From 217dd1b3b03cd40b4bb926631464c684f7f84a69 Mon Sep 17 00:00:00 2001
From: Shawn Rutledge <shawn.rutledge@qt.io>
Date: Mon, 16 Sep 2019 13:55:57 +0200
Subject: [PATCH] Mark stationary touch points as updated if pressure or
 velocity changes
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This is to inform Qt Quick when a stationary touchpoint is delivered
that it is because of a changed property. Qt Quick still needs to avoid
delivering item-customized events (with only the touch points that occur
inside the item) that contain only stationary touch points without
changed properties. To be able to check this private flag,
QQuickPointerTouchEvent needs to be a friend.

Task-number: QTBUG-77142
Change-Id: I6ee0dffbbeca9e513c77227b757252e2eec6a4ef
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@qt.io>
---
 src/gui/kernel/qevent.h            | 1 +
 src/gui/kernel/qevent_p.h          | 4 +++-
 src/gui/kernel/qguiapplication.cpp | 2 ++
 3 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/src/gui/kernel/qevent.h b/src/gui/kernel/qevent.h
index b73d90529a4..bf00d4a9a33 100644
--- a/src/gui/kernel/qevent.h
+++ b/src/gui/kernel/qevent.h
@@ -959,6 +959,7 @@ public:
         friend class QGuiApplicationPrivate;
         friend class QApplication;
         friend class QApplicationPrivate;
+        friend class QQuickPointerTouchEvent;
     };
 
 #if QT_DEPRECATED_SINCE(5, 0)
diff --git a/src/gui/kernel/qevent_p.h b/src/gui/kernel/qevent_p.h
index c2d8bd72b9c..b7645496f83 100644
--- a/src/gui/kernel/qevent_p.h
+++ b/src/gui/kernel/qevent_p.h
@@ -67,7 +67,8 @@ public:
           state(Qt::TouchPointReleased),
           pressure(-1),
           rotation(0),
-          ellipseDiameters(0, 0)
+          ellipseDiameters(0, 0),
+          stationaryWithModifiedProperty(false)
     { }
 
     inline QTouchEventTouchPointPrivate *detach()
@@ -91,6 +92,7 @@ public:
     QSizeF ellipseDiameters;
     QVector2D velocity;
     QTouchEvent::TouchPoint::InfoFlags flags;
+    bool stationaryWithModifiedProperty : 1;
     QVector<QPointF> rawScreenPositions;
 };
 
diff --git a/src/gui/kernel/qguiapplication.cpp b/src/gui/kernel/qguiapplication.cpp
index a3ef3b23144..83ca337aaae 100644
--- a/src/gui/kernel/qguiapplication.cpp
+++ b/src/gui/kernel/qguiapplication.cpp
@@ -2843,10 +2843,12 @@ void QGuiApplicationPrivate::processTouchEvent(QWindowSystemInterfacePrivate::To
             if (touchPoint.state() == Qt::TouchPointStationary) {
                 if (touchInfo.touchPoint.velocity() != touchPoint.velocity()) {
                     touchInfo.touchPoint.setVelocity(touchPoint.velocity());
+                    touchPoint.d->stationaryWithModifiedProperty = true;
                     stationaryTouchPointChangedProperty = true;
                 }
                 if (!qFuzzyCompare(touchInfo.touchPoint.pressure(), touchPoint.pressure())) {
                     touchInfo.touchPoint.setPressure(touchPoint.pressure());
+                    touchPoint.d->stationaryWithModifiedProperty = true;
                     stationaryTouchPointChangedProperty = true;
                 }
             } else {