/**@class android.os.AsyncTask
@extends java.lang.Object

 <p>AsyncTask enables proper and easy use of the UI thread. This class allows you
 to perform background operations and publish results on the UI thread without
 having to manipulate threads and/or handlers.</p>

 <p>AsyncTask is designed to be a helper class around {@link Thread} and {@link android.os.Handler}
 and does not constitute a generic threading framework. AsyncTasks should ideally be
 used for short operations (a few seconds at the most.) If you need to keep threads
 running for long periods of time, it is highly recommended you use the various APIs
 provided by the <code>java.util.concurrent</code> package such as {@link Executor},
 {@link ThreadPoolExecutor} and {@link FutureTask}.</p>

 <p>An asynchronous task is defined by a computation that runs on a background thread and
 whose result is published on the UI thread. An asynchronous task is defined by 3 generic
 types, called <code>Params</code>, <code>Progress</code> and <code>Result</code>,
 and 4 steps, called <code>onPreExecute</code>, <code>doInBackground</code>,
 <code>onProgressUpdate</code> and <code>onPostExecute</code>.</p>

 <div class="special reference">
 <h3>Developer Guides</h3>
 <p>For more information about using tasks and threads, read the
 <a href="{@docRoot}guide/components/processes-and-threads.html">Processes and
 Threads</a> developer guide.</p>
 </div>

 <h2>Usage</h2>
 <p>AsyncTask must be subclassed to be used. The subclass will override at least
 one method ({@link #doInBackground}), and most often will override a
 second one ({@link #onPostExecute}.)</p>

 <p>Here is an example of subclassing:</p>
 <pre class="prettyprint">
 private class DownloadFilesTask extends AsyncTask&lt;URL, Integer, Long&gt; {
     protected Long doInBackground(URL... urls) {
         int count = urls.length;
         long totalSize = 0;
         for (int i = 0; i &lt; count; i++) {
             totalSize += Downloader.downloadFile(urls[i]);
             publishProgress((int) ((i / (float) count) * 100));
             // Escape early if cancel() is called
             if (isCancelled()) break;
         }
         return totalSize;
     }

     protected void onProgressUpdate(Integer... progress) {
         setProgressPercent(progress[0]);
     }

     protected void onPostExecute(Long result) {
         showDialog("Downloaded " + result + " bytes");
     }
 }
 </pre>

 <p>Once created, a task is executed very simply:</p>
 <pre class="prettyprint">
 new DownloadFilesTask().execute(url1, url2, url3);
 </pre>

 <h2>AsyncTask's generic types</h2>
 <p>The three types used by an asynchronous task are the following:</p>
 <ol>
     <li><code>Params</code>, the type of the parameters sent to the task upon
     execution.</li>
     <li><code>Progress</code>, the type of the progress units published during
     the background computation.</li>
     <li><code>Result</code>, the type of the result of the background
     computation.</li>
 </ol>
 <p>Not all types are always used by an asynchronous task. To mark a type as unused,
 simply use the type {@link Void}:</p>
 <pre>
 private class MyTask extends AsyncTask&lt;Void, Void, Void&gt; { ... }
 </pre>

 <h2>The 4 steps</h2>
 <p>When an asynchronous task is executed, the task goes through 4 steps:</p>
 <ol>
     <li>{@link #onPreExecute}(), invoked on the UI thread before the task
     is executed. This step is normally used to setup the task, for instance by
     showing a progress bar in the user interface.</li>
     <li>{@link #doInBackground}, invoked on the background thread
     immediately after {@link #onPreExecute}() finishes executing. This step is used
     to perform background computation that can take a long time. The parameters
     of the asynchronous task are passed to this step. The result of the computation must
     be returned by this step and will be passed back to the last step. This step
     can also use {@link #publishProgress} to publish one or more units
     of progress. These values are published on the UI thread, in the
     {@link #onProgressUpdate} step.</li>
     <li>{@link #onProgressUpdate}, invoked on the UI thread after a
     call to {@link #publishProgress}. The timing of the execution is
     undefined. This method is used to display any form of progress in the user
     interface while the background computation is still executing. For instance,
     it can be used to animate a progress bar or show logs in a text field.</li>
     <li>{@link #onPostExecute}, invoked on the UI thread after the background
     computation finishes. The result of the background computation is passed to
     this step as a parameter.</li>
 </ol>
 
 <h2>Cancelling a task</h2>
 <p>A task can be cancelled at any time by invoking {@link #cancel}(boolean). Invoking
 this method will cause subsequent calls to {@link #isCancelled}() to return true.
 After invoking this method, {@link #onCancelled}(Object), instead of
 {@link #onPostExecute}(Object) will be invoked after {@link #doInBackground(Object[])}
 returns. To ensure that a task is cancelled as quickly as possible, you should always
 check the return value of {@link #isCancelled}() periodically from
 {@link #doInBackground(Object[])}, if possible (inside a loop for instance.)</p>

 <h2>Threading rules</h2>
 <p>There are a few threading rules that must be followed for this class to
 work properly:</p>
 <ul>
     <li>The AsyncTask class must be loaded on the UI thread. This is done
     automatically as of {@link android.os.Build.VERSION_CODES#JELLY_BEAN}.</li>
     <li>The task instance must be created on the UI thread.</li>
     <li>{@link #execute} must be invoked on the UI thread.</li>
     <li>Do not call {@link #onPreExecute}(), {@link #onPostExecute},
     {@link #doInBackground}, {@link #onProgressUpdate} manually.</li>
     <li>The task can be executed only once (an exception will be thrown if
     a second execution is attempted.)</li>
 </ul>

 <h2>Memory observability</h2>
 <p>AsyncTask guarantees that all callback calls are synchronized to ensure the following
 without explicit synchronizations.</p>
 <ul>
     <li>The memory effects of {@link #onPreExecute}, and anything else
     executed before the call to {@link #execute}, including the construction
     of the AsyncTask object, are visible to {@link #doInBackground}.
     <li>The memory effects of {@link #doInBackground} are visible to
     {@link #onPostExecute}.
     <li>Any memory effects of {@link #doInBackground} preceding a call
     to {@link #publishProgress} are visible to the corresponding
     {@link #onProgressUpdate} call. (But {@link #doInBackground} continues to
     run, and care needs to be taken that later updates in {@link #doInBackground}
     do not interfere with an in-progress {@link #onProgressUpdate} call.)
     <li>Any memory effects preceding a call to {@link #cancel} are visible
     after a call to {@link #isCancelled} that returns true as a result, or
     during and after a resulting call to {@link #onCancelled}.
 </ul>

 <h2>Order of execution</h2>
 <p>When first introduced, AsyncTasks were executed serially on a single background
 thread. Starting with {@link android.os.Build.VERSION_CODES#DONUT}, this was changed
 to a pool of threads allowing multiple tasks to operate in parallel. Starting with
 {@link android.os.Build.VERSION_CODES#HONEYCOMB}, tasks are executed on a single
 thread to avoid common application errors caused by parallel execution.</p>
 <p>If you truly want parallel execution, you can invoke
 {@link #executeOnExecutor(java.util.concurrent.Executor, Object[])} with
 {@link #THREAD_POOL_EXECUTOR}.</p>
*/
var AsyncTask = {

/** An {@link Executor} that can be used to execute tasks in parallel.
*/
THREAD_POOL_EXECUTOR : "null",
/** An {@link Executor} that executes tasks one at a time in serial
 order.  This serialization is global to a particular process.
*/
SERIAL_EXECUTOR : "null",
/**
@hide 
*/
setDefaultExecutor : function(  ) {},

/**Returns the current status of this task.
@return {Object {android.os.AsyncTask.Status}} The current status.
*/
getStatus : function(  ) {},

/**Returns <tt>true</tt> if this task was cancelled before it completed
 normally. If you are calling {@link #cancel}(boolean) on the task,
 the value returned by this method should be checked periodically from
 {@link #doInBackground(Object[])} to end the task as soon as possible.
@return {Boolean} <tt>true</tt> if task was cancelled before it completed
@see #cancel(boolean)
*/
isCancelled : function(  ) {},

/**<p>Attempts to cancel execution of this task.  This attempt will
 fail if the task has already completed, already been cancelled,
 or could not be cancelled for some other reason. If successful,
 and this task has not started when <tt>cancel</tt> is called,
 this task should never run. If the task has already started,
 then the <tt>mayInterruptIfRunning</tt> parameter determines
 whether the thread executing this task should be interrupted in
 an attempt to stop the task.</p>
 
 <p>Calling this method will result in {@link #onCancelled}(Object) being
 invoked on the UI thread after {@link #doInBackground(Object[])} returns.
 Calling this method guarantees that onPostExecute(Object) is never
 subsequently invoked, even if <tt>cancel</tt> returns false, but
 {@link #onPostExecute} has not yet run.  To finish the
 task as early as possible, check {@link #isCancelled}() periodically from
 {@link #doInBackground(Object[])}.</p>

 <p>This only requests cancellation. It never waits for a running
 background task to terminate, even if <tt>mayInterruptIfRunning</tt> is
 true.</p>
@param {Boolean} mayInterruptIfRunning <tt>true</tt> if the thread executing this
        task should be interrupted; otherwise, in-progress tasks are allowed
        to complete.
@return {Boolean} <tt>false</tt> if the task could not be cancelled,
         typically because it has already completed normally;
         <tt>true</tt> otherwise
@see #isCancelled()
@see #onCancelled(Object)
*/
cancel : function(  ) {},

/**Waits if necessary for the computation to complete, and then
 retrieves its result.
@return {Object {java.lang.Object}} The computed result.
@throws CancellationException If the computation was cancelled.
@throws ExecutionException If the computation threw an exception.
@throws InterruptedException If the current thread was interrupted
         while waiting.
*/
get : function(  ) {},

/**Waits if necessary for at most the given time for the computation
 to complete, and then retrieves its result.
@param {Number} timeout Time to wait before cancelling the operation.
@param {Object {TimeUnit}} unit The time unit for the timeout.
@return {Object {java.lang.Object}} The computed result.
@throws CancellationException If the computation was cancelled.
@throws ExecutionException If the computation threw an exception.
@throws InterruptedException If the current thread was interrupted
         while waiting.
@throws TimeoutException If the wait timed out.
*/
get : function(  ) {},

/**Executes the task with the specified parameters. The task returns
 itself (this) so that the caller can keep a reference to it.
 
 <p>Note: this function schedules the task on a queue for a single background
 thread or pool of threads depending on the platform version.  When first
 introduced, AsyncTasks were executed serially on a single background thread.
 Starting with {@link android.os.Build.VERSION_CODES#DONUT}, this was changed
 to a pool of threads allowing multiple tasks to operate in parallel. Starting
 {@link android.os.Build.VERSION_CODES#HONEYCOMB}, tasks are back to being
 executed on a single thread to avoid common application errors caused
 by parallel execution.  If you truly want parallel execution, you can use
 the {@link #executeOnExecutor} version of this method
 with {@link #THREAD_POOL_EXECUTOR}; however, see commentary there for warnings
 on its use.

 <p>This method must be invoked on the UI thread.
@param {Object {java.lang.Object[]}} params The parameters of the task.
@return {Object {android.os.AsyncTask}} This instance of AsyncTask.
@throws IllegalStateException If {@link #getStatus()} returns either
         {@link AsyncTask.Status#RUNNING} or {@link AsyncTask.Status#FINISHED}.
@see #executeOnExecutor(java.util.concurrent.Executor, Object[])
@see #execute(Runnable)
*/
execute : function(  ) {},

/**Executes the task with the specified parameters. The task returns
 itself (this) so that the caller can keep a reference to it.
 
 <p>This method is typically used with {@link #THREAD_POOL_EXECUTOR} to
 allow multiple tasks to run in parallel on a pool of threads managed by
 AsyncTask, however you can also use your own {@link Executor} for custom
 behavior.
 
 <p><em>Warning:</em> Allowing multiple tasks to run in parallel from
 a thread pool is generally <em>not</em> what one wants, because the order
 of their operation is not defined.  For example, if these tasks are used
 to modify any state in common (such as writing a file due to a button click),
 there are no guarantees on the order of the modifications.
 Without careful work it is possible in rare cases for the newer version
 of the data to be over-written by an older one, leading to obscure data
 loss and stability issues.  Such changes are best
 executed in serial; to guarantee such work is serialized regardless of
 platform version you can use this function with {@link #SERIAL_EXECUTOR}.

 <p>This method must be invoked on the UI thread.
@param {Object {Executor}} exec The executor to use.  {@link #THREAD_POOL_EXECUTOR} is available as a
              convenient process-wide thread pool for tasks that are loosely coupled.
@param {Object {java.lang.Object[]}} params The parameters of the task.
@return {Object {android.os.AsyncTask}} This instance of AsyncTask.
@throws IllegalStateException If {@link #getStatus()} returns either
         {@link AsyncTask.Status#RUNNING} or {@link AsyncTask.Status#FINISHED}.
@see #execute(Object[])
*/
executeOnExecutor : function(  ) {},

/**Convenience version of {@link #execute(Object...)} for use with
 a simple Runnable object. See {@link #execute(Object[])} for more
 information on the order of execution.
@see #execute(Object[])
@see #executeOnExecutor(java.util.concurrent.Executor, Object[])
*/
execute : function(  ) {},


};