[mutter] surface-role-cursor: Send frame callbacks for backend handled cursors

[Rui Matos <rtcm src gnome org>]

commit f692c527e7ab1bf843e1a79ff11d28d116f30426
Author: Rui Matos <tiagomatos gmail com>
Date:   Tue Aug 16 18:21:46 2016 +0200

    surface-role-cursor: Send frame callbacks for backend handled cursors
    
    For backend handled cursors, if nothing else changes on the clutter
    stage, we end up not sending out frame callbacks since clutter doesn't
    draw a new frame.
    
    To fix this, we'll keep cursor surfaces' frame callbacks separate from
    other surfaces' and trigger them from the new
    MetaCursorRenderer::cursor-painted signal which handles both software
    and hardware cursors.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=749913

 src/wayland/meta-wayland-surface-role-cursor.c |   54 +++++++++++++++++++++--
 1 files changed, 49 insertions(+), 5 deletions(-)
---
diff --git a/src/wayland/meta-wayland-surface-role-cursor.c b/src/wayland/meta-wayland-surface-role-cursor.c
index 2dbbc55..ec93f73 100644
--- a/src/wayland/meta-wayland-surface-role-cursor.c
+++ b/src/wayland/meta-wayland-surface-role-cursor.c
@@ -27,6 +27,7 @@
 #include "meta-wayland-buffer.h"
 #include "meta-xwayland.h"
 #include "screen-private.h"
+#include "meta-wayland-private.h"
 
 typedef struct _MetaWaylandSurfaceRoleCursorPrivate MetaWaylandSurfaceRoleCursorPrivate;
 
@@ -37,6 +38,8 @@ struct _MetaWaylandSurfaceRoleCursorPrivate
   MetaCursorSprite *cursor_sprite;
   MetaCursorRenderer *cursor_renderer;
   MetaWaylandBuffer *buffer;
+  struct wl_list frame_callbacks;
+  gulong cursor_painted_handler_id;
 };
 
 G_DEFINE_TYPE_WITH_PRIVATE (MetaWaylandSurfaceRoleCursor,
@@ -124,7 +127,9 @@ cursor_surface_role_assigned (MetaWaylandSurfaceRole *surface_role)
       meta_wayland_surface_ref_buffer_use_count (surface);
     }
 
-  meta_wayland_surface_queue_pending_frame_callbacks (surface);
+  wl_list_insert_list (&priv->frame_callbacks,
+                       &surface->pending_frame_callback_list);
+  wl_list_init (&surface->pending_frame_callback_list);
 }
 
 static void
@@ -164,7 +169,9 @@ cursor_surface_role_commit (MetaWaylandSurfaceRole  *surface_role,
         meta_wayland_surface_ref_buffer_use_count (surface);
     }
 
-  meta_wayland_surface_queue_pending_state_frame_callbacks (surface, pending);
+  wl_list_insert_list (&priv->frame_callbacks,
+                       &pending->frame_callback_list);
+  wl_list_init (&pending->frame_callback_list);
 
   if (pending->newly_attached)
     update_cursor_sprite_texture (META_WAYLAND_SURFACE_ROLE_CURSOR (surface_role));
@@ -196,6 +203,10 @@ cursor_surface_role_dispose (GObject *object)
     meta_wayland_surface_role_cursor_get_instance_private (cursor_role);
   MetaWaylandSurface *surface =
     meta_wayland_surface_role_get_surface (META_WAYLAND_SURFACE_ROLE (object));
+  MetaWaylandFrameCallback *cb, *next;
+
+  wl_list_for_each_safe (cb, next, &priv->frame_callbacks, link)
+    wl_resource_destroy (cb->resource);
 
   g_signal_handlers_disconnect_by_func (priv->cursor_sprite,
                                         cursor_sprite_prepare_at, cursor_role);
@@ -224,6 +235,7 @@ meta_wayland_surface_role_cursor_init (MetaWaylandSurfaceRoleCursor *role)
                            G_CALLBACK (cursor_sprite_prepare_at),
                            role,
                            0);
+  wl_list_init (&priv->frame_callbacks);
 }
 
 static void
@@ -281,6 +293,28 @@ meta_wayland_surface_role_cursor_get_hotspot (MetaWaylandSurfaceRoleCursor *curs
     *hotspot_y = priv->hot_y;
 }
 
+static void
+on_cursor_painted (MetaCursorRenderer           *renderer,
+                   MetaCursorSprite             *displayed_sprite,
+                   MetaWaylandSurfaceRoleCursor *cursor_role)
+{
+  MetaWaylandSurfaceRoleCursorPrivate *priv =
+    meta_wayland_surface_role_cursor_get_instance_private (cursor_role);
+  guint32 time = (guint32) (g_get_monotonic_time () / 1000);
+
+  if (displayed_sprite != priv->cursor_sprite)
+    return;
+
+  while (!wl_list_empty (&priv->frame_callbacks))
+    {
+      MetaWaylandFrameCallback *callback =
+        wl_container_of (priv->frame_callbacks.next, callback, link);
+
+      wl_callback_send_done (callback->resource, time);
+      wl_resource_destroy (callback->resource);
+    }
+}
+
 void
 meta_wayland_surface_role_cursor_set_renderer (MetaWaylandSurfaceRoleCursor *cursor_role,
                                                MetaCursorRenderer           *renderer)
@@ -291,10 +325,20 @@ meta_wayland_surface_role_cursor_set_renderer (MetaWaylandSurfaceRoleCursor *cur
   if (priv->cursor_renderer == renderer)
     return;
 
-  if (renderer)
-    g_object_ref (renderer);
   if (priv->cursor_renderer)
-    g_object_unref (priv->cursor_renderer);
+    {
+      g_signal_handler_disconnect (priv->cursor_renderer,
+                                   priv->cursor_painted_handler_id);
+      priv->cursor_painted_handler_id = 0;
+      g_object_unref (priv->cursor_renderer);
+    }
+  if (renderer)
+    {
+      priv->cursor_painted_handler_id =
+        g_signal_connect_object (renderer, "cursor-painted",
+                                 G_CALLBACK (on_cursor_painted), cursor_role, 0);
+      g_object_ref (renderer);
+    }
 
   priv->cursor_renderer = renderer;
   update_cursor_sprite_texture (cursor_role);