I have an acitivity with three fragments is attched on it and there is a class that is responsible for my tcp connection in activity. TCP class works as async. Inside onCreate method of main activity I am starting the tcp connection. Then when I click a button I am starting a new activity and getting the current tcp connection in new activity using a singleton class. I can send messages from the new activity to server using the available tcp. However it is an asyc task so I can't do changes in new activity according to the message that is received from server.
How can I change the layout of new activity from async task?
//Activity code:
public class MainScreen extends FragmentActivity implements ActionBar.TabListener {
TCPClient mTcpClient;
connectTask cnnTask;
///The class is responsible for tcp connection
public class connectTask extends AsyncTask<String, String, TCPClient> {
#Override
public TCPClient doInBackground(String... message) {
//we create a TCPClient object
mTcpClient = new TCPClient(new TCPClient.OnMessageReceived() {
#Override
//here the messageReceived method is implemented
public void messageReceived(String message) {
//do process
}
}
protected void onCreate(Bundle savedInstanceState) {
SharedPreferences preferences = null;
super.onCreate(savedInstanceState);
try {
cnnTask = new connectTask();
preferences = this.getSharedPreferences("MyPreferences",
Context.MODE_PRIVATE);
mTcpClient.SERVERIP = preferences.getString("IPAddress", "0");
mTcpClient.SERVERPORT = Integer.parseInt(preferences.getString("Port", "13759"));
cnnTask.execute("");
} catch (Exception e) {
}
//..
SingletonTCP .getInstance().setmTCPClient(mTcpClient);
}
//Fragment code:
public class FragmentDesign extends Fragment implements View.OnClickListener {
public void onClick(View v) {
String name = v.getTag().toString();
Intent intent = new Intent(getActivity(),NewActivity.class);
intent.putExtra("Name", this._name);
startActivity(intent);
}
}
//Singleton class to set and get the current TCPClient.
public class SingletonTCP {
private TCPClient mTCPClient;
public TCPClient getmTCPClient() { return mTCPClient; }
public void setmTCPClient(TCPClient mTCPClient) {this.mTCPClient = mTCPClient;}
private static final SingletonTCP holder = new SingletonTCP ();
public static SingletonTCP getInstance() {return holder;}
}
enter code here
//New activity code.
public class NewActivity extends Activity implements View.OnClickListener {
public class TCP extends AsyncTask<String, String, TCPClient> {
#Override
protected TCPClient doInBackground(String... params) {
mTCPClient = new TCPClient(new TCPClient.OnMessageReceived() {
#Override
public void messageReceived(String message) {
mes = message;
}
});
return null;
}
}
#Override
public void onClick(View v) {
String command = "<message>";
this.mTCPClient.sendMessage(command);
}
#Override
protected void onCreate(Bundle savedInstanceState) {
mTCPClient = SingletonTCP .getInstance().getmTCPClient();
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_new_activity);
Bundle extras = getIntent().getExtras();
departmanAdi = extras.getString("Name");
Button button = (Button) findViewById(R.id.button);
button.setOnClickListener(this);
tcp = new TCP();
tcp.execute("");
}
}
You could call publishProgress() from inside doInBackground(), which will call the onProgressUpdate() on the UI thread. In onProgessUpdate(), you can access and make changes to your activity.
This is described in the documentation here.
Related
I seems having an issue where an instance variable is not updated in MainAtivity. the text still show "testing" instead of the message received by onMessage()
public class MainActivity extends AppCompatActivity {
pacioWebSocketListener myWS = new pacioWebSocketListener();
private String pacioMsg = myWS.getPacioMsg();
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
TextView tv = findViewById(R.id.textView);
tv.setText("Message: " + pacioMsg);
And here is the pacioWebsocketListener.java
public class pacioWebSocketListener extends WebSocketListener {
private static final int NORMAL_CLOSURE_STATUS = 1000;
WebSocket ws;
public String pacioMsg = "testing";
public void setPacioMsg(String paciomsg){
pacioMsg = paciomsg;
}
public String getPacioMsg(){
return pacioMsg;
}
#Override
public void onOpen(WebSocket webSocket, Response response) {
super.onOpen(webSocket, response);
Log.v(TAG,"onOpen");
}
#Override
public void onMessage(WebSocket webSocket, String message) {
super.onMessage(webSocket, message);
setPacioMsg(message);
In your activity, you are getting the value of pacioMsg before its value is changed by the method onMessage. onMessage is not called when you instantiate pacioWebSocketListener, it's only called in the event of a new message
So, If you want your activity to know every time a message arrives and update its textview, you need to find a way to make your activity and your class pacioWebSocketListener communicate.
You can do it by creating an Interface Listener like this:
in your class pacioWebSocketListener, create an interface
public class pacioWebSocketListener extends WebSocketListener {
MessageListener msgListener;
private static final int NORMAL_CLOSURE_STATUS = 1000;
WebSocket ws;
public pacioWebSocketListener(MessageListener listener){
this.msgListener = listener;
}
// interface
public interface MessageListener{
void onMessageReceived(String message)
}
#Override
public void onOpen(WebSocket webSocket, Response response) {
super.onOpen(webSocket, response);
Log.v(TAG,"onOpen");
}
#Override
public void onMessage(WebSocket webSocket, String message) {
super.onMessage(webSocket, message);
// When a new Message arrives , call the MessageListener.onMessageReceived
msgListener.onMessageReceived(message);
}
Now, in your activity implements the interface created in the pacioWebSocketListener class and override the method onMessageReceived, it goes like this
public class MainActivity extends AppCompatActivity implements pacioWebSocketListener.MessageListener {
TextView tv;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
// Pass "this" in the constructor, to show that this activity is
// Listening for changes
pacioWebSocketListener myWS = new pacioWebSocketListener(this);
tv = findViewById(R.id.textView);
}
// Override the method in MessageListener Inteface
public void onMessageReceived(String message){
// Then from here you can update your UI
tv.setText("Message: " + message);
}
Now Every time a new message arrives, your TextView will be updated with the text
I am trying to accept socket connections from clients.
But in my AsyncTask i came across two situations where I'll need to update UI thread. the first case where as soon as socket is connected, it should change the current content view. And 2nd case where I'm receiving constant stream of objects which I'm updating on UI through publishProgress().
How do I go about doing so?
public class MainActivity extends AppCompatActivity {
myCustomDrawingView view;
....
....
.
public static MainActivity getContext(){return context;}
....
..
public class myCustomDrawingView extends View {
..
..
}
setNewContentView(){
view = new myCustomDrawingView(this);
setContentView(view);
}
}
class ServerTask extends AsyncTask<Void, Action, Void>
{
private WeakReference<MainActivity> mainActivity;
private Action action;
#Override
protected void onPreExecute() {
super.onPreExecute();
mainActivity = new WeakReference<>(MainActivity.getContext());
}
#Override
protected Void doInBackground(Void... voids) {
ObjectInputStream stream;
try{
mainActivity.get().server = new ServerSocket(3107);
mainActivity.get().socket = mainActivity.get().server.accept();
stream = new ObjectInputStream(mainActivity.get().socket.getInputStream());
(mainActivity.get()).setNewContentView();
/*I know this won't work....
But I want something like this to happen.
What are Alternatives?*/
while(true)
{
if(isCancelled()){
break;
}
action = (Action)stream.readObject();
publishProgress(action);
}
}catch (Exception exception)
{
exception.printStackTrace();
}
return null;
}
#Override
protected void onProgressUpdate(Action... actions) {
super.onProgressUpdate(actions);
((mainActivity.get()).myCustomDrawingView).draw(actions[0]);
}
}
What i want :
wait for connection. Until the connection is received, display a
blank screen
as soon as connected, set the current view to a custom view ( using setContentView() ). This I'm trying to do from Background Thread( AsyncTask )
Then after that I'll keep accepting the points from client and keep updating them on UI thread. For this I'm accepting points from client and sending to publishProgess()
But for some reason, the second step itself isn't working.
MainActivity.java
public class MainActivity extends AppCompatActivity {
public ServerSocket server;
public Socket socket;
public Slate slate ;
private Paint mPaint;
public static MainActivity context;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
context = this;
(new ServerTask()).execute();
}
public static MainActivity getContext()
{
return context;
}
public void start_slate(){
slate = new Slate(this);
slate.setBackgroundColor(Color.parseColor("#000000"));
setContentView(slate);
}
public class Slate extends View {
.....
.....
draw(){
....
....
}
} /*custom drawing view*/
}
Background Task
/*Background Task*/
class ServerTask extends AsyncTask<Void, Action, Void>
{
private WeakReference<MainActivity> mainActivity;
private Action action;
#Override
protected void onPreExecute() {
super.onPreExecute();
mainActivity = new WeakReference<>(MainActivity.getContext());
}
#Override
protected Void doInBackground(Void... voids) {
ObjectInputStream stream;
try{
mainActivity.get().server = new ServerSocket(3107);
mainActivity.get().socket = mainActivity.get().server.accept();
stream = new ObjectInputStream(mainActivity.get().socket.getInputStream());
MainActivity.getContext().runOnUiThread(new Runnable() {
#Override
public void run() {
MainActivity.getContext().start_slate();
}
}); /*BUT THE VIEW IS NOT CHANGING*/
while(true)
{
if(isCancelled()){
break;
}
action = (Action)stream.readObject();
publishProgress(action);
}
}catch (Exception exception)
{
exception.printStackTrace();
}
return null;
}
#Override
protected void onProgressUpdate(Action... actions) {
super.onProgressUpdate(actions);
((mainActivity.get()).slate).draw(actions[0]);
}/*this will send the co-ordinates to current drawing view*/
}
NOTE : even if i try to set the view in onProgressUpdate() , it still does not happen.
It happens only in onPostExecute(). But I don't want that because, after changing the view, I still have to accept coordinates (The while loop part)
I have a specific scenario and I need your help.
I'm trying to build an App in Android that involves network communication.
I am using AsyncTask for the http POST requests.
I have another class called Proxy (not a good one.. will be changed) which holds different kinds of functionalities (registerUser, setUserName, getUserPermission...)
And Of course, I have an Activity.
My Activity holds an instance of Proxy class.
My goal, is to push a button in the activity, it will call a method from Proxy class, which in its turn calls the AsyncTask's execute() method that actually run the http POST.
I was wondering how to get the data from AsyncTask's onPostExecute to my activity.
What I have in mind is to have an interface in AsyncTask, which will be implemented in Proxy class, and another interface in Proxy class which will be implemented in my Activity class.
Roll the data all the way to my Activity.
I want to hear your thoughts about whether this is the way to go, or another approach is preffered.
Thanks a lot for your help.
Adding some code
public class RegisterActivity extends FragmentActivity implements Proxy.OnProxyHttpPostResponseListener {
private Proxy proxy;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_register);
this.proxy = new Proxy();
this.proxy.setHttpPostResponseListener(this);
}
#Override
public void onProxyHttpPostResponse(String response) {
//Do something when http post returns
}
}
public class Proxy {
public interface OnProxyHttpPostResponseListener {
void onProxyHttpPostResponse(String response);
}
private OnProxyHttpPostResponseListener httpPostResponseListener;
public void setHttpPostResponseListener(OnProxyHttpPostResponseListener listener) {
this.httpPostResponseListener = listener;
}
private class HttpPostAsync extends AsyncTask<Pair<String, ArrayList<Pair<String, String>>>, Void, String> {
#Override
protected String doInBackground(Pair<String, ArrayList<Pair<String, String>>>... params) {
return this.httpPost(params[0].first, params[0].second);
}
protected void onPostExecute(String response) {
httpPostResponseListener.onProxyHttpPostResponse(response);
}
}
If you're just needing HTTP POST functionality then an AsyncTask might not be the best choice. AsyncTask really shines if you need to get progress updates as the task is executing (with onProgressUpdate(Progress... progress)). If you'd like to use AsyncTask nonetheless, iroiroys' reply should help.
A bit more simply, you could just use a Handler thread straight up. Something like this:
public class HandlerExampleActivity extends Activity {
private Button postButton;
private Button getButton;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_handler_example);
backgroundThread = new BackgroundThread();
backgroundThread.start();
postButton = (Button) findViewById(R.id.button_post);
postbutton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
backgroundThread.post("DATA_HERE");
}
});
getButton = (Button) findViewById(R.id.button_get);
getbutton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
backgroundThread.get("URL_HERE");
}
});
}
#Override
protected void onDestroy() {
super.onDestroy();
backgroundThread.exit();
}
private class BackgroundThread extends Thread {
private Handler backgroundHandler;
public void run() {
Looper.prepare();
backgroundHandler = new Handler();
Looper.loop();
}
public void post(DataType data) {
backgroundHandler.post(new Runnable() {
#Override
public void run() {
// pull data and do the POST
uiMsg = uiHandler.obtainMessage(POST_COMPLETE, whatever_data_passing_back, 0, null);
uiHandler.sendMessage(uiMsg);
}
});
}
public void get(URL data) {
backgroundHandler.post(new Runnable() {
#Override
public void run() {
// GET data
uiMsg = uiHandler.obtainMessage(GET_COMPLETE, whatever_data_passing_back, 0, null);
uiHandler.sendMessage(uiMsg);
}
});
}
public void exit() {
backgroundHandler.getLooper().quit();
}
}
private final Handler uiHandler = new Handler() {
public void handleMessage(Message msg) {
switch(msg.what) {
case POST_COMPLETE:
// handle it
break;
case GET_COMPLETE:
// handle it
break
case MESSAGE_BACK_TO_UI_THREAD:
// do something
break;
case OPERATION_FAIL:
// oh no!
break;
case OPERATION_SUCCESS:
// yay!
break;
}
}
};
}
I suggest you try Handler and Handler.Callback.
Below I made it simple example..
import android.app.Activity;
import android.os.AsyncTask;
import android.os.Bundle;
import android.os.Handler;
import android.os.Handler.Callback;
import android.os.Message;
public class MainActivity extends Activity implements Callback {
Handler handler;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
handler = new Handler(this);
Proxy proxy = new Proxy(handler);
proxy.foo();
}
private class Proxy {
Handler handler;
public Proxy(Handler handler) {
this.handler = handler;
}
private void foo() {
new myAsync().execute();
}
private class myAsync extends AsyncTask<Void, Void, Void> {
#Override
protected Void doInBackground(Void... params) {
return null;
}
#Override
protected void onPostExecute(Void result) {
super.onPostExecute(result);
Message msg = handler.obtainMessage();
msg.obj = result;
handler.sendMessage(msg);
}
}
}
#Override
public boolean handleMessage(Message msg) {
// Handle Message here!
return false;
}
}
In my app I have three buttons and when one button is clicked it calls a thread to start thing is i want to be able to input in edittext string in to the threads and the do some work to it then have it returned to the UI Thread where i can display it or put it into an opengl to display an Object. I've read up on Handles and im not sure i fully understand them and maybe if anyone knows a way to make my own handler code. Also I've read up on Async and I dont think it would benifit my app.(personal opion if it would benifit my app let me know) My question is how would i get the info from UI edittext when enter is pressed to the line thread in DrawingUtils class then work is done to it then it comes back to the UI to be ethier displayed or inputed in an openGl program?
Here is MainActivity class:
public class MainActivity extends Activity implements OnClickListener {
EditText cl;
TextView info;
Button enter;
Button line;
Button arc;
Line callLine = new DrawingUtils.Line();
Enter callEnter = new DrawingUtils.Enter();
Arc callArc = new DrawingUtils.Arc();
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
info = (TextView) findViewById(R.id.info);
enter = (Button) findViewById(R.id.enter);
line = (Button) findViewById(R.id.line);
arc = (Button) findViewById(R.id.arc);
Handler UIhandler = new Handler() {
#Override
public void handleMessage(Message msg) {
Bundle bundle = msg.getData();
String string = bundle.getString("myKey");
}
};
}
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
switch (v.getId()) {
case R.id.enter:
callEnter.start();
break;
case R.id.line:
callLine.start();
break;
case R.id.arc:
callArc.start();
break;
}
};
}
Here is DrawingUtils class:
public class DrawingUtils {
MainActivity handle = new MainActivity();
// Thread classes for buttons
public static class Enter extends Thread {
Thread enter = new Thread() {
public void run() {
}
};
public static class Line extends Thread {
Thread line = new Thread() {
public void run() {
}
};
}
public static class Arc extends Thread {
Thread arc = new Thread() {
public void run() {
}
};
}
}
}
public class MyActivity extends Activity {
#Override
protected void onCreate(Bundle savedInstance) {
// ....
Handler myHandler = new Handler() {
#Override
public void handleMessage (Message msg) {
doCoolStuffWhenMessageReceived();
}
}
MySecondClass secondClass = new MySecondClass(myHandler);
// ....
}
}
public class MySecondClass {
private handler;
public MySecondClass(Handler handler){
this.handler = handler;
}
private void someMethodToCallActivity() {
handler.sendEmptyMessage(0);
}
}