Fixes #16852 by adding click_x and click_y variables to resolve actions

src/app/qgsidentifyresultsdialog.cpp

@@ -1237,7 +1237,7 @@ void QgsIdentifyResultsDialog::doAction( QTreeWidgetItem *item, int action )
   }
 
   int featIdx = featItem->data( 0, Qt::UserRole + 1 ).toInt();
-  layer->actions()->doAction( action, mFeatures[ featIdx ], idx );
+  layer->actions()->doAction( action, mFeatures[ featIdx ], idx, mExpressionContextScope );
 }
 
 void QgsIdentifyResultsDialog::doMapLayerAction( QTreeWidgetItem *item, QgsMapLayerAction* action )
@@ -1951,6 +1951,16 @@ void QgsIdentifyResultsDialog::formatChanged( int index )
   }
 }
 
+void QgsIdentifyResultsDialog::setExpressionContextScope( const QgsExpressionContextScope &scope )
+{
+  mExpressionContextScope = scope;
+}
+
+QgsExpressionContextScope QgsIdentifyResultsDialog::expressionContextScope() const
+{
+  return mExpressionContextScope;
+}
+
 /*
  * QgsIdentifyResultsDialogMapLayerAction
  */

src/app/qgsidentifyresultsdialog.h

@@ -152,6 +152,22 @@ class APP_EXPORT QgsIdentifyResultsDialog: public QDialog, private Ui::QgsIdenti
     /** Map tool was activated */
     void activate();
 
+    /**
+     * Sets an expression context scope to consider for resolving underlying
+     * actions.
+     *
+     * @note Added in QGIS 2.18
+     */
+    void setExpressionContextScope( const QgsExpressionContextScope &scope );
+
+    /**
+     * Returns an expression context scope used for resolving underlying
+     * actions.
+     *
+     * @note Added in QGIS 2.18
+     */
+    QgsExpressionContextScope expressionContextScope() const;
+
   signals:
     void selectedFeatureChanged( QgsVectorLayer *, QgsFeatureId featureId );
 
@@ -263,6 +279,8 @@ class APP_EXPORT QgsIdentifyResultsDialog: public QDialog, private Ui::QgsIdenti
     QgsDockWidget *mDock;
 
     QVector<QgsIdentifyPlotCurve *> mPlotCurves;
+
+    QgsExpressionContextScope mExpressionContextScope;
 };
 
 class QgsIdentifyResultsDialogMapLayerAction : public QAction

src/app/qgsmaptoolidentifyaction.cpp

@@ -118,6 +118,8 @@ void QgsMapToolIdentifyAction::canvasReleaseEvent( QgsMapMouseEvent* e )
   connect( this, SIGNAL( identifyProgress( int, int ) ), QgisApp::instance(), SLOT( showProgress( int, int ) ) );
   connect( this, SIGNAL( identifyMessage( QString ) ), QgisApp::instance(), SLOT( showStatusMessage( QString ) ) );
 
+  setClickContextScope( toMapCoordinates( e->pos() ) );
+
   identifyMenu()->setResultsIfExternalAction( false );
 
   // enable the right click for extended menu so it behaves as a contextual menu
@@ -200,4 +202,16 @@ void QgsMapToolIdentifyAction::handleCopyToClipboard( QgsFeatureStore & featureS
   emit copyToClipboard( featureStore );
 }
 
+void QgsMapToolIdentifyAction::setClickContextScope( const QgsPoint &point )
+{
+  QgsExpressionContextScope clickScope;
+  clickScope.addVariable( QgsExpressionContextScope::StaticVariable( QString( "click_x" ), point.x(), true ) );
+  clickScope.addVariable( QgsExpressionContextScope::StaticVariable( QString( "click_y" ), point.y(), true ) );
+
+  resultsDialog()->setExpressionContextScope( clickScope );
 
+  if ( mIdentifyMenu )
+  {
+    mIdentifyMenu->setExpressionContextScope( clickScope );
+  }
+}

src/app/qgsmaptoolidentifyaction.h

@@ -82,7 +82,7 @@ class APP_EXPORT QgsMapToolIdentifyAction : public QgsMapToolIdentify
 
     virtual QGis::UnitType displayDistanceUnits() const override;
     virtual QgsUnitTypes::AreaUnit displayAreaUnits() const override;
-
+    void setClickContextScope( const QgsPoint &point );
 };
 
 #endif

src/core/qgsactionmanager.cpp

@@ -63,10 +63,10 @@ void QgsActionManager::removeAction( int index )
   }
 }
 
-void QgsActionManager::doAction( int index, const QgsFeature& feat, int defaultValueIndex )
+void QgsActionManager::doAction( int index, const QgsFeature& feat, int defaultValueIndex, const QgsExpressionContextScope &scope )
 {
   QgsExpressionContext context = createExpressionContext();
-  QgsExpressionContextScope* actionScope = new QgsExpressionContextScope();
+  QgsExpressionContextScope* actionScope = new QgsExpressionContextScope( scope );
   actionScope->addVariable( QgsExpressionContextScope::StaticVariable( QString( "current_field" ), feat.attribute( defaultValueIndex ), true ) );
   context << actionScope;
   doAction( index, feat, context );

src/core/qgsactionmanager.h

@@ -78,13 +78,20 @@ class CORE_EXPORT QgsActionManager
     //! Remove an action at given index
     void removeAction( int index );
 
-    /** Does the given values. defaultValueIndex is the index of the
-     *  field to be used if the action has a $currfield placeholder.
-     *  @note available in python bindings as doActionFeature
+    /**
+     * Does the given action.
+     *
+     * @param actionId action id
+     * @param feature feature to run action for
+     * @param defaultValueIndex index of the field to be used if the action has a $currfield placeholder.
+     * @param scope expression context scope to add during expression evaluation
+     *
+     * @note available in python bindings as doActionFeature
      */
     void doAction( int index,
                    const QgsFeature &feat,
-                   int defaultValueIndex = 0 );
+                   int defaultValueIndex = 0,
+                   const QgsExpressionContextScope &scope = QgsExpressionContextScope() );
 
     /** Does the action using the expression engine to replace any embedded expressions
      * in the action definition.

src/gui/qgsactionmenu.cpp

@@ -106,7 +106,7 @@ void QgsActionMenu::triggerAction()
   }
   else if ( data.actionType == AttributeAction )
   {
-    mActions->doAction( data.actionId.id, *feature() );
+    mActions->doAction( data.actionId.id, *feature(), 0, mExpressionContextScope );
   }
 }
 
@@ -159,3 +159,12 @@ void QgsActionMenu::reloadActions()
   emit reinit();
 }
 
+void QgsActionMenu::setExpressionContextScope( const QgsExpressionContextScope &scope )
+{
+  mExpressionContextScope = scope;
+}
+
+QgsExpressionContextScope QgsActionMenu::expressionContextScope() const
+{
+  return mExpressionContextScope;
+}

src/gui/qgsactionmenu.h

@@ -108,6 +108,20 @@ class GUI_EXPORT QgsActionMenu : public QMenu
      */
     void setFeature( QgsFeature* feature );
 
+    /**
+     * Sets an expression context scope used to resolve underlying actions.
+     *
+     * @note Added in QGIS 2.18
+     */
+    void setExpressionContextScope( const QgsExpressionContextScope &scope );
+
+    /**
+     * Returns an expression context scope used to resolve underlying actions.
+     *
+     * @note Added in QGIS 2.18
+     */
+    QgsExpressionContextScope expressionContextScope() const;
+
   private slots:
     void triggerAction();
     void reloadActions();
@@ -124,6 +138,7 @@ class GUI_EXPORT QgsActionMenu : public QMenu
     const QgsFeature* mFeature;
     QgsFeatureId mFeatureId;
     bool mOwnsFeature;
+    QgsExpressionContextScope mExpressionContextScope;
 };
 
 Q_DECLARE_METATYPE( QgsActionMenu::ActionData )

src/gui/qgsidentifymenu.cpp

@@ -349,6 +349,7 @@ void QgsIdentifyMenu::addVectorLayer( QgsVectorLayer* layer, const QList<QgsMapT
     if ( mShowFeatureActions )
     {
       featureActionMenu = new QgsActionMenu( layer, result.mFeature.id(), layerMenu );
+      featureActionMenu->setExpressionContextScope( mExpressionContextScope );
     }
 
     // feature title
@@ -643,3 +644,13 @@ void QgsIdentifyMenu::removeCustomActions()
   mCustomActionRegistry.clear();
 
 }
+
+void QgsIdentifyMenu::setExpressionContextScope( const QgsExpressionContextScope &scope )
+{
+  mExpressionContextScope = scope;
+}
+
+QgsExpressionContextScope QgsIdentifyMenu::expressionContextScope() const
+{
+  return mExpressionContextScope;
+}

src/gui/qgsidentifymenu.h

@@ -148,6 +148,20 @@ class GUI_EXPORT QgsIdentifyMenu : public QMenu
      */
     QList<QgsMapToolIdentify::IdentifyResult> exec( const QList<QgsMapToolIdentify::IdentifyResult>& idResults, QPoint pos );
 
+    /**
+     * Sets an expression context scope used to resolve underlying actions.
+     *
+     * @note Added in QGIS 2.18
+     */
+    void setExpressionContextScope( const QgsExpressionContextScope &scope );
+
+    /**
+     * Returns an expression context scope used to resolve underlying actions.
+     *
+     * @note Added in QGIS 2.18
+     */
+    QgsExpressionContextScope expressionContextScope() const;
+
   protected:
     virtual void closeEvent( QCloseEvent *e ) override;
 
@@ -178,6 +192,8 @@ class GUI_EXPORT QgsIdentifyMenu : public QMenu
     int mMaxLayerDisplay;
     int mMaxFeatureDisplay;
 
+    QgsExpressionContextScope mExpressionContextScope;
+
     // name of the action to be displayed for feature default action, if other actions are shown
     QString mDefaultActionName;