Show a snap indicator for measure tool

src/app/qgsmeasuretool.cpp

@@ -27,13 +27,15 @@
 #include "qgsmessagelog.h"
 #include "qgssettings.h"
 #include "qgsproject.h"
+#include "qgssnapindicator.h"
 
 #include <QMessageBox>
 #include <QMouseEvent>
 
 QgsMeasureTool::QgsMeasureTool( QgsMapCanvas *canvas, bool measureArea )
   : QgsMapTool( canvas )
   , mWrongProjectProjection( false )
+  , mSnapIndicator( new QgsSnapIndicator( canvas ) )
 {
   mMeasureArea = measureArea;
 
@@ -98,6 +100,8 @@ void QgsMeasureTool::activate()
 
 void QgsMeasureTool::deactivate()
 {
+  mSnapIndicator->setMatch( QgsPointLocator::Match() );
+
   mDialog->hide();
   QgsMapTool::deactivate();
 }
@@ -182,10 +186,11 @@ void QgsMeasureTool::canvasPressEvent( QgsMapMouseEvent *e )
 
 void QgsMeasureTool::canvasMoveEvent( QgsMapMouseEvent *e )
 {
+  QgsPointXY point = e->snapPoint();
+  mSnapIndicator->setMatch( e->mapPointMatch() );
+
   if ( ! mDone )
   {
-    QgsPointXY point = snapPoint( e->pos() );
-
     mRubberBand->movePoint( point );
     mDialog->mouseMove( point );
   }
@@ -194,7 +199,7 @@ void QgsMeasureTool::canvasMoveEvent( QgsMapMouseEvent *e )
 
 void QgsMeasureTool::canvasReleaseEvent( QgsMapMouseEvent *e )
 {
-  QgsPointXY point = snapPoint( e->pos() );
+  QgsPointXY point = e->snapPoint();
 
   if ( mDone ) // if we have stopped measuring any mouse click restart measuring
   {
@@ -281,10 +286,3 @@ void QgsMeasureTool::addPoint( const QgsPointXY &point )
     mDialog->addPoint();
   }
 }
-
-
-QgsPointXY QgsMeasureTool::snapPoint( QPoint p )
-{
-  QgsPointLocator::Match m = mCanvas->snappingUtils()->snapToMap( p );
-  return m.isValid() ? m.point() : mCanvas->getCoordinateTransform()->toMapCoordinates( p );
-}

src/app/qgsmeasuretool.h

@@ -24,7 +24,7 @@ class QgsDistanceArea;
 class QgsMapCanvas;
 class QgsMeasureDialog;
 class QgsRubberBand;
-
+class QgsSnapIndicator;
 
 
 class APP_EXPORT QgsMeasureTool : public QgsMapTool
@@ -102,9 +102,7 @@ class APP_EXPORT QgsMeasureTool : public QgsMapTool
     //! Destination CoordinateReferenceSystem used by the MapCanvas
     QgsCoordinateReferenceSystem mDestinationCrs;
 
-    //! Returns the snapped (map) coordinate
-    //\param p (pixel) coordinate
-    QgsPointXY snapPoint( QPoint p );
+    std::unique_ptr<QgsSnapIndicator> mSnapIndicator;
 
     //! Removes the last vertex from mRubberBand
     void undo();