session-lock: fix flashing screen when the session is locked

The protocol says screen should be filled with opaque color when the
session is locked, but it allows some delay to wait for the session-lock
client to offer surfaces.

With this commit, filling the sceen with opaque color is delayed by 100ms.

diff --git a/src/session-lock.c b/src/session-lock.c
index 11f0c58701c8adbb37f9a9eda0b9830359fa2337..d9968f089f45b9a5e185414df028bb3909823e8e 100644 (file)
--- a/src/session-lock.c
+++ b/src/session-lock.c
@@ -10,6 +10,7 @@ struct session_lock_output {
        struct session_lock_manager *manager;
        struct output *output;
        struct wlr_session_lock_surface_v1 *surface;
+       struct wl_event_source *blank_timer;
 
        struct wl_list link; /* session_lock_manager.outputs */
 
@@ -124,6 +125,7 @@ session_lock_output_destroy(struct session_lock_output *output)
        wl_list_remove(&output->commit.link);
        wl_list_remove(&output->destroy.link);
        wl_list_remove(&output->link);
+       wl_event_source_remove(output->blank_timer);
        free(output);
 }
 
@@ -155,6 +157,14 @@ align_session_lock_tree(struct output *output)
        wlr_scene_node_set_position(&output->session_lock_tree->node, box.x, box.y);
 }
 
+static int
+handle_output_blank_timeout(void *data)
+{
+       struct session_lock_output *lock_output = data;
+       wlr_scene_node_set_enabled(&lock_output->background->node, true);
+       return 0;
+}
+
 void
 session_lock_output_create(struct session_lock_manager *manager, struct output *output)
 {
@@ -181,6 +191,15 @@ session_lock_output_create(struct session_lock_manager *manager, struct output *
                goto exit_session;
        }
 
+       /* Delay blanking output by 100ms to prevent flashing */
+       lock_output->blank_timer =
+               wl_event_loop_add_timer(manager->server->wl_event_loop,
+                       handle_output_blank_timeout, lock_output);
+       if (!manager->locked) {
+               wlr_scene_node_set_enabled(&background->node, false);
+               wl_event_source_timer_update(lock_output->blank_timer, 100);
+       }
+
        align_session_lock_tree(output);
 
        lock_output->output = output;