to be called.
   void setCanvasLayers();
 
+  void readProject( const QDomDocument& doc );
+  void writeProject( QDomDocument& doc );
+
 signals:
   void hasCustomLayerOrderChanged(bool);
   void customLayerOrderChanged(const QStringList& order);