[FEATURE] Legend for markers with data-defined size

(Merge pull request #4752 from wonder-sk/legend-data-defined-size)

Author: wonder-sk

doc/api_break.dox

@@ -987,7 +987,7 @@ QgsDiagramRenderer        {#qgis_api_break_3_0_QgsDiagramRenderer}
 - renderDiagram() now takes an optional data defined overrides collection argument.
 - readXml(), _readXml(), writeXml(), _writeXml() do not take QgsVectorLayer as an argument anymore.
 - readXml(), _readXml(), writeXml(), _writeXml() require a new argument: a reference to QgsReadWriteContext
-
+- sizeLegend(), setSizeLegend(), sizeLegendSymbol() and setSizeLegendSymbol() have been replaced by dataDefinedSizeLegend() and setDataDefinedSizeLegend() methods in QgsLinearlyInterpolatedDiagramRenderer.
 
 
 QgsDiagramLayerSettings        {#qgis_api_break_3_0_QgsDiagramLayerSettings}
@@ -2110,6 +2110,7 @@ QgsSingleSymbolRendererWidget        {#qgis_api_break_3_0_QgsSingleSymbolRendere
 
 - sizeScaleFieldChanged() and scaleMethodChanged() were removed. These settings are no longer exposed in the widget's GUI.
 - The Mode enum was removed.
+- changeSingleSymbol() and showSymbolLevels() slots were made private.
 
 QgsSlider        {#qgis_api_break_3_0_QgsSlider}
 ---------

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

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                      *
  *                                                                      *

python/core/qgsdatadefinedsizelegend.sip

@@ -0,0 +1,177 @@
+/************************************************************************
+ * This file has been generated automatically from                      *
+ *                                                                      *
+ * src/core/qgsdatadefinedsizelegend.h                                  *
+ *                                                                      *
+ * Do not edit manually ! Edit header and run scripts/sipify.pl again   *
+ ************************************************************************/
+
+
+
+
+
+
+class QgsDataDefinedSizeLegend
+{
+%Docstring
+ Object that keeps configuration of appearance of marker symbol's data-defined size in legend.
+ For example: the list of classes (size values), whether the classes should appear in separate
+ legend nodes or whether to collapse them into one legend node.
+
+.. versionadded:: 3.0
+%End
+
+%TypeHeaderCode
+#include "qgsdatadefinedsizelegend.h"
+%End
+  public:
+    QgsDataDefinedSizeLegend();
+
+    QgsDataDefinedSizeLegend( const QgsDataDefinedSizeLegend &other );
+%Docstring
+Copy constructor
+%End
+
+    enum LegendType
+    {
+      LegendSeparated,
+      LegendCollapsed,
+    };
+
+    enum VerticalAlignment
+    {
+      AlignCenter,
+      AlignBottom,
+    };
+
+    struct SizeClass
+    {
+      SizeClass( double size, const QString &label );
+
+      double size;    //!< Marker size in units used by the symbol (usually millimeters)
+      QString label;  //!< Label to be shown with the particular symbol size
+    };
+
+    void setLegendType( LegendType type );
+%Docstring
+Sets how the legend should be rendered
+%End
+    LegendType legendType() const;
+%Docstring
+Returns how the legend should be rendered
+ :rtype: LegendType
+%End
+
+    void setSymbol( QgsMarkerSymbol *symbol /Transfer/ );
+%Docstring
+Sets marker symbol that will be used to draw markers in legend
+%End
+    QgsMarkerSymbol *symbol() const;
+%Docstring
+Returns marker symbol that will be used to draw markers in legend
+ :rtype: QgsMarkerSymbol
+%End
+
+    void setClasses( const QList<QgsDataDefinedSizeLegend::SizeClass> &classes );
+%Docstring
+Sets list of classes: each class is a pair of symbol size (in units used by the symbol) and label
+%End
+    QList<QgsDataDefinedSizeLegend::SizeClass> classes() const;
+%Docstring
+Returns list of classes: each class is a pair of symbol size (in units used by the symbol) and label
+ :rtype: list of QgsDataDefinedSizeLegend.SizeClass
+%End
+
+    void setTitle( const QString &title );
+%Docstring
+Sets title label for data-defined size legend
+%End
+    QString title() const;
+%Docstring
+Returns title label for data-defined size legend
+ :rtype: str
+%End
+
+    void setVerticalAlignment( VerticalAlignment vAlign );
+%Docstring
+Sets vertical alignment of symbols - only valid for collapsed legend
+%End
+    VerticalAlignment verticalAlignment() const;
+%Docstring
+Returns vertical alignment of symbols - only valid for collapsed legend
+ :rtype: VerticalAlignment
+%End
+
+    void setFont( const QFont &font );
+%Docstring
+Sets font used for rendering of labels - only valid for collapsed legend
+%End
+    QFont font() const;
+%Docstring
+Returns font used for rendering of labels - only valid for collapsed legend
+ :rtype: QFont
+%End
+
+    void setTextColor( const QColor &color );
+%Docstring
+Sets text color for rendering of labels - only valid for collapsed legend
+%End
+    QColor textColor() const;
+%Docstring
+Returns text color for rendering of labels - only valid for collapsed legend
+ :rtype: QColor
+%End
+
+    void setTextAlignment( Qt::AlignmentFlag flag );
+%Docstring
+Sets horizontal text alignment for rendering of labels - only valid for collapsed legend
+%End
+    Qt::AlignmentFlag textAlignment() const;
+%Docstring
+Returns horizontal text alignment for rendering of labels - only valid for collapsed legend
+ :rtype: Qt.AlignmentFlag
+%End
+
+
+    void updateFromSymbolAndProperty( const QgsMarkerSymbol *symbol, const QgsProperty &ddSize );
+%Docstring
+Updates the list of classes, source symbol and title label from given symbol and property
+%End
+
+    QgsLegendSymbolList legendSymbolList() const;
+%Docstring
+Generates legend symbol items according to the configuration
+ :rtype: QgsLegendSymbolList
+%End
+
+    void drawCollapsedLegend( QgsRenderContext &context, QSize *outputSize /Out/ = 0, int *labelXOffset /Out/ = 0 ) const;
+%Docstring
+Does nothing if legend is not configured as collapsed.
+%End
+
+    QImage collapsedLegendImage( QgsRenderContext &context, const QColor &backgroundColor = Qt::transparent, double paddingMM = 1 ) const;
+%Docstring
+Returns output image that would be shown in the legend. Returns invalid image if legend is not configured as collapsed.
+ :rtype: QImage
+%End
+
+    static QgsDataDefinedSizeLegend *readXml( const QDomElement &elem, const QgsReadWriteContext &context ) /Factory/;
+%Docstring
+Creates instance from given element and returns it (caller takes ownership). Returns null on error.
+ :rtype: QgsDataDefinedSizeLegend
+%End
+
+    void writeXml( QDomElement &elem, const QgsReadWriteContext &context ) const;
+%Docstring
+Writes configuration to the given XML element.
+%End
+
+};
+
+/************************************************************************
+ * This file has been generated automatically from                      *
+ *                                                                      *
+ * src/core/qgsdatadefinedsizelegend.h                                  *
+ *                                                                      *
+ * Do not edit manually ! Edit header and run scripts/sipify.pl again   *
+ ************************************************************************/

python/core/qgsdiagramrenderer.sip

@@ -450,6 +450,15 @@ class QgsDiagramRenderer
 
 %TypeHeaderCode
 #include "qgsdiagramrenderer.h"
+%End
+
+%ConvertToSubClassCode
+    if ( sipCpp->rendererName() == QStringLiteral( "SingleCategory" ) )
+      sipType = sipType_QgsSingleCategoryDiagramRenderer;
+    else if ( sipCpp->rendererName() == QStringLiteral( "LinearlyInterpolated" ) )
+      sipType = sipType_QgsLinearlyInterpolatedDiagramRenderer;
+    else
+      sipType = NULL;
 %End
   public:
 
@@ -545,44 +554,6 @@ Returns list with all diagram settings in the renderer
 .. versionadded:: 2.16
 .. seealso:: attributeLegend()
 .. seealso:: setSizeLegend()
-%End
-
-    bool sizeLegend() const;
-%Docstring
- Returns true if renderer will show legend items for diagram sizes.
-.. versionadded:: 2.16
-.. seealso:: setSizeLegend()
-.. seealso:: attributeLegend()
-.. seealso:: sizeLegendSymbol()
- :rtype: bool
-%End
-
-    void setSizeLegend( bool enabled );
-%Docstring
- Sets whether the renderer will show legend items for diagram sizes.
- \param enabled set to true to show diagram size legend
-.. versionadded:: 2.16
-.. seealso:: sizeLegend()
-.. seealso:: setAttributeLegend()
-.. seealso:: setSizeLegendSymbol()
-%End
-
-    QgsMarkerSymbol *sizeLegendSymbol() const;
-%Docstring
- Returns the marker symbol used for rendering the diagram size legend.
-.. versionadded:: 2.16
-.. seealso:: setSizeLegendSymbol()
-.. seealso:: sizeLegend()
- :rtype: QgsMarkerSymbol
-%End
-
-    void setSizeLegendSymbol( QgsMarkerSymbol *symbol /Transfer/ );
-%Docstring
- Sets the marker symbol used for rendering the diagram size legend.
- \param symbol marker symbol, ownership is transferred to the renderer.
-.. versionadded:: 2.16
-.. seealso:: sizeLegendSymbol()
-.. seealso:: setSizeLegend()
 %End
 
   protected:
@@ -628,8 +599,6 @@ Returns the paint device dpi (or -1 in case of error
 %End
 
 
-
-
 };
 
 class QgsSingleCategoryDiagramRenderer : QgsDiagramRenderer
@@ -760,13 +729,31 @@ 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 );
+%Docstring
+Copy constructor
+%End
+
 };
 
 /************************************************************************

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