QQuickSwitch: fix event handling

Switch implemented custom event handling for the indicator, and used
QQuickAbstractButton's event handling for the background. This lead to
inconsistent signals depending on whether interacting with the handle
or the background. This change gets rid of the child mouse event filter
for the indicator and makes QQuickSwitch fully utilize the base class
event handlers.

Change-Id: I773e2eb939cbbf4bc9086cdf2b34e876597ea08e
Reviewed-by: Mitch Curtis <mitch.curtis@qt.io>

3 files changed, 108 insertions, 91 deletions

diff --git a/src/quicktemplates2/qquickswitch.cpp b/src/quicktemplates2/qquickswitch.cpp
index beb9a764..27043c8b 100644
--- a/src/quicktemplates2/qquickswitch.cpp
+++ b/src/quicktemplates2/qquickswitch.cpp
@@ -90,97 +90,28 @@ class QQuickSwitchPrivate : public QQuickAbstractButtonPrivate
 public:
     QQuickSwitchPrivate() : position(0) { }
 
-    qreal positionAt(const QPoint &point) const;
-
-    bool handleMousePressEvent(QQuickItem *child, QMouseEvent *event);
-    bool handleMouseMoveEvent(QQuickItem *child, QMouseEvent *event);
-    bool handleMouseReleaseEvent(QQuickItem *child, QMouseEvent *event);
-    bool handleMouseUngrabEvent(QQuickItem *child);
+    qreal positionAt(const QPointF &point) const;
 
     qreal position;
-    QPoint pressPoint;
 };
 
-qreal QQuickSwitchPrivate::positionAt(const QPoint &point) const
+qreal QQuickSwitchPrivate::positionAt(const QPointF &point) const
 {
     Q_Q(const QQuickSwitch);
-    qreal pos = point.x() / indicator->width();
+    qreal pos = 0.0;
+    if (indicator)
+        pos = indicator->mapFromItem(q, point).x() / indicator->width();
     if (q->isMirrored())
         return 1.0 - pos;
     return pos;
 }
 
-bool QQuickSwitchPrivate::handleMousePressEvent(QQuickItem *child, QMouseEvent *event)
-{
-    Q_Q(QQuickSwitch);
-    Q_UNUSED(child);
-    if ((focusPolicy & Qt::ClickFocus) == Qt::ClickFocus && !QGuiApplication::styleHints()->setFocusOnTouchRelease())
-        q->forceActiveFocus(Qt::MouseFocusReason);
-
-    pressPoint = event->pos();
-    q->setPressed(true);
-    emit q->pressed();
-    event->accept();
-    return true;
-}
-
-bool QQuickSwitchPrivate::handleMouseMoveEvent(QQuickItem *child, QMouseEvent *event)
-{
-    Q_Q(QQuickSwitch);
-    if (!child->keepMouseGrab())
-        child->setKeepMouseGrab(QQuickWindowPrivate::dragOverThreshold(event->pos().x() - pressPoint.x(), Qt::XAxis, event));
-    if (child->keepMouseGrab()) {
-        q->setPosition(positionAt(event->pos()));
-        event->accept();
-    }
-    return true;
-}
-
-bool QQuickSwitchPrivate::handleMouseReleaseEvent(QQuickItem *child, QMouseEvent *event)
-{
-    Q_Q(QQuickSwitch);
-    if ((focusPolicy & Qt::ClickFocus) == Qt::ClickFocus && QGuiApplication::styleHints()->setFocusOnTouchRelease())
-        q->forceActiveFocus(Qt::MouseFocusReason);
-
-    pressPoint = QPoint();
-    q->setPressed(false);
-    if (child->keepMouseGrab()) {
-        bool wasChecked = checked;
-        q->setChecked(position > 0.5);
-        q->setPosition(checked ? 1.0 : 0.0);
-        child->setKeepMouseGrab(false);
-        if (wasChecked != checked) {
-            emit q->released();
-            emit q->clicked();
-        }
-        event->accept();
-    } else {
-        q->toggle();
-        emit q->released();
-        emit q->clicked();
-        event->accept();
-    }
-    return true;
-}
-
-bool QQuickSwitchPrivate::handleMouseUngrabEvent(QQuickItem *child)
-{
-    Q_Q(QQuickSwitch);
-    Q_UNUSED(child);
-    pressPoint = QPoint();
-    q->setChecked(position > 0.5);
-    q->setPosition(checked ? 1.0 : 0.0);
-    q->setPressed(false);
-    return true;
-}
-
 QQuickSwitch::QQuickSwitch(QQuickItem *parent) :
     QQuickAbstractButton(*(new QQuickSwitchPrivate), parent)
 {
     Q_D(QQuickSwitch);
     d->keepPressed = true;
     setCheckable(true);
-    setFiltersChildMouseEvents(true);
 }
 
 /*!
@@ -221,30 +152,42 @@ qreal QQuickSwitch::visualPosition() const
     return d->position;
 }
 
+void QQuickSwitch::mousePressEvent(QMouseEvent *event)
+{
+    QQuickAbstractButton::mousePressEvent(event);
+}
+
+void QQuickSwitch::mouseMoveEvent(QMouseEvent *event)
+{
+    Q_D(QQuickSwitch);
+    QQuickAbstractButton::mouseMoveEvent(event);
+
+    const QPointF movePoint = event->localPos();
+    if (!keepMouseGrab())
+        setKeepMouseGrab(QQuickWindowPrivate::dragOverThreshold(movePoint.x() - d->pressPoint.x(), Qt::XAxis, event));
+    if (keepMouseGrab())
+        setPosition(d->positionAt(movePoint));
+}
+
+void QQuickSwitch::mouseReleaseEvent(QMouseEvent *event)
+{
+    QQuickAbstractButton::mouseReleaseEvent(event);
+    setKeepMouseGrab(false);
+}
+
 void QQuickSwitch::mirrorChange()
 {
     QQuickAbstractButton::mirrorChange();
     emit visualPositionChanged();
 }
 
-bool QQuickSwitch::childMouseEventFilter(QQuickItem *child, QEvent *event)
+void QQuickSwitch::nextCheckState()
 {
     Q_D(QQuickSwitch);
-    if (child == indicator()) {
-        switch (event->type()) {
-        case QEvent::MouseButtonPress:
-            return d->handleMousePressEvent(child, static_cast<QMouseEvent *>(event));
-        case QEvent::MouseMove:
-            return d->handleMouseMoveEvent(child, static_cast<QMouseEvent *>(event));
-        case QEvent::MouseButtonRelease:
-            return d->handleMouseReleaseEvent(child, static_cast<QMouseEvent *>(event));
-        case QEvent::UngrabMouse:
-            return d->handleMouseUngrabEvent(child);
-        default:
-            return false;
-        }
-    }
-    return false;
+    if (keepMouseGrab())
+        setChecked(d->position > 0.5);
+    else
+        QQuickAbstractButton::nextCheckState();
 }
 
 void QQuickSwitch::checkStateSet()
diff --git a/src/quicktemplates2/qquickswitch_p.h b/src/quicktemplates2/qquickswitch_p.h
index bfbcceed..27a065b4 100644
--- a/src/quicktemplates2/qquickswitch_p.h
+++ b/src/quicktemplates2/qquickswitch_p.h
@@ -73,9 +73,13 @@ Q_SIGNALS:
     void visualPositionChanged();
 
 protected:
+    void mousePressEvent(QMouseEvent *event) override;
+    void mouseMoveEvent(QMouseEvent *event) override;
+    void mouseReleaseEvent(QMouseEvent *event) override;
+
     void mirrorChange() override;
-    bool childMouseEventFilter(QQuickItem *child, QEvent *event) override;
 
+    void nextCheckState() override;
     void checkStateSet() override;
 
 private:
diff --git a/tests/auto/controls/data/tst_switch.qml b/tests/auto/controls/data/tst_switch.qml
index 1b77ff42..f854526c 100644
--- a/tests/auto/controls/data/tst_switch.qml
+++ b/tests/auto/controls/data/tst_switch.qml
@@ -200,6 +200,76 @@ TestCase {
         control.destroy()
     }
 
+    function test_drag() {
+        var control = swtch.createObject(testCase, {leftPadding: 100, rightPadding: 100})
+        verify(control)
+
+        var spy = signalSequenceSpy.createObject(control, {target: control})
+        compare(control.position, 0.0)
+        compare(control.checked, false)
+        compare(control.pressed, false)
+
+        // press-drag-release inside the indicator
+        spy.expectedSequence = [["pressedChanged", { "pressed": true, "checked": false }],
+                                "pressed"]
+        mousePress(control.indicator, 0)
+        compare(control.position, 0.0)
+        compare(control.checked, false)
+        compare(control.pressed, true)
+        verify(spy.success)
+
+        mouseMove(control.indicator, control.width)
+        compare(control.position, 1.0)
+        compare(control.checked, false)
+        compare(control.pressed, true)
+
+        spy.expectedSequence = [["pressedChanged", { "pressed": false, "checked": false }],
+                                ["checkedChanged", { "pressed": false, "checked": true }],
+                                "released",
+                                "clicked"]
+        mouseRelease(control.indicator, control.indicator.width)
+        compare(control.position, 1.0)
+        compare(control.checked, true)
+        compare(control.pressed, false)
+        verify(spy.success)
+
+        // press-drag-release outside the indicator
+        spy.expectedSequence = [["pressedChanged", { "pressed": true, "checked": true }],
+                                "pressed"]
+        mousePress(control, 0)
+        compare(control.position, 1.0)
+        compare(control.checked, true)
+        compare(control.pressed, true)
+        verify(spy.success)
+
+        mouseMove(control, control.width - control.rightPadding)
+        compare(control.position, 1.0)
+        compare(control.checked, true)
+        compare(control.pressed, true)
+
+        mouseMove(control, control.width / 2)
+        compare(control.position, 0.5)
+        compare(control.checked, true)
+        compare(control.pressed, true)
+
+        mouseMove(control, control.leftPadding)
+        compare(control.position, 0.0)
+        compare(control.checked, true)
+        compare(control.pressed, true)
+
+        spy.expectedSequence = [["pressedChanged", { "pressed": false, "checked": true }],
+                                ["checkedChanged", { "pressed": false, "checked": false }],
+                                "released",
+                                "clicked"]
+        mouseRelease(control, control.width)
+        compare(control.position, 0.0)
+        compare(control.checked, false)
+        compare(control.pressed, false)
+        verify(spy.success)
+
+        control.destroy()
+    }
+
     function test_keys() {
         var control = swtch.createObject(testCase)
         verify(control)