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>

6 files changed, 8 insertions, 15 deletions

diff --git a/src/gui/kernel/qguiapplication.cpp b/src/gui/kernel/qguiapplication.cpp
index 0d5a130dfd..61addab9d6 100644
--- a/src/gui/kernel/qguiapplication.cpp
+++ b/src/gui/kernel/qguiapplication.cpp
@@ -788,12 +788,6 @@ bool QGuiApplicationPrivate::isWindowBlocked(QWindow *window, QWindow **blocking
     return false;
 }
 
-bool QGuiApplicationPrivate::synthesizeMouseFromTouchEventsEnabled()
-{
-    return QCoreApplication::testAttribute(Qt::AA_SynthesizeMouseForUnhandledTouchEvents)
-            && QGuiApplicationPrivate::platformIntegration()->styleHint(QPlatformIntegration::SynthesizeMouseFromTouchEvents).toBool();
-}
-
 /*!
     Returns the QWindow that receives events tied to focus,
     such as key events.
@@ -2423,9 +2417,9 @@ void QGuiApplicationPrivate::processTouchEvent(QWindowSystemInterfacePrivate::To
         }
 
         QGuiApplication::sendSpontaneousEvent(w, &touchEvent);
-        if (!e->synthetic() && !touchEvent.isAccepted() && synthesizeMouseFromTouchEventsEnabled()) {
-            // exclude touchpads as those generate their own mouse events
-            if (touchEvent.device()->type() != QTouchDevice::TouchPad) {
+        if (!e->synthetic() && !touchEvent.isAccepted() && qApp->testAttribute(Qt::AA_SynthesizeMouseForUnhandledTouchEvents)) {
+            // exclude devices which generate their own mouse events
+            if (!(touchEvent.device()->capabilities() & QTouchDevice::MouseEmulation)) {
                 Qt::MouseButtons b = eventType == QEvent::TouchEnd ? Qt::NoButton : Qt::LeftButton;
                 if (b == Qt::NoButton)
                     self->synthesizedMousePoints.clear();
diff --git a/src/gui/kernel/qguiapplication_p.h b/src/gui/kernel/qguiapplication_p.h
index d29ebf5f10..ddbc446759 100644
--- a/src/gui/kernel/qguiapplication_p.h
+++ b/src/gui/kernel/qguiapplication_p.h
@@ -190,8 +190,6 @@ public:
     static void updateBlockedStatus(QWindow *window);
     virtual bool isWindowBlocked(QWindow *window, QWindow **blockingWindow = 0) const;
 
-    static bool synthesizeMouseFromTouchEventsEnabled();
-
     static Qt::MouseButtons buttons;
     static ulong mousePressTime;
     static Qt::MouseButton mousePressButton;
diff --git a/src/gui/kernel/qplatformintegration.cpp b/src/gui/kernel/qplatformintegration.cpp
index 6043ae0cfd..6147a2a53a 100644
--- a/src/gui/kernel/qplatformintegration.cpp
+++ b/src/gui/kernel/qplatformintegration.cpp
@@ -386,8 +386,6 @@ QVariant QPlatformIntegration::styleHint(StyleHint hint) const
         return QPlatformTheme::defaultThemeHint(QPlatformTheme::StartDragVelocity);
     case UseRtlExtensions:
         return QVariant(false);
-    case SynthesizeMouseFromTouchEvents:
-        return true;
     case SetFocusOnTouchRelease:
         return QVariant(false);
     case MousePressAndHoldInterval:
diff --git a/src/gui/kernel/qplatformintegration.h b/src/gui/kernel/qplatformintegration.h
index e6a2ef6a1f..24e19f68e6 100644
--- a/src/gui/kernel/qplatformintegration.h
+++ b/src/gui/kernel/qplatformintegration.h
@@ -141,7 +141,6 @@ public:
         FontSmoothingGamma,
         StartDragVelocity,
         UseRtlExtensions,
-        SynthesizeMouseFromTouchEvents,
         PasswordMaskCharacter,
         SetFocusOnTouchRelease,
         ShowIsMaximized,
diff --git a/src/gui/kernel/qtouchdevice.cpp b/src/gui/kernel/qtouchdevice.cpp
index cbba171276..8737825de0 100644
--- a/src/gui/kernel/qtouchdevice.cpp
+++ b/src/gui/kernel/qtouchdevice.cpp
@@ -96,6 +96,9 @@ QT_BEGIN_NAMESPACE
 
     \value NormalizedPosition Indicates that the normalized position is available, meaning that normalizedPos()
                               returns a valid value.
+
+    \value MouseEmulation Indicates that the device synthesizes mouse events.
+                          This enum value has been introduced in Qt 5.5.
 */
 
 /*!
diff --git a/src/gui/kernel/qtouchdevice.h b/src/gui/kernel/qtouchdevice.h
index 4a2d05a7b9..f2157ce2d6 100644
--- a/src/gui/kernel/qtouchdevice.h
+++ b/src/gui/kernel/qtouchdevice.h
@@ -55,7 +55,8 @@ public:
         Pressure = 0x0004,
         Velocity = 0x0008,
         RawPositions = 0x0010,
-        NormalizedPosition = 0x0020
+        NormalizedPosition = 0x0020,
+        MouseEmulation = 0x0040
     };
     Q_DECLARE_FLAGS(Capabilities, CapabilityFlag)