Develop Reference

Removing spinner of ParseFacebookUtils on Login and Link

I implemented logging in with facebook with ParseFacebookUtils.logInWithReadPermissionsInBackground
and the linking with ParseFacebookUtils.linkWithReadPermissionsInBackground
The only problem I have is that it shows a spinner in the middle of my screen. After that it launches a webview of facebook.
Because of this the spinner sometimes overlap with my progress dialog. I bypassed this temporarily with:
Handler handler = new Handler();
handler.postDelayed(new Runnable() {
public void run() {
progressDialog.show();
}
}, 4000);
Although there are situations where the spinner slow because of the internet connection and I don't know how to solve this

Closing an activity after a number of second

After pushing a button, i want to close an activity. But, I’d like to wait some seconds before closing it, because users have to read a short message displayed on that activity.
I tried using Thread inside the onClick event
try{
Thread.sleep(2000);
finish();
}
catch(Exception e){}
But, when I push the button, the entire objects are freeze (for example, the button stay pushed).
Then I used a simple Timer
timer.schedule(task(), 2000);
And it seems to work well. Is it correct to use a Timer in this situation, or should I use a Thread or something else?

new Handler().postDelayed(new Runnable() {
#Override
public void run() {
Activity.this.finish();
}
}, 2000) ;

The easiest way is probably to use a Handler
private Handler h = new Handler();
...
h.postDelayed(new Runnable() {
#Override
public void run() {
finish();
}
}, 2000);

android - calling ui thread from worker thread

Hi I want to make Toast available to me no-matter-what and available from any thread whenever I like within my application. So to do this I extended the Activity class:
import android.app.Activity;
import android.os.Bundle;
import android.os.Handler;
import android.widget.Toast;
public class MyActivity extends Activity{
private Handler mHandler;
#Override
public void onCreate(Bundle savedInstanceState) {
mHandler = new Handler();
super.onCreate(savedInstanceState);
}
private class ToastRunnable implements Runnable {
String mText;
public ToastRunnable(String text) {
mText = text;
}
public void run(){
Toast.makeText(getApplicationContext(), mText, Toast.LENGTH_SHORT).show();
}
}
public void doToast(String msg) {
mHandler.post(new ToastRunnable(msg));
}
}
so that all Activity classes in my app are now simply
public class AppMain extends MyActivity {
//blah
}
what I expected to be able to do (in a worker thread) was this:
try{
MyActivity me = (MyActivity) Looper.getMainLooper().getThread();
me.doToast("Hello World");
}
catch (Exception ex){
Log.e("oh dear", ex.getMessage());
}
and so long as the Activity was a "MyActivity" it should work - but the problem is ---> the Looper.getMainLooper().getThread(); isn't returning the MyActivity to me and it's making me cry - what am I doing wrong?
: EDIT :
some background to explain "why" I am stuck with this type of implmentation.
I need to be able to confirm to the user that a "HTTP POST" event has been a success. Now. If the User clicks "OK" on the UI Form it MAY or MAY NOT have internet at that time.. If it has Internet - all well and good - it posts the form via HTTP POST all well and good.. but if there is NO Internet most (99.999% of Android apps lame /pathetic / mewling at this, and basically offer the user no plan "b" assuming that at all times the internet is there - when it is NOT)
My App will not "go lame (as I call it)" - it does have a plan "b" instead it "Queues" the post event and retries every x minutes.. now this is a silent thread in the background.. I have plenty of user interaction all over the app I don't know where the user will "be" but eventually when the HTTP POST that queue/retries/queue/retries returns "! Success! " I want to Toast that as a message to the user (EG: "your form was sent")

What's wrong with runOnUiThread?
http://developer.android.com/reference/android/app/Activity.html#runOnUiThread(java.lang.Runnable)
activity.runOnUiThread(new Runnable() {
public void run() {
Toast.makeText(activity, "Hello, world!", Toast.LENGTH_SHORT).show();
}
});

use below code. create activity object which contains your activity instance..
activity.runOnUiThread(new Runnable() {
public void run() {
Toast.makeText(activity.getApplicationContext(),"Toast text",Toast.LENGTH_SHORT).show();
}
);

This will allow you to display the message without needing to rely on the context to launch the toast, only to reference when displaying the message itself.
runOnUiThread was not working from an OpenGL View thread and this was the solution. Hope it helps.
private Handler handler = new Handler();
handler.post(new Runnable() {
public void run() {
Toast.makeText(activity, "Hello, world!", Toast.LENGTH_SHORT).show();
}
});

You can't just cast the result of getThread() to an instance of your MyActivity base class. getThread() returns a Thread which has nothing to do with Activity.
There's no great -- read: clean -- way of doing what you want to do. At some point, your "worker thread" abstraction will have to have a reference to something that can create a Toast for you. Saving off some static variable containing a reference to your Activity subclass simply to be able to shortcut Toast creation is a recipe for memory leaks and pain.

Why don't you send an intent that is captured by a BroadCastReceiver, then the broadcast receiver can create a notification in the notification tray. It's not a toast, but its a way to inform the user that his post has been successful.

If it's within your own activity, why can't you just call doToast()?

if you have the context with you, you can call the ui thread like this from non activity class.
((Activity)context).runOnUiThread(new Runnable() {
public void run() {
// things need to work on ui thread
}
});

Android Button Response Problem

hi all
since i am using a button and on the click of that button it connects to a Web Service.
But the problem is that when i press the button it does not showed me that it has been clicked and goes to connect to the internet and web service. after connecting it shows me the response that it has been clicked. in short the response of button is very slow. if that buton has some INternet connectvity in its Listener.
i know it has something to do with UI thread. but please friends guide me through this.
Thanks a bunch,

Put the following code in your class:
// Need handler for callbacks to UI Threads
// For background operations
final Handler mHandler = new Handler();
// Create Runnable for posting results
final Runnable mUpdateResults = new Runnable() {
public void run() {
// Do your task which needs to get done after webservice call is complete.
}
};
And for calling the webservice use the following code in button event:
new Thread() {
public void run() {
// Place the webservice call here.
mHandler.post(mUpdateResults);
}
}.start();
Actually what are you looking for is multithreading, all the webservice calls and network activities should go in separate thread.
After the thread start() call you can do what ever you want and would be done instantly without any delay (in your case showing that button pressed).

You have to use Handler for this background operation already ask on OS follow this link
progress dialog not showing in android?

You should write a class say MyWebService and extend it from AsyncTask. Perform the connect operation in its overridden doInBackground() method and update any UI changes in its onPostExecute() method.

Create a new Thread in the onClickListener that does the heavy work in the background. That way the UI thread will be able to update the state of the button:
button.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
new Thread(new Runnable() {
#Override
public void run() {
// Code that connects to web service goes here...
}
}).start();
});

Android: Stopping method to be called twice if already running

I am trying to prevent my application calling the same method twice in the event of a double-click, or if the user presses different buttons quickly, almost at the same time.
I have clickable Views, acting as buttons, that call the same method but passing different parameters. This is the call:
startTheSearch(context, getState(), what, where);
Inside this method I'm creating a new Thread, because it queries a web server for the result:
new Thread(new Runnable() {
public void run() {
progDiag = ProgressDialog.show(ctx, null, "Searching", true);
getServerXML(context, what, where, searchIsCustom, mOffset);
handler.sendEmptyMessage(0);
}
}).start();
The problem is that upon two quick clicks, the method is fired twice, two threads are created, and consequently two new activities are created. That makes my app crash.
When the methods are done, and we have the result from the server, we call the handler:
private Handler handler = new Handler() {
#Override
public void handleMessage(Message msg) {
super.handleMessage(msg);
try {
Intent i = new Intent(Golf.this, Result.class);
Bundle b = new Bundle();
b.putString("what", mWhat);
b.putString("where", mWhere);
b.putInt("offset", mOffset);
b.putBoolean("searchIsCustom", searchIsCustom);
i.putExtras(b);
startActivityForResult(i, Activity.RESULT_OK);
progDiag.dismiss();
} catch (Exception e) {
Alerts.generalDialogAlert("Error", "settings", ctx);
}
}
};
I tried to have a global boolean variable called "blocked" initially set to false, creating a condition like:
if(!blocked){
blocked = true;
new Thread(new Runnable() {
public void run() {
But this only seems to work on slower phones like the G1, I tried on Nexus and before it set blocked = true, the second request has was granted. So is there any way I can block the method being called if it's already running, or if the thread has started so it wont create a new one?

In the book Hello Android the author Ed Burnette gives a very nice solution for this problem.
To leave your app snappy and responsive you should create a second thread to do the web request.
Instead of creating a new thread for every request you can use a SingleThreadExecutor. If you start a second thread you can check if you are waiting for the result of another thread and block until this thread is ready, or cancel the old thread and start a new one if you think that the user now wants to do some other thing.
You can find the source code from the book on this page. Look for the Translate folder inside the source. It is a nice example on how to react to user commands and how to prevent too many web requests because of a user touching a lot on the gui.

Instead of using the "blocked" Boolean, you might investigate using a mutex. They're designed for this kind of problem.

I tried on Nexus and before it set
blocked = true, the second request has
was granted
That is impossible. Android UIs are single-threaded. There is no way that two onClick() methods of OnClickListeners will be called at the same time.