Add method to load paletted renderer classes from file

qgis · Apr 3, 2017 · d542a1a · d542a1a
1 parent a6d3af7
commit d542a1a
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Showing 4 changed files with 54 additions and 0 deletions.
diff --git a/python/core/raster/qgspalettedrasterrenderer.sip b/python/core/raster/qgspalettedrasterrenderer.sip
@@ -38,6 +38,7 @@ class QgsPalettedRasterRenderer : QgsRasterRenderer
     QgsColorRamp *sourceColorRamp() const;
     static QgsPalettedRasterRenderer::ClassData colorTableToClassData( const QList<QgsColorRampShader::ColorRampItem> &table );
     static QgsPalettedRasterRenderer::ClassData classDataFromString( const QString &string );
+    static QgsPalettedRasterRenderer::ClassData classDataFromFile( const QString &path );
 
   private:
 

diff --git a/src/core/raster/qgspalettedrasterrenderer.cpp b/src/core/raster/qgspalettedrasterrenderer.cpp
@@ -362,6 +362,19 @@ QgsPalettedRasterRenderer::ClassData QgsPalettedRasterRenderer::classDataFromStr
   return classes;
 }
 
+QgsPalettedRasterRenderer::ClassData QgsPalettedRasterRenderer::classDataFromFile( const QString &path )
+{
+  QFile inputFile( path );
+  QString input;
+  if ( inputFile.open( QIODevice::ReadOnly ) )
+  {
+    QTextStream in( &inputFile );
+    input = in.readAll();
+    inputFile.close();
+  }
+  return classDataFromString( input );
+}
+
 void QgsPalettedRasterRenderer::updateArrays()
 {
   // find maximum color index

diff --git a/src/core/raster/qgspalettedrasterrenderer.h b/src/core/raster/qgspalettedrasterrenderer.h
@@ -116,9 +116,17 @@ class CORE_EXPORT QgsPalettedRasterRenderer: public QgsRasterRenderer
     /**
      * Converts a \a string containing a color table or class data to to paletted renderer class data.
      * @note added in QGIS 3.0
+     * @see classDataFromFile()
      */
     static QgsPalettedRasterRenderer::ClassData classDataFromString( const QString &string );
 
+    /**
+     * Opens a color table file and returns corresponding paletted renderer class data.
+     * @note added in QGIS 3.0
+     * @see classDataFromString()
+     */
+    static QgsPalettedRasterRenderer::ClassData classDataFromFile( const QString &path );
+
   private:
 
     int mBand;

diff --git a/tests/src/python/test_qgsrasterlayer.py b/tests/src/python/test_qgsrasterlayer.py
@@ -500,6 +500,38 @@ def testLoadPalettedColorDataFromString(self):
         classes = QgsPalettedRasterRenderer.classDataFromString(bad)
         self.assertEqual(len(classes), 0)
 
+    def testLoadPalettedClassDataFromFile(self):
+        # bad file
+        classes = QgsPalettedRasterRenderer.classDataFromFile('ajdhjashjkdh kjahjkdhk')
+        self.assertEqual(len(classes), 0)
+
+        # good file!
+        path = os.path.join(unitTestDataPath('raster'),
+                            'test.clr')
+        classes = QgsPalettedRasterRenderer.classDataFromFile(path)
+        self.assertEqual(len(classes), 10)
+        self.assertEqual(classes[0].value, 1)
+        self.assertEqual(classes[0].color.name(), '#000000')
+        self.assertEqual(classes[0].color.alpha(), 255)
+        self.assertEqual(classes[1].value, 2)
+        self.assertEqual(classes[1].color.name(), '#c8c8c8')
+        self.assertEqual(classes[2].value, 3)
+        self.assertEqual(classes[2].color.name(), '#006e00')
+        self.assertEqual(classes[3].value, 4)
+        self.assertEqual(classes[3].color.name(), '#6e4100')
+        self.assertEqual(classes[4].value, 5)
+        self.assertEqual(classes[4].color.name(), '#0000ff')
+        self.assertEqual(classes[4].color.alpha(), 255)
+        self.assertEqual(classes[5].value, 6)
+        self.assertEqual(classes[5].color.name(), '#0059ff')
+        self.assertEqual(classes[6].value, 7)
+        self.assertEqual(classes[6].color.name(), '#00aeff')
+        self.assertEqual(classes[7].value, 8)
+        self.assertEqual(classes[7].color.name(), '#00fff6')
+        self.assertEqual(classes[8].value, 9)
+        self.assertEqual(classes[8].color.name(), '#eeff00')
+        self.assertEqual(classes[9].value, 10)
+        self.assertEqual(classes[9].color.name(), '#ffb600')
 
 if __name__ == '__main__':
     unittest.main()