Android Open Source - cat-walk Safe A Sync Task

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License

The source code is released under:

MIT License

Java Source Code

package net.rdyonline.catwalk.tasks;
//w ww  .  j a v a 2 s. co  m
import java.lang.ref.WeakReference;

import android.app.Activity;
import android.content.Context;
import android.os.AsyncTask;

/**
 * Once the task has been run, make sure that the Activity hasn't been disposed
 * or isn't being disposed to avoid null pointers where a Context being passed
 * around it used.
 * 
 * @author Ben Pearson
 * 
 * @param <T>
 *            result to be passed back from {@link ASyncTask}
 */
abstract public class SafeASyncTask<T> extends AsyncTask<Void, Void, T> {

  WeakReference<Activity> weakActivity;

  public SafeASyncTask(Activity activity) {
    weakActivity = new WeakReference<Activity>(activity);
  }

  @Override
  protected final T doInBackground(Void... voids) {
    return onRun();
  }

  protected Context getContext() {
    return weakActivity.get();
  }

  private boolean canContinue() {
    Activity activity = weakActivity.get();
    return activity != null && activity.isFinishing() == false;
  }

  @Override
  protected void onPostExecute(T t) {
    if (canContinue()) {
      onSuccess(t);
    }
  }

  abstract protected T onRun();

  abstract protected void onSuccess(T result);
}

Java Source Code List

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