Don't show label hover highlights while a map redraw is in progress,

because these will show for outdated label positions
qgis · Mar 15, 2021 · 5bceda8 · 5bceda8
1 parent 879f892
commit 5bceda8
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Showing 6 changed files with 26 additions and 13 deletions.
diff --git a/python/gui/auto_generated/qgsmapcanvas.sip.in b/python/gui/auto_generated/qgsmapcanvas.sip.in
@@ -106,9 +106,12 @@ Resets the ``flags`` for the canvas' map settings.
 .. versionadded:: 3.0
 %End
 
-    const QgsLabelingResults *labelingResults() const;
+    const QgsLabelingResults *labelingResults( bool allowOutdatedResults = true ) const;
 %Docstring
-Gets access to the labeling results (may be ``None``)
+Gets access to the labeling results (may be ``None``).
+
+Since QGIS 3.20, if the ``allowOutdatedResults`` flag is ``False`` then outdated labeling results (e.g.
+as a result of an ongoing canvas render) will not be returned, and instead ``None`` will be returned.
 
 .. versionadded:: 2.4
 %End

diff --git a/src/app/labeling/qgsmaptoollabel.cpp b/src/app/labeling/qgsmaptoollabel.cpp
@@ -62,7 +62,7 @@ void QgsMapToolLabel::deactivate()
 bool QgsMapToolLabel::labelAtPosition( QMouseEvent *e, QgsLabelPosition &p )
 {
   QgsPointXY pt = toMapCoordinates( e->pos() );
-  const QgsLabelingResults *labelingResults = mCanvas->labelingResults();
+  const QgsLabelingResults *labelingResults = mCanvas->labelingResults( false );
   if ( !labelingResults )
     return false;
 
@@ -123,7 +123,7 @@ bool QgsMapToolLabel::labelAtPosition( QMouseEvent *e, QgsLabelPosition &p )
 bool QgsMapToolLabel::calloutAtPosition( QMouseEvent *e, QgsCalloutPosition &p, bool &isOrigin )
 {
   QgsPointXY pt = toMapCoordinates( e->pos() );
-  const QgsLabelingResults *labelingResults = mCanvas->labelingResults();
+  const QgsLabelingResults *labelingResults = mCanvas->labelingResults( false );
   if ( !labelingResults )
     return false;
 

diff --git a/src/app/labeling/qgsmaptoolpinlabels.cpp b/src/app/labeling/qgsmaptoolpinlabels.cpp
@@ -167,10 +167,9 @@ void QgsMapToolPinLabels::highlightPinnedLabels()
   QgsDebugMsg( QStringLiteral( "Highlighting pinned labels" ) );
 
   // get list of all drawn labels from all layers within given extent
-  const QgsLabelingResults *labelingResults = mCanvas->labelingResults();
+  const QgsLabelingResults *labelingResults = mCanvas->labelingResults( false );
   if ( !labelingResults )
   {
-    QgsDebugMsg( QStringLiteral( "No labeling engine" ) );
     return;
   }
 
@@ -238,10 +237,9 @@ void QgsMapToolPinLabels::pinUnpinLabels( const QgsRectangle &ext, QMouseEvent *
   bool toggleUnpinOrPin = e->modifiers() & Qt::ControlModifier;
 
   // get list of all drawn labels from all layers within, or touching, chosen extent
-  const QgsLabelingResults *labelingResults = mCanvas->labelingResults();
+  const QgsLabelingResults *labelingResults = mCanvas->labelingResults( false );
   if ( !labelingResults )
   {
-    QgsDebugMsg( QStringLiteral( "No labeling engine" ) );
     return;
   }
 

diff --git a/src/app/labeling/qgsmaptoolshowhidelabels.cpp b/src/app/labeling/qgsmaptoolshowhidelabels.cpp
@@ -284,10 +284,9 @@ bool QgsMapToolShowHideLabels::selectedLabelFeatures( QgsVectorLayer *vlayer,
   listPos.clear();
 
   // get list of all drawn labels from current layer that intersect rubberband
-  const QgsLabelingResults *labelingResults = mCanvas->labelingResults();
+  const QgsLabelingResults *labelingResults = mCanvas->labelingResults( false );
   if ( !labelingResults )
   {
-    QgsDebugMsg( QStringLiteral( "No labeling engine" ) );
     return false;
   }
 

diff --git a/src/gui/qgsmapcanvas.cpp b/src/gui/qgsmapcanvas.cpp
@@ -469,8 +469,11 @@ void QgsMapCanvas::setMapSettingsFlags( QgsMapSettings::Flags flags )
   refresh();
 }
 
-const QgsLabelingResults *QgsMapCanvas::labelingResults() const
+const QgsLabelingResults *QgsMapCanvas::labelingResults( bool allowOutdatedResults ) const
 {
+  if ( !allowOutdatedResults && mLabelingResultsOutdated )
+    return nullptr;
+
   return mLabelingResults.get();
 }
 
@@ -567,6 +570,8 @@ void QgsMapCanvas::refresh()
 
   // schedule a refresh
   mRefreshTimer->start( 1 );
+
+  mLabelingResultsOutdated = true;
 }
 
 void QgsMapCanvas::refreshMap()
@@ -692,6 +697,7 @@ void QgsMapCanvas::rendererJobFinished()
     {
       mLabelingResults.reset( mJob->takeLabelingResults() );
     }
+    mLabelingResultsOutdated = false;
 
     QImage img = mJob->renderedImage();
 

diff --git a/src/gui/qgsmapcanvas.h b/src/gui/qgsmapcanvas.h
@@ -161,10 +161,14 @@ class GUI_EXPORT QgsMapCanvas : public QGraphicsView
     void setMapSettingsFlags( QgsMapSettings::Flags flags );
 
     /**
-     * Gets access to the labeling results (may be NULLPTR)
+     * Gets access to the labeling results (may be NULLPTR).
+     *
+     * Since QGIS 3.20, if the \a allowOutdatedResults flag is FALSE then outdated labeling results (e.g.
+     * as a result of an ongoing canvas render) will not be returned, and instead NULLPTR will be returned.
+     *
      * \since QGIS 2.4
      */
-    const QgsLabelingResults *labelingResults() const;
+    const QgsLabelingResults *labelingResults( bool allowOutdatedResults = true ) const;
 
     /**
      * Set whether to cache images of rendered layers
@@ -1255,6 +1259,9 @@ class GUI_EXPORT QgsMapCanvas : public QGraphicsView
     //! Labeling results from the recently rendered map
     std::unique_ptr< QgsLabelingResults > mLabelingResults;
 
+    //! TRUE if the labeling results stored in mLabelingResults are outdated (e.g. as a result of an ongoing canvas render)
+    bool mLabelingResultsOutdated = false;
+
     //! Whether layers are rendered sequentially or in parallel
     bool mUseParallelRendering = false;