[gnome-shell] st/texture-cache: Return a GIcon from bind_cairo_surface_property()

[Georges Basile Stavracas Neto <gbsneto src gnome org>]

commit d7cb2eeebcced0c0af43453e81ce5a7c14dcb4c4
Author: Florian Müllner <fmuellner gnome org>
Date:   Tue Jun 30 16:48:16 2020 +0200

    st/texture-cache: Return a GIcon from bind_cairo_surface_property()
    
    We still load the surface into an StImageContent, but instead of
    adding the content to an actor we hand out, return the content
    itself (as GIcon).
    
    That means we lose the ability to specify an icon size, but as we
    get the pixel data from a fixed-size surface anyway, that shouldn't
    matter much in practice.
    
    Not to mention that the function is only used for fallback X11 icons,
    which are already shit more often than not.
    
    https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/1342

 src/shell-app.c           | 77 +++++++++++++----------------------------------
 src/st/st-texture-cache.c | 64 +++++++++++++++------------------------
 src/st/st-texture-cache.h |  7 ++---
 3 files changed, 49 insertions(+), 99 deletions(-)
---
diff --git a/src/shell-app.c b/src/shell-app.c
index f70bb7d3e7..7937dacdd6 100644
--- a/src/shell-app.c
+++ b/src/shell-app.c
@@ -180,66 +180,24 @@ window_backed_app_get_window (ShellApp     *app)
     return NULL;
 }
 
-static ClutterActor *
-window_backed_app_get_icon (ShellApp *app,
-                            int       size)
+static GIcon *
+window_backed_app_get_icon (ShellApp *app)
 {
   MetaWindow *window = NULL;
-  StWidget *widget;
-  int scale, scaled_size;
-  ShellGlobal *global;
-  StThemeContext *context;
-
-  global = shell_global_get ();
-  context = st_theme_context_get_for_stage (shell_global_get_stage (global));
-  g_object_get (context, "scale-factor", &scale, NULL);
-
-  scaled_size = size * scale;
 
   /* During a state transition from running to not-running for
    * window-backend apps, it's possible we get a request for the icon.
-   * Avoid asserting here and just return an empty image.
+   * Avoid asserting here and just return a fallback icon
    */
   if (app->running_state != NULL)
     window = window_backed_app_get_window (app);
 
-  if (window == NULL)
-    {
-      ClutterActor *actor;
-
-      actor = clutter_actor_new ();
-      g_object_set (actor,
-                    "opacity", 0,
-                    "width", (float) scaled_size,
-                    "height", (float) scaled_size,
-                    NULL);
-      return actor;
-    }
-
-  if (meta_window_get_client_type (window) == META_WINDOW_CLIENT_TYPE_X11)
-    {
-      StWidget *texture_actor;
-
-      texture_actor =
-        st_texture_cache_bind_cairo_surface_property (st_texture_cache_get_default (),
-                                                      G_OBJECT (window),
-                                                      "icon",
-                                                      scaled_size);
-
-      widget = g_object_new (ST_TYPE_BIN,
-                             "child", texture_actor,
-                             NULL);
-    }
-  else
-    {
-      widget = g_object_new (ST_TYPE_ICON,
-                             "icon-size", size,
-                             "icon-name", "application-x-executable",
-                             NULL);
-    }
-  st_widget_add_style_class_name (widget, "fallback-app-icon");
-
-  return CLUTTER_ACTOR (widget);
+  if (window &&
+      meta_window_get_client_type (window) == META_WINDOW_CLIENT_TYPE_X11)
+    return st_texture_cache_bind_cairo_surface_property (st_texture_cache_get_default (),
+                                                         G_OBJECT (window),
+                                                         "icon");
+  return g_themed_icon_new ("application-x-executable");
 }
 
 /**
@@ -254,17 +212,24 @@ ClutterActor *
 shell_app_create_icon_texture (ShellApp   *app,
                                int         size)
 {
-  GIcon *icon;
+  g_autoptr (GIcon) icon = NULL;
   ClutterActor *ret;
 
-  if (app->info == NULL)
-    return window_backed_app_get_icon (app, size);
-
   ret = st_icon_new ();
   st_icon_set_icon_size (ST_ICON (ret), size);
   st_icon_set_fallback_icon_name (ST_ICON (ret), "application-x-executable");
 
-  icon = g_app_info_get_icon (G_APP_INFO (app->info));
+  if (app->info == NULL)
+    {
+      icon = window_backed_app_get_icon (app);
+      st_widget_add_style_class_name (ST_WIDGET (ret), "fallback-app-icon");
+    }
+  else
+    {
+      icon = g_app_info_get_icon (G_APP_INFO (app->info));
+      g_object_ref (icon);
+    }
+
   st_icon_set_gicon (ST_ICON (ret), icon);
 
   return ret;
diff --git a/src/st/st-texture-cache.c b/src/st/st-texture-cache.c
index e44cf0259a..0359534e2e 100644
--- a/src/st/st-texture-cache.c
+++ b/src/st/st-texture-cache.c
@@ -722,8 +722,7 @@ load_texture_async (StTextureCache       *cache,
 
 typedef struct {
   StTextureCache *cache;
-  ClutterActor *actor;
-  gint size;
+  ClutterContent *image;
   GObject *source;
   gulong notify_signal_id;
   gboolean weakref_active;
@@ -742,37 +741,33 @@ st_texture_cache_reset_texture (StTextureCachePropertyBind *bind,
       (cairo_image_surface_get_format (surface) == CAIRO_FORMAT_ARGB32 ||
        cairo_image_surface_get_format (surface) == CAIRO_FORMAT_RGB24))
     {
-      g_autoptr(ClutterContent) image = NULL;
       g_autoptr(GError) error = NULL;
-      int size = bind->size;
+      int width, height, size;
 
-      if (size < 0)
-        clutter_actor_get_preferred_width (bind->actor, -1, NULL, (float *)&size);
+      width = cairo_image_surface_get_width (surface);
+      height = cairo_image_surface_get_width (surface);
+      size = MAX(width, height);
 
-      image = clutter_actor_get_content (bind->actor);
-      if (!image || !CLUTTER_IS_IMAGE (image))
-        image = st_image_content_new_with_preferred_size (size, size);
-      else
-        g_object_ref (image);
+      if (!bind->image)
+        bind->image = st_image_content_new_with_preferred_size (size, size);
 
-      clutter_image_set_data (CLUTTER_IMAGE (image),
+      clutter_image_set_data (CLUTTER_IMAGE (bind->image),
                               cairo_image_surface_get_data (surface),
                               cairo_image_surface_get_format (surface) == CAIRO_FORMAT_ARGB32 ?
                               COGL_PIXEL_FORMAT_BGRA_8888 : COGL_PIXEL_FORMAT_BGR_888,
-                              cairo_image_surface_get_width (surface),
-                              cairo_image_surface_get_height (surface),
+                              width,
+                              height,
                               cairo_image_surface_get_stride (surface),
                               &error);
 
-      if (image)
-        clutter_actor_set_content (bind->actor, image);
-      else if (error)
+      if (error)
         g_warning ("Failed to allocate texture: %s", error->message);
-
-      clutter_actor_set_opacity (bind->actor, 255);
     }
   else
-    clutter_actor_set_opacity (bind->actor, 0);
+    bind->image = g_object_new (ST_TYPE_IMAGE_CONTENT,
+                                "preferred-width", 0, /* tough luck */
+                                "preferred-height", 0,
+                                NULL);
 }
 
 static void
@@ -798,57 +793,48 @@ st_texture_cache_free_bind (gpointer data)
 {
   StTextureCachePropertyBind *bind = data;
   if (bind->weakref_active)
-    g_object_weak_unref (G_OBJECT (bind->actor), st_texture_cache_bind_weak_notify, bind);
+    g_object_weak_unref (G_OBJECT (bind->image), st_texture_cache_bind_weak_notify, bind);
   g_slice_free (StTextureCachePropertyBind, bind);
 }
 
 /**
  * st_texture_cache_bind_cairo_surface_property:
  * @cache:
- * @object: A #GObject with a property @property_name of type #GdkPixbuf
+ * @object: A #GObject with a property @property_name of type #cairo_surface_t
  * @property_name: Name of a property
  *
- * Create a #ClutterActor which tracks the #cairo_surface_t value of a GObject property
+ * Create a #GIcon which tracks the #cairo_surface_t value of a GObject property
  * named by @property_name.  Unlike other methods in StTextureCache, the underlying
  * #CoglTexture is not shared by default with other invocations to this method.
  *
  * If the source object is destroyed, the texture will continue to show the last
  * value of the property.
  *
- * Return value: (transfer none): A new #StWidget
+ * Return value: (transfer none): A new #GIcon
  */
-StWidget *
+GIcon *
 st_texture_cache_bind_cairo_surface_property (StTextureCache    *cache,
                                               GObject           *object,
-                                              const char        *property_name,
-                                              gint               size)
+                                              const char        *property_name)
 {
-  StWidget *widget;
   gchar *notify_key;
   StTextureCachePropertyBind *bind;
 
-  widget = g_object_new (ST_TYPE_WIDGET,
-                         "opacity", 0,
-                         "width", (float)size,
-                         "height", (float)size,
-                         NULL);
-
   bind = g_slice_new0 (StTextureCachePropertyBind);
   bind->cache = cache;
-  bind->actor = CLUTTER_ACTOR (widget);
-  bind->size = size;
   bind->source = object;
-  g_object_weak_ref (G_OBJECT (widget), st_texture_cache_bind_weak_notify, bind);
-  bind->weakref_active = TRUE;
 
   st_texture_cache_reset_texture (bind, property_name);
 
+  g_object_weak_ref (G_OBJECT (bind->image), st_texture_cache_bind_weak_notify, bind);
+  bind->weakref_active = TRUE;
+
   notify_key = g_strdup_printf ("notify::%s", property_name);
   bind->notify_signal_id = g_signal_connect_data (object, notify_key, 
G_CALLBACK(st_texture_cache_on_pixbuf_notify),
                                                   bind, (GClosureNotify)st_texture_cache_free_bind, 0);
   g_free (notify_key);
 
-  return widget;
+  return G_ICON (bind->image);
 }
 
 /**
diff --git a/src/st/st-texture-cache.h b/src/st/st-texture-cache.h
index a99316da8f..0e8407ea26 100644
--- a/src/st/st-texture-cache.h
+++ b/src/st/st-texture-cache.h
@@ -64,10 +64,9 @@ st_texture_cache_load_sliced_image (StTextureCache *cache,
                                     GFunc           load_callback,
                                     gpointer        user_data);
 
-StWidget *st_texture_cache_bind_cairo_surface_property (StTextureCache    *cache,
-                                                        GObject           *object,
-                                                        const char        *property_name,
-                                                        gint               size);
+GIcon *st_texture_cache_bind_cairo_surface_property (StTextureCache    *cache,
+                                                     GObject           *object,
+                                                     const char *property_name);
 
 ClutterActor *st_texture_cache_load_gicon (StTextureCache *cache,
                                            StThemeNode    *theme_node,