Fix highlights disappear after changing canvas CRS

qgis · Jan 18, 2021 · 797a060 · 797a060
1 parent c6a4331
commit 797a060
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Showing 2 changed files with 36 additions and 8 deletions.
diff --git a/src/gui/qgshighlight.cpp b/src/gui/qgshighlight.cpp
@@ -68,30 +68,54 @@ QgsHighlight::QgsHighlight( QgsMapCanvas *mapCanvas, const QgsFeature &feature,
 }
 
 void QgsHighlight::init()
+{
+  mOriginalGeometry = mGeometry.isNull() ? mFeature.geometry() : mGeometry;
+  setColor( QColor( Qt::lightGray ) );
+
+  connect( mMapCanvas, &QgsMapCanvas::destinationCrsChanged, this, &QgsHighlight::updateTransformedGeometry );
+  updateTransformedGeometry();
+
+  if ( mGeometry.type() == QgsWkbTypes::PointGeometry )
+  {
+    mRenderContext = createRenderContext();
+  }
+}
+
+void QgsHighlight::updateTransformedGeometry()
 {
   QgsCoordinateTransform ct = mMapCanvas->mapSettings().layerTransform( mLayer );
   if ( ct.isValid() )
   {
+    // reset to original geometry and transform
     if ( !mGeometry.isNull() )
     {
-      mGeometry.transform( ct );
-
-      if ( mGeometry.type() == QgsWkbTypes::PointGeometry )
+      mGeometry = mOriginalGeometry;
+      try
+      {
+        mGeometry.transform( ct );
+      }
+      catch ( QgsCsException & )
       {
-        mRenderContext = createRenderContext();
+        QgsDebugMsg( QStringLiteral( "Could not transform highlight geometry to canvas CRS" ) );
       }
     }
     else if ( mFeature.hasGeometry() )
     {
+      mFeature.setGeometry( mOriginalGeometry );
       QgsGeometry g = mFeature.geometry();
-      g.transform( ct );
-      mFeature.setGeometry( g );
+      try
+      {
+        g.transform( ct );
+        mFeature.setGeometry( g );
+      }
+      catch ( QgsCsException & )
+      {
+        QgsDebugMsg( QStringLiteral( "Could not transform highlight geometry to canvas CRS" ) );
+      }
     }
   }
-
   updateRect();
   update();
-  setColor( QColor( Qt::lightGray ) );
 }
 
 QgsHighlight::~QgsHighlight() = default;

diff --git a/src/gui/qgshighlight.h b/src/gui/qgshighlight.h
@@ -168,6 +168,9 @@ class GUI_EXPORT QgsHighlight : public QgsMapCanvasItem
     //! recalculates needed rectangle
     void updateRect();
 
+  private slots:
+    void updateTransformedGeometry();
+
   private:
     enum PointSymbol
     {
@@ -190,6 +193,7 @@ class GUI_EXPORT QgsHighlight : public QgsMapCanvasItem
     QColor mFillColor; // line / stroke fillColor property
     QBrush mBrush;
     QPen mPen;
+    QgsGeometry mOriginalGeometry;
     QgsGeometry mGeometry;
     QgsMapLayer *mLayer = nullptr;
     QgsFeature mFeature;