x11: Remove hide-titlebar-when-maximized support

It's a UI pattern that has been superseded by client-side decorations,
apps that used to set the hint have generally moved on to headerbars.
Given that and the limitation to server-side decorated X11 windows,
GTK4 removed the client-side API for setting the hint, it's time to
follow suite and retire the feature.

https://gitlab.gnome.org/GNOME/mutter/merge_requests/221

src/core/prefs.c

@@ -110,7 +110,6 @@ static int   drag_threshold;
 static gboolean resize_with_right_button = FALSE;
 static gboolean edge_tiling = FALSE;
 static gboolean force_fullscreen = TRUE;
-static gboolean ignore_request_hide_titlebar = FALSE;
 static gboolean auto_maximize = TRUE;
 static gboolean show_fallback_app_menu = FALSE;
 
@@ -2085,15 +2084,3 @@ meta_prefs_set_force_fullscreen (gboolean whether)
 {
   force_fullscreen = whether;
 }
-
-gboolean
-meta_prefs_get_ignore_request_hide_titlebar (void)
-{
-  return ignore_request_hide_titlebar;
-}
-
-void
-meta_prefs_set_ignore_request_hide_titlebar (gboolean whether)
-{
-  ignore_request_hide_titlebar = whether;
-}

src/core/window-private.h

@@ -189,7 +189,6 @@ struct _MetaWindow
   char *gtk_app_menu_object_path;
   char *gtk_menubar_object_path;
 
-  int hide_titlebar_when_maximized;
   int net_wm_pid;
 
   Window xtransient_for;

src/core/window.c

@@ -7708,9 +7708,7 @@ meta_window_get_frame_type (MetaWindow *window)
       /* can't add border if undecorated */
       return META_FRAME_TYPE_LAST;
     }
-  else if (window->border_only ||
+  else if (window->border_only)
-           (window->hide_titlebar_when_maximized && META_WINDOW_MAXIMIZED (window)) ||
-           (window->hide_titlebar_when_maximized && META_WINDOW_TILED_SIDE_BY_SIDE (window)))
     {
       /* override base frame type */
       return META_FRAME_TYPE_BORDER;

src/meta/prefs.h

@@ -166,9 +166,6 @@ gboolean meta_prefs_get_workspaces_only_on_primary (void);
 int      meta_prefs_get_draggable_border_width (void);
 int      meta_prefs_get_drag_threshold (void);
 
-gboolean meta_prefs_get_ignore_request_hide_titlebar (void);
-void     meta_prefs_set_ignore_request_hide_titlebar (gboolean whether);
-
 /**
  * MetaKeyBindingAction:
  * @META_KEYBINDING_ACTION_NONE: FILLME

src/x11/atomnames.h

@@ -54,7 +54,6 @@ item(WM_ICON_SIZE)
 item(_KWM_WIN_ICON)
 item(_MUTTER_HINTS)
 item(_GTK_THEME_VARIANT)
-item(_GTK_HIDE_TITLEBAR_WHEN_MAXIMIZED)
 item(_GTK_APPLICATION_ID)
 item(_GTK_UNIQUE_BUS_NAME)
 item(_GTK_APPLICATION_OBJECT_PATH)

src/x11/window-props.c

@@ -1710,35 +1710,6 @@ reload_gtk_theme_variant (MetaWindow    *window,
     }
 }
 
-static void
-reload_gtk_hide_titlebar_when_maximized (MetaWindow    *window,
-                                         MetaPropValue *value,
-                                         gboolean       initial)
-{
-  gboolean requested_value = FALSE;
-  gboolean current_value = window->hide_titlebar_when_maximized;
-
-  if (!meta_prefs_get_ignore_request_hide_titlebar () && value->type != META_PROP_VALUE_INVALID)
-    {
-      requested_value = ((int) value->v.cardinal == 1);
-      meta_verbose ("Request to hide titlebar for window %s.\n", window->desc);
-    }
-
-  if (requested_value == current_value)
-    return;
-
-  window->hide_titlebar_when_maximized = requested_value;
-
-  if (META_WINDOW_MAXIMIZED (window))
-    {
-      meta_window_queue (window, META_QUEUE_MOVE_RESIZE);
-      meta_window_frame_size_changed (window);
-
-      if (window->frame)
-        meta_frame_update_style (window->frame);
-    }
-}
-
 static void
 reload_bypass_compositor (MetaWindow    *window,
                           MetaPropValue *value,
@@ -1854,7 +1825,6 @@ meta_x11_display_init_window_prop_hooks (MetaX11Display *x11_display)
     { x11_display->atom__MOTIF_WM_HINTS,   META_PROP_VALUE_MOTIF_HINTS, reload_mwm_hints,      LOAD_INIT },
     { XA_WM_TRANSIENT_FOR,                 META_PROP_VALUE_WINDOW,    reload_transient_for,    LOAD_INIT },
     { x11_display->atom__GTK_THEME_VARIANT, META_PROP_VALUE_UTF8,     reload_gtk_theme_variant, LOAD_INIT },
-    { x11_display->atom__GTK_HIDE_TITLEBAR_WHEN_MAXIMIZED, META_PROP_VALUE_CARDINAL,     reload_gtk_hide_titlebar_when_maximized, LOAD_INIT },
     { x11_display->atom__GTK_APPLICATION_ID,               META_PROP_VALUE_UTF8,         reload_gtk_application_id,               LOAD_INIT },
     { x11_display->atom__GTK_UNIQUE_BUS_NAME,              META_PROP_VALUE_UTF8,         reload_gtk_unique_bus_name,              LOAD_INIT },
     { x11_display->atom__GTK_APPLICATION_OBJECT_PATH,      META_PROP_VALUE_UTF8,         reload_gtk_application_object_path,      LOAD_INIT },

src/x11/window-x11.c

@@ -2205,7 +2205,6 @@ meta_window_move_resize_request (MetaWindow *window,
            * the monitor.
            */
           if (meta_prefs_get_force_fullscreen() &&
-              !window->hide_titlebar_when_maximized &&
               (window->decorated || !meta_window_is_client_decorated (window)) &&
               meta_rectangle_equal (&rect, &monitor_rect) &&
               window->has_fullscreen_func &&