Early exit if snap to grid item is disabled

src/gui/qgssnaptogridcanvasitem.cpp

@@ -28,6 +28,9 @@ QgsSnapToGridCanvasItem::QgsSnapToGridCanvasItem( QgsMapCanvas *mapCanvas )
 
 void QgsSnapToGridCanvasItem::paint( QPainter *painter )
 {
+  if ( !mEnabled || !mAvailableByZoomFactor )
+    return;
+
   painter->save();
   QgsRectangle mapRect = mMapCanvas->extent();
   if ( rect() != mapRect )
@@ -36,44 +39,41 @@ void QgsSnapToGridCanvasItem::paint( QPainter *painter )
   painter->setRenderHints( QPainter::Antialiasing );
   painter->setCompositionMode( QPainter::CompositionMode_Difference );
 
-  if ( mEnabled && mAvailableByZoomFactor )
+  try
   {
-    try
-    {
-      const QgsRectangle layerExtent = mTransform.transformBoundingBox( mapRect, QgsCoordinateTransform::ReverseTransform );
-      const QgsPointXY layerPt = mTransform.transform( mPoint, QgsCoordinateTransform::ReverseTransform );
+    const QgsRectangle layerExtent = mTransform.transformBoundingBox( mapRect, QgsCoordinateTransform::ReverseTransform );
+    const QgsPointXY layerPt = mTransform.transform( mPoint, QgsCoordinateTransform::ReverseTransform );
 
-      const double gridXMin = std::ceil( layerExtent.xMinimum() / mPrecision ) * mPrecision;
-      const double gridXMax = std::ceil( layerExtent.xMaximum() / mPrecision ) * mPrecision;
-      const double gridYMin = std::ceil( layerExtent.yMinimum() / mPrecision ) * mPrecision;
-      const double gridYMax = std::ceil( layerExtent.yMaximum() / mPrecision ) * mPrecision;
+    const double gridXMin = std::ceil( layerExtent.xMinimum() / mPrecision ) * mPrecision;
+    const double gridXMax = std::ceil( layerExtent.xMaximum() / mPrecision ) * mPrecision;
+    const double gridYMin = std::ceil( layerExtent.yMinimum() / mPrecision ) * mPrecision;
+    const double gridYMax = std::ceil( layerExtent.yMaximum() / mPrecision ) * mPrecision;
 
-      for ( int x = gridXMin ; x < gridXMax; x += mPrecision )
+    for ( int x = gridXMin ; x < gridXMax; x += mPrecision )
+    {
+      for ( int y = gridYMin ; y < gridYMax; y += mPrecision )
       {
-        for ( int y = gridYMin ; y < gridYMax; y += mPrecision )
-        {
-          const QgsPointXY pt = mTransform.transform( x, y );
-          const QPointF canvasPt = toCanvasCoordinates( pt );
-
-          if ( qgsDoubleNear( layerPt.x(), x, mPrecision / 3 ) && qgsDoubleNear( layerPt.y(), y, mPrecision / 3 ) )
-          {
-            painter->setPen( mCurrentPointPen );
-          }
-          else
-          {
-            painter->setPen( mGridPen );
-          }
-          painter->drawLine( canvasPt.x() - 3, canvasPt.y(), canvasPt.x() + 3, canvasPt.y() );
-          painter->drawLine( canvasPt.x(), canvasPt.y() - 3, canvasPt.x(), canvasPt.y() + 3 );
+        const QgsPointXY pt = mTransform.transform( x, y );
+        const QPointF canvasPt = toCanvasCoordinates( pt );
 
+        if ( qgsDoubleNear( layerPt.x(), x, mPrecision / 3 ) && qgsDoubleNear( layerPt.y(), y, mPrecision / 3 ) )
+        {
+          painter->setPen( mCurrentPointPen );
+        }
+        else
+        {
+          painter->setPen( mGridPen );
         }
+        painter->drawLine( canvasPt.x() - 3, canvasPt.y(), canvasPt.x() + 3, canvasPt.y() );
+        painter->drawLine( canvasPt.x(), canvasPt.y() - 3, canvasPt.x(), canvasPt.y() + 3 );
+
       }
     }
-    catch ( QgsCsException &e )
-    {
-      Q_UNUSED( e )
-      mAvailableByZoomFactor = false;
-    }
+  }
+  catch ( QgsCsException &e )
+  {
+    Q_UNUSED( e )
+    mAvailableByZoomFactor = false;
   }
 
   painter->restore();