window.c; Only redraw once per frame

Based on a patch from Martin Minarik <minarik11@student.fiit.stuba.sk> who
tracked down the excessive redraw problem.

diff --git a/clients/window.c b/clients/window.c
index 49b0188..4c859aa 100644 (file)
--- a/clients/window.c
+++ b/clients/window.c
@@ -123,6 +123,7 @@ struct window {
        int x, y;
        int resize_edges;
        int redraw_scheduled;
+       int redraw_needed;
        struct task redraw_task;
        int resize_scheduled;
        struct task resize_task;
@@ -2133,20 +2134,40 @@ widget_redraw(struct widget *widget)
 }
 
 static void
+frame_callback(void *data, struct wl_callback *callback, uint32_t time)
+{
+       struct window *window = data;
+
+       wl_callback_destroy(callback);
+       window->redraw_scheduled = 0;
+       if (window->redraw_needed)
+               window_schedule_redraw(window);
+}
+
+static const struct wl_callback_listener listener = {
+       frame_callback
+};
+
+static void
 idle_redraw(struct task *task, uint32_t events)
 {
        struct window *window =
                container_of(task, struct window, redraw_task);
+       struct wl_callback *callback;
 
        window_create_surface(window);
        widget_redraw(window->widget);
        window_flush(window);
-       window->redraw_scheduled = 0;
+       window->redraw_needed = 0;
+
+       callback = wl_surface_frame(window->surface);
+       wl_callback_add_listener(callback, &listener, window);
 }
 
 void
 window_schedule_redraw(struct window *window)
 {
+       window->redraw_needed = 1;
        if (!window->redraw_scheduled) {
                window->redraw_task.run = idle_redraw;
                display_defer(window->display, &window->redraw_task);