+
+ /** adds a task to the front of the queue (guaranteed to run next) */
+ public static void addAtFront(Task t) { singleton.runnable.prepend(t); }
+
+ public static void init() { if (singleton == null) (singleton = Platform.getScheduler()).run(); }
+
+ // API which must be supported by subclasses /////////////////////////////////////
+
+ /**
+ * SCHEDULER INVARIANT: all scheduler implementations MUST invoke
+ * Surface.renderAll() after performing a Task if no tasks remain
+ * in the queue. A scheduler may choose to invoke
+ * Surface.renderAll() more often than that if it so chooses.
+ */
+ public void run() { defaultRun(); }
+ protected Scheduler() { }
+
+
+ // Default Implementation //////////////////////////////////////////////////////
+
+ protected static Queue runnable = new Queue(50);
+ public void defaultRun() {