-Updated transparency setting for WMS layers

-Should close ticket #1533

git-svn-id: http://svn.osgeo.org/qgis/trunk@10146 c8812cc2-4d05-0410-92ff-de0c093fc19c

src/core/raster/qgsrasterlayer.cpp

@@ -1508,9 +1508,19 @@ bool QgsRasterLayer::draw( QgsRenderContext& rendererContext )
     QgsDebugMsg( QString( "(int)origin y: %1" ).arg( static_cast<int>( myRasterViewPort->topLeftPoint.y() ) ) );
 
     //Set the transparency for the whole layer
-    QImage myAlphaChannel( image->width(), image->height(), QImage::Format_Indexed8 );
-    myAlphaChannel.fill(( uint ) mTransparencyLevel );
-    image->setAlphaChannel( myAlphaChannel );
+    //QImage::setAlphaChannel does not work quite as expected so set each pixel individually
+    //Currently this is only done for WMS images, which should be small enough not to impact performance
+    int myWidth = image->width();
+    int myHeight = image->height();
+    QRgb myRgb;
+    for( int myHeightRunner = 0; myHeightRunner < myHeight; myHeightRunner++ )
+    {
+        for( int myWidthRunner = 0; myWidthRunner < myWidth; myWidthRunner++ )
+        {
+            myRgb = image->pixel( myWidthRunner, myHeightRunner );
+            image->setPixel( myWidthRunner, myHeightRunner, qRgba( qRed( myRgb ), qGreen( myRgb ), qBlue( myRgb ), mTransparencyLevel ) );
+        }
+    }
 
     // Since GDAL's RasterIO can't handle floating point, we have to round to
     // the nearest pixel.  Add 0.5 to get rounding instead of truncation

src/providers/wms/qgswmsprovider.cpp

@@ -523,8 +523,10 @@ QImage* QgsWmsProvider::draw( QgsRectangle  const & viewExtent, int pixelWidth,
   {
     delete cachedImage;
   }
-  cachedImage = new QImage();
-  *cachedImage = QImage::fromData( imagesource );
+
+  //Create a local image from source then convert it to RGBA, so we can set the transparency later
+  QImage myLocalImage = QImage::fromData( imagesource );
+  cachedImage = new QImage( myLocalImage.convertToFormat( QImage::Format_ARGB32 ) );
 
   // Remember settings for useful caching next time.
   cachedViewExtent = viewExtent;