Account for when a touch event is synthesized by Qt as a mouse event

When a control is on a Flickable with a pressDelay then any press events
sent from a touch device will be replayed as mouse events due to the
delay. As a result we cannot depend on the fact that we got the first
press as a touch event when checking if the id matches before accepting
it. So we need to keep the previous pos when it is a synthesized mouse
event so we can ensure the release is also accepted.

Fixes: QTBUG-77202
Change-Id: I6f5d8506bd803daf834093e8fd412504150c4ca6
Reviewed-by: Shawn Rutledge <shawn.rutledge@qt.io>
Reviewed-by: Mitch Curtis <mitch.curtis@qt.io>

1 files changed, 12 insertions, 0 deletions

diff --git a/src/quicktemplates2/qquickcontrol.cpp b/src/quicktemplates2/qquickcontrol.cpp
index 7e249dae..838a841d 100644
--- a/src/quicktemplates2/qquickcontrol.cpp
+++ b/src/quicktemplates2/qquickcontrol.cpp
@@ -178,6 +178,12 @@ bool QQuickControlPrivate::acceptTouch(const QTouchEvent::TouchPoint &point)
         return true;
     }
 
+    // If the control is on a Flickable that has a pressDelay, then the press is never
+    // sent as a touch event, therefore we need to check for this case.
+    if (touchId == -1 && pressWasTouch && point.state() == Qt::TouchPointReleased &&
+        point.pos() == previousPressPos) {
+        return true;
+    }
     return false;
 }
 #endif
@@ -213,6 +219,8 @@ void QQuickControlPrivate::handleRelease(const QPointF &)
     if ((focusPolicy & Qt::ClickFocus) == Qt::ClickFocus && QGuiApplication::styleHints()->setFocusOnTouchRelease())
         setActiveFocus(q, Qt::MouseFocusReason);
     touchId = -1;
+    pressWasTouch = false;
+    previousPressPos = QPointF();
 }
 
 void QQuickControlPrivate::handleUngrab()
@@ -2103,6 +2111,10 @@ void QQuickControl::mousePressEvent(QMouseEvent *event)
 {
     Q_D(QQuickControl);
     d->handlePress(event->localPos());
+    if (event->source() == Qt::MouseEventSynthesizedByQt) {
+        d->pressWasTouch = true;
+        d->previousPressPos = event->localPos();
+    }
     event->accept();
 }