Fixed incorrect handling of extra mouse buttons in XCB platform plugin.

translateMouseButtons() was only able to correctly handle the left,
right, and mid mouse buttons. Thus, if any buttons outside of those were
pressed, the motion notify event would basically unset the mouse button
mask, leading to a release event being sent instead. Later on, when the
actual release event arrives, that button gets xor'ed into the empty
button mask generating another press, and later another motion event
will generate a release. In the end that means two press-release
sequences are sent for any extra mouse buttons.

Instead of getting the mask of the buttons currently being pressed from
the event, we need to keep track of the mask ourselves.

Task-number: QTBUG-28561
Change-Id: Iaa67e784a13d792deef8fc29dbd5456a5471a861
Reviewed-by: Oliver Wolff <oliver.wolff@digia.com>
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@digia.com>
Reviewed-by: Shawn Rutledge <shawn.rutledge@digia.com>
Reviewed-by: Rick Stockton <rickstockton@reno-computerhelp.com>
Reviewed-by: Lars Knoll <lars.knoll@digia.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/src/plugins/platforms/xcb/qxcbconnection.h b/src/plugins/platforms/xcb/qxcbconnection.h
index c67acb3218..f1e707e0cd 100644
--- a/src/plugins/platforms/xcb/qxcbconnection.h
+++ b/src/plugins/platforms/xcb/qxcbconnection.h
@@ -380,6 +380,8 @@ public:
 
     xcb_timestamp_t getTimestamp();
 
+    Qt::MouseButtons buttons() const { return m_buttons; }
+
 private slots:
     void processXcbEvents();
 
@@ -400,6 +402,8 @@ private:
     QXcbScreen* findOrCreateScreen(QList<QXcbScreen *>& newScreens, int screenNumber,
         xcb_screen_t* xcbScreen, xcb_randr_get_output_info_reply_t *output = NULL);
     void updateScreens();
+    void handleButtonPress(xcb_generic_event_t *event);
+    void handleButtonRelease(xcb_generic_event_t *event);
 
     bool m_xi2Enabled;
     int m_xi2Minor;
@@ -501,6 +505,8 @@ private:
     bool has_shape_extension;
     bool has_randr_extension;
     bool has_input_shape;
+
+    Qt::MouseButtons m_buttons;
 };
 
 #define DISPLAY_FROM_XCB(object) ((Display *)(object->connection()->xlib_display()))