Set raster no data color back to 0,0,0,0 and overwrite that in raster drawer only for PDF output. Fixes #9101 and #9343

Author: blazek

src/core/raster/qgsrasterblock.cpp

@@ -23,7 +23,8 @@
 #include "qgslogger.h"
 #include "qgsrasterblock.h"
 
-const QRgb QgsRasterBlock::mNoDataColor = qRgba( 255, 255, 255, 0 );
+// See #9101 before any change of NODATA_COLOR!
+const QRgb QgsRasterBlock::mNoDataColor = qRgba( 0, 0, 0, 0 );
 
 QgsRasterBlock::QgsRasterBlock()
     : mValid( true )
@@ -301,7 +302,7 @@ QRgb QgsRasterBlock::color( qgssize index ) const
 
 QRgb QgsRasterBlock::color( int row, int column ) const
 {
-  if ( !mImage ) return qRgba( 255, 255, 255, 0 );
+  if ( !mImage ) return mNoDataColor;
 
   return mImage->pixel( column, row );
 }
@@ -597,7 +598,7 @@ bool QgsRasterBlock::setIsNoDataExcept( const QRect & theExceptRect )
       return false;
     }
 
-    QRgb nodataRgba = qRgba( 0, 0, 0, 0 );
+    QRgb nodataRgba = mNoDataColor;
     QRgb *nodataRow = new QRgb[mWidth]; // full row of no data
     int rgbSize = sizeof( QRgb );
     for ( int c = 0; c < mWidth; c ++ )

src/core/raster/qgsrasterdrawer.cpp

@@ -22,6 +22,7 @@
 #include "qgsmaptopixel.h"
 #include <QImage>
 #include <QPainter>
+#include <QPrinter>
 
 QgsRasterDrawer::QgsRasterDrawer( QgsRasterIterator* iterator ): mIterator( iterator )
 {
@@ -66,6 +67,28 @@ void QgsRasterDrawer::draw( QPainter* p, QgsRasterViewPort* viewPort, const QgsM
 
     QImage img = block->image();
 
+    // Because of bug in Acrobat Reader we must use "white" transparent color instead
+    // of "black" for PDF. See #9101.
+    QPrinter *printer = dynamic_cast<QPrinter *>( p->device() );
+    if ( printer && printer->outputFormat() == QPrinter::PdfFormat )
+    {
+      QgsDebugMsg( "PdfFormat" );
+
+      img = img.convertToFormat( QImage::Format_ARGB32 );
+      QRgb transparentBlack = qRgba( 0, 0, 0, 0 );
+      QRgb transparentWhite = qRgba( 255, 255, 255, 0 );
+      for ( int x = 0; x < img.width(); x++ )
+      {
+        for ( int y = 0; y < img.height(); y++ )
+        {
+          if ( img.pixel( x, y ) == transparentBlack )
+          {
+            img.setPixel( x, y, transparentWhite );
+          }
+        }
+      }
+    }
+
     drawImage( p, viewPort, img, topLeftCol, topLeftRow );
 
     delete block;

src/core/raster/qgsrasterrenderer.cpp

@@ -26,10 +26,8 @@
 
 #define tr( sourceText ) QCoreApplication::translate ( "QgsRasterRenderer", sourceText )
 
-// Changing RGB components of NODATA_COLOR may break tests
-// (changed 2013-11-30 from 0,0,0,0 to 255,255,255,0)
-// kepp NODATA_COLOR white, see #9101
-const QRgb QgsRasterRenderer::NODATA_COLOR = qRgba( 255, 255, 255, 0 );
+// See #9101 before any change of NODATA_COLOR!
+const QRgb QgsRasterRenderer::NODATA_COLOR = qRgba( 0, 0, 0, 0 );
 
 QgsRasterRenderer::QgsRasterRenderer( QgsRasterInterface* input, const QString& type )
     : QgsRasterInterface( input )