QQuickSlider: handle touch events

In comparison to handling synthesized mouse events, handling touch
events has the advantage that it gives multi-touch support. That is,
it is possible to move multiple sliders at the same time, each
handling its own touch point.

Change-Id: I713307b0e6b5ee777496fc9ba68a5180d13a6aca
Reviewed-by: Mitch Curtis <mitch.curtis@qt.io>

6 files changed, 274 insertions, 2 deletions

diff --git a/src/quicktemplates2/qquickslider.cpp b/src/quicktemplates2/qquickslider.cpp
index bb3c0158..2398b1e1 100644
--- a/src/quicktemplates2/qquickslider.cpp
+++ b/src/quicktemplates2/qquickslider.cpp
@@ -89,7 +89,7 @@ class QQuickSliderPrivate : public QQuickControlPrivate
 
 public:
     QQuickSliderPrivate() : from(0), to(1), value(0), position(0), stepSize(0), live(false), pressed(false),
-        orientation(Qt::Horizontal), snapMode(QQuickSlider::NoSnap),
+        touchId(-1), orientation(Qt::Horizontal), snapMode(QQuickSlider::NoSnap),
         handle(nullptr)
     {
     }
@@ -111,6 +111,7 @@ public:
     qreal stepSize;
     bool live;
     bool pressed;
+    int touchId;
     QPointF pressPoint;
     Qt::Orientation orientation;
     QQuickSlider::SnapMode snapMode;
@@ -201,6 +202,7 @@ void QQuickSliderPrivate::handleMove(const QPointF &point)
 void QQuickSliderPrivate::handleRelease(const QPointF &point)
 {
     Q_Q(QQuickSlider);
+    touchId = -1;
     pressPoint = QPointF();
     const qreal oldPos = position;
     qreal pos = positionAt(point);
@@ -220,6 +222,7 @@ void QQuickSliderPrivate::handleRelease(const QPointF &point)
 void QQuickSliderPrivate::handleUngrab()
 {
     Q_Q(QQuickSlider);
+    touchId = -1;
     pressPoint = QPointF();
     q->setPressed(false);
 }
@@ -645,6 +648,61 @@ void QQuickSlider::mouseUngrabEvent()
     d->handleUngrab();
 }
 
+void QQuickSlider::touchEvent(QTouchEvent *event)
+{
+    Q_D(QQuickSlider);
+    switch (event->type()) {
+    case QEvent::TouchBegin:
+        if (d->touchId == -1) {
+            const QTouchEvent::TouchPoint point = event->touchPoints().first();
+            d->touchId = point.id();
+            d->handlePress(point.pos());
+        } else {
+            event->ignore();
+        }
+        break;
+
+    case QEvent::TouchUpdate:
+        for (const QTouchEvent::TouchPoint &point : event->touchPoints()) {
+            if (point.id() != d->touchId)
+                continue;
+
+            if (!keepMouseGrab()) {
+                if (d->orientation == Qt::Horizontal)
+                    setKeepMouseGrab(QQuickWindowPrivate::dragOverThreshold(point.pos().x() - d->pressPoint.x(), Qt::XAxis, &point));
+                else
+                    setKeepMouseGrab(QQuickWindowPrivate::dragOverThreshold(point.pos().y() - d->pressPoint.y(), Qt::YAxis, &point));
+            }
+            d->handleMove(point.pos());
+        }
+        break;
+
+    case QEvent::TouchEnd:
+        for (const QTouchEvent::TouchPoint &point : event->touchPoints()) {
+            if (point.id() != d->touchId)
+                continue;
+
+            d->handleRelease(point.pos());
+        }
+        break;
+
+    case QEvent::TouchCancel:
+        d->handleUngrab();
+        break;
+
+    default:
+        QQuickControl::touchEvent(event);
+        break;
+    }
+}
+
+void QQuickSlider::touchUngrabEvent()
+{
+    Q_D(QQuickSlider);
+    QQuickControl::touchUngrabEvent();
+    d->handleUngrab();
+}
+
 void QQuickSlider::wheelEvent(QWheelEvent *event)
 {
     Q_D(QQuickSlider);
diff --git a/src/quicktemplates2/qquickslider_p.h b/src/quicktemplates2/qquickslider_p.h
index 7b96168a..972dfd65 100644
--- a/src/quicktemplates2/qquickslider_p.h
+++ b/src/quicktemplates2/qquickslider_p.h
@@ -136,6 +136,8 @@ protected:
     void mouseMoveEvent(QMouseEvent *event) override;
     void mouseReleaseEvent(QMouseEvent *event) override;
     void mouseUngrabEvent() override;
+    void touchEvent(QTouchEvent *event) override;
+    void touchUngrabEvent() override;
     void wheelEvent(QWheelEvent *event) override;
 
     void mirrorChange() override;
diff --git a/tests/auto/controls/data/tst_slider.qml b/tests/auto/controls/data/tst_slider.qml
index d5c734a1..ef57d8d2 100644
--- a/tests/auto/controls/data/tst_slider.qml
+++ b/tests/auto/controls/data/tst_slider.qml
@@ -286,6 +286,184 @@ TestCase {
         compare(control.position, 0.5)
     }
 
+    function test_touch_data() {
+        return [
+            { tag: "horizontal", orientation: Qt.Horizontal, live: false },
+            { tag: "vertical", orientation: Qt.Vertical, live: false },
+            { tag: "horizontal:live", orientation: Qt.Horizontal, live: true },
+            { tag: "vertical:live", orientation: Qt.Vertical, live: true }
+        ]
+    }
+
+    function test_touch(data) {
+        var control = createTemporaryObject(slider, testCase, {orientation: data.orientation, live: data.live})
+        verify(control)
+
+        var pressedCount = 0
+        var movedCount = 0
+
+        var pressedSpy = signalSpy.createObject(control, {target: control, signalName: "pressedChanged"})
+        verify(pressedSpy.valid)
+
+        var movedSpy = signalSpy.createObject(control, {target: control, signalName: "moved"})
+        verify(movedSpy.valid)
+
+        var touch = touchEvent(control)
+        touch.press(0, control, 0, 0).commit()
+        compare(pressedSpy.count, ++pressedCount)
+        compare(movedSpy.count, movedCount)
+        compare(control.pressed, true)
+        compare(control.value, 0.0)
+        compare(control.position, 0.0)
+
+        // mininum on the left in horizontal vs. at the bottom in vertical
+        touch.move(0, control, -control.width, 2 * control.height, 0).commit()
+        compare(pressedSpy.count, pressedCount)
+        compare(movedSpy.count, movedCount)
+        compare(control.pressed, true)
+        compare(control.value, 0.0)
+        compare(control.position, 0.0)
+
+        touch.move(0, control, control.width * 0.5, control.height * 0.5, 0).commit()
+        compare(pressedSpy.count, pressedCount)
+        compare(movedSpy.count, ++movedCount)
+        compare(control.pressed, true)
+        compare(control.value, data.live ? 0.5 : 0.0)
+        compare(control.position, 0.5)
+
+        touch.release(0, control, control.width * 0.5, control.height * 0.5).commit()
+        compare(pressedSpy.count, ++pressedCount)
+        compare(movedSpy.count, movedCount)
+        compare(control.pressed, false)
+        compare(control.value, 0.5)
+        compare(control.position, 0.5)
+
+        touch.press(0, control, control.width, control.height).commit()
+        compare(pressedSpy.count, ++pressedCount)
+        compare(movedSpy.count, movedCount)
+        compare(control.pressed, true)
+        compare(control.value, 0.5)
+        compare(control.position, 0.5)
+
+        // maximum on the right in horizontal vs. at the top in vertical
+        touch.move(0, control, control.width * 2, -control.height, 0).commit()
+        compare(pressedSpy.count, pressedCount)
+        compare(movedSpy.count, ++movedCount)
+        compare(control.pressed, true)
+        compare(control.value, data.live ? 1.0 : 0.5)
+        compare(control.position, 1.0)
+
+        touch.move(0, control, control.width * 0.75, control.height * 0.25, 0).commit()
+        compare(pressedSpy.count, pressedCount)
+        compare(movedSpy.count, ++movedCount)
+        compare(control.pressed, true)
+        compare(control.value, data.live ? control.position : 0.5)
+        verify(control.position >= 0.75)
+
+        touch.release(0, control, control.width * 0.25, control.height * 0.75).commit()
+        compare(pressedSpy.count, ++pressedCount)
+        compare(movedSpy.count, ++movedCount)
+        compare(control.pressed, false)
+        compare(control.value, control.position)
+        verify(control.value <= 0.25 && control.value >= 0.0)
+        verify(control.position <= 0.25 && control.position >= 0.0)
+
+        // QTBUG-53846
+        touch.press(0, control).commit().release(0, control).commit()
+        compare(movedSpy.count, ++movedCount)
+        compare(pressedSpy.count, pressedCount += 2)
+        compare(control.value, 0.5)
+        compare(control.position, 0.5)
+    }
+
+    function test_multiTouch() {
+        var control1 = createTemporaryObject(slider, testCase)
+        verify(control1)
+
+        var pressedCount1 = 0
+        var movedCount1 = 0
+
+        var pressedSpy1 = signalSpy.createObject(control1, {target: control1, signalName: "pressedChanged"})
+        verify(pressedSpy1.valid)
+
+        var movedSpy1 = signalSpy.createObject(control1, {target: control1, signalName: "moved"})
+        verify(movedSpy1.valid)
+
+        var touch = touchEvent(control1)
+        touch.press(0, control1, 0, 0).commit().move(0, control1, control1.width, control1.height).commit()
+
+        compare(pressedSpy1.count, ++pressedCount1)
+        compare(movedSpy1.count, ++movedCount1)
+        compare(control1.pressed, true)
+        compare(control1.position, 1.0)
+
+        // second touch point on the same control is ignored
+        touch.stationary(0).press(1, control1, 0, 0).commit()
+        touch.stationary(0).move(1, control1).commit()
+        touch.stationary(0).release(1).commit()
+
+        compare(pressedSpy1.count, pressedCount1)
+        compare(movedSpy1.count, movedCount1)
+        compare(control1.pressed, true)
+        compare(control1.position, 1.0)
+
+        var control2 = createTemporaryObject(slider, testCase, {y: control1.height})
+        verify(control2)
+        waitForRendering(control2)
+
+        var pressedCount2 = 0
+        var movedCount2 = 0
+
+        var pressedSpy2 = signalSpy.createObject(control2, {target: control2, signalName: "pressedChanged"})
+        verify(pressedSpy2.valid)
+
+        var movedSpy2 = signalSpy.createObject(control2, {target: control2, signalName: "moved"})
+        verify(movedSpy2.valid)
+
+        // press the second slider
+        touch.stationary(0).press(2, control2, 0, 0).commit()
+
+        compare(pressedSpy2.count, ++pressedCount2)
+        compare(movedSpy2.count, movedCount2)
+        compare(control2.pressed, true)
+        compare(control2.position, 0.0)
+
+        compare(pressedSpy1.count, pressedCount1)
+        compare(movedSpy1.count, movedCount1)
+        compare(control1.pressed, true)
+        compare(control1.position, 1.0)
+
+        // move both sliders
+        touch.move(0, control1).move(2, control2).commit()
+
+        compare(pressedSpy2.count, pressedCount2)
+        compare(movedSpy2.count, ++movedCount2)
+        compare(control2.pressed, true)
+        compare(control2.position, 0.5)
+        compare(control2.value, 0.0)
+
+        compare(pressedSpy1.count, pressedCount1)
+        compare(movedSpy1.count, ++movedCount1)
+        compare(control1.pressed, true)
+        compare(control1.position, 0.5)
+        compare(control1.value, 0.0)
+
+        // release both sliders
+        touch.release(0, control1).release(2, control2).commit()
+
+        compare(pressedSpy2.count, ++pressedCount2)
+        compare(movedSpy2.count, movedCount2)
+        compare(control2.pressed, false)
+        compare(control2.position, 0.5)
+        compare(control2.value, 0.5)
+
+        compare(pressedSpy1.count, ++pressedCount1)
+        compare(movedSpy1.count, movedCount1)
+        compare(control1.pressed, false)
+        compare(control1.position, 0.5)
+        compare(control1.value, 0.5)
+    }
+
     function test_keys_data() {
         return [
             { tag: "horizontal", orientation: Qt.Horizontal, decrease: Qt.Key_Left, increase: Qt.Key_Right },
@@ -468,7 +646,11 @@ TestCase {
         ]
     }
 
-    function test_snapMode(data) {
+    function test_snapMode_mouse_data() {
+        return test_snapMode_data()
+    }
+
+    function test_snapMode_mouse(data) {
         var control = createTemporaryObject(slider, testCase, {snapMode: data.snapMode, from: data.from, to: data.to, stepSize: 0.2})
         verify(control)
 
@@ -490,6 +672,33 @@ TestCase {
         verify(sliderCompare(control.position, data.positions[2]))
     }
 
+    function test_snapMode_touch_data() {
+        return test_snapMode_data()
+    }
+
+    function test_snapMode_touch(data) {
+        var control = createTemporaryObject(slider, testCase, {snapMode: data.snapMode, from: data.from, to: data.to, stepSize: 0.2})
+        verify(control)
+
+        function sliderCompare(left, right) {
+            return Math.abs(left - right) < 0.05
+        }
+
+        var touch = touchEvent(control)
+        touch.press(0, control, control.leftPadding).commit()
+        compare(control.value, data.values[0])
+        compare(control.position, data.positions[0])
+
+        touch.move(0, control, control.leftPadding + 0.15 * (control.availableWidth + control.handle.width / 2)).commit()
+
+        verify(sliderCompare(control.value, data.values[1]))
+        verify(sliderCompare(control.position, data.positions[1]))
+
+        touch.release(0, control, control.leftPadding + 0.15 * (control.availableWidth + control.handle.width / 2)).commit()
+        verify(sliderCompare(control.value, data.values[2]))
+        verify(sliderCompare(control.position, data.positions[2]))
+    }
+
     function test_wheel_data() {
         return [
             { tag: "horizontal", orientation: Qt.Horizontal, dx: 120, dy: 0 },
diff --git a/tests/auto/controls/default/tst_default.cpp b/tests/auto/controls/default/tst_default.cpp
index 68c3ab8f..7bf3078f 100644
--- a/tests/auto/controls/default/tst_default.cpp
+++ b/tests/auto/controls/default/tst_default.cpp
@@ -40,5 +40,6 @@ int main(int argc, char *argv[])
 {
     QTEST_ADD_GPU_BLACKLIST_SUPPORT
     QTEST_SET_MAIN_SOURCE_PATH
+    qputenv("QML_NO_TOUCH_COMPRESSION", "1");
     return quick_test_main(argc, argv, "tst_controls::Default", TST_CONTROLS_DATA);
 }
diff --git a/tests/auto/controls/material/tst_material.cpp b/tests/auto/controls/material/tst_material.cpp
index 2825b127..5d82c030 100644
--- a/tests/auto/controls/material/tst_material.cpp
+++ b/tests/auto/controls/material/tst_material.cpp
@@ -41,6 +41,7 @@ int main(int argc, char *argv[])
 {
     QTEST_ADD_GPU_BLACKLIST_SUPPORT
     QTEST_SET_MAIN_SOURCE_PATH
+    qputenv("QML_NO_TOUCH_COMPRESSION", "1");
     QQuickStyle::setStyle("Material");
     return quick_test_main(argc, argv, "tst_controls::Material", TST_CONTROLS_DATA);
 }
diff --git a/tests/auto/controls/universal/tst_universal.cpp b/tests/auto/controls/universal/tst_universal.cpp
index de4ca85c..c06e1fc3 100644
--- a/tests/auto/controls/universal/tst_universal.cpp
+++ b/tests/auto/controls/universal/tst_universal.cpp
@@ -41,6 +41,7 @@ int main(int argc, char *argv[])
 {
     QTEST_ADD_GPU_BLACKLIST_SUPPORT
     QTEST_SET_MAIN_SOURCE_PATH
+    qputenv("QML_NO_TOUCH_COMPRESSION", "1");
     QQuickStyle::setStyle("Universal");
     return quick_test_main(argc, argv, "tst_controls::Universal", TST_CONTROLS_DATA);
 }