Control in pressDelay Flickable: detect touch release near press pos

When a control is on a Flickable with a pressDelay, any press event from
a touch device will be replayed as a mouse event due to the delay; so it
was known already that we cannot depend on the fact that we got the
first press as a touch event when checking whether the id matches before
accepting it. So we keep the previous pos when it is a synthesized mouse
event, so that we can ensure the release is also accepted. That was in
place already; but now we no longer require that the release position is
identical to the press position: staying within a distance less than the
drag threshold is also ok. Some touchscreens are too sensitive, some
users have shaky hands, so a "tap" gesture may come with some gratuitous
TouchMove events in between the press and the release.

Amends 025f938c1b4676782674d54375e1e4e560e4b6cd

Fixes: QTBUG-102036
Fixes: QTBUG-102037
Task-number: QTBUG-77202
Change-Id: Ic48b0cca2b1c05b36429925f219d75b1b0085f69
Reviewed-by: Mitch Curtis <mitch.curtis@qt.io>

2 files changed, 9 insertions, 5 deletions

diff --git a/src/quicktemplates2/qquickcontrol.cpp b/src/quicktemplates2/qquickcontrol.cpp
index 08b925ae..2c9fb71f 100644
--- a/src/quicktemplates2/qquickcontrol.cpp
+++ b/src/quicktemplates2/qquickcontrol.cpp
@@ -179,9 +179,10 @@ bool QQuickControlPrivate::acceptTouch(const QTouchEvent::TouchPoint &point)
 
     // 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;
+    if (touchId == -1 && pressWasTouch && point.state() == Qt::TouchPointReleased) {
+        const auto delta = QVector2D(point.pos() - previousPressPos);
+        if (!QQuickWindowPrivate::dragOverThreshold(delta))
+            return true;
     }
     return false;
 }
diff --git a/tests/auto/qquickcontrol/tst_qquickcontrol.cpp b/tests/auto/qquickcontrol/tst_qquickcontrol.cpp
index c8d34756..df3b31c8 100644
--- a/tests/auto/qquickcontrol/tst_qquickcontrol.cpp
+++ b/tests/auto/qquickcontrol/tst_qquickcontrol.cpp
@@ -98,9 +98,12 @@ void tst_QQuickControl::flickable()
     QSignalSpy buttonClickedSpy(button, SIGNAL(clicked()));
     QVERIFY(buttonClickedSpy.isValid());
 
-    QTest::touchEvent(window, touchDevice.data()).press(0, QPoint(button->width() / 2, button->height() / 2));
+    QPoint p(button->width() / 2, button->height() / 2);
+    QTest::touchEvent(window, touchDevice.data()).press(0, p);
     QTRY_COMPARE(buttonPressedSpy.count(), 1);
-    QTest::touchEvent(window, touchDevice.data()).release(0, QPoint(button->width() / 2, button->height() / 2));
+    p += QPoint(1, 1); // less than the drag threshold
+    QTest::touchEvent(window, touchDevice.data()).move(0, p);
+    QTest::touchEvent(window, touchDevice.data()).release(0, p);
     QTRY_COMPARE(buttonReleasedSpy.count(), 1);
     QTRY_COMPARE(buttonClickedSpy.count(), 1);
 }