Add tests for python bindings for layer blend modes

tests/src/python/CMakeLists.txt

@@ -4,6 +4,7 @@ ADD_PYTHON_TEST(PyQgsFeature test_qgsfeature.py)
 ADD_PYTHON_TEST(PyQgsGeometry test_qgsgeometry.py)
 ADD_PYTHON_TEST(PyQgsVectorLayer test_qgsvectorlayer.py)
 ADD_PYTHON_TEST(PyQgsRasterLayer test_qgsrasterlayer.py)
+ADD_PYTHON_TEST(PyQgsBlendModes test_qgsblendmodes.py)
 ADD_PYTHON_TEST(PyQgsRasterFileWriter test_qgsrasterfilewriter.py)
 ADD_PYTHON_TEST(PyQgsMemoryProvider test_qgsmemoryprovider.py)
 ADD_PYTHON_TEST(PyQgsDelimitedTextProvider test_qgsdelimitedtextprovider.py)

tests/src/python/test_qgsblendmodes.py

@@ -0,0 +1,131 @@
+# -*- coding: utf-8 -*-
+
+"""
+***************************************************************************
+    test_qgsblendmodes.py
+    ---------------------
+    Date                 : May 2013
+    Copyright            : (C) 2013 by Nyall Dawson, Massimo Endrighi
+    Email                : nyall dot dawson at gmail.com
+***************************************************************************
+*                                                                         *
+*   This program is free software; you can redistribute it and/or modify  *
+*   it under the terms of the GNU General Public License as published by  *
+*   the Free Software Foundation; either version 2 of the License, or     *
+*   (at your option) any later version.                                   *
+*                                                                         *
+***************************************************************************
+"""
+
+__author__ = 'Nyall Dawson'
+__date__ = 'May 2013'
+__copyright__ = '(C) 2013, Nyall Dawson, Massimo Endrighi'
+# This will get replaced with a git SHA1 when you do a git archive
+__revision__ = '$Format:%H$'
+
+import os
+
+from PyQt4.QtCore import *
+from PyQt4.QtGui import *
+
+from qgis.core import (QgsVectorLayer,
+                       QgsMapLayerRegistry,
+                       QgsMapRenderer,
+                       QgsCoordinateReferenceSystem,
+                       QgsRenderChecker,
+                       QgsRasterLayer,
+                       QgsRasterDataProvider,
+                       QgsMultiBandColorRenderer,
+                       QGis)
+
+from utilities import (unitTestDataPath,
+                       getQgisTestApp,
+                       TestCase,
+                       unittest,
+                       expectedFailure
+                       )
+# Convenience instances in case you may need them
+QGISAPP, CANVAS, IFACE, PARENT = getQgisTestApp()
+TEST_DATA_DIR = unitTestDataPath()
+
+class TestQgsBlendModes(TestCase):
+
+    def __init__(self, methodName):
+        """Run once on class initialisation."""
+        unittest.TestCase.__init__(self, methodName)
+
+        # initialize class MapRegistry, Canvas, MapRenderer, Map and PAL
+        self.mMapRegistry = QgsMapLayerRegistry.instance()
+
+        # create point layer
+        myShpFile = os.path.join(TEST_DATA_DIR, 'points.shp')
+        self.mPointLayer = QgsVectorLayer(myShpFile, 'Points', 'ogr')
+        self.mMapRegistry.addMapLayer(self.mPointLayer)
+
+        # create polygon layer
+        myShpFile = os.path.join(TEST_DATA_DIR, 'polys.shp')
+        self.mPolygonLayer = QgsVectorLayer(myShpFile, 'Polygons', 'ogr')        
+        self.mMapRegistry.addMapLayer(self.mPolygonLayer)
+
+        # create two raster layers
+        myRasterFile = os.path.join(TEST_DATA_DIR, 'landsat.tif')       
+        self.mRasterLayer1 = QgsRasterLayer(myRasterFile, "raster1")
+        self.mRasterLayer2 = QgsRasterLayer(myRasterFile, "raster2")
+        myMultiBandRenderer1 = QgsMultiBandColorRenderer(self.mRasterLayer1.dataProvider(), 2, 3, 4)
+        self.mRasterLayer1.setRenderer(myMultiBandRenderer1)
+        self.mMapRegistry.addMapLayer(self.mRasterLayer1)
+        myMultiBandRenderer2 = QgsMultiBandColorRenderer(self.mRasterLayer2.dataProvider(), 2, 3, 4)        
+        self.mRasterLayer2.setRenderer(myMultiBandRenderer2)
+        self.mMapRegistry.addMapLayer(self.mRasterLayer2)        
+
+        # to match blend modes test comparisons background
+        self.mCanvas = CANVAS
+        self.mCanvas.setCanvasColor(QColor(152, 219, 249))
+        self.mMap = self.mCanvas.map()
+        self.mMap.resize(QSize(400, 400))
+        self.mMapRenderer = self.mCanvas.mapRenderer()
+        self.mMapRenderer.setOutputSize(QSize(400, 400), 72)
+
+    def testVectorBlending(self):
+        """Test that blend modes work for vector layers."""
+
+        #Add vector layers to map
+        myLayers = QStringList()
+        myLayers.append(self.mPointLayer.id())
+        myLayers.append(self.mPolygonLayer.id())        
+        self.mMapRenderer.setLayerSet(myLayers)
+        self.mMapRenderer.setExtent(self.mPointLayer.extent())  
+
+        #Set blending modes for both layers
+        self.mPointLayer.setBlendMode(QPainter.CompositionMode_Overlay)
+        self.mPolygonLayer.setBlendMode(QPainter.CompositionMode_Multiply)     
+
+        checker = QgsRenderChecker()
+        checker.setControlName("expected_vector_blendmodes")
+        checker.setMapRenderer(self.mMapRenderer) 
+
+        myResult = checker.runTest("vector_blendmodes");
+        myMessage = ('vector blending failed')
+        assert myResult, myMessage
+
+    def testRasterBlending(self):
+        """Test that blend modes work for raster layers."""
+        #Add raster layers to map
+        myLayers = QStringList()
+        myLayers.append(self.mRasterLayer1.id())
+        myLayers.append(self.mRasterLayer2.id())        
+        self.mMapRenderer.setLayerSet(myLayers)
+        self.mMapRenderer.setExtent(self.mRasterLayer1.extent())  
+
+        #Set blending mode for top layer
+        self.mRasterLayer1.setBlendMode(QPainter.CompositionMode_Plus)
+        checker = QgsRenderChecker()
+        checker.setControlName("expected_raster_blendmodes")
+        checker.setMapRenderer(self.mMapRenderer) 
+
+        myResult = checker.runTest("raster_blendmodes");
+        myMessage = ('raster blending failed')
+        assert myResult, myMessage                            
+
+if __name__ == '__main__':
+    unittest.main()