frame: Preserve client position when removing decorationsfix-tray-restore-position-shift

Windows using StaticGravity (like Qt apps) would shift up and left by
the visible frame border size each time they were hidden to system tray
and restored. The position drift compounded with each cycle. This
changes those windows to use the client's actual root position.

Fixes #534

1 files changed, 21 insertions, 2 deletions

diff --git a/src/core/frame.c b/src/core/frame.c
index a8ba65c0..caf8af94 100644
--- a/src/core/frame.c
+++ b/src/core/frame.c
@@ -170,6 +170,7 @@ meta_window_destroy_frame (MetaWindow *window)
 {
   MetaFrame *frame;
   MetaFrameBorders borders;
+  int offset_x, offset_y;
 
   if (window->frame == NULL)
     return;
@@ -198,6 +199,24 @@ meta_window_destroy_frame (MetaWindow *window)
                   "Incrementing unmaps_pending on %s for reparent back to root\n", window->desc);
       window->unmaps_pending += 1;
     }
+
+  /* Account for window gravity when choosing where to place the client
+   * on the root window, so that re-managing it doesn't shift its
+   * position. StaticGravity clients (e.g. Qt) expect the client's own
+   * position; other gravities need the visible frame corner so that
+   * adjust_for_gravity() can add the borders back correctly.
+   */
+  if (window->size_hints.win_gravity == StaticGravity)
+    {
+      offset_x = frame->child_x;
+      offset_y = frame->child_y;
+    }
+  else
+    {
+      offset_x = borders.invisible.left;
+      offset_y = borders.invisible.top;
+    }
+
   XReparentWindow (window->display->xdisplay,
                    window->xwindow,
                    window->screen->xroot,
@@ -205,8 +224,8 @@ meta_window_destroy_frame (MetaWindow *window)
                     * coordinates here means we'll need to ensure a configure
                     * notify event is sent; see bug 399552.
                     */
-                   window->frame->rect.x + borders.invisible.left,
-                   window->frame->rect.y + borders.invisible.top);
+                   window->frame->rect.x + offset_x,
+                   window->frame->rect.y + offset_y);
   meta_error_trap_pop (window->display, FALSE);
 
   meta_ui_destroy_frame_window (window->screen->ui, frame->xwindow);