From 3146f29d3ae3abae33822bcdf3eaf44b5b19cd7e Mon Sep 17 00:00:00 2001
From: Carlos Garnacho <carlosg@gnome.org>
Date: Tue, 13 Feb 2018 14:28:44 +0100
Subject: [PATCH] gdk/wayland: Add GdkDisplay call to query available globals

The internal known_globals hashtable is used to carry accounting for
interfaces that depend on others (as ordering is not guaranteed), extend
its usage so it also keeps track of unimplemented interfaces (here at
least).

The API call will then use this to allow querying the globals offered by
the compositor, it will be useful to determine whether we can use
text-input protocols or should fallback to other IMs.
---
 docs/reference/gdk/gdk3-sections.txt |  1 +
 gdk/wayland/gdkdisplay-wayland.c     | 42 ++++++++++++++++++++++++----
 gdk/wayland/gdkwaylanddisplay.h      |  4 +++
 3 files changed, 41 insertions(+), 6 deletions(-)

diff --git a/docs/reference/gdk/gdk3-sections.txt b/docs/reference/gdk/gdk3-sections.txt
index f26c22d3c6..4e5c403670 100644
--- a/docs/reference/gdk/gdk3-sections.txt
+++ b/docs/reference/gdk/gdk3-sections.txt
@@ -1270,6 +1270,7 @@ gdk_wayland_device_get_wl_seat
 gdk_wayland_display_get_wl_compositor
 gdk_wayland_display_get_wl_display
 gdk_wayland_display_get_xdg_shell
+gdk_wayland_display_query_registry
 gdk_wayland_window_get_wl_surface
 gdk_wayland_window_set_use_custom_surface
 GdkWaylandWindowExported
diff --git a/gdk/wayland/gdkdisplay-wayland.c b/gdk/wayland/gdkdisplay-wayland.c
index 8bcd6755a6..3e9ca8465d 100644
--- a/gdk/wayland/gdkdisplay-wayland.c
+++ b/gdk/wayland/gdkdisplay-wayland.c
@@ -372,7 +372,6 @@ gdk_registry_handle_global (void               *data,
 {
   GdkWaylandDisplay *display_wayland = data;
   struct wl_output *output;
-  gboolean handled = TRUE;
 
   GDK_NOTE (MISC,
             g_message ("add global %u, interface %s, version %u", id, interface, version));
@@ -495,12 +494,9 @@ gdk_registry_handle_global (void               *data,
                                                            &server_decoration_listener,
                                                            display_wayland);
     }
-  else
-    handled = FALSE;
 
-  if (handled)
-    g_hash_table_insert (display_wayland->known_globals,
-                         GUINT_TO_POINTER (id), g_strdup (interface));
+  g_hash_table_insert (display_wayland->known_globals,
+                       GUINT_TO_POINTER (id), g_strdup (interface));
 
   process_on_globals_closures (display_wayland);
 }
@@ -1386,3 +1382,37 @@ gdk_wayland_display_get_selection (GdkDisplay *display)
 
   return display_wayland->selection;
 }
+
+/**
+ * gdk_wayland_display_query_registry:
+ * @display: a wayland #GdkDisplay
+ * @interface: global interface to query in the registry
+ *
+ * Returns %TRUE if the the interface was found in the display
+ * wl_registry.global handler.
+ *
+ * Returns: %TRUE if the global is offered by the compositor
+ *
+ * Since: 3.22.27
+ **/
+gboolean
+gdk_wayland_display_query_registry (GdkDisplay  *display,
+				    const gchar *global)
+{
+  GdkWaylandDisplay *display_wayland = GDK_WAYLAND_DISPLAY (display);
+  GHashTableIter iter;
+  gchar *value;
+
+  g_return_val_if_fail (GDK_IS_WAYLAND_DISPLAY (display), FALSE);
+  g_return_val_if_fail (global != NULL, FALSE);
+
+  g_hash_table_iter_init (&iter, display_wayland->known_globals);
+
+  while (g_hash_table_iter_next (&iter, NULL, (gpointer*) &value))
+    {
+      if (strcmp (value, global) == 0)
+        return TRUE;
+    }
+
+  return FALSE;
+}
diff --git a/gdk/wayland/gdkwaylanddisplay.h b/gdk/wayland/gdkwaylanddisplay.h
index d980d6cf87..af9cc896be 100644
--- a/gdk/wayland/gdkwaylanddisplay.h
+++ b/gdk/wayland/gdkwaylanddisplay.h
@@ -60,6 +60,10 @@ void                    gdk_wayland_display_set_startup_notification_id (GdkDisp
 GDK_AVAILABLE_IN_3_22
 gboolean                gdk_wayland_display_prefers_ssd         (GdkDisplay *display);
 
+GDK_AVAILABLE_IN_3_22
+gboolean                gdk_wayland_display_query_registry      (GdkDisplay  *display,
+								 const gchar *global);
+
 G_END_DECLS
 
 #endif /* __GDK_WAYLAND_DISPLAY_H__ */