Add equality operator for gradients, ensure stops are always in order

python/core/symbology-ng/qgsvectorcolorrampv2.sip

@@ -78,6 +78,8 @@ class QgsGradientStop
 
     //! Gradient color at stop
     QColor color;
+
+    bool operator==( const QgsGradientStop& other ) const;
 };
 
 //! List of gradient stops

src/core/symbology-ng/qgsvectorcolorrampv2.cpp

@@ -235,6 +235,19 @@ void QgsVectorGradientColorRampV2::convertToDiscrete( bool discrete )
   mDiscrete = discrete;
 }
 
+bool stopLessThan( const QgsGradientStop &s1, const QgsGradientStop &s2 )
+{
+  return s1.offset < s2.offset;
+}
+
+void QgsVectorGradientColorRampV2::setStops( const QgsGradientStopsList &stops )
+{
+  mStops = stops;
+
+  //sort stops by offset
+  qSort( mStops.begin(), mStops.end(), stopLessThan );
+}
+
 void QgsVectorGradientColorRampV2::addStopsToGradient( QGradient* gradient, double alpha )
 {
   //copy color ramp stops to a QGradient

src/core/symbology-ng/qgsvectorcolorrampv2.h

@@ -81,6 +81,11 @@ class CORE_EXPORT QgsGradientStop
     double offset;
     //! Gradient color at stop
     QColor color;
+
+    bool operator==( const QgsGradientStop& other ) const
+    {
+      return other.color == color && qgsDoubleNear( other.offset, offset );
+    }
 };
 
 //! List of gradient stops
@@ -170,10 +175,12 @@ class CORE_EXPORT QgsVectorGradientColorRampV2 : public QgsVectorColorRampV2
     void convertToDiscrete( bool discrete );
 
     /** Sets the list of intermediate gradient stops for the ramp.
-     * @param stops list of stops. Any existing color stops will be replaced
+     * @param stops list of stops. Any existing color stops will be replaced. The stop
+     * list will be automatically reordered so that stops are listed in ascending offset
+     * order.
      * @see stops()
      */
-    void setStops( const QgsGradientStopsList& stops ) { mStops = stops; }
+    void setStops( const QgsGradientStopsList& stops );
 
     /** Returns the list of intermediate gradient stops for the ramp.
      * @see setStops()

tests/src/python/test_qgsvectorcolorramp.py

@@ -26,6 +26,14 @@ from qgis.testing import unittest
 class PyQgsVectorColorRamp(unittest.TestCase):
 
     def testQgsVectorGradientRampV2(self):
+        # test QgsGradientStop
+        stop = QgsGradientStop(0.9, QColor(200, 150, 100))
+        self.assertEqual(stop.offset, 0.9)
+        self.assertEqual(stop.color, QColor(200, 150, 100))
+        self.assertEqual(QgsGradientStop(0.1, QColor(180, 20, 30)), QgsGradientStop(0.1, QColor(180, 20, 30)))
+        self.assertNotEqual(QgsGradientStop(0.1, QColor(180, 20, 30)), QgsGradientStop(0.2, QColor(180, 20, 30)))
+        self.assertNotEqual(QgsGradientStop(0.1, QColor(180, 20, 30)), QgsGradientStop(0.1, QColor(180, 40, 30)))
+
         # test gradient with only start/end color
         r = QgsVectorGradientColorRampV2(QColor(200, 0, 0, 100), QColor(0, 200, 0, 200))
         self.assertEqual(r.type(), 'gradient')
@@ -135,6 +143,23 @@ class PyQgsVectorColorRamp(unittest.TestCase):
         self.assertEqual(g.stops()[2], (0.9, QColor(40, 60, 100, 127)))
         self.assertEqual(g.stops()[3], (1.0, QColor(0, 200, 0, 127)))
 
+        # test that stops are ordered when setting them
+        # first add some out-of-order stops
+        r.setStops([QgsGradientStop(0.4, QColor(100, 100, 40)),
+                    QgsGradientStop(0.2, QColor(200, 200, 80)),
+                    QgsGradientStop(0.8, QColor(50, 20, 10)),
+                    QgsGradientStop(0.6, QColor(10, 10, 4))])
+        s = r.stops()
+        self.assertEqual(len(s), 4)
+        self.assertEqual(s[0].offset, 0.2)
+        self.assertEqual(s[0].color, QColor(200, 200, 80))
+        self.assertEqual(s[1].offset, 0.4)
+        self.assertEqual(s[1].color, QColor(100, 100, 40))
+        self.assertEqual(s[2].offset, 0.6)
+        self.assertEqual(s[2].color, QColor(10, 10, 4))
+        self.assertEqual(s[3].offset, 0.8)
+        self.assertEqual(s[3].color, QColor(50, 20, 10))
+
     def testQgsVectorRandomColorRampV2(self):
         # test random color ramp
         r = QgsVectorRandomColorRampV2(5)