/* -*- Mode: Java; c-basic-offset: 4; tab-width: 4; indent-tabs-mode: nil; -*-
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 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
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 * The Original Code is Mozilla Android code.
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 * The Initial Developer of the Original Code is Mozilla Foundation.
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 * Contributor(s):
 *  Brad Lassey <blassey@mozilla.com>
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package org.mozilla.gecko;

// AsyncTask runs onPostExecute on the thread it is constructed on
// We construct these off of the main thread, and we want that to run
// on the main UI thread, so this is a convenience class to do that
public abstract class GeckoAsyncTask<Params, Progress, Result> {
    public static final int PRIORITY_NORMAL = 0;
    public static final int PRIORITY_HIGH = 1;

    private int mPriority;

    public GeckoAsyncTask() {
        mPriority = PRIORITY_NORMAL;
    }

    private class BackgroundTaskRunnable implements Runnable {
        private Params[] mParams;

        public BackgroundTaskRunnable(Params... params) {
            mParams = params;
        }

        public void run() {
            final Result result = doInBackground(mParams);
            GeckoApp.mAppContext.runOnUiThread(new Runnable() {
                public void run() {
                    onPostExecute(result);
                }
            });
        }
    }

    public void execute(final Params... params) {
        if (mPriority == PRIORITY_HIGH)
            GeckoAppShell.getHandler().postAtFrontOfQueue(new BackgroundTaskRunnable(params));
        else
            GeckoAppShell.getHandler().post(new BackgroundTaskRunnable(params));
    }

    public GeckoAsyncTask<Params, Progress, Result> setPriority(int priority) {
        mPriority = priority;
        return this;
    }

    protected abstract Result doInBackground(Params... params);
    protected abstract void  onPostExecute(Result result);
}