Keep track whether ScrollBar::interactive is explicitly set

The upcoming ScrollView toggles between interactive and non-interactive
scroll bars depending on whether it is interacted via touch or a mouse
device. This allows ScrollView to check whether the user or style
explicitly requested a specific mode and respect it.

Change-Id: I69d21652b3a91cb9db0f76ba52adc35ccd612ab1
Reviewed-by: Mitch Curtis <mitch.curtis@qt.io>

3 files changed, 26 insertions, 8 deletions

diff --git a/src/quicktemplates2/qquickscrollbar.cpp b/src/quicktemplates2/qquickscrollbar.cpp
index ac786649..f0dd640b 100644
--- a/src/quicktemplates2/qquickscrollbar.cpp
+++ b/src/quicktemplates2/qquickscrollbar.cpp
@@ -163,6 +163,7 @@ QQuickScrollBarPrivate::QQuickScrollBarPrivate()
       pressed(false),
       moving(false),
       interactive(true),
+      explicitInteractive(false),
       orientation(Qt::Vertical),
       snapMode(QQuickScrollBar::NoSnap),
       policy(QQuickScrollBar::AsNeeded)
@@ -187,6 +188,19 @@ qreal QQuickScrollBarPrivate::positionAt(const QPointF &point) const
         return (point.y() - q->topPadding()) / q->availableHeight();
 }
 
+void QQuickScrollBarPrivate::setInteractive(bool enabled)
+{
+    Q_Q(QQuickScrollBar);
+    if (interactive == enabled)
+        return;
+
+    interactive = enabled;
+    q->setAcceptedMouseButtons(interactive ? Qt::LeftButton : Qt::NoButton);
+    if (!interactive)
+        q->ungrabMouse();
+    emit q->interactiveChanged();
+}
+
 void QQuickScrollBarPrivate::updateActive()
 {
     Q_Q(QQuickScrollBar);
@@ -480,14 +494,15 @@ bool QQuickScrollBar::isInteractive() const
 void QQuickScrollBar::setInteractive(bool interactive)
 {
     Q_D(QQuickScrollBar);
-    if (d->interactive == interactive)
-        return;
+    d->explicitInteractive = true;
+    d->setInteractive(interactive);
+}
 
-    d->interactive = interactive;
-    setAcceptedMouseButtons(interactive ? Qt::LeftButton : Qt::NoButton);
-    if (!interactive)
-        ungrabMouse();
-    emit interactiveChanged();
+void QQuickScrollBar::resetInteractive()
+{
+    Q_D(QQuickScrollBar);
+    d->explicitInteractive = false;
+    d->setInteractive(true);
 }
 
 /*!
diff --git a/src/quicktemplates2/qquickscrollbar_p.h b/src/quicktemplates2/qquickscrollbar_p.h
index dabc860b..868cb5d8 100644
--- a/src/quicktemplates2/qquickscrollbar_p.h
+++ b/src/quicktemplates2/qquickscrollbar_p.h
@@ -65,7 +65,7 @@ class Q_QUICKTEMPLATES2_PRIVATE_EXPORT QQuickScrollBar : public QQuickControl
     Q_PROPERTY(bool pressed READ isPressed WRITE setPressed NOTIFY pressedChanged FINAL)
     Q_PROPERTY(Qt::Orientation orientation READ orientation WRITE setOrientation NOTIFY orientationChanged FINAL)
     Q_PROPERTY(SnapMode snapMode READ snapMode WRITE setSnapMode NOTIFY snapModeChanged FINAL REVISION 2)
-    Q_PROPERTY(bool interactive READ isInteractive WRITE setInteractive NOTIFY interactiveChanged FINAL REVISION 2)
+    Q_PROPERTY(bool interactive READ isInteractive WRITE setInteractive RESET resetInteractive NOTIFY interactiveChanged FINAL REVISION 2)
     Q_PROPERTY(Policy policy READ policy WRITE setPolicy NOTIFY policyChanged FINAL REVISION 2)
 
 public:
@@ -100,6 +100,7 @@ public:
 
     bool isInteractive() const;
     void setInteractive(bool interactive);
+    void resetInteractive();
 
     enum Policy {
         AsNeeded = Qt::ScrollBarAsNeeded,
diff --git a/src/quicktemplates2/qquickscrollbar_p_p.h b/src/quicktemplates2/qquickscrollbar_p_p.h
index fa5bd0b5..cbbef2c8 100644
--- a/src/quicktemplates2/qquickscrollbar_p_p.h
+++ b/src/quicktemplates2/qquickscrollbar_p_p.h
@@ -70,6 +70,7 @@ public:
 
     qreal snapPosition(qreal position) const;
     qreal positionAt(const QPointF &point) const;
+    void setInteractive(bool interactive);
     void updateActive();
     void resizeContent() override;
 
@@ -86,6 +87,7 @@ public:
     bool pressed;
     bool moving;
     bool interactive;
+    bool explicitInteractive;
     Qt::Orientation orientation;
     QQuickScrollBar::SnapMode snapMode;
     QQuickScrollBar::Policy policy;