Add load and saving a Layer Definition file. Fix #9688

Author: NathanW2

python/core/qgsmaplayer.sip

@@ -204,6 +204,18 @@ class QgsMapLayer : QObject
     */
     bool writeLayerXML( QDomElement& layerElement, QDomDocument& document );
 
+    /** Returns the layer as a layer definition document
+        Layer definitions store the data source as well as styling and custom properties.
+
+        Layer definitions can be used to load a layer and styling all from a single file.
+    */
+    QDomDocument asLayerDefinition ( );
+
+    /** Creates a new layer from a layer defininition document
+    */
+    static QgsMapLayer* fromLayerDefinition( QDomDocument& document );
+    static QgsMapLayer* fromLayerDefinitionFile(const QString qlrfile );
+
     /** Set a custom property for layer. Properties are stored in a map and saved in project file.
      *  @note Added in v1.4 */
     void setCustomProperty( const QString& key, const QVariant& value );

src/app/legend/qgslegendlayer.cpp

@@ -435,6 +435,7 @@ void QgsLegendLayer::addToPopupMenu( QMenu& theMenu )
 
     // save as vector file
     theMenu.addAction( tr( "Save As..." ), QgisApp::instance(), SLOT( saveAsFile() ) );
+    theMenu.addAction( tr( "Save As Layer Definition File..." ), QgisApp::instance(), SLOT( saveAsLayerDefinition() ) );
 
     if ( !vlayer->isEditable() && vlayer->dataProvider()->supportsSubsetString() && vlayer->vectorJoins().isEmpty() )
       theMenu.addAction( tr( "&Filter..." ), QgisApp::instance(), SLOT( layerSubsetString() ) );
@@ -450,6 +451,7 @@ void QgsLegendLayer::addToPopupMenu( QMenu& theMenu )
   else if ( lyr->type() == QgsMapLayer::RasterLayer )
   {
     theMenu.addAction( tr( "Save As..." ), QgisApp::instance(), SLOT( saveAsRasterFile() ) );
+    theMenu.addAction( tr( "Save As Layer Definition File..." ), QgisApp::instance(), SLOT( saveAsLayerDefinition() ) );
   }
   else if ( lyr->type() == QgsMapLayer::PluginLayer && legend()->selectedLayers().count() == 1 )
   {

src/app/qgisapp.cpp

@@ -1050,6 +1050,7 @@ void QgisApp::createActions()
   connect( mActionNewSpatiaLiteLayer, SIGNAL( triggered() ), this, SLOT( newSpatialiteLayer() ) );
   connect( mActionShowRasterCalculator, SIGNAL( triggered() ), this, SLOT( showRasterCalculator() ) );
   connect( mActionEmbedLayers, SIGNAL( triggered() ) , this, SLOT( embedLayers() ) );
+  connect( mActionAddLayerDefinition, SIGNAL( triggered() ), this, SLOT( addLayerDefinition () ) );
   connect( mActionAddOgrLayer, SIGNAL( triggered() ), this, SLOT( addVectorLayer() ) );
   connect( mActionAddRasterLayer, SIGNAL( triggered() ), this, SLOT( addRasterLayer() ) );
   connect( mActionAddPgLayer, SIGNAL( triggered() ), this, SLOT( addDatabaseLayer() ) );
@@ -2456,6 +2457,17 @@ void QgisApp::about()
   abt->activateWindow();
 }
 
+void QgisApp::addLayerDefinition ()
+{
+  QString path = QFileDialog::getOpenFileName( this, "Add Layer Definition File", QDir::home().path(), "*.qlr" );
+  if ( path.isEmpty() )
+    return;
+
+  QgsMapLayer* layer = QgsMapLayer::fromLayerDefinitionFile( path );
+  if ( layer && layer->isValid() )
+    QgsMapLayerRegistry::instance()->addMapLayer( layer );
+}
+
 /**
   This method prompts the user for a list of vector file names  with a dialog.
   */
@@ -4590,6 +4602,26 @@ void QgisApp::saveAsFile()
   }
 }
 
+void QgisApp::saveAsLayerDefinition()
+{
+  QgsMapLayer* layer = activeLayer();
+  if ( !layer )
+    return;
+
+  QString path = QFileDialog::getSaveFileName( this, "Save as Layer Definition File", QDir::home().path(), "*.qlr" );
+  QgsDebugMsg( path );
+  if ( path.isEmpty() )
+    return;
+
+  QDomDocument doc = layer->asLayerDefinition();
+  QFile file( path );
+  if ( file.open( QFile::WriteOnly | QFile::Truncate ) )
+  {
+    QTextStream qlayerstream( &file );
+    doc.save( qlayerstream, 2 );
+  }
+}
+
 void QgisApp::saveAsVectorFileGeneral( QgsVectorLayer* vlayer, bool symbologyOption )
 {
   if ( !mMapLegend )

src/app/qgisapp.h

@@ -1019,6 +1019,8 @@ class APP_EXPORT QgisApp : public QMainWindow, private Ui::MainWindow
     void hasCrsTransformEnabled( bool theFlag );
     void destinationCrsChanged();
     //    void debugHook();
+    //! Add a Layer Definition file
+    void addLayerDefinition ();
     //! Add a vector layer to the map
     void addVectorLayer();
     //! Exit Qgis
@@ -1087,6 +1089,8 @@ class APP_EXPORT QgisApp : public QMainWindow, private Ui::MainWindow
     //! save current vector layer
     void saveAsFile();
 
+    void saveAsLayerDefinition();
+
     //! save current raster layer
     void saveAsRasterFile();
 

src/core/qgsmaplayer.cpp

@@ -36,9 +36,12 @@
 #include "qgscoordinatereferencesystem.h"
 #include "qgsapplication.h"
 #include "qgsproject.h"
+#include "qgspluginlayerregistry.h"
 #include "qgsprojectfiletransform.h"
 #include "qgsdatasourceuri.h"
 #include "qgsvectorlayer.h"
+#include "qgsrasterlayer.h"
+#include "qgspluginlayer.h"
 #include "qgsproviderregistry.h"
 
 QgsMapLayer::QgsMapLayer( QgsMapLayer::LayerType type,
@@ -574,6 +577,63 @@ bool QgsMapLayer::writeLayerXML( QDomElement& layerElement, QDomDocument& docume
 
 } // bool QgsMapLayer::writeXML
 
+QDomDocument QgsMapLayer::asLayerDefinition ()
+{
+  QDomDocument doc( "qgis-layer-definition");
+  QDomElement maplayer = doc.createElement( "maplayer" );
+  this->writeLayerXML( maplayer, doc );
+  maplayer.removeChild( maplayer.firstChildElement( "id" ) );
+  doc.appendChild( maplayer );
+  return doc;
+}
+
+QgsMapLayer* QgsMapLayer::fromLayerDefinition( QDomDocument& document )
+{
+  QDomNode layernode = document.elementsByTagName( "maplayer" ).at(0);
+  QDomElement layerElem = layernode.toElement();
+
+  QString type = layerElem.attribute( "type" );
+  QgsDebugMsg(type);
+  QgsMapLayer *layer = NULL;
+
+  if ( type == "vector" )
+  {
+    layer = new QgsVectorLayer;
+  }
+  else if ( type == "raster" )
+  {
+    layer = new QgsRasterLayer;
+  }
+  else if ( type == "plugin" )
+  {
+    QString typeName = layerElem.attribute( "name" );
+    layer = QgsPluginLayerRegistry::instance()->createLayer( typeName );
+  }
+
+  bool ok = layer->readLayerXML( layerElem );
+  if ( ok )
+    return layer;
+}
+
+QgsMapLayer* QgsMapLayer::fromLayerDefinitionFile( const QString qlrfile )
+{
+  QFile file( qlrfile );
+  if ( !file.open( QIODevice::ReadOnly ) )
+  {
+    QgsDebugMsg("Can't open file");
+    return 0;
+  }
+
+  QDomDocument doc;
+  if ( !doc.setContent( &file ) )
+  {
+    QgsDebugMsg("Can't set content");
+    return 0;
+  }
+
+  return QgsMapLayer::fromLayerDefinition( doc );
+}
+
 
 bool QgsMapLayer::writeXml( QDomNode & layer_node, QDomDocument & document )
 {

src/core/qgsmaplayer.h

@@ -217,6 +217,18 @@ class CORE_EXPORT QgsMapLayer : public QObject
     */
     bool writeLayerXML( QDomElement& layerElement, QDomDocument& document );
 
+    /** Returns the layer as a layer definition document
+        Layer definitions store the data source as well as styling and custom properties.
+
+        Layer definitions can be used to load a layer and styling all from a single file.
+    */
+    QDomDocument asLayerDefinition ( );
+
+    /** Creates a new layer from a layer defininition document
+    */
+    static QgsMapLayer* fromLayerDefinition( QDomDocument& document );
+    static QgsMapLayer* fromLayerDefinitionFile(const QString qlrfile );
+
     /** Set a custom property for layer. Properties are stored in a map and saved in project file.
      *  @note Added in v1.4 */
     void setCustomProperty( const QString& key, const QVariant& value );

src/ui/qgisapp.ui

@@ -7,7 +7,7 @@
     <x>0</x>
     <y>0</y>
     <width>1050</width>
-    <height>487</height>
+    <height>506</height>
    </rect>
   </property>
   <widget class="QWidget" name="centralwidget"/>
@@ -123,6 +123,7 @@
     </widget>
     <addaction name="mNewLayerMenu"/>
     <addaction name="mActionEmbedLayers"/>
+    <addaction name="mActionAddLayerDefinition"/>
     <addaction name="mActionAddOgrLayer"/>
     <addaction name="mActionAddRasterLayer"/>
     <addaction name="mActionAddPgLayer"/>
@@ -2160,6 +2161,11 @@ Acts on currently active editable layer</string>
   <action name="mActionResetUIdefaults">
    <property name="text">
     <string>Reset UI defaults</string>
+	   </property>
+     </action>
+  <action name="mActionAddLayerDefinition">
+   <property name="text">
+    <string>Add from Layer Definition File..</string>
    </property>
   </action>
  </widget>