xcb: Use XIGrabDevice instead of xcb_grab_pointer with XI 2.2

Switch to using the pointer events from XI2 when touch is available (i.e.
version is >= 2.2). This allows us to select and grab the button and motion
events together with the touch ones. This prevents the issue of not getting
touch events when grabbing via the plain xcb functions.

To prevent touch sequences from being replayed after ungrabbing (for example after
dismissing a popup that caused a grab), we try to accept touches via XIAllowTouchEvents.
Unfortunately this leads to a deadlock and therefore we can only do it when we know
we have a new enough libXi. This is a configure time check which is not ideal since
the system on which apps run can have a newer libXi than the machine that did the Qt
build, but seems like the best we can do.

The environment variable QT_XCB_NO_XI2_MOUSE can be set to 1 in order to prevent
processing mouse events through XInput. This restores the old behavior with broken
grabbing.

[ChangeLog][QtGui] Pointer event delivery on X11 is now done via XInput 2.2+ when available.

Done-with: Michal Klocek <michal.klocek@theqtcompany.com>
Done-with: Alexander Volkov <a.volkov@rusbitech.ru>
Task-number: QTBUG-43525
Task-number: QTBUG-45054
Task-number: QTBUG-30417
Change-Id: I7cb2002b31bef4cd527aa427549dcf2d5467968e
Reviewed-by: Laszlo Agocs <laszlo.agocs@theqtcompany.com>
Reviewed-by: Shawn Rutledge <shawn.rutledge@digia.com>

1 files changed, 23 insertions, 12 deletions

diff --git a/src/plugins/platforms/xcb/qxcbconnection.h b/src/plugins/platforms/xcb/qxcbconnection.h
index e4274eca4d..2005ae0701 100644
--- a/src/plugins/platforms/xcb/qxcbconnection.h
+++ b/src/plugins/platforms/xcb/qxcbconnection.h
@@ -69,7 +69,8 @@
 #endif
 #endif
 struct XInput2TouchDeviceData;
-#endif
+#endif // XCB_USE_XINPUT2
+
 struct xcb_randr_get_output_info_reply_t;
 
 //#define Q_XCB_DEBUG
@@ -347,6 +348,7 @@ public:
     virtual void handleFocusInEvent(const xcb_focus_in_event_t *) {}
     virtual void handleFocusOutEvent(const xcb_focus_out_event_t *) {}
     virtual void handlePropertyNotifyEvent(const xcb_property_notify_event_t *) {}
+    virtual void handleXIMouseEvent(xcb_ge_event_t *) {}
 
     virtual QXcbWindow *toWindow() { return 0; }
 };
@@ -413,14 +415,14 @@ public:
     void xi2Select(xcb_window_t window);
 #endif
 #ifdef XCB_USE_XINPUT21
-    bool isUsingXInput21() const { return m_xi2Enabled && m_xi2Minor >= 1; }
+    bool isAtLeastXI21() const { return m_xi2Enabled && m_xi2Minor >= 1; }
 #else
-    bool isUsingXInput21() const { return false; }
+    bool isAtLeastXI21() const { return false; }
 #endif
 #ifdef XCB_USE_XINPUT22
-    bool isUsingXInput22() const { return m_xi2Enabled && m_xi2Minor >= 2; }
+    bool isAtLeastXI22() const { return m_xi2Enabled && m_xi2Minor >= 2; }
 #else
-    bool isUsingXInput22() const { return false; }
+    bool isAtLeastXI22() const { return false; }
 #endif
 
     void sync();
@@ -457,7 +459,9 @@ public:
 
     xcb_timestamp_t getTimestamp();
 
+    void setButton(Qt::MouseButton button, bool down) { if (down) m_buttons |= button; else m_buttons &= ~button; }
     Qt::MouseButtons buttons() const { return m_buttons; }
+    Qt::MouseButton translateMouseButton(xcb_button_t s);
 
     QXcbWindow *focusWindow() const { return m_focusWindow; }
     void setFocusWindow(QXcbWindow *);
@@ -477,11 +481,19 @@ public:
     void handleEnterEvent(const xcb_enter_notify_event_t *);
 #endif
 
+#ifdef XCB_USE_XINPUT22
+    bool xi2SetMouseGrabEnabled(xcb_window_t w, bool grab);
+#endif
+    Qt::MouseButton xiToQtMouseButton(uint32_t b);
+
     QXcbEventReader *eventReader() const { return m_reader; }
 
     bool canGrab() const { return m_canGrabServer; }
 
     QXcbGlIntegration *glIntegration() const { return m_glIntegration; }
+
+    bool xi2MouseEvents() const;
+
 protected:
     bool event(QEvent *e) Q_DECL_OVERRIDE;
 
@@ -509,9 +521,6 @@ private:
     bool checkOutputIsPrimary(xcb_window_t rootWindow, xcb_randr_output_t output);
     void initializeScreens();
     void updateScreens(const xcb_randr_notify_event_t *event);
-    void handleButtonPress(xcb_generic_event_t *event);
-    void handleButtonRelease(xcb_generic_event_t *event);
-    void handleMotionNotify(xcb_generic_event_t *event);
 
     bool m_xi2Enabled;
     int m_xi2Minor;
@@ -524,6 +533,9 @@ private:
     void xi2HandleHierachyEvent(void *event);
     void xi2HandleDeviceChangedEvent(void *event);
     int m_xiOpCode, m_xiEventBase, m_xiErrorBase;
+#ifdef XCB_USE_XINPUT22
+    void xi2ProcessTouch(void *xiDevEvent, QXcbWindow *platformWindow);
+#endif // XCB_USE_XINPUT22
 #ifndef QT_NO_TABLETEVENT
     struct TabletData {
         TabletData() : deviceId(0), pointerType(QTabletEvent::UnknownPointer),
@@ -543,10 +555,10 @@ private:
         };
         QHash<int, ValuatorClassInfo> valuatorInfo;
     };
-    bool xi2HandleTabletEvent(void *event, TabletData *tabletData);
+    bool xi2HandleTabletEvent(void *event, TabletData *tabletData, QXcbWindowEventListener *eventListener);
     void xi2ReportTabletEvent(TabletData &tabletData, void *event);
     QVector<TabletData> m_tabletData;
-#endif
+#endif // !QT_NO_TABLETEVENT
     struct ScrollingDevice {
         ScrollingDevice() : deviceId(0), verticalIndex(0), horizontalIndex(0), orientations(0), legacyOrientations(0) { }
         int deviceId;
@@ -559,9 +571,7 @@ private:
     void updateScrollingDevice(ScrollingDevice& scrollingDevice, int num_classes, void *classes);
     void xi2HandleScrollEvent(void *event, ScrollingDevice &scrollingDevice);
     QHash<int, ScrollingDevice> m_scrollingDevices;
-#endif // XCB_USE_XINPUT2
 
-#if defined(XCB_USE_XINPUT2)
     static bool xi2GetValuatorValueIfSet(void *event, int valuatorNum, double *value);
     static bool xi2PrepareXIGenericDeviceEvent(xcb_ge_event_t *event, int opCode);
 #endif
@@ -633,6 +643,7 @@ private:
     QByteArray m_startupId;
     QXcbSystemTrayTracker *m_systemTrayTracker;
     QXcbGlIntegration *m_glIntegration;
+    bool m_xiGrab;
 
     friend class QXcbEventReader;
 };