x11: Implement inhibit_system_shortcuts API

On X11, there is no such equivalent to the inhibit shortcut protocol
found on Wayland.

To implement the inhibit_system_shortcuts API on X11, we emulate the
same behavior using grabs on the keyboard.

To avoid keeping active grabs on the keyboard that would affect other
X11 applications even when the surface isn't focused, the X11
implementation takes care of releasing the grabs as soon as the toplevel
loses focus.

1 files changed, 74 insertions, 0 deletions

diff --git a/gdk/x11/gdksurface-x11.c b/gdk/x11/gdksurface-x11.c
index d4348a4e18..3607629819 100644
--- a/gdk/x11/gdksurface-x11.c
+++ b/gdk/x11/gdksurface-x11.c
@@ -109,6 +109,7 @@ static void     set_wm_name                       (GdkDisplay  *display,
 						   Window       xwindow,
 						   const gchar *name);
 static void     move_to_current_desktop           (GdkSurface *surface);
+static void     gdk_x11_toplevel_state_callback   (GdkSurface *surface);
 
 /* Return whether time1 is considered later than time2 as far as xserver
  * time is concerned.  Accounts for wraparound.
@@ -148,6 +149,9 @@ _gdk_x11_surface_get_toplevel (GdkSurface *surface)
     {
       impl->toplevel = g_new0 (GdkToplevelX11, 1);
       impl->toplevel->have_focused = FALSE;
+      g_signal_connect (surface, "notify::state",
+                        G_CALLBACK (gdk_x11_toplevel_state_callback),
+                        NULL);
     }
 
   return impl->toplevel;
@@ -445,6 +449,10 @@ gdk_x11_surface_finalize (GObject *object)
   if (impl->toplevel->in_frame)
     unhook_surface_changed (GDK_SURFACE (impl));
 
+  g_signal_handlers_disconnect_by_func (GDK_SURFACE (impl),
+                                        gdk_x11_toplevel_state_callback,
+                                        NULL);
+
   _gdk_x11_surface_grab_check_destroy (GDK_SURFACE (impl));
 
   if (!GDK_SURFACE_DESTROYED (impl))
@@ -4725,6 +4733,9 @@ gdk_x11_toplevel_set_property (GObject      *object,
       g_object_notify_by_pspec (G_OBJECT (surface), pspec);
       break;
 
+    case LAST_PROP + GDK_TOPLEVEL_PROP_SHORTCUTS_INHIBITED:
+      break;
+
     default:
       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
       break;
@@ -4785,6 +4796,10 @@ gdk_x11_toplevel_get_property (GObject    *object,
       g_value_set_enum (value, surface->fullscreen_mode);
       break;
 
+    case LAST_PROP + GDK_TOPLEVEL_PROP_SHORTCUTS_INHIBITED:
+      g_value_set_boolean (value, surface->shortcuts_inhibited);
+      break;
+
     default:
       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
       break;
@@ -4909,6 +4924,63 @@ gdk_x11_toplevel_supports_edge_constraints (GdkToplevel *toplevel)
 }
 
 static void
+gdk_x11_toplevel_inhibit_system_shortcuts (GdkToplevel *toplevel,
+                                           GdkEvent    *gdk_event)
+{
+  GdkSurface *surface = GDK_SURFACE (toplevel);
+  GdkSeat *gdk_seat;
+  GdkGrabStatus status;
+
+  if (surface->shortcuts_inhibited)
+    return; /* Already inhibited */
+
+  if (!(surface->state & GDK_SURFACE_STATE_FOCUSED))
+    return;
+
+  gdk_seat = gdk_surface_get_seat_from_event (surface, gdk_event);
+
+  if (!(gdk_seat_get_capabilities (gdk_seat) & GDK_SEAT_CAPABILITY_KEYBOARD))
+    return;
+
+  status = gdk_seat_grab (gdk_seat, surface, GDK_SEAT_CAPABILITY_KEYBOARD,
+                          TRUE, NULL, gdk_event, NULL, NULL);
+
+  if (status != GDK_GRAB_SUCCESS)
+    return;
+
+  surface->shortcuts_inhibited = TRUE;
+  surface->current_shortcuts_inhibited_seat = gdk_seat;
+  g_object_notify (G_OBJECT (toplevel), "shortcuts-inhibited");
+}
+
+static void
+gdk_x11_toplevel_restore_system_shortcuts (GdkToplevel *toplevel)
+{
+  GdkSurface *surface = GDK_SURFACE (toplevel);
+  GdkSeat *gdk_seat;
+
+  if (!surface->shortcuts_inhibited)
+    return; /* Not inhibited */
+
+  gdk_seat = surface->current_shortcuts_inhibited_seat;
+  gdk_seat_ungrab (gdk_seat);
+  surface->current_shortcuts_inhibited_seat = NULL;
+
+  surface->shortcuts_inhibited = FALSE;
+  g_object_notify (G_OBJECT (toplevel), "shortcuts-inhibited");
+}
+
+static void
+gdk_x11_toplevel_state_callback (GdkSurface *surface)
+{
+  if (surface->state & GDK_SURFACE_STATE_FOCUSED)
+    return;
+
+  if (surface->shortcuts_inhibited)
+    gdk_x11_toplevel_restore_system_shortcuts (GDK_TOPLEVEL (surface));
+}
+
+static void
 gdk_x11_toplevel_iface_init (GdkToplevelInterface *iface)
 {
   iface->present = gdk_x11_toplevel_present;
@@ -4917,6 +4989,8 @@ gdk_x11_toplevel_iface_init (GdkToplevelInterface *iface)
   iface->focus = gdk_x11_toplevel_focus;
   iface->show_window_menu = gdk_x11_toplevel_show_window_menu;
   iface->supports_edge_constraints = gdk_x11_toplevel_supports_edge_constraints;
+  iface->inhibit_system_shortcuts = gdk_x11_toplevel_inhibit_system_shortcuts;
+  iface->restore_system_shortcuts = gdk_x11_toplevel_restore_system_shortcuts;
 }
 
 typedef struct {