Cancel ProgressDialog and stop thread

Question

I have a thread that run several operations once and I would like to stop it when the user cancels the ProgressDialog.

public void run() {

    //operation 1

    //operation 2

    //operation 3

    //operation 4
}

This thread runs only once, so I can't implement a loop to check if he thread should still be running.

Here is my ProgressDialog :

//Wait dialog
m_dlgWaiting = ProgressDialog.show(m_ctxContext, 
                                    m_ctxContext.getText(R.string.app_name), 
                                    m_ctxContext.getText(R.string.msg_dlg_analyse_pic), 
                                    true, //indeterminate
                                    true,
                                    new OnCancelListener() {
                                        @Override
                                        public void onCancel(DialogInterface dialog) {
                                            m_bRunning = false;
                                        }
                                    });

As I don't know how to stop the thread, would it be correct to sequence the thread's operations through a loop to see if it should still be running, or is there a better way ?

public void run() {
    int op = 0;
    while(m_bRunning) {
       switch(op) {
          case 0 :
              //operation 1
              break;
          case 1 :
              //operation 2
              break;
          case 2 :
              //operation 3
              break;
          case 3 :
              //operation 4
              break;
       }
       op++;
    }
}

Even with this solution, if there are too much operations in the thread, it could be hard to sequence the operations. Is there a better way to achieve this ?

Answer 1

Use callbacks or AsyncTask

http://developer.android.com/reference/android/os/AsyncTask.html

final AsyncTask<Void, Void, Void> task = new AsyncTask<Void, Void, Void>() {
        private ProgressDialog dialog;

        @Override
        protected void onPreExecute()
        {
            this.dialog = new ProgressDialog(context);
            this.dialog.setMessage("Loading...");
            this.dialog.setCancelable(true);
            this.dialog.setOnCancelListener(new DialogInterface.OnCancelListener()
            {
                @Override
                public void onCancel(DialogInterface dialog)
                {
                    // cancel AsyncTask
                    cancel(false);
                }
            });

            this.dialog.show();

        }

        @Override
        protected Void doInBackground(Void... params)
        {
            // do your stuff
            return null;
        }

        @Override
        protected void onPostExecute(Void result)
        {
            //called on ui thread
            if (this.dialog != null) {
                this.dialog.dismiss();
            }
        }

        @Override
        protected void onCancelled()
        {
            //called on ui thread
            if (this.dialog != null) {
                this.dialog.dismiss();
            }
        }
};
task.execute();