Don't commit same buffer multiple times

In Qt we call flush() when we think the window might need to be
updated. It is also possible to trigger a flush while painting.

Two fixes:

1) If there are attempted flushes between beginPaint() and endPaint,
queue them up, and do them in endPaint().

2) Make sure we only commit the buffer once: after that the
compositor owns the buffer, and it can repaint on its own.

Change-Id: Ibf61068fa95760eb67dbc0b1d0534854114ea528
Reviewed-by: Johan Helsing <johan.helsing@qt.io>

1 files changed, 4 insertions, 0 deletions

diff --git a/src/client/qwaylandbuffer_p.h b/src/client/qwaylandbuffer_p.h
index 156ea9530..eea090f35 100644
--- a/src/client/qwaylandbuffer_p.h
+++ b/src/client/qwaylandbuffer_p.h
@@ -76,11 +76,15 @@ public:
     void setBusy() { mBusy = true; }
     bool busy() const { return mBusy; }
 
+    void setCommitted() { mCommitted = true; }
+    bool committed() const { return mCommitted; }
+
 protected:
     struct wl_buffer *mBuffer = nullptr;
 
 private:
     bool mBusy = false;
+    bool mCommitted = false;
 
     static void release(void *data, wl_buffer *);
     static const wl_buffer_listener listener;