Decide whether to synthesize mouse events on a per device basis

Currently Qt uses the QPlatformIntegration::StyleHint
SynthesizeMouseFromTouchEvents to check whether to synthesize mouse
events from touch events. But not only platform plugins can produce
touch events, they can be created by e.g. QTest::touchEvent() and in
this case we almost definitely need synthesizing regardless of the
platform.

This commit introduces a QTouchDevice::MouseEmulation capability which
replaces use of the QPlatformIntegration::SynthesizeMouseFromTouchEvents.
So it's possible to pass QTouchDevice without this capability to
QTest::touchEvent() and be sure that mouse events will be synthesized.
Notice that touch pads always emulate mouse events.
As a result we can activate some tests which were disabled for specific
platform configurations by commits 6c1670d8c273819435867c42725c0db0eee597dc
and e9760f1559361c39f269fb89f1ebd01f6ee8378d.

Change-Id: Idc82fa4007a095fc1cb5934979361b0023d2b793
Reviewed-by: Laszlo Agocs <laszlo.agocs@theqtcompany.com>

1 files changed, 12 insertions, 7 deletions

diff --git a/src/plugins/platforms/windows/qwindowsintegration.cpp b/src/plugins/platforms/windows/qwindowsintegration.cpp
index 63dcb6abf8..af7ecd5834 100644
--- a/src/plugins/platforms/windows/qwindowsintegration.cpp
+++ b/src/plugins/platforms/windows/qwindowsintegration.cpp
@@ -227,6 +227,18 @@ QWindowsIntegrationPrivate::QWindowsIntegrationPrivate(const QStringList &paramL
     qCDebug(lcQpaWindows)
         << __FUNCTION__ << "DpiAwareness=" << dpiAwareness <<",Scaling="
         << QWindowsScaling::factor();
+
+    QTouchDevice *touchDevice = m_context.touchDevice();
+    if (touchDevice) {
+#ifdef Q_OS_WINCE
+        touchDevice->setCapabilities(touchDevice->capabilities() | QTouchDevice::MouseEmulation);
+#else
+        if (!(m_options & QWindowsIntegration::DontPassOsMouseEventsSynthesizedFromTouch)) {
+            touchDevice->setCapabilities(touchDevice->capabilities() | QTouchDevice::MouseEmulation);
+        }
+#endif
+        QWindowSystemInterface::registerTouchDevice(touchDevice);
+    }
 }
 
 QWindowsIntegrationPrivate::~QWindowsIntegrationPrivate()
@@ -496,13 +508,6 @@ QVariant QWindowsIntegration::styleHint(QPlatformIntegration::StyleHint hint) co
         break;
     case QPlatformIntegration::UseRtlExtensions:
         return QVariant(d->m_context.useRTLExtensions());
-    case QPlatformIntegration::SynthesizeMouseFromTouchEvents:
-#ifdef Q_OS_WINCE
-        // We do not want Qt to synthesize mouse events as Windows also does that.
-       return false;
-#else // Q_OS_WINCE
-       return QVariant(bool(d->m_options & DontPassOsMouseEventsSynthesizedFromTouch));
-#endif // !Q_OS_WINCE
     default:
         break;
     }