Symbol aware legend expression (#9648)

qgis · Jul 15, 2019 · 248af94 · 248af94
1 parent eb73702
commit 248af94
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Showing 24 changed files with 571 additions and 57 deletions.
diff --git a/images/images.qrc b/images/images.qrc
@@ -177,6 +177,7 @@
         <file>themes/default/mActionDistributeTop.svg</file>
         <file>themes/default/mActionDistributeVCenter.svg</file>
         <file>themes/default/mActionDistributeVSpace.svg</file>
+        <file>themes/default/mActionAddExpression.svg</file>
         <file>themes/default/mActionAddLayer.svg</file>
         <file>themes/default/mActionAddMeshLayer.svg</file>
         <file>themes/default/mActionAddAllToOverview.svg</file>

diff --git a/images/themes/default/mActionAddExpression.svg b/images/themes/default/mActionAddExpression.svg
diff --git a/python/core/auto_generated/layertree/qgslayertreelayer.sip.in b/python/core/auto_generated/layertree/qgslayertreelayer.sip.in
@@ -122,6 +122,20 @@ Also resolves textual references to layers from the project (calls resolveRefere
 Resolves reference to layer from stored layer ID (if it has not been resolved already)
 
 .. versionadded:: 3.0
+%End
+
+    void setLabelExpression( const QString &expression );
+%Docstring
+set the expression to evaluate
+
+.. versionadded:: 3.10
+%End
+
+    QString labelExpression() const;
+%Docstring
+Returns the expression member of the LayerTreeNode
+
+.. versionadded:: 3.10
 %End
 
   signals:

diff --git a/python/core/auto_generated/layertree/qgslayertreemodellegendnode.sip.in b/python/core/auto_generated/layertree/qgslayertreemodellegendnode.sip.in
@@ -12,6 +12,7 @@
 
 
 
+
 class QgsLayerTreeModelLegendNode : QObject
 {
 %Docstring
@@ -26,6 +27,12 @@ and customized look.
 
 %TypeHeaderCode
 #include "qgslayertreemodellegendnode.h"
+%End
+%ConvertToSubClassCode
+    if ( qobject_cast<QgsSymbolLegendNode *> ( sipCpp ) )
+      sipType = sipType_QgsSymbolLegendNode;
+    else
+      sipType = 0;
 %End
   public:
 
@@ -309,6 +316,23 @@ Returns text format of the label to be shown on top of the symbol.
 Sets format of text to be shown on top of the symbol.
 
 .. versionadded:: 3.2
+%End
+
+    QString symbolLabel() const;
+%Docstring
+Label of the symbol, user defined label will be used, otherwise will default to the label made by QGIS.
+
+.. versionadded:: 3.10
+%End
+
+    QString evaluateLabel( const QgsExpressionContext &context = QgsExpressionContext(), const QString &label = QString() );
+%Docstring
+Evaluates  and returns the text label of the current node
+
+:param context: extra QgsExpressionContext to use for evaluating the expression
+:param label: text to evaluate instead of the layer layertree string
+
+.. versionadded:: 3.10
 %End
 
   public slots:

diff --git a/python/core/auto_generated/layout/qgslayoutitemlegend.sip.in b/python/core/auto_generated/layout/qgslayoutitemlegend.sip.in
@@ -24,16 +24,31 @@ Overrides some functionality of QgsLayerTreeModel to better fit the needs of lay
 #include "qgslayoutitemlegend.h"
 %End
   public:
-    QgsLegendModel( QgsLayerTree *rootNode, QObject *parent /TransferThis/ = 0 );
+    QgsLegendModel( QgsLayerTree *rootNode, QObject *parent /TransferThis/ = 0, QgsLayoutItemLegend *layout = 0 );
 %Docstring
 Construct the model based on the given layer tree
+%End
+
+    QgsLegendModel( QgsLayerTree *rootNode,  QgsLayoutItemLegend *layout );
+%Docstring
+Alternative constructor.
 %End
 
     virtual QVariant data( const QModelIndex &index, int role ) const;
 
 
     virtual Qt::ItemFlags flags( const QModelIndex &index ) const;
 
+
+  signals:
+
+    void refreshLegend();
+%Docstring
+Emitted to refresh the legend.
+
+.. versionadded:: 3.10
+%End
+
 };
 
 
@@ -513,7 +528,6 @@ Returns the legend's renderer settings object.
     virtual QgsExpressionContext createExpressionContext() const;
 
 
-
   public slots:
 
     virtual void refresh();

diff --git a/python/core/auto_generated/qgsvectorlayer.sip.in b/python/core/auto_generated/qgsvectorlayer.sip.in
@@ -2279,7 +2279,6 @@ Configuration and logic to apply automatically on any edit happening on this lay
 
 
 
-
   public slots:
 
     void select( QgsFeatureId featureId );
@@ -2653,6 +2652,7 @@ Emitted when the feature count for symbols on this layer has been recalculated.
 .. versionadded:: 3.0
 %End
 
+
   protected:
     virtual void setExtent( const QgsRectangle &rect ) ${SIP_FINAL};
 

diff --git a/python/core/auto_generated/qgsvectorlayerfeaturecounter.sip.in b/python/core/auto_generated/qgsvectorlayerfeaturecounter.sip.in
@@ -29,16 +29,29 @@ QgsVectorLayer.countSymbolFeatures() and connect to the signal
 Create a new feature counter for ``layer``.
 %End
 
+
     virtual bool run();
 
+%Docstring
+Calculates the feature count and Ids per symbol
+%End
 
 
     long featureCount( const QString &legendKey ) const;
 %Docstring
-Gets the feature count for a particular ``legendKey``.
+Returns the feature count for a particular ``legendKey``.
 If the key has not been found, -1 will be returned.
 %End
 
+
+    QgsFeatureIds featureIds( const QString &symbolkey ) const;
+%Docstring
+Returns the feature Ids for a particular ``legendKey``.
+If the key has not been found an empty QSet will be returned.
+
+.. versionadded:: 3.10
+%End
+
   signals:
 
     void symbolsCounted();

diff --git a/src/app/layout/qgslayoutlegendwidget.cpp b/src/app/layout/qgslayoutlegendwidget.cpp
@@ -38,6 +38,7 @@
 #include "qgslayoutitemlegend.h"
 #include "qgslayoutmeasurementconverter.h"
 #include "qgsunittypes.h"
+#include "qgsexpressionbuilderdialog.h"
 
 #include <QMessageBox>
 #include <QInputDialog>
@@ -104,6 +105,7 @@ QgsLayoutLegendWidget::QgsLayoutLegendWidget( QgsLayoutItemLegend *legend )
   connect( mEditPushButton, &QToolButton::clicked, this, &QgsLayoutLegendWidget::mEditPushButton_clicked );
   connect( mCountToolButton, &QToolButton::clicked, this, &QgsLayoutLegendWidget::mCountToolButton_clicked );
   connect( mExpressionFilterButton, &QgsLegendFilterButton::toggled, this, &QgsLayoutLegendWidget::mExpressionFilterButton_toggled );
+  connect( mLayerExpressionButton, &QToolButton::clicked, this, &QgsLayoutLegendWidget::mLayerExpressionButton_clicked );
   connect( mFilterByMapToolButton, &QToolButton::toggled, this, &QgsLayoutLegendWidget::mFilterByMapToolButton_toggled );
   connect( mUpdateAllPushButton, &QToolButton::clicked, this, &QgsLayoutLegendWidget::mUpdateAllPushButton_clicked );
   connect( mAddGroupToolButton, &QToolButton::clicked, this, &QgsLayoutLegendWidget::mAddGroupToolButton_clicked );
@@ -136,6 +138,7 @@ QgsLayoutLegendWidget::QgsLayoutLegendWidget( QgsLayoutItemLegend *legend )
   mMoveUpToolButton->setIcon( QIcon( QgsApplication::iconPath( "mActionArrowUp.svg" ) ) );
   mMoveDownToolButton->setIcon( QIcon( QgsApplication::iconPath( "mActionArrowDown.svg" ) ) );
   mCountToolButton->setIcon( QIcon( QgsApplication::iconPath( "mActionSum.svg" ) ) );
+  mLayerExpressionButton->setIcon( QIcon( QgsApplication::iconPath( "mActionAddExpression.svg" ) ) );
 
   mFontColorButton->setColorDialogTitle( tr( "Select Font Color" ) );
   mFontColorButton->setContext( QStringLiteral( "composer" ) );
@@ -994,6 +997,45 @@ void QgsLayoutLegendWidget::mExpressionFilterButton_toggled( bool checked )
   mLegend->endCommand();
 }
 
+void QgsLayoutLegendWidget::mLayerExpressionButton_clicked()
+{
+
+  if ( !mLegend )
+  {
+    return;
+  }
+
+  QModelIndex currentIndex = mItemTreeView->currentIndex();
+  if ( !currentIndex.isValid() )
+    return;
+
+  QgsLayerTreeNode *currentNode = mItemTreeView->currentNode();
+  if ( !QgsLayerTree::isLayer( currentNode ) )
+    return;
+
+  QgsLayerTreeLayer *layerNode = qobject_cast<QgsLayerTreeLayer *>( currentNode );
+  QgsVectorLayer *vl = qobject_cast<QgsVectorLayer *>( layerNode->layer() );
+
+  if ( !vl )
+    return;
+
+  QString currentExpression;
+  if ( layerNode->labelExpression().isEmpty() )
+    currentExpression = QStringLiteral( "@symbol_label" );
+  else
+    currentExpression = layerNode->labelExpression();
+  QgsExpressionContext legendContext = mLegend->createExpressionContext();
+  legendContext.appendScope( vl->createExpressionContextScope() );
+  QgsExpressionBuilderDialog expressiondialog( vl, currentExpression, nullptr, "generic", legendContext );
+  if ( expressiondialog.exec() )
+    layerNode->setLabelExpression( expressiondialog.expressionText() );
+
+  mLegend->beginCommand( tr( "Update Legend" ) );
+  mLegend->updateLegend();
+  mLegend->adjustBoxSize();
+  mLegend->endCommand();
+}
+
 void QgsLayoutLegendWidget::mUpdateAllPushButton_clicked()
 {
   updateLegend();
@@ -1105,12 +1147,27 @@ void QgsLayoutLegendWidget::selectedChanged( const QModelIndex &current, const Q
   Q_UNUSED( current )
   Q_UNUSED( previous )
 
+  mLayerExpressionButton->setEnabled( false );
+
   if ( mLegend && mLegend->autoUpdateModel() )
+  {
+    QgsLayerTreeNode *currentNode = mItemTreeView->currentNode();
+    if ( !QgsLayerTree::isLayer( currentNode ) )
+      return;
+
+    QgsLayerTreeLayer *currentLayerNode = QgsLayerTree::toLayer( currentNode );
+    QgsVectorLayer *vl = qobject_cast<QgsVectorLayer *>( currentLayerNode->layer() );
+    if ( !vl )
+      return;
+
+    mLayerExpressionButton->setEnabled( true );
     return;
+  }
 
   mCountToolButton->setChecked( false );
   mCountToolButton->setEnabled( false );
 
+
   mExpressionFilterButton->blockSignals( true );
   mExpressionFilterButton->setChecked( false );
   mExpressionFilterButton->setEnabled( false );
@@ -1127,6 +1184,7 @@ void QgsLayoutLegendWidget::selectedChanged( const QModelIndex &current, const Q
 
   mCountToolButton->setChecked( currentNode->customProperty( QStringLiteral( "showFeatureCount" ), 0 ).toInt() );
   mCountToolButton->setEnabled( true );
+  mLayerExpressionButton->setEnabled( true );
 
   bool exprEnabled;
   QString expr = QgsLayerTreeUtils::legendFilterByExpression( *qobject_cast<QgsLayerTreeLayer *>( currentNode ), &exprEnabled );

diff --git a/src/app/layout/qgslayoutlegendwidget.h b/src/app/layout/qgslayoutlegendwidget.h
@@ -85,6 +85,7 @@ class QgsLayoutLegendWidget: public QgsLayoutItemBaseWidget, private Ui::QgsLayo
     void resetLayerNodeToDefaults();
     void mUpdateAllPushButton_clicked();
     void mAddGroupToolButton_clicked();
+    void mLayerExpressionButton_clicked();
 
     void mFilterLegendByAtlasCheckBox_toggled( bool checked );
 

diff --git a/src/core/expression/qgsexpression.cpp b/src/core/expression/qgsexpression.cpp
@@ -830,6 +830,10 @@ void QgsExpression::initVariableHelp()
   sVariableHelpTexts.insert( QStringLiteral( "symbol_color" ), QCoreApplication::translate( "symbol_color", "Color of symbol used to render the feature." ) );
   sVariableHelpTexts.insert( QStringLiteral( "symbol_angle" ), QCoreApplication::translate( "symbol_angle", "Angle of symbol used to render the feature (valid for marker symbols only)." ) );
 
+  sVariableHelpTexts.insert( QStringLiteral( "symbol_label" ), QCoreApplication::translate( "symbol_label", "Label of the symbol, user defined label will be used, otherwise will default to the label made by QGIS." ) );
+  sVariableHelpTexts.insert( QStringLiteral( "symbol_id" ), QCoreApplication::translate( "symbol_id", "Id of the symbol." ) );
+  sVariableHelpTexts.insert( QStringLiteral( "symbol_count" ), QCoreApplication::translate( "symbol_count", "Total number of features defined by this symbol." ) );
+
   //cluster variables
   sVariableHelpTexts.insert( QStringLiteral( "cluster_color" ), QCoreApplication::translate( "cluster_color", "Color of symbols within a cluster, or NULL if symbols have mixed colors." ) );
   sVariableHelpTexts.insert( QStringLiteral( "cluster_size" ), QCoreApplication::translate( "cluster_size", "Number of symbols contained within a cluster." ) );

diff --git a/src/core/layertree/qgslayertreelayer.cpp b/src/core/layertree/qgslayertreelayer.cpp
@@ -188,3 +188,9 @@ void QgsLayerTreeLayer::layerNameChanged()
   Q_ASSERT( mRef );
   emit nameChanged( this, mRef->name() );
 }
+
+void QgsLayerTreeLayer::setLabelExpression( const QString &expression )
+{
+  mLabelExpression = expression;
+}
+
diff --git a/src/core/layertree/qgslayertreelayer.h b/src/core/layertree/qgslayertreelayer.h
@@ -128,6 +128,20 @@ class CORE_EXPORT QgsLayerTreeLayer : public QgsLayerTreeNode
      */
     void resolveReferences( const QgsProject *project, bool looseMatching = false ) override;
 
+    /**
+     * set the expression to evaluate
+     *
+     * \since QGIS 3.10
+     */
+    void setLabelExpression( const QString &expression );
+
+    /**
+     * Returns the expression member of the LayerTreeNode
+     *
+     * \since QGIS 3.10
+     */
+    QString labelExpression() const { return mLabelExpression; }
+
   signals:
 
     /**
@@ -148,6 +162,8 @@ class CORE_EXPORT QgsLayerTreeLayer : public QgsLayerTreeNode
     QgsMapLayerRef mRef;
     //! Layer name - only used if layer does not exist or if mUseLayerName is false
     QString mLayerName;
+    //! Expression to evaluate in the legend
+    QString mLabelExpression;
 
     //!
     bool mUseLayerName = true;