Merge pull request #1734 from strk/zoom-by-wheel-glitch2

Fix zoomwheel regression (temporary hack)
qgis · Dec 21, 2014 · 1d9eb8f · 1d9eb8f
2 parents f3bcaf4 + 0e4b7e6
commit 1d9eb8f
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Showing 4 changed files with 27 additions and 38 deletions.
diff --git a/src/gui/qgsmapcanvas.cpp b/src/gui/qgsmapcanvas.cpp
@@ -723,7 +723,13 @@ void QgsMapCanvas::rendererJobFinished()
 
     p.end();
 
-    QgsRectangle rect = mSettings.visibleExtent();
+    // This is an hack to pass QgsMapCanvasItem::setRect what it
+    // expects (encoding of position and size of the item)
+    const QgsMapToPixel& m2p = mSettings.mapToPixel();
+    QgsPoint topLeft = m2p.toMapPoint(0,0);
+    double res = m2p.mapUnitsPerPixel();
+    QgsRectangle rect(topLeft.x(), topLeft.y(), topLeft.x() + img.width()*res, topLeft.y() - img.height()*res);
+
     mMap->setContent( img, rect );
   }
 

diff --git a/src/gui/qgsmapcanvasitem.cpp b/src/gui/qgsmapcanvasitem.cpp
@@ -67,21 +67,6 @@ QPointF QgsMapCanvasItem::toCanvasCoordinates( const QgsPoint& point )
   return QPointF( x, y ) + mPanningOffset;
 }
 
-// private
-QRectF QgsMapCanvasItem::toCanvasCoordinates( const QRectF& rect )
-{
-  QPointF tl( toCanvasCoordinates( rect.topLeft() ) );
-  QPointF bl( toCanvasCoordinates( rect.bottomLeft() ) );
-  QPointF br( toCanvasCoordinates( rect.bottomRight() ) );
-  QPointF tr( toCanvasCoordinates( rect.topRight() ) );
-  double xmin = std::min( tl.x(), std::min( bl.x(), std::min( br.x(), tr.x() ) ) );
-  double ymin = std::min( tl.y(), std::min( bl.y(), std::min( br.y(), tr.y() ) ) );
-  double xmax = std::max( tl.x(), std::max( bl.x(), std::max( br.x(), tr.x() ) ) );
-  double ymax = std::max( tl.y(), std::max( bl.y(), std::max( br.y(), tr.y() ) ) );
-  return QRectF( QPointF( xmin, ymin ), QPointF( xmax, ymax ) );
-}
-
-
 QgsRectangle QgsMapCanvasItem::rect() const
 {
   return mRect;
@@ -96,13 +81,17 @@ void QgsMapCanvasItem::setRect( const QgsRectangle& rect )
   QRectF r; // empty rect by default
   if ( !mRect.isEmpty() )
   {
-    r = toCanvasCoordinates( mRect.toRectF() );
-    r = r.normalized();
+    // rect encodes origin of the item (xMin,yMax from map to canvas units)
+    // and size (rect size / map units per pixel)
+    r.setTopLeft( toCanvasCoordinates( QPointF(mRect.xMinimum(), mRect.yMaximum()) ) );
+    const QgsMapToPixel* m2p = mMapCanvas->getCoordinateTransform();
+    double res = m2p->mapUnitsPerPixel();
+    r.setSize( QSizeF(mRect.width()/res, mRect.height()/res) );
   }
 
   // set position in canvas where the item will have coordinate (0,0)
   prepareGeometryChange();
-  setPos( r.topLeft() ); // TODO: compute from (0,0) using toMapCoordinates ?
+  setPos( r.topLeft() );
   mItemSize = QSizeF( r.width() + 2, r.height() + 2 );
 
   // QgsDebugMsg(QString("[%1,%2]-[%3x%4]").arg((int) r.left()).arg((int) r.top()).arg((int) r.width()).arg((int) r.height()));

diff --git a/src/gui/qgsmapcanvasitem.h b/src/gui/qgsmapcanvasitem.h
@@ -82,23 +82,24 @@ class GUI_EXPORT QgsMapCanvasItem : public QGraphicsItem
     //! pointer to map canvas
     QgsMapCanvas* mMapCanvas;
 
-    //! canvas item rectangle (in map coordinates)
+    //! cached canvas item rectangle in map coordinates
+    //! encodes position (xmin,ymax) and size (width/height)
+    //! used to re-position and re-size the item on zoom/pan
+    //! while waiting for the renderer to complete.
+    //!
+    //! NOTE: does not include rotation information, so cannot
+    //!       be used to correctly present pre-rendered map
+    //!       on rotation change
     QgsRectangle mRect;
 
     //! offset from normal position due current panning operation,
     //! used when converting map coordinates to move map canvas items
+    //! @deprecated since v2.4
     QPoint mPanningOffset;
 
     //! cached size of the item (to return in boundingRect())
     QSizeF mItemSize;
 
-  private:
-
-    //! transformation from map coordinates to screen coordinates
-    //! if rotation is set it is taken in consideration so that
-    //! the returned rectangle is the bounding box of the rotated input
-    QRectF toCanvasCoordinates( const QRectF& rect );
-
 };
 
 

diff --git a/src/gui/qgsmapcanvasmap.cpp b/src/gui/qgsmapcanvasmap.cpp
@@ -50,19 +50,12 @@ void QgsMapCanvasMap::paint( QPainter* painter )
   if ( mImage.size() != QSize( w, h ) )
   {
     QgsDebugMsg( QString( "map paint DIFFERENT SIZE: img %1,%2  item %3,%4" ).arg( mImage.width() ).arg( mImage.height() ).arg( w ).arg( h ) );
-    int tX = ( w - mImage.width() ) / 2.0;
-    int tY = ( h - mImage.height() ) / 2.0;
-    int fX = 0;
-    int fY = 0;
-    int fW = w;
-    int fH = h;
-    painter->drawImage( tX, tY, mImage, fX, fY, fW, fH );
-  }
-  else
-  {
-    painter->drawImage( QRect( 0, 0, w, h ), mImage );
+    // This happens on zoom events when ::paint is called before
+    // the renderer has completed
   }
 
+  painter->drawImage( QRect( 0, 0, w, h ), mImage );
+
   // For debugging:
 #if 0
   QRectF br = boundingRect();