xcb: Enhance SHM management code

- extract the creation of a shared memory segment into a separate
  function
- do extra checks for errors
- check that MIT-SHM extension is present once in QXcbConnection

Change-Id: I956bdf76b879ec5c95a7ed219a59ae722dc5afba
Reviewed-by: Gatis Paeglis <gatis.paeglis@qt.io>

1 files changed, 4 insertions, 0 deletions

diff --git a/src/plugins/platforms/xcb/qxcbconnection.h b/src/plugins/platforms/xcb/qxcbconnection.h
index 07df963ec5..b2713b8ac7 100644
--- a/src/plugins/platforms/xcb/qxcbconnection.h
+++ b/src/plugins/platforms/xcb/qxcbconnection.h
@@ -441,6 +441,7 @@ public:
     void sync();
 
     void handleXcbError(xcb_generic_error_t *error);
+    void printXcbError(const char *message, xcb_generic_error_t *error);
     void handleXcbEvent(xcb_generic_event_t *event);
     void printXcbEvent(const QLoggingCategory &log, const char *message,
                        xcb_generic_event_t *event) const;
@@ -478,6 +479,7 @@ public:
     bool hasXKB() const { return has_xkb; }
     bool hasXRender() const { return has_render_extension; }
     bool hasXInput2() const { return m_xi2Enabled; }
+    bool hasShm() const { return has_shm; }
 
     bool threadedEventHandling() const { return m_reader->isRunning(); }
 
@@ -545,6 +547,7 @@ private slots:
 private:
     void initializeAllAtoms();
     void sendConnectionEvent(QXcbAtom::Atom atom, uint id = 0);
+    void initializeShm();
     void initializeXFixes();
     void initializeXRender();
     void initializeXRandr();
@@ -699,6 +702,7 @@ private:
     bool has_input_shape;
     bool has_xkb = false;
     bool has_render_extension = false;
+    bool has_shm = false;
 
     Qt::MouseButtons m_buttonState = 0;
     Qt::MouseButton m_button = Qt::NoButton;