core: Untangle input focus management

In all places (including src/wayland) we tap into meta_x11_display* focus
API, which then calls meta_display* API. This relation is backwards, so
rework input focus management so it's the other way around.

We now have high-level meta_display_(un)set_input_focus functions, which
perform the backend-independent maintenance, and calls into the X11
functions where relevant. These functions are what callers should use.

https://gitlab.gnome.org/GNOME/mutter/merge_requests/420

9 files changed, 89 insertions, 91 deletions

diff --git a/src/core/display.c b/src/core/display.c
index 413b62a04..01e97dafd 100644
--- a/src/core/display.c
+++ b/src/core/display.c
@@ -779,10 +779,12 @@ meta_display_open (void)
       if (old_active_window)
         meta_window_focus (old_active_window, timestamp);
       else
-        meta_x11_display_focus_the_no_focus_window (display->x11_display, timestamp);
+        meta_display_unset_input_focus (display, timestamp);
+    }
+  else
+    {
+      meta_display_unset_input_focus (display, timestamp);
     }
-  else if (display->x11_display)
-    meta_x11_display_focus_the_no_focus_window (display->x11_display, timestamp);
 
   meta_idle_monitor_init_dbus ();
 
@@ -1308,6 +1310,51 @@ meta_display_timestamp_too_old (MetaDisplay *display,
 }
 
 void
+meta_display_set_input_focus (MetaDisplay *display,
+                              MetaWindow  *window,
+                              gboolean     focus_frame,
+                              guint32      timestamp)
+{
+  if (meta_display_timestamp_too_old (display, &timestamp))
+    return;
+
+  if (display->x11_display)
+    {
+      MetaX11Display *x11_display = display->x11_display;
+      Window xwindow;
+      gulong serial;
+
+      meta_x11_error_trap_push (x11_display);
+
+      if (window)
+        xwindow = focus_frame ? window->frame->xwindow : window->xwindow;
+      else
+        xwindow = x11_display->no_focus_window;
+
+      meta_x11_display_set_input_focus (x11_display, xwindow, timestamp);
+      serial = XNextRequest (x11_display->xdisplay);
+
+      meta_x11_display_update_focus_window (x11_display, xwindow, serial, TRUE);
+
+      meta_x11_error_trap_pop (display->x11_display);
+    }
+
+  meta_display_update_focus_window (display, window);
+
+  display->last_focus_time = timestamp;
+
+  if (window == NULL || window != display->autoraise_window)
+    meta_display_remove_autoraise_callback (display);
+}
+
+void
+meta_display_unset_input_focus (MetaDisplay *display,
+                                guint32      timestamp)
+{
+  meta_display_set_input_focus (display, NULL, FALSE, timestamp);
+}
+
+void
 meta_display_register_wayland_window (MetaDisplay *display,
                                       MetaWindow  *window)
 {
diff --git a/src/core/window.c b/src/core/window.c
index 5721dadf1..caa1059e3 100644
--- a/src/core/window.c
+++ b/src/core/window.c
@@ -8088,8 +8088,7 @@ mouse_mode_focus (MetaWindow  *window,
                       "Unsetting focus from %s due to mouse entering "
                       "the DESKTOP window\n",
                       display->focus_window->desc);
-          meta_x11_display_focus_the_no_focus_window (display->x11_display,
-                                                      timestamp);
+          meta_display_unset_input_focus (display, timestamp);
         }
     }
 }
diff --git a/src/core/workspace.c b/src/core/workspace.c
index b4fd836c9..71c54d229 100644
--- a/src/core/workspace.c
+++ b/src/core/workspace.c
@@ -1308,8 +1308,7 @@ meta_workspace_focus_default_window (MetaWorkspace *workspace,
           meta_topic (META_DEBUG_FOCUS,
                       "Setting focus to no_focus_window, since no valid "
                       "window to focus found.\n");
-          meta_x11_display_focus_the_no_focus_window (workspace->display->x11_display,
-                                                      timestamp);
+          meta_display_unset_input_focus (workspace->display, timestamp);
         }
     }
 }
@@ -1381,8 +1380,7 @@ focus_ancestor_or_top_window (MetaWorkspace *workspace,
   else
     {
       meta_topic (META_DEBUG_FOCUS, "No MRU window to focus found; focusing no_focus_window.\n");
-      meta_x11_display_focus_the_no_focus_window (workspace->display->x11_display,
-                                                  timestamp);
+      meta_display_unset_input_focus (workspace->display, timestamp);
     }
 }
 
diff --git a/src/meta/display.h b/src/meta/display.h
index 09c1f99ec..5cf99cfea 100644
--- a/src/meta/display.h
+++ b/src/meta/display.h
@@ -297,4 +297,13 @@ MetaSoundPlayer * meta_display_get_sound_player (MetaDisplay *display);
 META_EXPORT
 MetaSelection * meta_display_get_selection (MetaDisplay *display);
 
+META_EXPORT
+void meta_display_set_input_focus   (MetaDisplay *display,
+                                     MetaWindow  *window,
+                                     gboolean     focus_frame,
+                                     guint32      timestamp);
+META_EXPORT
+void meta_display_unset_input_focus (MetaDisplay *display,
+                                     guint32      timestamp);
+
 #endif
diff --git a/src/meta/meta-x11-display.h b/src/meta/meta-x11-display.h
index f5167af7d..9c9adf9b7 100644
--- a/src/meta/meta-x11-display.h
+++ b/src/meta/meta-x11-display.h
@@ -63,27 +63,4 @@ META_EXPORT
 gboolean meta_x11_display_xwindow_is_a_no_focus_window (MetaX11Display *x11_display,
                                                         Window xwindow);
 
-/* meta_x11_display_set_input_focus_window is like XSetInputFocus, except
- * that (a) it can't detect timestamps later than the current time,
- * since Mutter isn't part of the XServer, and thus gives erroneous
- * behavior in this circumstance (so don't do it), (b) it uses
- * display->last_focus_time since we don't have access to the true
- * Xserver one, (c) it makes use of display->user_time since checking
- * whether a window should be allowed to be focused should depend
- * on user_time events (see bug 167358, comment 15 in particular)
- */
-META_EXPORT
-void meta_x11_display_set_input_focus_window (MetaX11Display *x11_display,
-                                              MetaWindow     *window,
-                                              gboolean        focus_frame,
-                                              guint32         timestamp);
-
-/* meta_x11_display_focus_the_no_focus_window is called when the
- * designated no_focus_window should be focused, but is otherwise the
- * same as meta_display_set_input_focus_window
- */
-META_EXPORT
-void meta_x11_display_focus_the_no_focus_window (MetaX11Display *x11_display,
-                                                 guint32         timestamp);
-
 #endif /* META_X11_DISPLAY_H */
diff --git a/src/wayland/meta-window-wayland.c b/src/wayland/meta-window-wayland.c
index 0b0f6bb66..8191adadd 100644
--- a/src/wayland/meta-window-wayland.c
+++ b/src/wayland/meta-window-wayland.c
@@ -142,10 +142,12 @@ meta_window_wayland_focus (MetaWindow *window,
                            guint32     timestamp)
 {
   if (meta_window_is_focusable (window))
-    meta_x11_display_set_input_focus_window (window->display->x11_display,
-                                             window,
-                                             FALSE,
-                                             timestamp);
+    {
+      meta_display_set_input_focus (window->display,
+                                    window,
+                                    FALSE,
+                                    timestamp);
+    }
 }
 
 static void
diff --git a/src/x11/meta-x11-display-private.h b/src/x11/meta-x11-display-private.h
index 0a6cafda0..3f545ce28 100644
--- a/src/x11/meta-x11-display-private.h
+++ b/src/x11/meta-x11-display-private.h
@@ -245,5 +245,8 @@ void meta_x11_display_update_focus_window (MetaX11Display *x11_display,
                                            Window          xwindow,
                                            gulong          serial,
                                            gboolean        focused_by_us);
+void meta_x11_display_set_input_focus (MetaX11Display *x11_display,
+                                       Window          xwindow,
+                                       guint32         timestamp);
 
 #endif /* META_X11_DISPLAY_PRIVATE_H */
diff --git a/src/x11/meta-x11-display.c b/src/x11/meta-x11-display.c
index 4711ca0aa..f7e0c2f56 100644
--- a/src/x11/meta-x11-display.c
+++ b/src/x11/meta-x11-display.c
@@ -1838,17 +1838,11 @@ meta_x11_display_update_focus_window (MetaX11Display *x11_display,
   meta_x11_display_update_active_window_hint (x11_display);
 }
 
-static void
-request_xserver_input_focus_change (MetaX11Display *x11_display,
-                                    MetaWindow     *meta_window,
-                                    Window          xwindow,
-                                    guint32         timestamp)
+void
+meta_x11_display_set_input_focus (MetaX11Display *x11_display,
+                                  Window          xwindow,
+                                  guint32         timestamp)
 {
-  gulong serial;
-
-  if (meta_display_timestamp_too_old (x11_display->display, &timestamp))
-    return;
-
   meta_x11_error_trap_push (x11_display);
 
   /* In order for mutter to know that the focus request succeeded, we track
@@ -1861,8 +1855,6 @@ request_xserver_input_focus_change (MetaX11Display *x11_display,
    */
   XGrabServer (x11_display->xdisplay);
 
-  serial = XNextRequest (x11_display->xdisplay);
-
   XSetInputFocus (x11_display->xdisplay,
                   xwindow,
                   RevertToPointerRoot,
@@ -1876,27 +1868,7 @@ request_xserver_input_focus_change (MetaX11Display *x11_display,
   XUngrabServer (x11_display->xdisplay);
   XFlush (x11_display->xdisplay);
 
-  meta_display_update_focus_window (x11_display->display, meta_window);
-  meta_x11_display_update_focus_window (x11_display, xwindow, serial, TRUE);
-
   meta_x11_error_trap_pop (x11_display);
-
-  x11_display->display->last_focus_time = timestamp;
-
-  if (meta_window == NULL || meta_window != x11_display->display->autoraise_window)
-    meta_display_remove_autoraise_callback (x11_display->display);
-}
-
-void
-meta_x11_display_set_input_focus_window (MetaX11Display *x11_display,
-                                         MetaWindow     *window,
-                                         gboolean        focus_frame,
-                                         guint32         timestamp)
-{
-  request_xserver_input_focus_change (x11_display,
-                                      window,
-                                      focus_frame ? window->frame->xwindow : window->xwindow,
-                                      timestamp);
 }
 
 void
@@ -1904,20 +1876,12 @@ meta_x11_display_set_input_focus_xwindow (MetaX11Display *x11_display,
                                           Window          window,
                                           guint32         timestamp)
 {
-  request_xserver_input_focus_change (x11_display,
-                                      NULL,
-                                      window,
-                                      timestamp);
-}
+  gulong serial;
 
-void
-meta_x11_display_focus_the_no_focus_window (MetaX11Display *x11_display,
-                                            guint32         timestamp)
-{
-  request_xserver_input_focus_change (x11_display,
-                                      NULL,
-                                      x11_display->no_focus_window,
-                                      timestamp);
+  meta_display_unset_input_focus (x11_display->display, timestamp);
+  serial = XNextRequest (x11_display->xdisplay);
+  meta_x11_display_set_input_focus (x11_display, window, timestamp);
+  meta_x11_display_update_focus_window (x11_display, window, serial, TRUE);
 }
 
 static MetaX11DisplayLogicalMonitorData *
diff --git a/src/x11/window-x11.c b/src/x11/window-x11.c
index fd19766bb..1f492984e 100644
--- a/src/x11/window-x11.c
+++ b/src/x11/window-x11.c
@@ -794,10 +794,10 @@ meta_window_x11_focus (MetaWindow *window,
     {
       meta_topic (META_DEBUG_FOCUS,
                   "Focusing frame of %s\n", window->desc);
-      meta_x11_display_set_input_focus_window (window->display->x11_display,
-                                               window,
-                                               TRUE,
-                                               timestamp);
+      meta_display_set_input_focus (window->display,
+                                    window,
+                                    TRUE,
+                                    timestamp);
     }
   else
     {
@@ -806,10 +806,10 @@ meta_window_x11_focus (MetaWindow *window,
           meta_topic (META_DEBUG_FOCUS,
                       "Setting input focus on %s since input = true\n",
                       window->desc);
-          meta_x11_display_set_input_focus_window (window->display->x11_display,
-                                                   window,
-                                                   FALSE,
-                                                   timestamp);
+          meta_display_set_input_focus (window->display,
+                                        window,
+                                        FALSE,
+                                        timestamp);
         }
 
       if (priv->wm_take_focus)
@@ -832,8 +832,7 @@ meta_window_x11_focus (MetaWindow *window,
                */
               if (window->display->focus_window != NULL &&
                   window->display->focus_window->unmanaging)
-                meta_x11_display_focus_the_no_focus_window (window->display->x11_display,
-                                                            timestamp);
+                meta_display_unset_input_focus (window->display, timestamp);
             }
 
           request_take_focus (window, timestamp);