[mutter] window: Expose Flatpak application ID

[Florian Müllner <fmuellner src gnome org>]

commit bccff5bdd85c5512f7977488b12a9367f06c2ce6
Author: Florian Müllner <fmuellner gnome org>
Date:   Fri Oct 7 17:55:32 2016 +0200

    window: Expose Flatpak application ID
    
    GNOME Shell's window matching currently fails frequently with Flatpak
    applications, as one of the primary hints used to link windows with
    .desktop files - the WM_CLASS - no longer matches when flatpak renames
    the exported .desktop file. Luckily, Flatpak provides us with a fail-safe
    way to map from the PID to the corresponding application ID, so expose an
    appropriate method that allows GNOME Shell to reliably match windows to
    the corresponding Flatpak app.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=772614

 src/core/window-private.h |    1 +
 src/core/window.c         |   35 +++++++++++++++++++++++++++++++++++
 src/meta/window.h         |    1 +
 3 files changed, 37 insertions(+), 0 deletions(-)
---
diff --git a/src/core/window-private.h b/src/core/window-private.h
index 67abbcc..c7d6934 100644
--- a/src/core/window-private.h
+++ b/src/core/window-private.h
@@ -164,6 +164,7 @@ struct _MetaWindow
 
   char *startup_id;
   char *mutter_hints;
+  char *flatpak_id;
   char *gtk_theme_variant;
   char *gtk_application_id;
   char *gtk_unique_bus_name;
diff --git a/src/core/window.c b/src/core/window.c
index 3fea483..458e2d7 100644
--- a/src/core/window.c
+++ b/src/core/window.c
@@ -293,6 +293,7 @@ meta_window_finalize (GObject *object)
   g_free (window->res_name);
   g_free (window->title);
   g_free (window->desc);
+  g_free (window->flatpak_id);
   g_free (window->gtk_theme_variant);
   g_free (window->gtk_application_id);
   g_free (window->gtk_unique_bus_name);
@@ -765,6 +766,27 @@ sync_client_window_mapped (MetaWindow *window)
 }
 
 static void
+meta_window_update_flatpak_id (MetaWindow *window)
+{
+  uint32_t pid = meta_window_get_client_pid (window);
+  g_autoptr(GKeyFile) key_file = NULL;
+  g_autofree char *info_filename = NULL;
+
+  g_clear_pointer (&window->flatpak_id, g_free);
+
+  if (pid == 0)
+    return;
+
+  key_file = g_key_file_new ();
+  info_filename = g_strdup_printf ("/proc/%u/root/.flatpak-info", pid);
+
+  if (!g_key_file_load_from_file (key_file, info_filename, G_KEY_FILE_NONE, NULL))
+    return;
+
+  window->flatpak_id = g_key_file_get_string (key_file, "Application", "name", NULL);
+}
+
+static void
 meta_window_update_desc (MetaWindow *window)
 {
   g_autofree gchar *title = NULL;
@@ -863,6 +885,7 @@ _meta_window_shared_new (MetaDisplay         *display,
 
   window->screen = screen;
 
+  meta_window_update_flatpak_id (window);
   meta_window_update_desc (window);
 
   window->override_redirect = attrs->override_redirect;
@@ -6898,6 +6921,18 @@ meta_window_get_wm_class_instance (MetaWindow *window)
 }
 
 /**
+ * meta_window_get_flatpak_id:
+ * @window: a #MetaWindow
+ *
+ * Return value: (transfer none): the Flatpak application ID or %NULL
+ **/
+const char *
+meta_window_get_flatpak_id (MetaWindow *window)
+{
+  return window->flatpak_id;
+}
+
+/**
  * meta_window_get_gtk_theme_variant:
  * @window: a #MetaWindow
  *
diff --git a/src/meta/window.h b/src/meta/window.h
index 60c9997..2ae325e 100644
--- a/src/meta/window.h
+++ b/src/meta/window.h
@@ -138,6 +138,7 @@ const char * meta_window_get_wm_class (MetaWindow *window);
 const char * meta_window_get_wm_class_instance (MetaWindow *window);
 gboolean    meta_window_showing_on_its_workspace (MetaWindow *window);
 
+const char * meta_window_get_flatpak_id (MetaWindow *window);
 const char * meta_window_get_gtk_theme_variant (MetaWindow *window);
 const char * meta_window_get_gtk_application_id (MetaWindow *window);
 const char * meta_window_get_gtk_unique_bus_name (MetaWindow *window);