Add unit tests for QgsRasterBandComboBox

src/gui/raster/qgsrasterbandcombobox.cpp

@@ -25,6 +25,7 @@ QgsRasterBandComboBox::QgsRasterBandComboBox( QWidget *parent )
   {
     emit bandChanged( currentIndex() >= 0 ? currentData().toInt() : -1 );
   } );
+  setEnabled( false );
 }
 
 QgsRasterLayer *QgsRasterBandComboBox::layer() const
@@ -41,6 +42,8 @@ void QgsRasterBandComboBox::setLayer( QgsMapLayer *layer )
 {
   QgsRasterLayer *rl = qobject_cast< QgsRasterLayer * >( layer );
   mLayer = rl;
+  int oldBand = currentBand();
+
   blockSignals( true );
   clear();
 
@@ -63,7 +66,7 @@ void QgsRasterBandComboBox::setLayer( QgsMapLayer *layer )
   setEnabled( count() > 1 );
 
   if ( count() > 0 )
-    setCurrentIndex( 0 );
+    setCurrentIndex( findData( oldBand ) >= 0 ? findData( oldBand ) : 0 );
 
   blockSignals( false );
   emit bandChanged( currentIndex() >= 0 ? currentData().toInt() : -1 );

tests/src/python/CMakeLists.txt

@@ -103,6 +103,7 @@ ADD_PYTHON_TEST(PyQgsPointDisplacementRenderer test_qgspointdisplacementrenderer
 ADD_PYTHON_TEST(PyQgsProjectionSelectionWidgets test_qgsprojectionselectionwidgets.py)
 ADD_PYTHON_TEST(PyQgsRange test_qgsrange.py)
 ADD_PYTHON_TEST(PyQgsRangeWidgets test_qgsrangewidgets.py)
+ADD_PYTHON_TEST(PyQgsRasterBandComboBox test_qgsrasterbandcombobox.py)
 ADD_PYTHON_TEST(PyQgsRasterFileWriter test_qgsrasterfilewriter.py)
 ADD_PYTHON_TEST(PyQgsRasterFileWriterTask test_qgsrasterfilewritertask.py)
 ADD_PYTHON_TEST(PyQgsRasterLayer test_qgsrasterlayer.py)

tests/src/python/test_qgsrasterbandcombobox.py

@@ -0,0 +1,127 @@
+# -*- coding: utf-8 -*-
+"""QGIS Unit tests for QgsRasterBandComboBox.
+
+.. note:: 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__ = '09/05/2017'
+__copyright__ = 'Copyright 2017, The QGIS Project'
+# This will get replaced with a git SHA1 when you do a git archive
+__revision__ = '$Format:%H$'
+
+import qgis  # NOQA
+import os
+
+from qgis.core import QgsRasterLayer
+from qgis.gui import QgsRasterBandComboBox
+from qgis.testing import start_app, unittest
+from qgis.PyQt.QtCore import QFileInfo
+from qgis.PyQt.QtTest import QSignalSpy
+from utilities import unitTestDataPath
+
+start_app()
+
+
+class TestQgsRasterBandComboBox(unittest.TestCase):
+
+    def testNoLayer(self):
+        """
+        Test widget with no layer
+        """
+
+        combo = QgsRasterBandComboBox()
+        self.assertFalse(combo.layer())
+        self.assertEqual(combo.currentBand(), -1)
+        self.assertFalse(combo.isEnabled())
+
+        combo.setShowNotSetOption(True)
+        self.assertEqual(combo.currentBand(), -1)
+        self.assertFalse(combo.isEnabled())
+
+        combo.setBand(11111)
+        self.assertEqual(combo.currentBand(), -1)
+        combo.setBand(-11111)
+        self.assertEqual(combo.currentBand(), -1)
+
+    def testOneBandRaster(self):
+        path = os.path.join(unitTestDataPath('raster'),
+                            'band1_float32_noct_epsg4326.tif')
+        info = QFileInfo(path)
+        base_name = info.baseName()
+        layer = QgsRasterLayer(path, base_name)
+        self.assertTrue(layer)
+
+        combo = QgsRasterBandComboBox()
+        combo.setLayer(layer)
+        self.assertEqual(combo.layer(), layer)
+        self.assertEqual(combo.currentBand(), 1)
+        # only one choice, should be disabled
+        self.assertEqual(combo.count(), 1)
+        self.assertFalse(combo.isEnabled())
+
+        combo.setShowNotSetOption(True)
+        self.assertEqual(combo.currentBand(), 1)
+        self.assertEqual(combo.count(), 2)
+        self.assertTrue(combo.isEnabled())
+        combo.setBand(-1)
+        self.assertEqual(combo.currentBand(), -1)
+        combo.setBand(1)
+        self.assertEqual(combo.currentBand(), 1)
+
+        combo.setShowNotSetOption(False)
+        self.assertEqual(combo.currentBand(), 1)
+        self.assertEqual(combo.count(), 1)
+        self.assertFalse(combo.isEnabled())
+
+    def testMultiBandRaster(self):
+        path = os.path.join(unitTestDataPath('raster'),
+                            'band3_float32_noct_epsg4326.tif')
+        info = QFileInfo(path)
+        base_name = info.baseName()
+        layer = QgsRasterLayer(path, base_name)
+        self.assertTrue(layer)
+
+        combo = QgsRasterBandComboBox()
+        combo.setLayer(layer)
+        self.assertEqual(combo.layer(), layer)
+        self.assertEqual(combo.currentBand(), 1)
+        self.assertEqual(combo.count(), 3)
+        self.assertTrue(combo.isEnabled())
+        combo.setBand(2)
+        self.assertEqual(combo.currentBand(), 2)
+
+        combo.setShowNotSetOption(True)
+        self.assertEqual(combo.currentBand(), 2)
+        self.assertEqual(combo.count(), 4)
+        self.assertTrue(combo.isEnabled())
+
+        combo.setShowNotSetOption(False)
+        self.assertEqual(combo.currentBand(), 2)
+        self.assertEqual(combo.count(), 3)
+        self.assertTrue(combo.isEnabled())
+
+    def testSignals(self):
+        path = os.path.join(unitTestDataPath('raster'),
+                            'band3_float32_noct_epsg4326.tif')
+        info = QFileInfo(path)
+        base_name = info.baseName()
+        layer = QgsRasterLayer(path, base_name)
+        self.assertTrue(layer)
+
+        combo = QgsRasterBandComboBox()
+        combo.setLayer(layer)
+
+        signal_spy = QSignalSpy(combo.bandChanged)
+        combo.setBand(2)
+        self.assertEqual(len(signal_spy), 1)
+        self.assertEqual(signal_spy[0][0], 2)
+        combo.setBand(3)
+        self.assertEqual(len(signal_spy), 2)
+        self.assertEqual(signal_spy[1][0], 3)
+
+
+if __name__ == '__main__':
+    unittest.main()