Revise QScrollBar internals

Move the press/move/release/ungrab logic from mouse event handlers to
QQuickScrollBarPrivate methods that can be re-used for touch events.

Change-Id: Id0b0f225a4f86a9d9cc8b77c9253001dd6c40bf4
Reviewed-by: Mitch Curtis <mitch.curtis@qt.io>

1 files changed, 47 insertions, 10 deletions

diff --git a/src/quicktemplates2/qquickscrollbar.cpp b/src/quicktemplates2/qquickscrollbar.cpp
index c291e4b1..a4ed68bf 100644
--- a/src/quicktemplates2/qquickscrollbar.cpp
+++ b/src/quicktemplates2/qquickscrollbar.cpp
@@ -167,10 +167,15 @@ public:
         return bar->d_func();
     }
 
-    qreal positionAt(const QPoint &point) const;
+    qreal positionAt(const QPointF &point) const;
     void updateActive();
     void resizeContent() override;
 
+    void handlePress(const QPointF &point);
+    void handleMove(const QPointF &point);
+    void handleRelease(const QPointF &point);
+    void handleUngrab();
+
     qreal size;
     qreal position;
     qreal stepSize;
@@ -181,7 +186,7 @@ public:
     Qt::Orientation orientation;
 };
 
-qreal QQuickScrollBarPrivate::positionAt(const QPoint &point) const
+qreal QQuickScrollBarPrivate::positionAt(const QPointF &point) const
 {
     Q_Q(const QQuickScrollBar);
     if (orientation == Qt::Horizontal)
@@ -211,6 +216,36 @@ void QQuickScrollBarPrivate::resizeContent()
     }
 }
 
+void QQuickScrollBarPrivate::handlePress(const QPointF &point)
+{
+    Q_Q(QQuickScrollBar);
+    offset = positionAt(point) - position;
+    if (offset < 0 || offset > size)
+        offset = size / 2;
+    q->setPressed(true);
+}
+
+void QQuickScrollBarPrivate::handleMove(const QPointF &point)
+{
+    Q_Q(QQuickScrollBar);
+    q->setPosition(qBound<qreal>(0.0, positionAt(point) - offset, 1.0 - size));
+}
+
+void QQuickScrollBarPrivate::handleRelease(const QPointF &point)
+{
+    Q_Q(QQuickScrollBar);
+    q->setPosition(qBound<qreal>(0.0, positionAt(point) - offset, 1.0 - size));
+    offset = 0.0;
+    q->setPressed(false);
+}
+
+void QQuickScrollBarPrivate::handleUngrab()
+{
+    Q_Q(QQuickScrollBar);
+    offset = 0.0;
+    q->setPressed(false);
+}
+
 QQuickScrollBar::QQuickScrollBar(QQuickItem *parent) :
     QQuickControl(*(new QQuickScrollBarPrivate), parent)
 {
@@ -427,26 +462,28 @@ void QQuickScrollBar::mousePressEvent(QMouseEvent *event)
 {
     Q_D(QQuickScrollBar);
     QQuickControl::mousePressEvent(event);
-    d->offset = d->positionAt(event->pos()) - d->position;
-    if (d->offset < 0 || d->offset > d->size)
-        d->offset = d->size / 2;
-    setPressed(true);
+    d->handlePress(event->localPos());
 }
 
 void QQuickScrollBar::mouseMoveEvent(QMouseEvent *event)
 {
     Q_D(QQuickScrollBar);
     QQuickControl::mouseMoveEvent(event);
-    setPosition(qBound<qreal>(0.0, d->positionAt(event->pos()) - d->offset, 1.0 - d->size));
+    d->handleMove(event->localPos());
 }
 
 void QQuickScrollBar::mouseReleaseEvent(QMouseEvent *event)
 {
     Q_D(QQuickScrollBar);
     QQuickControl::mouseReleaseEvent(event);
-    setPosition(qBound<qreal>(0.0, d->positionAt(event->pos()) - d->offset, 1.0 - d->size));
-    d->offset = 0.0;
-    setPressed(false);
+    d->handleRelease(event->localPos());
+}
+
+void QQuickScrollBar::mouseUngrabEvent()
+{
+    Q_D(QQuickScrollBar);
+    QQuickControl::mouseUngrabEvent();
+    d->handleUngrab();
 }
 
 void QQuickScrollBar::hoverChange()