Port cursor marker from Aux Window plugin to multi canvas

Shows a marker in map views indicating the position of the cursor
in the main canvas. Can be toggled on/off as desired.

src/app/qgisapp.cpp

@@ -3113,7 +3113,7 @@ QgsMapCanvas *QgisApp::mapCanvas()
   return mMapCanvas;
 }
 
-QgsMapCanvas *QgisApp::createNewMapCanvas( const QString &name, bool isFloating, const QRect &dockGeometry, bool synced )
+QgsMapCanvas *QgisApp::createNewMapCanvas( const QString &name, bool isFloating, const QRect &dockGeometry, bool synced, bool showCursor )
 {
   Q_FOREACH ( QgsMapCanvas *canvas, mapCanvases() )
   {
@@ -3169,6 +3169,7 @@ QgsMapCanvas *QgisApp::createNewMapCanvas( const QString &name, bool isFloating,
   connect( mapCanvasWidget, &QgsMapCanvasDockWidget::renameTriggered, this, &QgisApp::renameView );
 
   mapCanvasWidget->setViewExtentSynchronized( synced );
+  mapCanvasWidget->setCursorMarkerVisible( showCursor );
 
   return mapCanvas;
 }
@@ -11753,6 +11754,7 @@ void QgisApp::writeProject( QDomDocument &doc )
     node.setAttribute( QStringLiteral( "height" ), w->height() );
     node.setAttribute( QStringLiteral( "floating" ), w->isFloating() );
     node.setAttribute( QStringLiteral( "synced" ), w->isViewExtentSynchronized() );
+    node.setAttribute( QStringLiteral( "showCursor" ), w->isCursorMarkerVisible() );
     mapViewNode.appendChild( node );
   }
   qgisNode.appendChild( mapViewNode );
@@ -11788,8 +11790,9 @@ void QgisApp::readProject( const QDomDocument &doc )
       int h = elementNode.attribute( QStringLiteral( "height" ), QStringLiteral( "400" ) ).toInt();
       bool floating = elementNode.attribute( QStringLiteral( "floating" ), QStringLiteral( "0" ) ).toInt();
       bool synced = elementNode.attribute( QStringLiteral( "synced" ), QStringLiteral( "0" ) ).toInt();
+      bool showCursor = elementNode.attribute( QStringLiteral( "showCursor" ), QStringLiteral( "0" ) ).toInt();
 
-      QgsMapCanvas *mapCanvas = createNewMapCanvas( mapName, floating, QRect( x, y, w, h ), synced );
+      QgsMapCanvas *mapCanvas = createNewMapCanvas( mapName, floating, QRect( x, y, w, h ), synced, showCursor );
       mapCanvas->readProject( doc );
     }
   }

src/app/qgisapp.h

@@ -242,7 +242,7 @@ class APP_EXPORT QgisApp : public QMainWindow, private Ui::MainWindow
      * and widget geometry rect for the dock.
      */
     QgsMapCanvas *createNewMapCanvas( const QString &name, bool isFloating = false, const QRect &dockGeometry = QRect(),
-                                      bool synced = false );
+                                      bool synced = false, bool showCursor = true );
 
     /**
      * Closes any additional map canvases. The main map canvas will not

src/app/qgsmapcanvasdockwidget.cpp

@@ -26,6 +26,7 @@
 #include "qgslayertreeview.h"
 #include "qgslayertreeviewdefaultactions.h"
 #include "qgisapp.h"
+#include "qgsvertexmarker.h"
 #include <QMessageBox>
 #include <QMenu>
 #include <QToolBar>
@@ -43,7 +44,10 @@ QgsMapCanvasDockWidget::QgsMapCanvasDockWidget( const QString &name, QWidget *pa
 
   setWindowTitle( name );
   mMapCanvas = new QgsMapCanvas( this );
-
+  mXyMarker = new QgsVertexMarker( mMapCanvas );
+  mXyMarker->setIconType( QgsVertexMarker::ICON_CIRCLE );
+  mXyMarker->setIconSize( 6 );
+  mXyMarker->setColor( QColor( 30, 30, 30, 225 ) );
   mPanTool = new QgsMapToolPan( mMapCanvas );
   mMapCanvas->setMapTool( mPanTool );
 
@@ -92,13 +96,16 @@ QgsMapCanvasDockWidget::QgsMapCanvasDockWidget( const QString &name, QWidget *pa
   settingsMenu->addSeparator();
   settingsMenu->addAction( mActionSetCrs );
   settingsMenu->addAction( mActionShowAnnotations );
+  settingsMenu->addAction( mActionShowCursor );
   settingsMenu->addAction( mActionRename );
 
   connect( settingsMenu, &QMenu::aboutToShow, this, &QgsMapCanvasDockWidget::settingsMenuAboutToShow );
 
   connect( mActionRename, &QAction::triggered, this, &QgsMapCanvasDockWidget::renameTriggered );
   mActionShowAnnotations->setChecked( mMapCanvas->annotationsVisible() );
   connect( mActionShowAnnotations, &QAction::toggled, this, [ = ]( bool checked ) { mMapCanvas->setAnnotationsVisible( checked ); } );
+  mActionShowCursor->setChecked( true );
+  connect( mActionShowCursor, &QAction::toggled, this, [ = ]( bool checked ) { mXyMarker->setVisible( checked ); } );
 
   mScaleCombo = settingsAction->scaleCombo();
   mRotationEdit = settingsAction->rotationSpinBox();
@@ -172,6 +179,17 @@ QgsMapCanvasDockWidget::QgsMapCanvasDockWidget( const QString &name, QWidget *pa
   } );
 }
 
+void QgsMapCanvasDockWidget::setMainCanvas( QgsMapCanvas *canvas )
+{
+  if ( mMainCanvas )
+  {
+    disconnect( mMainCanvas, &QgsMapCanvas::xyCoordinates, this, &QgsMapCanvasDockWidget::syncMarker );
+  }
+
+  mMainCanvas = canvas;
+  connect( mMainCanvas, &QgsMapCanvas::xyCoordinates, this, &QgsMapCanvasDockWidget::syncMarker );
+}
+
 QgsMapCanvas *QgsMapCanvasDockWidget::mapCanvas()
 {
   return mMapCanvas;
@@ -187,6 +205,16 @@ bool QgsMapCanvasDockWidget::isViewExtentSynchronized() const
   return mActionSyncView->isChecked();
 }
 
+void QgsMapCanvasDockWidget::setCursorMarkerVisible( bool visible )
+{
+  mActionShowCursor->setChecked( visible );
+}
+
+bool QgsMapCanvasDockWidget::isCursorMarkerVisible() const
+{
+  return mXyMarker->isVisible();
+}
+
 void QgsMapCanvasDockWidget::resizeEvent( QResizeEvent * )
 {
   mBlockExtentSync = true;
@@ -304,6 +332,24 @@ void QgsMapCanvasDockWidget::settingsMenuAboutToShow()
   whileBlocking( mActionShowAnnotations )->setChecked( mMapCanvas->annotationsVisible() );
 }
 
+void QgsMapCanvasDockWidget::syncMarker( const QgsPoint &p )
+{
+  if ( !mXyMarker->isVisible() )
+    return;
+
+  // reproject point
+  QgsCoordinateTransform ct( mMainCanvas->mapSettings().destinationCrs(),
+                             mMapCanvas->mapSettings().destinationCrs() );
+  QgsPoint t = p;
+  try
+  {
+    t = ct.transform( p );
+  }
+  catch ( QgsCsException & )
+  {}
+
+  mXyMarker->setCenter( t );
+}
 
 QgsMapSettingsAction::QgsMapSettingsAction( QWidget *parent )
   : QWidgetAction( parent )

src/app/qgsmapcanvasdockwidget.h

@@ -18,6 +18,7 @@
 #include <ui_qgsmapcanvasdockwidgetbase.h>
 
 #include "qgsdockwidget.h"
+#include "qgspoint.h"
 #include "qgis_app.h"
 #include <QWidgetAction>
 #include <QTimer>
@@ -28,6 +29,7 @@ class QgsScaleComboBox;
 class QgsDoubleSpinBox;
 class QgsStatusBarMagnifierWidget;
 class QgsMapToolPan;
+class QgsVertexMarker;
 
 /**
  * \class QgsMapCanvasDockWidget
@@ -43,7 +45,7 @@ class APP_EXPORT QgsMapCanvasDockWidget : public QgsDockWidget, private Ui::QgsM
     /**
      * Sets the main app map canvas.
      */
-    void setMainCanvas( QgsMapCanvas *canvas ) { mMainCanvas = canvas; }
+    void setMainCanvas( QgsMapCanvas *canvas );
 
     /**
      * Returns the map canvas contained in the dock widget.
@@ -52,11 +54,28 @@ class APP_EXPORT QgsMapCanvasDockWidget : public QgsDockWidget, private Ui::QgsM
 
     /**
      * Sets whether the view extent should be synchronized with the main canvas extent.
+     * @see isViewExtentSynchronized()
      */
     void setViewExtentSynchronized( bool enabled );
 
+    /**
+     * Returns true if the view extent is synchronized with the main canvas extent.
+     * @see setViewExtentSynchronized()
+     */
     bool isViewExtentSynchronized() const;
 
+    /**
+     * Sets whether the cursor position marker is visible.
+     * @see isCursorMarkerVisible()
+     */
+    void setCursorMarkerVisible( bool visible );
+
+    /**
+     * Returns true if the cursor position marker is visible.
+     * @see setCursorMarkerVisible()
+     */
+    bool isCursorMarkerVisible() const;
+
   signals:
 
     void renameTriggered();
@@ -73,6 +92,7 @@ class APP_EXPORT QgsMapCanvasDockWidget : public QgsDockWidget, private Ui::QgsM
     void mapCrsChanged();
     void menuAboutToShow();
     void settingsMenuAboutToShow();
+    void syncMarker( const QgsPoint &p );
 
   private:
 
@@ -89,6 +109,7 @@ class APP_EXPORT QgsMapCanvasDockWidget : public QgsDockWidget, private Ui::QgsM
     bool mBlockExtentSync = false;
     QgsMapToolPan *mPanTool = nullptr;
     QTimer mResizeTimer;
+    QgsVertexMarker *mXyMarker = nullptr;
     void syncViewExtent( QgsMapCanvas *sourceCanvas );
 };
 

src/ui/qgsmapcanvasdockwidgetbase.ui

@@ -143,6 +143,14 @@
     <string>Show Annotations</string>
    </property>
   </action>
+  <action name="mActionShowCursor">
+   <property name="checkable">
+    <bool>true</bool>
+   </property>
+   <property name="text">
+    <string>Show Cursor Position</string>
+   </property>
+  </action>
  </widget>
  <customwidgets>
   <customwidget>