public LayoutQueue() 
{
        tasks = new Vector< Runnable >();
}

Construct a layout queue.

 public synchronized  void addTask(Runnable task) 
{
        if (worker == null) {
            worker = new LayoutThread();
            worker.start();
        }
        tasks.addElement(task);
        notifyAll();
}

Add a task that is not needed immediately because the results are not believed to be visible.

 public static LayoutQueue getDefaultQueue() 
{
        AppContext ac = AppContext.getAppContext();
        synchronized (DEFAULT_QUEUE) {
            LayoutQueue defaultQueue = (LayoutQueue) ac.get(DEFAULT_QUEUE);
            if (defaultQueue == null) {
                defaultQueue = new LayoutQueue();
                ac.put(DEFAULT_QUEUE, defaultQueue);
            }
            return defaultQueue;
        }
}

Fetch the default layout queue.

 public static  void setDefaultQueue(LayoutQueue q) 
{
        synchronized (DEFAULT_QUEUE) {
            AppContext.getAppContext().put(DEFAULT_QUEUE, q);
        }
}

Set the default layout queue.

 protected synchronized Runnable waitForWork() 
{
        while (tasks.size() == 0) {
            try {
                wait();
            } catch (InterruptedException ie) {
                return null;
            }
        }
        Runnable work = tasks.firstElement();
        tasks.removeElementAt(0);
        return work;
}

Used by the worker thread to get a new task to execute