[FEATURE] Rendering of data-defined size in legend in "collapsed" mode

Instead of having different marker sizes in legend as separate legend nodes, the new "collapsed" mode packs all sizes into one legend node. This commit only makes it available in the API, not exposed in GUI yet.
qgis · Jun 15, 2017 · 8c4d5bb · 8c4d5bb
1 parent a899963
commit 8c4d5bb
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Showing 23 changed files with 949 additions and 78 deletions.
diff --git a/python/core/core.sip b/python/core/core.sip
@@ -36,6 +36,7 @@
 %Include qgscoordinatetransform.sip
 %Include qgscredentials.sip
 %Include qgscrscache.sip
+%Include qgsdatadefinedsizelegend.sip
 %Include qgsdataitem.sip
 %Include qgsdataitemprovider.sip
 %Include qgsdataitemproviderregistry.sip

diff --git a/python/core/layertree/qgslayertreemodellegendnode.sip b/python/core/layertree/qgslayertreemodellegendnode.sip
@@ -151,6 +151,12 @@ Emitted on internal data change so the layer tree model can forward the signal t
 Construct the node with pointer to its parent layer node
 %End
 
+    QgsRenderContext *createTemporaryRenderContext() const /Factory/;
+%Docstring
+Returns a temporary context or null if legendMapViewData are not valid
+ :rtype: QgsRenderContext
+%End
+
   protected:
 };
 
@@ -371,6 +377,30 @@ class QgsWmsLegendNode : QgsLayerTreeModelLegendNode
 
 };
 
+
+class QgsDataDefinedSizeLegendNode : QgsLayerTreeModelLegendNode
+{
+%Docstring
+ Produces legend node with a marker symbol
+.. versionadded:: 3.0
+%End
+
+%TypeHeaderCode
+#include "qgslayertreemodellegendnode.h"
+%End
+  public:
+    QgsDataDefinedSizeLegendNode( QgsLayerTreeLayer *nodeLayer, const QgsDataDefinedSizeLegend &settings, QObject *parent /TransferThis/ = 0 );
+%Docstring
+Construct the node using QgsDataDefinedSizeLegend as definition of the node's appearance
+%End
+
+    virtual QVariant data( int role ) const;
+
+    virtual ItemMetrics draw( const QgsLegendSettings &settings, ItemContext *ctx );
+
+
+};
+
 /************************************************************************
  * This file has been generated automatically from                      *
  *                                                                      *

diff --git a/python/core/qgsdiagramrenderer.sip b/python/core/qgsdiagramrenderer.sip
@@ -760,13 +760,28 @@ Returns list with all diagram settings in the renderer
     virtual QList< QgsLayerTreeModelLegendNode * > legendItems( QgsLayerTreeLayer *nodeLayer ) const /Factory/;
 
 
+    void setDataDefinedSizeLegend( QgsDataDefinedSizeLegend *settings /Transfer/ );
+%Docstring
+ Configures appearance of legend. Takes ownership of the passed settings objects.
+.. versionadded:: 3.0
+%End
+
+    QgsDataDefinedSizeLegend *dataDefinedSizeLegend() const;
+%Docstring
+ Returns configuration of appearance of legend. Will return null if no configuration has been set.
+.. versionadded:: 3.0
+ :rtype: QgsDataDefinedSizeLegend
+%End
+
   protected:
     virtual bool diagramSettings( const QgsFeature &feature, const QgsRenderContext &c, QgsDiagramSettings &s ) const;
 
 
     virtual QSizeF diagramSize( const QgsFeature &, const QgsRenderContext &c ) const;
 
 
+    QgsLinearlyInterpolatedDiagramRenderer( const QgsLinearlyInterpolatedDiagramRenderer &other );
+
 };
 
 /************************************************************************

diff --git a/python/core/symbology-ng/qgscategorizedsymbolrenderer.sip b/python/core/symbology-ng/qgscategorizedsymbolrenderer.sip
@@ -78,6 +78,7 @@ class QgsCategorizedSymbolRenderer : QgsFeatureRenderer
   public:
 
     QgsCategorizedSymbolRenderer( const QString &attrName = QString(), const QgsCategoryList &categories = QgsCategoryList() );
+    ~QgsCategorizedSymbolRenderer();
 
     virtual QgsSymbol *symbolForFeature( QgsFeature &feature, QgsRenderContext &context );
     virtual QgsSymbol *originalSymbolForFeature( QgsFeature &feature, QgsRenderContext &context );
@@ -220,10 +221,31 @@ create renderer from XML element
  :rtype: QgsCategorizedSymbolRenderer
 %End
 
+    void setDataDefinedSizeLegend( QgsDataDefinedSizeLegend *settings /Transfer/ );
+%Docstring
+ Configures appearance of legend when renderer is configured to use data-defined size for marker symbols.
+ This allows to configure for what values (symbol sizes) should be shown in the legend, whether to display
+ different symbol sizes collapsed in one legend node or separated across multiple legend nodes etc.
+
+ When renderer does not use data-defined size or does not use marker symbols, these settings will be ignored.
+ Takes ownership of the passed settings objects. Null pointer is a valid input that disables data-defined
+ size legend.
+.. versionadded:: 3.0
+%End
+
+    QgsDataDefinedSizeLegend *dataDefinedSizeLegend() const;
+%Docstring
+ Returns configuration of appearance of legend when using data-defined size for marker symbols.
+ Will return null if the functionality is disabled.
+.. versionadded:: 3.0
+ :rtype: QgsDataDefinedSizeLegend
+%End
+
   protected:
 
 
 
+
     void rebuildHash();
 %Docstring
 hashtable for faster access to symbols

diff --git a/python/core/symbology-ng/qgsgraduatedsymbolrenderer.sip b/python/core/symbology-ng/qgsgraduatedsymbolrenderer.sip
@@ -7,6 +7,7 @@
  ************************************************************************/
 
 
+
 class QgsRendererRange
 {
 
@@ -405,9 +406,30 @@ create renderer from XML element
  :rtype: QgsGraduatedSymbolRenderer
 %End
 
+    void setDataDefinedSizeLegend( QgsDataDefinedSizeLegend *settings /Transfer/ );
+%Docstring
+ Configures appearance of legend when renderer is configured to use data-defined size for marker symbols.
+ This allows to configure for what values (symbol sizes) should be shown in the legend, whether to display
+ different symbol sizes collapsed in one legend node or separated across multiple legend nodes etc.
+
+ When renderer does not use data-defined size or does not use marker symbols, these settings will be ignored.
+ Takes ownership of the passed settings objects. Null pointer is a valid input that disables data-defined
+ size legend.
+.. versionadded:: 3.0
+%End
+
+    QgsDataDefinedSizeLegend *dataDefinedSizeLegend() const;
+%Docstring
+ Returns configuration of appearance of legend when using data-defined size for marker symbols.
+ Will return null if the functionality is disabled.
+.. versionadded:: 3.0
+ :rtype: QgsDataDefinedSizeLegend
+%End
+
   protected:
 
 
+
     QgsSymbol *symbolForValue( double value );
 %Docstring
 attribute index (derived from attribute name in startRender)

diff --git a/python/core/symbology-ng/qgslegendsymbolitem.sip b/python/core/symbology-ng/qgslegendsymbolitem.sip
@@ -94,6 +94,22 @@ Identation level that tells how deep the item is in a hierarchy of items. For fl
 Set symbol of the item. Takes ownership of symbol.
 %End
 
+    void setDataDefinedSizeLegendSettings( QgsDataDefinedSizeLegend *settings /Transfer/ );
+%Docstring
+ Sets extra information about data-defined size. If set, this item should be converted to QgsDataDefinedSizeLegendNode
+ rather than QgsSymbolLegendNode instance as usual. Passing null removes any data-defined size legend settings.
+
+ Takes ownership of the settings object.
+.. versionadded:: 3.0
+%End
+
+    QgsDataDefinedSizeLegend *dataDefinedSizeLegendSettings() const;
+%Docstring
+ Returns extra information for data-defined size legend rendering. Normally it returns null.
+.. versionadded:: 3.0
+ :rtype: QgsDataDefinedSizeLegend
+%End
+
 };
 
 

diff --git a/python/core/symbology-ng/qgssinglesymbolrenderer.sip b/python/core/symbology-ng/qgssinglesymbolrenderer.sip
@@ -7,6 +7,7 @@
  ************************************************************************/
 
 
+
 class QgsSingleSymbolRenderer : QgsFeatureRenderer
 {
 
@@ -16,6 +17,7 @@ class QgsSingleSymbolRenderer : QgsFeatureRenderer
   public:
 
     QgsSingleSymbolRenderer( QgsSymbol *symbol /Transfer/ );
+    ~QgsSingleSymbolRenderer();
 
     virtual QgsSymbol *symbolForFeature( QgsFeature &feature, QgsRenderContext &context );
     virtual QgsSymbol *originalSymbolForFeature( QgsFeature &feature, QgsRenderContext &context );
@@ -58,6 +60,26 @@ create renderer from XML element
  :rtype: QgsSingleSymbolRenderer
 %End
 
+    void setDataDefinedSizeLegend( QgsDataDefinedSizeLegend *settings /Transfer/ );
+%Docstring
+ Configures appearance of legend when renderer is configured to use data-defined size for marker symbols.
+ This allows to configure for what values (symbol sizes) should be shown in the legend, whether to display
+ different symbol sizes collapsed in one legend node or separated across multiple legend nodes etc.
+
+ When renderer does not use data-defined size or does not use marker symbols, these settings will be ignored.
+ Takes ownership of the passed settings objects. Null pointer is a valid input that disables data-defined
+ size legend.
+.. versionadded:: 3.0
+%End
+
+    QgsDataDefinedSizeLegend *dataDefinedSizeLegend() const;
+%Docstring
+ Returns configuration of appearance of legend when using data-defined size for marker symbols.
+ Will return null if the functionality is disabled.
+.. versionadded:: 3.0
+ :rtype: QgsDataDefinedSizeLegend
+%End
+
   protected:
 
   private:

diff --git a/src/core/CMakeLists.txt b/src/core/CMakeLists.txt
@@ -141,6 +141,7 @@ SET(QGIS_CORE_SRCS
   qgscredentials.cpp
   qgscrscache.cpp
   qgsdartmeasurement.cpp
+  qgsdatadefinedsizelegend.cpp
   qgsdataitem.cpp
   qgsdataitemprovider.cpp
   qgsdataitemproviderregistry.cpp
@@ -738,6 +739,7 @@ SET(QGIS_CORE_HDRS
   qgscrscache.h
   qgscsexception.h
   qgsdartmeasurement.h
+  qgsdatadefinedsizelegend.h
   qgsdataitem.h
   qgsdataitemprovider.h
   qgsdataitemproviderregistry.h

diff --git a/src/core/layertree/qgslayertreemodellegendnode.cpp b/src/core/layertree/qgslayertreemodellegendnode.cpp
@@ -18,6 +18,7 @@
 
 #include "qgslayertreemodellegendnode.h"
 
+#include "qgsdatadefinedsizelegend.h"
 #include "qgslayertree.h"
 #include "qgslayertreemodel.h"
 #include "qgslegendsettings.h"
@@ -215,22 +216,23 @@ void QgsSymbolLegendNode::uncheckAllItems()
   checkAll( false );
 }
 
-inline
-QgsRenderContext *QgsSymbolLegendNode::createTemporaryRenderContext() const
+QgsRenderContext *QgsLayerTreeModelLegendNode::createTemporaryRenderContext() const
 {
   double scale = 0.0;
   double mupp = 0.0;
   int dpi = 0;
   if ( model() )
     model()->legendMapViewData( &mupp, &dpi, &scale );
-  bool validData = !qgsDoubleNear( mupp, 0.0 ) && dpi != 0 && !qgsDoubleNear( scale, 0.0 );
+
+  if ( qgsDoubleNear( mupp, 0.0 ) || dpi == 0 || qgsDoubleNear( scale, 0.0 ) )
+    return nullptr;
 
   // setup temporary render context
-  std::unique_ptr<QgsRenderContext> context( new QgsRenderContext );
+  QgsRenderContext *context = new QgsRenderContext;
   context->setScaleFactor( dpi / 25.4 );
   context->setRendererScale( scale );
   context->setMapToPixel( QgsMapToPixel( mupp ) );
-  return validData ? context.release() : nullptr;
+  return context;
 }
 
 void QgsSymbolLegendNode::checkAll( bool state )
@@ -718,3 +720,71 @@ void QgsWmsLegendNode::invalidateMapBasedData()
   mValid = false;
   emit dataChanged();
 }
+
+// -------------------------------------------------------------------------
+
+QgsDataDefinedSizeLegendNode::QgsDataDefinedSizeLegendNode( QgsLayerTreeLayer *nodeLayer, const QgsDataDefinedSizeLegend &settings, QObject *parent )
+  : QgsLayerTreeModelLegendNode( nodeLayer, parent )
+  , mSettings( new QgsDataDefinedSizeLegend( settings ) )
+{
+}
+
+QVariant QgsDataDefinedSizeLegendNode::data( int role ) const
+{
+  if ( role == Qt::DecorationRole )
+  {
+    cacheImage();
+    return QPixmap::fromImage( mImage );
+  }
+  else if ( role == Qt::SizeHintRole )
+  {
+    cacheImage();
+    return mImage.size();
+  }
+  return QVariant();
+}
+
+QgsLayerTreeModelLegendNode::ItemMetrics QgsDataDefinedSizeLegendNode::draw( const QgsLegendSettings &settings, QgsLayerTreeModelLegendNode::ItemContext *ctx )
+{
+  // setup temporary render context
+  QgsRenderContext context;
+  context.setScaleFactor( settings.dpi() / 25.4 );
+  context.setRendererScale( settings.mapScale() );
+  context.setMapToPixel( QgsMapToPixel( 1 / ( settings.mmPerMapUnit() * context.scaleFactor() ) ) );
+  context.setForceVectorOutput( true );
+
+  if ( ctx )
+  {
+    context.setPainter( ctx->painter );
+    ctx->painter->save();
+    ctx->painter->setRenderHint( QPainter::Antialiasing );
+    ctx->painter->translate( ctx->point );
+    ctx->painter->scale( 1 / context.scaleFactor(), 1 / context.scaleFactor() );
+  }
+
+  QgsDataDefinedSizeLegend ddsLegend( *mSettings );
+  ddsLegend.setFont( settings.style( QgsLegendStyle::SymbolLabel ).font() );
+  ddsLegend.setTextColor( settings.fontColor() );
+
+  QSize contentSize;
+  int labelXOffset;
+  ddsLegend.drawCollapsedLegend( context, &contentSize, &labelXOffset );
+
+  if ( ctx )
+    ctx->painter->restore();
+
+  ItemMetrics im;
+  im.symbolSize = QSizeF( ( contentSize.width() - labelXOffset ) / context.scaleFactor(), contentSize.height() / context.scaleFactor() );
+  im.labelSize = QSizeF( labelXOffset / context.scaleFactor(), contentSize.height() / context.scaleFactor() );
+  return im;
+}
+
+
+void QgsDataDefinedSizeLegendNode::cacheImage() const
+{
+  if ( mImage.isNull() )
+  {
+    std::unique_ptr<QgsRenderContext> context( createTemporaryRenderContext() );
+    mImage = mSettings->collapsedLegendImage( *context.get() );
+  }
+}
diff --git a/src/core/layertree/qgslayertreemodellegendnode.h b/src/core/layertree/qgslayertreemodellegendnode.h
@@ -131,6 +131,9 @@ class CORE_EXPORT QgsLayerTreeModelLegendNode : public QObject
     //! Construct the node with pointer to its parent layer node
     explicit QgsLayerTreeModelLegendNode( QgsLayerTreeLayer *nodeL, QObject *parent SIP_TRANSFERTHIS = nullptr );
 
+    //! Returns a temporary context or null if legendMapViewData are not valid
+    QgsRenderContext *createTemporaryRenderContext() const SIP_FACTORY;
+
   protected:
     QgsLayerTreeLayer *mLayerNode = nullptr;
     bool mEmbeddedInParent;
@@ -237,9 +240,6 @@ class CORE_EXPORT QgsSymbolLegendNode : public QgsLayerTreeModelLegendNode
     // ident the symbol icon to make it look like a tree structure
     static const int INDENT_SIZE = 20;
 
-    // return a temporary context or null if legendMapViewData are not valid
-    QgsRenderContext *createTemporaryRenderContext() const;
-
     /** Sets all items belonging to the same layer as this node to the same check state.
      * \param state check state
      */
@@ -380,4 +380,27 @@ class CORE_EXPORT QgsWmsLegendNode : public QgsLayerTreeModelLegendNode
     mutable std::unique_ptr<QgsImageFetcher> mFetcher;
 };
 
+
+/**
+ * \ingroup core
+ * Produces legend node with a marker symbol
+ * \since QGIS 3.0
+ */
+class CORE_EXPORT QgsDataDefinedSizeLegendNode : public QgsLayerTreeModelLegendNode
+{
+  public:
+    //! Construct the node using QgsDataDefinedSizeLegend as definition of the node's appearance
+    QgsDataDefinedSizeLegendNode( QgsLayerTreeLayer *nodeLayer, const QgsDataDefinedSizeLegend &settings, QObject *parent SIP_TRANSFERTHIS = nullptr );
+
+    virtual QVariant data( int role ) const override;
+
+    ItemMetrics draw( const QgsLegendSettings &settings, ItemContext *ctx ) override;
+
+  private:
+    void cacheImage() const;
+
+    std::unique_ptr<QgsDataDefinedSizeLegend> mSettings;
+    mutable QImage mImage;
+};
+
 #endif // QGSLAYERTREEMODELLEGENDNODE_H