Fix raster set data source (with test)

elpaso · elpaso · commit 4481127b9abd · 2018-11-05T10:24:35.000+01:00
diff --git a/src/core/qgsmaplayerlegend.cpp b/src/core/qgsmaplayerlegend.cpp
@@ -307,7 +307,7 @@ QList<QgsLayerTreeModelLegendNode *> QgsDefaultRasterLayerLegend::createLayerTre
   QList<QgsLayerTreeModelLegendNode *> nodes;
 
   // temporary solution for WMS. Ideally should be done with a delegate.
-  if ( mLayer->dataProvider()->supportsLegendGraphic() )
+  if ( mLayer->dataProvider() && mLayer->dataProvider()->supportsLegendGraphic() )
   {
     nodes << new QgsWmsLegendNode( nodeLayer );
   }
diff --git a/src/core/raster/qgsrasterlayer.cpp b/src/core/raster/qgsrasterlayer.cpp
@@ -119,7 +119,6 @@ QgsRasterLayer::QgsRasterLayer( const QString &uri,
 {
   QgsDebugMsgLevel( QStringLiteral( "Entered" ), 4 );
   setProviderType( providerKey );
-  init();
 
   QgsDataProvider::ProviderOptions providerOptions;
 
@@ -789,12 +788,21 @@ void QgsRasterLayer::setDataSource( const QString &dataSource, const QString &ba
 {
   if ( mDataProvider )
     closeDataProvider();
+
+  init();
+
+  for ( int i = mPipe.size() - 1; i >= 0; --i )
+  {
+    mPipe.remove( i );
+  }
+
   mDataSource = dataSource;
   mLayerName = baseName;
+
   setDataProvider( provider, options );
+
   if ( mValid )
   {
-
     // load default style
     bool defaultLoadedFlag = false;
     if ( loadDefaultStyleFlag )
@@ -805,14 +813,10 @@ void QgsRasterLayer::setDataSource( const QString &dataSource, const QString &ba
     {
       setDefaultContrastEnhancement();
     }
-
-    // TODO: Connect signals from the dataprovider to the qgisapp
-
     emit statusChanged( tr( "QgsRasterLayer created" ) );
-
-    // Load default style
   }
   emit dataSourceChanged();
+  emit dataChanged();
 }
 
 void QgsRasterLayer::closeDataProvider()
@@ -1267,9 +1271,13 @@ QImage QgsRasterLayer::previewAsImage( QSize size, const QColor &bgColor, QImage
 {
   QImage myQImage( size, format );
 
+  if ( ! isValid( ) )
+    return  QImage();
+
   myQImage.setColor( 0, bgColor.rgba() );
   myQImage.fill( 0 );  //defaults to white, set to transparent for rendering on a map
 
+
   QgsRasterViewPort *myRasterViewPort = new QgsRasterViewPort();
 
   double myMapUnitsPerPixel;
diff --git a/tests/src/python/test_qgsrasterlayer.py b/tests/src/python/test_qgsrasterlayer.py
@@ -16,16 +16,25 @@
 import qgis  # NOQA
 
 import os
+import filecmp
 
-from qgis.PyQt.QtCore import QFileInfo
-from qgis.PyQt.QtGui import QColor
+from qgis.PyQt.QtCore import QSize, QFileInfo, Qt, QTemporaryDir
+
+from qgis.PyQt.QtGui import (
+    QColor,
+    QImage,
+    QPainter,
+    QResizeEvent
+)
 from qgis.PyQt.QtXml import QDomDocument
 
+
 from qgis.core import (QgsRaster,
                        QgsRasterLayer,
                        QgsReadWriteContext,
                        QgsColorRampShader,
                        QgsContrastEnhancement,
+                       QgsDataProvider,
                        QgsProject,
                        QgsMapSettings,
                        QgsPointXY,
@@ -40,6 +49,7 @@
                        QgsGradientColorRamp)
 from utilities import unitTestDataPath
 from qgis.testing import start_app, unittest
+from qgis.testing.mocked import get_iface
 
 # Convenience instances in case you may need them
 # not used in this test
@@ -48,6 +58,14 @@
 
 class TestQgsRasterLayer(unittest.TestCase):
 
+    def setUp(self):
+        self.iface = get_iface()
+        QgsProject.instance().removeAllMapLayers()
+
+        self.iface.mapCanvas().viewport().resize(400, 400)
+        # For some reason the resizeEvent is not delivered, fake it
+        self.iface.mapCanvas().resizeEvent(QResizeEvent(QSize(400, 400), self.iface.mapCanvas().size()))
+
     def testIdentify(self):
         myPath = os.path.join(unitTestDataPath(), 'landsat.tif')
         myFileInfo = QFileInfo(myPath)
@@ -694,6 +712,34 @@ def testClone(self):
         # compare xml documents
         self.assertEqual(layer_doc.toString(), clone_doc.toString())
 
+    def testSetDataSource(self):
+        """Test change data source"""
+
+        temp_dir = QTemporaryDir()
+        options = QgsDataProvider.ProviderOptions()
+        myPath = os.path.join(unitTestDataPath('raster'),
+                              'band1_float32_noct_epsg4326.tif')
+        myFileInfo = QFileInfo(myPath)
+        myBaseName = myFileInfo.baseName()
+        layer = QgsRasterLayer(myPath, myBaseName)
+
+        image = layer.previewAsImage(QSize(400, 400))
+        self.assertFalse(image.isNull())
+        self.assertTrue(image.save(os.path.join(temp_dir.path(), 'expected.png'), "PNG"))
+
+        layer.setDataSource(myPath.replace('4326.tif', '4326-BAD_SOURCE.tif'), 'bad_layer', 'gdal', options)
+        self.assertFalse(layer.isValid())
+        image = layer.previewAsImage(QSize(400, 400))
+        self.assertTrue(image.isNull())
+
+        layer.setDataSource(myPath.replace('4326-BAD_SOURCE.tif', '4326.tif'), 'bad_layer', 'gdal', options)
+        self.assertTrue(layer.isValid())
+        image = layer.previewAsImage(QSize(400, 400))
+        self.assertFalse(image.isNull())
+        self.assertTrue(image.save(os.path.join(temp_dir.path(), 'actual.png'), "PNG"))
+
+        self.assertTrue(filecmp.cmp(os.path.join(temp_dir.path(), 'actual.png'), os.path.join(temp_dir.path(), 'expected.png')))
+
 
 if __name__ == '__main__':
     unittest.main()

Original file line number	Diff line number	Diff line change
`@@ -307,7 +307,7 @@ QList<QgsLayerTreeModelLegendNode *> QgsDefaultRasterLayerLegend::createLayerTre`
`307`	`307`	`QList<QgsLayerTreeModelLegendNode *> nodes;`
`308`	`308`
`309`	`309`	`// temporary solution for WMS. Ideally should be done with a delegate.`
`310`		`- if ( mLayer->dataProvider()->supportsLegendGraphic() )`
	`310`	`+ if ( mLayer->dataProvider() && mLayer->dataProvider()->supportsLegendGraphic() )`
`311`	`311`	`{`
`312`	`312`	`nodes << new QgsWmsLegendNode( nodeLayer );`
`313`	`313`	`}`