QQuickWidget: don't set WA_AcceptTouchEvents on macOS

Usually, a QTouchEvent comes from a touchscreen, and we want those touch
events in Qt Quick. But on macOS, there are no touchscreens, and
WA_AcceptTouchEvents has a different meaning: since qtbase
03d057ff01332333b98f5298c3d0bd85b5604ac9, QApplication::notify()
calls the native-integration function registertouchwindow() to change
NSView::allowedTouchTypes to include NSTouchTypeMaskIndirect when the
trackpad cursor enters the window, and removes that mask when the cursor
exits. In other words, WA_AcceptTouchEvents enables getting discrete
touchpoints from the trackpad. We rather prefer to get mouse, wheel and
native gesture events from the trackpad (because those provide more of a
"native feel"). The only exception is for MultiPointTouchArea, and it
takes care of that for itself. So don't automatically set
WA_AcceptTouchEvents on macOS. The user can still do it, but we don't
recommend it. Amends dc8f44b14501ecd4acc196f5138aeff3f7502d0a

Fixes: QTBUG-113384
Pick-to: 6.5 6.2
Change-Id: I8b0e1d247adfc95f1c9a0881a6020eab1a42b0ab
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@qt.io>
(cherry picked from commit 2f1be4c51a1655697933468c10ba53316306d207)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>
(cherry picked from commit 485388263f55ac7c40c53fa3b0d4bfaa275e55f1)

2 files changed, 23 insertions, 1 deletions

diff --git a/src/quickwidgets/qquickwidget.cpp b/src/quickwidgets/qquickwidget.cpp
index c2c0f6f8d3..205c9e31c7 100644
--- a/src/quickwidgets/qquickwidget.cpp
+++ b/src/quickwidgets/qquickwidget.cpp
@@ -612,7 +612,24 @@ QQuickWidget::QQuickWidget(QWidget *parent)
 {
     setMouseTracking(true);
     setFocusPolicy(Qt::StrongFocus);
+#ifndef Q_OS_MACOS
+    /*
+        Usually, a QTouchEvent comes from a touchscreen, and we want those
+        touch events in Qt Quick. But on macOS, there are no touchscreens, and
+        WA_AcceptTouchEvents has a different meaning: QApplication::notify()
+        calls the native-integration function registertouchwindow() to change
+        NSView::allowedTouchTypes to include NSTouchTypeMaskIndirect when the
+        trackpad cursor enters the window, and removes that mask when the
+        cursor exits. In other words, WA_AcceptTouchEvents enables getting
+        discrete touchpoints from the trackpad. We rather prefer to get mouse,
+        wheel and native gesture events from the trackpad (because those
+        provide more of a "native feel"). The only exception is for
+        MultiPointTouchArea, and it takes care of that for itself. So don't
+        automatically set WA_AcceptTouchEvents on macOS. The user can still do
+        it, but we don't recommend it.
+    */
     setAttribute(Qt::WA_AcceptTouchEvents);
+#endif
     d_func()->init();
 }
 
diff --git a/tests/auto/quickwidgets/qquickwidget/tst_qquickwidget.cpp b/tests/auto/quickwidgets/qquickwidget/tst_qquickwidget.cpp
index 6d097409b0..6ff46ad983 100644
--- a/tests/auto/quickwidgets/qquickwidget/tst_qquickwidget.cpp
+++ b/tests/auto/quickwidgets/qquickwidget/tst_qquickwidget.cpp
@@ -703,7 +703,9 @@ void tst_qquickwidget::touchTapHandler()
 
     QCoreApplication::setAttribute(Qt::AA_SynthesizeMouseForUnhandledTouchEvents, guiSynthMouse);
     QQuickWidget quick;
-    QVERIFY(quick.testAttribute(Qt::WA_AcceptTouchEvents));
+    if (!quick.testAttribute(Qt::WA_AcceptTouchEvents))
+        QSKIP("irrelevant on non-touch platforms");
+
     quick.setSource(testFileUrl("tapHandler.qml"));
     quick.show();
     QVERIFY(QTest::qWaitForWindowExposed(&quick));
@@ -728,6 +730,9 @@ void tst_qquickwidget::touchMultipleWidgets()
     QWidget window;
     QQuickWidget *leftQuick = new QQuickWidget;
     leftQuick->setSource(testFileUrl("button.qml"));
+    if (!leftQuick->testAttribute(Qt::WA_AcceptTouchEvents))
+        QSKIP("irrelevant on non-touch platforms");
+
     QQuickWidget *rightQuick = new QQuickWidget;
     rightQuick->setSource(testFileUrl("button.qml"));