GNOME Bugzilla – Bug 757104
Black border appears during resize before content of window is displayed
Last modified: 2018-02-15 08:08:04 UTC
Created attachment 314092 [details] [review] Patch to set background of GTKWindow to bg color of theme When a toplevel window (GTK+3 application window) is enlarged, the additional space is drawn black until the widget has processed the reconfigure event and overdraws this blank space. A similar effect is seen when maximizing or panning in the window from the outside of the screen (no compositing WM used). After this commit, the effect became much more noticeable as apparently now the GDK default for the background is always used (solid black). https://git.gnome.org/browse/gtk+/commit/?h=gtk-3-18&id=74f2d9448f24bbfdaf32ae6b328ed3e126700afe In case you do not want to revert this commit, I suggest that the solid background color of the GDKWindow be set according to the theme used. This makes the reconfigure appear more smoothly again. I will attach a patch for this.
What window manager is this with ? GTK+ uses the _NET_WM_SYNC_REQUEST protocol specified in the window manager spec to avoid precisely this. http://standards.freedesktop.org/wm-spec/wm-spec-latest.html#idm140200472538288
The WM is MATE's Marco, which should indeed have support of _NET_WM_SYNC_REQUEST protocol. I still think there are cases not covered by _NET_WM_SYNC_REQUEST. For example, when the users moves in a window from outside of the screen. Or when the window's content is invalidated because another window is moved over it. Then Configure events may also be triggered.
Sebastian's patch has papered over https://bugzilla.gnome.org/show_bug.cgi?id=771708. Thank you Sebastian!
*** Bug 771708 has been marked as a duplicate of this bug. ***
*** This bug has been marked as a duplicate of bug 748498 ***