[FEATURE][QGIS-Server] Legend filtering based on map in GetPrint Request

Feature funded by Tecnostudi Ambiente, Faunalia and Andromede-oceanologie.

The legend in composition was fixed and did not represent the layers in the map.
With the work made by @wonder-sk on layer-tree and QgsComposerLegend users will be able
 to configure composer legend as based on all the project layer tree with auto-update
 model or filtered by map.
This commit reused these two QgsComposerLegend's properties to filter it based on map in
 GetPrint Request

The issue #4003 qgis_mapserver getPrint legend options can be closed.

python/core/layertree/qgslayertreegroup.sip

@@ -41,6 +41,8 @@ class QgsLayerTreeGroup : QgsLayerTreeNode
     void removeLayer( QgsMapLayer* layer );
     //! Remove child nodes from index "from". The nodes will be deleted.
     void removeChildren( int from, int count );
+    //! Remove all child group nodes without layers. The groupnodes will be deleted.
+    void removeChildrenGroupWithoutLayers();
     //! Remove all child nodes. The nodes will be deleted.
     void removeAllChildren();
 

src/core/composer/qgscomposerlabel.cpp

@@ -98,7 +98,6 @@ void QgsComposerLabel::paint( QPainter* painter, const QStyleOptionGraphicsItem*
   if ( mHtmlState )
   {
     painter->scale( 1.0 / mHtmlUnitsToMM / 10.0, 1.0 / mHtmlUnitsToMM / 10.0 );
-
     QWebPage *webPage = new QWebPage();
     webPage->setNetworkAccessManager( QgsNetworkAccessManager::instance() );
 
@@ -149,7 +148,6 @@ void QgsComposerLabel::paint( QPainter* painter, const QStyleOptionGraphicsItem*
       // Pause until html is loaded
       loop.exec();
     }
-
     webPage->mainFrame()->render( painter );//DELETE WEBPAGE ?
   }
   else

src/core/layertree/qgslayertreegroup.cpp

@@ -119,6 +119,22 @@ void QgsLayerTreeGroup::removeChildren( int from, int count )
   updateVisibilityFromChildren();
 }
 
+void QgsLayerTreeGroup::removeChildrenGroupWithoutLayers()
+{	
+  // clean the layer tree by removing empty group
+  foreach ( QgsLayerTreeNode* treeNode, children() )
+  {
+    if ( treeNode->nodeType() == QgsLayerTreeNode::NodeGroup )
+    {
+	  QgsLayerTreeGroup* treeGroup = qobject_cast<QgsLayerTreeGroup*>( treeNode );
+	  if ( treeGroup->findLayerIds().count() == 0 )
+	    removeChildNode( treeNode );
+	  else
+	    treeGroup->removeChildrenGroupWithoutLayers();
+    }
+  }
+}
+
 void QgsLayerTreeGroup::removeAllChildren()
 {
   removeChildren( 0, mChildren.count() );

src/core/layertree/qgslayertreegroup.h

@@ -62,6 +62,8 @@ class CORE_EXPORT QgsLayerTreeGroup : public QgsLayerTreeNode
     void removeLayer( QgsMapLayer* layer );
     //! Remove child nodes from index "from". The nodes will be deleted.
     void removeChildren( int from, int count );
+    //! Remove all child group nodes without layers. The groupnodes will be deleted.
+    void removeChildrenGroupWithoutLayers();
     //! Remove all child nodes. The nodes will be deleted.
     void removeAllChildren();
 

src/mapserver/qgssldconfigparser.cpp

@@ -696,11 +696,11 @@ QgsComposition* QgsSLDConfigParser::createPrintComposition( const QString& compo
   return 0;
 }
 
-QgsComposition* QgsSLDConfigParser::initComposition( const QString& composerTemplate, QgsMapRenderer* mapRenderer, QList< QgsComposerMap*>& mapList, QList< QgsComposerLabel* >& labelList, QList<const QgsComposerHtml *>& htmlFrameList ) const
+QgsComposition* QgsSLDConfigParser::initComposition( const QString& composerTemplate, QgsMapRenderer* mapRenderer, QList< QgsComposerMap*>& mapList, QList< QgsComposerLegend* >& legendList, QList< QgsComposerLabel* >& labelList, QList<const QgsComposerHtml *>& htmlFrameList ) const
 {
   if ( mFallbackParser )
   {
-    return mFallbackParser->initComposition( composerTemplate, mapRenderer, mapList, labelList, htmlFrameList );
+    return mFallbackParser->initComposition( composerTemplate, mapRenderer, mapList, legendList, labelList, htmlFrameList );
   }
   return 0;
 }

src/mapserver/qgssldconfigparser.h

@@ -107,7 +107,7 @@ class QgsSLDConfigParser : public QgsWMSConfigParser
     QgsComposition* createPrintComposition( const QString& composerTemplate, QgsMapRenderer* mapRenderer, const QMap< QString, QString >& parameterMap ) const;
 
     /**Creates a composition from the project file (probably delegated to the fallback parser)*/
-    QgsComposition* initComposition( const QString& composerTemplate, QgsMapRenderer* mapRenderer, QList< QgsComposerMap*>& mapList, QList< QgsComposerLabel* >& labelList, QList<const QgsComposerHtml *>& htmlFrameList ) const;
+    QgsComposition* initComposition( const QString& composerTemplate, QgsMapRenderer* mapRenderer, QList< QgsComposerMap*>& mapList, QList< QgsComposerLegend* >& legendList, QList< QgsComposerLabel* >& labelList, QList<const QgsComposerHtml *>& htmlFrameList ) const;
 
     /**Adds print capabilities to xml document. ParentElem usually is the <Capabilities> element*/
     void printCapabilities( QDomElement& parentElement, QDomDocument& doc ) const;

src/mapserver/qgswmsconfigparser.cpp

@@ -17,13 +17,18 @@
 
 #include "qgswmsconfigparser.h"
 #include "qgsmaplayer.h"
+#include "qgsmapserviceexception.h"
 
 #include "qgscomposerlabel.h"
+#include "qgscomposerlegend.h"
 #include "qgscomposermap.h"
 #include "qgscomposerhtml.h"
 #include "qgscomposerframe.h"
 #include "qgscomposition.h"
 
+#include "qgslayertreegroup.h"
+#include "qgslayertreelayer.h"
+
 QgsWMSConfigParser::QgsWMSConfigParser()
 {
 
@@ -37,10 +42,11 @@ QgsWMSConfigParser::~QgsWMSConfigParser()
 QgsComposition* QgsWMSConfigParser::createPrintComposition( const QString& composerTemplate, QgsMapRenderer* mapRenderer, const QMap< QString, QString >& parameterMap ) const
 {
   QList<QgsComposerMap*> composerMaps;
+  QList<QgsComposerLegend*> composerLegends;
   QList<QgsComposerLabel*> composerLabels;
   QList<const QgsComposerHtml*> composerHtmls;
 
-  QgsComposition* c = initComposition( composerTemplate, mapRenderer, composerMaps, composerLabels, composerHtmls );
+  QgsComposition* c = initComposition( composerTemplate, mapRenderer, composerMaps, composerLegends, composerLabels, composerHtmls );
   if ( !c )
   {
     return 0;
@@ -158,6 +164,66 @@ QgsComposition* QgsWMSConfigParser::createPrintComposition( const QString& compo
     currentMap->setGridIntervalX( parameterMap.value( mapId + ":GRID_INTERVAL_X" ).toDouble() );
     currentMap->setGridIntervalY( parameterMap.value( mapId + ":GRID_INTERVAL_Y" ).toDouble() );
   }
+  //update legend
+  // if it has an auto-update model
+  foreach ( QgsComposerLegend* currentLegend, composerLegends )
+  {
+    if ( !currentLegend )
+    {
+      continue;
+    }
+
+    if ( currentLegend->autoUpdateModel() || currentLegend->legendFilterByMapEnabled() )
+    {
+	  // the legend has an auto-update model or 
+	  // has to be filter by map
+	  // we will update it with map's layers
+      const QgsComposerMap* map = currentLegend->composerMap();
+      if ( !map )
+      {
+        continue;
+      }
+
+      // get model and layer tree root of the legend
+      QgsLegendModelV2* model = currentLegend->modelV2();
+      QgsLayerTreeGroup* root = model->rootGroup();
+
+
+      // get layerIds find in the layer tree root
+      QStringList layerIds = root->findLayerIds();
+      // get map layerIds
+      QStringList layerSet = map->layerSet();
+
+      // get map scale
+      double scale = map->scale();
+
+      // foreach layer find in the layer tree
+      // remove it if the layer id is not in map layerIds
+      foreach ( QString layerId, layerIds )
+      {
+        QgsLayerTreeLayer* nodeLayer = root->findLayer( layerId );
+        if ( !nodeLayer ) {
+		  continue;
+		}
+        if ( !layerSet.contains( layerId ) )
+        {
+          qobject_cast<QgsLayerTreeGroup*>( nodeLayer->parent() )->removeChildNode( nodeLayer );
+        }
+        else
+        {
+		  QgsMapLayer* layer = nodeLayer->layer();
+		  if ( layer->hasScaleBasedVisibility() )
+		  {
+			if ( layer->minimumScale() > scale )
+              qobject_cast<QgsLayerTreeGroup*>( nodeLayer->parent() )->removeChildNode( nodeLayer );
+			else if ( layer->maximumScale() < scale )
+              qobject_cast<QgsLayerTreeGroup*>( nodeLayer->parent() )->removeChildNode( nodeLayer );
+		  }
+		}
+      }
+      root->removeChildrenGroupWithoutLayers();
+    }
+  }
 
   //replace label text
   foreach ( QgsComposerLabel *currentLabel, composerLabels )

src/mapserver/qgswmsconfigparser.h

@@ -22,6 +22,7 @@
 
 class QgsComposerHtml;
 class QgsComposerLabel;
+class QgsComposerLegend;
 class QgsComposerMap;
 class QgsComposition;
 class QgsMapLayer;
@@ -107,7 +108,7 @@ class QgsWMSConfigParser
     QgsComposition* createPrintComposition( const QString& composerTemplate, QgsMapRenderer* mapRenderer, const QMap< QString, QString >& parameterMap ) const;
 
     /**Creates a composition from the project file (probably delegated to the fallback parser)*/
-    virtual QgsComposition* initComposition( const QString& composerTemplate, QgsMapRenderer* mapRenderer, QList< QgsComposerMap*>& mapList, QList< QgsComposerLabel* >& labelList, QList<const QgsComposerHtml *>& htmlFrameList ) const = 0;
+    virtual QgsComposition* initComposition( const QString& composerTemplate, QgsMapRenderer* mapRenderer, QList< QgsComposerMap*>& mapList, QList< QgsComposerLegend* >& legendList, QList< QgsComposerLabel* >& labelList, QList<const QgsComposerHtml *>& htmlFrameList ) const = 0;
 
     /**Adds print capabilities to xml document. ParentElem usually is the <Capabilities> element*/
     virtual void printCapabilities( QDomElement& parentElement, QDomDocument& doc ) const = 0;

src/mapserver/qgswmsprojectparser.cpp

@@ -34,6 +34,7 @@
 #include "qgscomposerpicture.h"
 #include "qgscomposerscalebar.h"
 #include "qgscomposershape.h"
+#include "qgslayertreegroup.h"
 
 #include <QFileInfo>
 #include <QTextDocument>
@@ -368,7 +369,7 @@ int QgsWMSProjectParser::WMSPrecision() const
   return WMSPrecision;
 }
 
-QgsComposition* QgsWMSProjectParser::initComposition( const QString& composerTemplate, QgsMapRenderer* mapRenderer, QList< QgsComposerMap*>& mapList, QList< QgsComposerLabel* >& labelList, QList<const QgsComposerHtml *>& htmlList ) const
+QgsComposition* QgsWMSProjectParser::initComposition( const QString& composerTemplate, QgsMapRenderer* mapRenderer, QList< QgsComposerMap* >& mapList, QList< QgsComposerLegend* >& legendList, QList< QgsComposerLabel* >& labelList, QList<const QgsComposerHtml *>& htmlList ) const
 {
   //Create composition from xml
   QDomElement composerElem = composerByName( composerTemplate );
@@ -394,6 +395,7 @@ QgsComposition* QgsWMSProjectParser::initComposition( const QString& composerTem
 
   labelList.clear();
   mapList.clear();
+  legendList.clear();
   htmlList.clear();
 
   QList<QgsComposerItem* > itemList;
@@ -413,6 +415,23 @@ QgsComposition* QgsWMSProjectParser::initComposition( const QString& composerTem
       mapList.push_back( map );
       continue;
     }
+    QgsComposerLegend* legend = dynamic_cast< QgsComposerLegend *>( *itemIt );
+    if ( legend )
+    {
+      /*
+      QgsLegendModelV2* model = legend->modelV2();
+      QgsLayerTreeGroup* root = model->rootGroup();
+      QStringList layerIds = root->findLayerIds();
+      throw QgsMapServiceException( "Error", "Composer legend layerIds "+layerIds.join(" ,") );
+      */
+      if ( legend->autoUpdateModel() )
+      {
+        QgsLegendModelV2* model = legend->modelV2();
+        model->setRootGroup( projectLayerTreeGroup() );
+      }
+      legendList.push_back( legend );
+      continue;
+    }
     QgsComposerPicture* pic = dynamic_cast< QgsComposerPicture *>( *itemIt );
     if ( pic )
     {
@@ -1913,6 +1932,27 @@ QDomElement QgsWMSProjectParser::composerByName( const QString& composerName ) c
   return composerElem;
 }
 
+QgsLayerTreeGroup* QgsWMSProjectParser::projectLayerTreeGroup() const
+{
+  const QDomDocument* projectDoc = mProjectParser.xmlDocument();
+  if ( !projectDoc )
+  {
+    return 0;
+  }
+
+  QDomElement qgisElem = projectDoc->documentElement();
+  if ( qgisElem.isNull() )
+  {
+    return 0;
+  }
+  QDomElement layerTreeElem = qgisElem.firstChildElement( "layer-tree-group" );
+  if ( layerTreeElem.isNull() )
+  {
+    return 0;
+  }
+  return QgsLayerTreeGroup::readXML( layerTreeElem );
+}
+
 bool QgsWMSProjectParser::annotationPosition( const QDomElement& elem, double scaleFactor, double& xPos, double& yPos )
 {
   Q_UNUSED( scaleFactor );

src/mapserver/qgswmsprojectparser.h

@@ -20,6 +20,7 @@
 
 #include "qgswmsconfigparser.h"
 #include "qgsserverprojectparser.h"
+#include "qgslayertreegroup.h"
 
 class QTextDocument;
 class QSvgRenderer;
@@ -59,7 +60,7 @@ class QgsWMSProjectParser : public QgsWMSConfigParser
     int WMSPrecision() const;
 
     //printing
-    QgsComposition* initComposition( const QString& composerTemplate, QgsMapRenderer* mapRenderer, QList< QgsComposerMap*>& mapList, QList< QgsComposerLabel* >& labelList, QList<const QgsComposerHtml *>& htmlFrameList ) const;
+    QgsComposition* initComposition( const QString& composerTemplate, QgsMapRenderer* mapRenderer, QList< QgsComposerMap* >& mapList, QList< QgsComposerLegend* >& legendList, QList< QgsComposerLabel* >& labelList, QList<const QgsComposerHtml *>& htmlFrameList ) const;
 
     void printCapabilities( QDomElement& parentElement, QDomDocument& doc ) const;
 
@@ -147,6 +148,7 @@ class QgsWMSProjectParser : public QgsWMSConfigParser
     void addLayersFromGroup( const QDomElement& legendGroupElem, QMap< int, QgsMapLayer*>& layers, bool useCache = true ) const;
 
     QDomElement composerByName( const QString& composerName ) const;
+    QgsLayerTreeGroup* projectLayerTreeGroup() const;
 
     static bool annotationPosition( const QDomElement& elem, double scaleFactor, double& xPos, double& yPos );
     static void drawAnnotationRectangle( QPainter* p, const QDomElement& elem, double scaleFactor, double xPos, double yPos, int itemWidth, int itemHeight );