Slider: fix stepSize handling when snapping is enabled

The value range and step size are configurable, whereas position is
always in the range [0.0..1.0]. The snap handling was applying step
size to the position as is, without taking the value range into
account. Thus, snapping worked correctly only for the default
[0.0..1.0] value range, which happens to match with the position range.

Change-Id: If2f48d36c95554de25598d507842576a49e643b9
Reviewed-by: Mitch Curtis <mitch.curtis@theqtcompany.com>

1 files changed, 32 insertions, 0 deletions

diff --git a/tests/auto/controls/data/tst_slider.qml b/tests/auto/controls/data/tst_slider.qml
index 5957442f..53e2fb8f 100644
--- a/tests/auto/controls/data/tst_slider.qml
+++ b/tests/auto/controls/data/tst_slider.qml
@@ -439,4 +439,36 @@ TestCase {
 
         control.destroy()
     }
+
+    function test_snapMode_data() {
+        return [
+            { tag: "NoSnap", snapMode: Slider.NoSnap, values: [0, 0, 0.25], positions: [0, 0.1, 0.1] },
+            { tag: "SnapAlways", snapMode: Slider.SnapAlways, values: [0, 0, 0.2], positions: [0, 0.1, 0.1] },
+            { tag: "SnapOnRelease", snapMode: Slider.SnapOnRelease, values: [0, 0, 0.2], positions: [0, 0.1, 0.1] }
+        ]
+    }
+
+    function test_snapMode(data) {
+        var control = slider.createObject(testCase, {snapMode: data.snapMode, from: 0, to: 2, stepSize: 0.2})
+        verify(control)
+
+        function sliderCompare(left, right) {
+            return Math.abs(left - right) < 0.05
+        }
+
+        mousePress(control, control.leftPadding)
+        compare(control.value, data.values[0])
+        compare(control.position, data.positions[0])
+
+        mouseMove(control, control.leftPadding + 0.15 * (control.availableWidth + control.handle.width / 2))
+
+        verify(sliderCompare(control.value, data.values[1]))
+        verify(sliderCompare(control.position, data.positions[1]))
+
+        mouseRelease(control, control.leftPadding + 0.15 * (control.availableWidth + control.handle.width / 2))
+        verify(sliderCompare(control.value, data.values[2]))
+        verify(sliderCompare(control.position, data.positions[2]))
+
+        control.destroy()
+    }
 }