replace QgsRasterLayer::thumbnailAsPixmap() with previewAsPixmap() : return QPixmap and add size and background color parameters ; remove QgsRasterLayer::thumbnailAsImage() as it's not used

Author: etiennesky

python/core/raster/qgsrasterlayer.sip

@@ -475,10 +475,13 @@ class QgsRasterLayer : QgsMapLayer
     /** \brief Draws a thumbnail of the rasterlayer into the supplied pixmap pointer */
     void thumbnailAsPixmap( QPixmap * theQPixmap );
 
+    /** \brief Draws a preview of the rasterlayer into a pixmap */
+    QPixmap previewAsPixmap( QSize size, QColor bgColor = QColor( 255, 255, 255 ) );
+
     /** \brief Draws a thumbnail of the rasterlayer into the supplied QImage pointer
      * @note added in QGIS 1.6
      * */
-    void thumbnailAsImage( QImage * thepImage );
+    /* void thumbnailAsImage( QImage * thepImage ); */
 
     /** \brief Emit a signal asking for a repaint. (inherited from maplayer) */
     void triggerRepaint();

src/app/legend/qgslegendlayer.cpp

@@ -388,9 +388,7 @@ QPixmap QgsLegendLayer::getOriginalPixmap()
       if ( s.value( "/qgis/createRasterLegendIcons", true ).toBool() )
       {
         QgsRasterLayer* rlayer = qobject_cast<QgsRasterLayer *>( theLayer );
-        QPixmap myPixmap( 32, 32 );
-        rlayer->thumbnailAsPixmap( &myPixmap );
-        return myPixmap;
+        return rlayer->previewAsPixmap( QSize( 32, 32 ) );
       }
       else
       {

src/app/qgsrasterlayerproperties.cpp

@@ -626,19 +626,19 @@ void QgsRasterLayerProperties::sync()
   }
 
   //get the thumbnail for the layer
-  QPixmap myQPixmap = QPixmap( pixmapThumbnail->width(), pixmapThumbnail->height() );
-  mRasterLayer->thumbnailAsPixmap( &myQPixmap );
-  pixmapThumbnail->setPixmap( myQPixmap );
+  pixmapThumbnail->setPixmap( mRasterLayer->previewAsPixmap( pixmapThumbnail->size() ) );
+
+  // TODO fix legend + palette pixmap
 
   //update the legend pixmap on this dialog
   //pixmapLegend->setPixmap( mRasterLayer->legendAsPixmap() );
-  pixmapLegend->setScaledContents( true );
-  pixmapLegend->repaint();
+  // pixmapLegend->setScaledContents( true );
+  // pixmapLegend->repaint();
 
   //set the palette pixmap
-  //pixmapPalette->setPixmap( mRasterLayer->paletteAsPixmap( mRasterLayer->bandNumber( mRasterLayer->grayBandName() ) ) );
-  pixmapPalette->setScaledContents( true );
-  pixmapPalette->repaint();
+  // pixmapPalette->setPixmap( mRasterLayer->paletteAsPixmap( mRasterLayer->bandNumber( mRasterLayer->grayBandName() ) ) );
+  // pixmapPalette->setScaledContents( true );
+  // pixmapPalette->repaint();
 
   QgsDebugMsg( "populate metadata tab" );
   /*
@@ -761,9 +761,9 @@ void QgsRasterLayerProperties::apply()
   mRasterLayer->setMaximumScale( 1.0 / cbMaximumScale->scale() );
 
   //update the legend pixmap
-  pixmapLegend->setPixmap( mRasterLayer->legendAsPixmap() );
-  pixmapLegend->setScaledContents( true );
-  pixmapLegend->repaint();
+  // pixmapLegend->setPixmap( mRasterLayer->legendAsPixmap() );
+  // pixmapLegend->setScaledContents( true );
+  // pixmapLegend->repaint();
 
   QgsRasterResampleFilter* resampleFilter = mRasterLayer->resampleFilter();
 
@@ -803,9 +803,7 @@ void QgsRasterLayerProperties::apply()
 
 
   //get the thumbnail for the layer
-  QPixmap myQPixmap = QPixmap( pixmapThumbnail->width(), pixmapThumbnail->height() );
-  mRasterLayer->thumbnailAsPixmap( &myQPixmap );
-  pixmapThumbnail->setPixmap( myQPixmap );
+  pixmapThumbnail->setPixmap( mRasterLayer->previewAsPixmap( pixmapThumbnail->size() ) );
 
   mRasterLayer->setTitle( mLayerTitleLineEdit->text() );
   mRasterLayer->setAbstract( mLayerAbstractTextEdit->toPlainText() );
@@ -914,9 +912,10 @@ void QgsRasterLayerProperties::on_buttonBuildPyramids_clicked()
     }
   }
   //update the legend pixmap
-  pixmapLegend->setPixmap( mRasterLayer->legendAsPixmap() );
-  pixmapLegend->setScaledContents( true );
-  pixmapLegend->repaint();
+  // pixmapLegend->setPixmap( mRasterLayer->legendAsPixmap() );
+  // pixmapLegend->setScaledContents( true );
+  // pixmapLegend->repaint();
+
   //populate the metadata tab's text browser widget with gdal metadata info
   QString myStyle = QgsApplication::reportStyleSheet();
   txtbMetadata->setHtml( mRasterLayer->metadata() );

src/core/raster/qgsrasterlayer.cpp

@@ -2321,7 +2321,7 @@ QStringList QgsRasterLayer::subLayers() const
 
 void QgsRasterLayer::thumbnailAsPixmap( QPixmap * theQPixmap )
 {
-  //TODO: This should be depreciated and a new function written that just returns a new QPixmap, it will be safer
+  //deprecated, use previewAsPixmap() instead
   if ( !theQPixmap )
     return;
 
@@ -2372,9 +2372,64 @@ void QgsRasterLayer::thumbnailAsPixmap( QPixmap * theQPixmap )
   delete myQPainter;
 }
 
+QPixmap QgsRasterLayer::previewAsPixmap( QSize size, QColor bgColor )
+{
+  QPixmap myQPixmap( size );
+
+  myQPixmap.fill( bgColor );  //defaults to white, set to transparent for rendering on a map
+
+  QgsRasterViewPort *myRasterViewPort = new QgsRasterViewPort();
+
+  double myMapUnitsPerPixel;
+  double myX = 0.0;
+  double myY = 0.0;
+  QgsRectangle myExtent = mDataProvider->extent();
+  if ( myExtent.width() / myExtent.height() >=  myQPixmap.width() / myQPixmap.height() )
+  {
+    myMapUnitsPerPixel = myExtent.width() / myQPixmap.width();
+    myY = ( myQPixmap.height() - myExtent.height() / myMapUnitsPerPixel ) / 2;
+  }
+  else
+  {
+    myMapUnitsPerPixel = myExtent.height() / myQPixmap.height();
+    myX = ( myQPixmap.width() - myExtent.width() / myMapUnitsPerPixel ) / 2;
+  }
+
+  double myPixelWidth = myExtent.width() / myMapUnitsPerPixel;
+  double myPixelHeight = myExtent.height() / myMapUnitsPerPixel;
+
+  //myRasterViewPort->topLeftPoint = QgsPoint( 0, 0 );
+  myRasterViewPort->topLeftPoint = QgsPoint( myX, myY );
+
+  //myRasterViewPort->bottomRightPoint = QgsPoint( myQPixmap.width(), myQPixmap.height() );
+
+  myRasterViewPort->bottomRightPoint = QgsPoint( myPixelWidth, myPixelHeight );
+  myRasterViewPort->drawableAreaXDim = myQPixmap.width();
+  myRasterViewPort->drawableAreaYDim = myQPixmap.height();
+  //myRasterViewPort->drawableAreaXDim = myPixelWidth;
+  //myRasterViewPort->drawableAreaYDim = myPixelHeight;
+
+  myRasterViewPort->mDrawnExtent = myExtent;
+  myRasterViewPort->mSrcCRS = QgsCoordinateReferenceSystem(); // will be invalid
+  myRasterViewPort->mDestCRS = QgsCoordinateReferenceSystem(); // will be invalid
+
+  QgsMapToPixel *myMapToPixel = new QgsMapToPixel( myMapUnitsPerPixel );
+
+  QPainter * myQPainter = new QPainter( &myQPixmap );
+  draw( myQPainter, myRasterViewPort, myMapToPixel );
+  delete myRasterViewPort;
+  delete myMapToPixel;
+  myQPainter->end();
+  delete myQPainter;
+
+  return myQPixmap;
+}
+
+#if 0
 void QgsRasterLayer::thumbnailAsImage( QImage * thepImage )
 {
   //TODO: This should be depreciated and a new function written that just returns a new QImage, it will be safer
+  // removed as it's not used anywhere, use previewAsPixmap() instead
   if ( !thepImage )
     return;
 
@@ -2398,6 +2453,7 @@ void QgsRasterLayer::thumbnailAsImage( QImage * thepImage )
   }
 
 }
+#endif
 
 void QgsRasterLayer::triggerRepaint()
 {

src/core/raster/qgsrasterlayer.h

@@ -501,7 +501,7 @@ class CORE_EXPORT QgsRasterLayer : public QgsMapLayer
     QList< QPair< QString, QColor > > legendSymbologyItems() const;
 
     /** \brief Get a legend image for this layer */
-    QPixmap legendAsPixmap();
+    Q_DECL_DEPRECATED QPixmap legendAsPixmap();
 
     /** \brief  Overloaded version of above function that can print layer name onto legend */
     //! @deprecated
@@ -639,12 +639,15 @@ class CORE_EXPORT QgsRasterLayer : public QgsMapLayer
     virtual QStringList subLayers() const;
 
     /** \brief Draws a thumbnail of the rasterlayer into the supplied pixmap pointer */
-    void thumbnailAsPixmap( QPixmap * theQPixmap );
+    Q_DECL_DEPRECATED void thumbnailAsPixmap( QPixmap * theQPixmap );
+
+    /** \brief Draws a preview of the rasterlayer into a pixmap */
+    QPixmap previewAsPixmap( QSize size, QColor bgColor = Qt::white );
 
     /** \brief Draws a thumbnail of the rasterlayer into the supplied QImage pointer
      * @note added in QGIS 1.6
      * */
-    void thumbnailAsImage( QImage * thepImage );
+    /* Q_DECL_DEPRECATED void thumbnailAsImage( QImage * thepImage ); */
 
     /** \brief Emit a signal asking for a repaint. (inherited from maplayer) */
     void triggerRepaint();