import android.os.Handler;
import android.os.HandlerThread;
import android.os.Looper;
import android.os.Message;
public abstract class ThreadTask<Params, Progress, Result> {
private HandlerThread mHandlerThread;
private TaskHandler mHandler;
private TaskHandler mUiHandler;
private Params[] mParams;
public ThreadTask() {
mHandlerThread =
new HandlerThread("ThreadTask", android.os.Process.THREAD_PRIORITY_BACKGROUND);
mHandlerThread.start();
mHandler =
new TaskHandler(mHandlerThread.getLooper());
mUiHandler =
new TaskHandler(Looper.getMainLooper());
}
protected abstract Result doInBackground(Params... params);
protected void onPreExecute() {
}
protected void onProgressUpdate(Progress... values) {
}
protected final void publishProgress(Progress... values) {
mUiHandler.obtainMessage(MESSAGE_PROGRESS, values).sendToTarget();
}
protected void onPostExecute(Result result) {
}
public final boolean isCancelled() {
return mHandlerThread.isInterrupted();
}
public final void cancel(
boolean mayInterruptIfRunning) {
if (!mHandlerThread.isInterrupted()) {
try {
mHandlerThread.quit();
mHandlerThread.interrupt();
}
catch (SecurityException e) {
e.printStackTrace();
}
catch (Exception e) {
e.printStackTrace();
}
}
onCancelled();
}
protected void onCancelled() {
}
public void execute(Params... params) {
mParams = params;
onPreExecute();
mHandler.sendEmptyMessage(MESSAGE_INBACKGROUND);
}
private static final int MESSAGE_INBACKGROUND = 0;
private static final int MESSAGE_POSTEXECUTE = 1;
private static final int MESSAGE_PROGRESS = 2;
private class TaskHandler
extends Handler {
public TaskHandler(Looper looper) {
super(looper);
}
@SuppressWarnings("unchecked")
@Override
public void handleMessage(Message msg) {
switch (msg.what) {
case MESSAGE_INBACKGROUND:
mUiHandler.obtainMessage(MESSAGE_POSTEXECUTE, doInBackground(mParams)).sendToTarget();
break;
case MESSAGE_POSTEXECUTE:
onPostExecute((Result) msg.obj);
mHandlerThread.quit();
break;
case MESSAGE_PROGRESS:
onProgressUpdate((Progress[]) msg.obj);
break;
}
}
}
}