Merge "Use CopyOnWriteArrayList for listeners."

import java.util.ArrayList;

import java.util.HashSet;

import java.util.LinkedList;

import java.util.List;

import java.util.concurrent.CopyOnWriteArrayList;

/**

 * A service responsible for saving changes to the content provider.

        public void onServiceCompleted(Intent callbackIntent);

    }

    private static final LinkedList<Listener> sListeners = new LinkedList<Listener>();

    private static final CopyOnWriteArrayList<Listener> sListeners =

            new CopyOnWriteArrayList<Listener>();

    private Handler mMainHandler;

            throw new ClassCastException("Only activities can be registered to"

                    + " receive callback from " + ContactSaveService.class.getName());

        }

        synchronized (sListeners) {

            sListeners.addFirst(listener);

        }

        sListeners.add(0, listener);

    }

    public static void unregisterListener(Listener listener) {

        synchronized (sListeners) {

        sListeners.remove(listener);

    }

    }

    @Override

    public Object getSystemService(String name) {

        // TODO: this assumes that if there are multiple instances of the same

        // activity registered, the last one registered is the one waiting for

        // the callback. Validity of this assumption needs to be verified.

        synchronized (sListeners) {

        for (Listener listener : sListeners) {

            if (callbackIntent.getComponent().equals(

                    ((Activity) listener).getIntent().getComponent())) {

        }

    }

}

}