In my app, I am showing a dialog during a long-running background process which is modal.
This dialog is dismissed when android returns from the background task.
final ProgressDialog progressDialog = ProgressDialog.show(activity, "", "Doing something long running", true, true);
new Thread(new Runnable() {
public void run() {
someLongRunningCode(); // (not using AsyncTask!)
activity.runOnUiThread(new Runnable() {
public void run() {
progressDialog.dismiss();
}
});
}
}).start();
Now, however, when the user rotates his device while the background process is still running the activity is recreated and thus, the progressdialog gets detached from the activity.
When the long running process is done, android obviously tries to hide the (now detached) progress dialog which then results in an exception: java.lang.IllegalArgumentException: View not attached to window manager.
Is there any way to check if it is safe to dismiss the dialog?
Edit: Or better still, is there any way to attach the existing dialog to the newly created activity?
A new, cloned dialog would be fine aswell.
Just catch the exception and ignore it. Android's decision to restart the activity on rotation makes threads have a few odd exceptions like that. But the end result you want is no dialog box displayed. If you just catch the exception, no dialog box is displayed. So you're good.
If you aren't using a separate layout/drawables for landscape and portrait, you can just override configChange in your manifest for the activity so it doesn't destroy the activity (it will still correctly rotate and resize everything for you). That way the same dialog will be up and you shouldn't get the exception. The other option would require a lot of work around onSaveInstanceState and onRestoreInstanceState, and you'd need to be very careful of timing issues if the thread actually finishes during that time. The whole recreate activity on rotation idea doesn't work well with multithreading.
if (progressDialog != null) {
progressDialog.dismiss();
}
I've faced this issue before and solved using the below code.
private boolean isDialogViewAttachedToWindowManager() {
if (dialog.getWindow() == null) return false;
View decorView = progressDialog.getWindow().getDecorView();
return decorView != null && decorView.getParent() != null;
}
Related
I have an activity that calls a second java class. I want after the second class is called to show a progressbar and then return to normal activity execution. I found some other threads but i couldn't make the progressbar to stop.
There's a full example over here.
Quote:
Declare your progress dialog:
ProgressDialog progress;
When you're ready to start the progress dialog:
progress = ProgressDialog.show(this, "dialog title",
"dialog message", true);
and to make it go away when you're done:
progress.dismiss();
Here's a little thread example for you:
// Note: declare ProgressDialog progress as a field in your class.
progress = ProgressDialog.show(this, "dialog title",
"dialog message", true);
new Thread(new Runnable() {
#Override
public void run()
{
// do the thing that takes a long time
runOnUiThread(new Runnable() {
#Override
public void run()
{
progress.dismiss();
}
});
}
}).start();
ProgressDialog is deprecated, so you might want to use a ProgressBar.
I've found this post about deleting one of them.
Well, I think this is rather ridiculous, but here is how I fixed it.
In my xml for the ProgressBar, I added android:visibility="gone"
to hide it by default. Then, in my code, I first told it to display
(View.VISIBLE) before it tried getting the server list, then I told
it to hide (View.GONE) after it was done. This worked (I could see
the progress indicator while the data loaded, then it went away). So
I suppose I couldn't get it to hide in the code because the code is
not what forced it to be visible to begin with... That seems like a
bug to me.
Its very Simple:
to show a Progress
ProgressDialog dialog = ProgressDialog.show(getContext(), "Title", "Message");
and to stop it:
dialog.dismiss();
I have a menu button, that when I click it, it sends some data to the cloud. While it is sending the data, I display a progress dialog. Every thing goes swimmingly and seems to be fine and I can press the button as many times as I want and the data is properly sent to the cloud.
But when I go to exit the activity I get a error saying that there was a window leak:
com.android.internal.policy.impl.PhoneWindow$DecorView{4321fd38 V.E..... R......D 0,0-1026,288} that was originally added here
the "here" is referring to when I insatiate my progress dialog.
Here is my code:
#Override
public boolean onOptionsItemSelected(MenuItem item) {
progressDialog = ProgressDialog.show(CruiseDetailRollCallActivity.this, "", "Loading...", true);//set up & show progress dialog
switch(item.getItemId()){
case R.id.menu_roll_call_opt_in:
//saveing something into Parse -- (a database online, check Parse.com if you want more info, but just treat this like I am saving something into the cloud)
currentUser.put("somethingBoolean", false);
currentUser.saveInBackground(new SaveCallback(){
#Override
public void done(ParseException e) { //once data has been put into the cloud
progressDialog.dismiss();//dismiss the dialog
supportInvalidateOptionsMenu();//refreshes the options menu
}
});
return true;
default:
return super.onOptionsItemSelected(item);
}
}
I should mention that this is not crashing my application but merely displaying the error. I have no clue why it is happening, and I feel like I shouldn't just ignore it.
EDIT: found my mistake. It was failing because works was because I was hitting back on the action bar and the progress dialog would be created but never dismissed since it was only being dismissed inside the done code.
My guess is that you're leaking the activity into the currentUser object, when you pass the CruiseDetailRollCallActivity into currentUser.saveInBackground(new SaveCallback().... The SaveCallback class that you just created now has a strong reference to the Activity. It will never be garbage collected, even though you exit the method. You should use a WeakReference and then it can be garbage collected.
WeakReference<CruiseDetailRollCallActivity> weakRef = new WeakReference<CruiseDetailRollCallActivity>(CruiseDetailRollCallActivity.this)
Then, pass the weakRef in to the ProgressDialog constructor:
progressDialog = ProgressDialog.show(weakRef.get(), "", "Loading...", true);
Whenever you're passing around the Context in Android, check to see if you need a WeakReference so it can be garbage collected. It's easy to leak the entire application.
It was failing because works was because I was hitting back on the action bar and the progress dialog would be created but never dismissed since it was only being dismissed inside the done code.
I moved
progressDialog = ProgressDialog.show(CruiseDetailRollCallActivity.this, "", "Loading...", true);//set up & show progress dialog
into
case R.id.menu_roll_call_opt_in:
//saveing something into Parse -- (a database online, check Parse.com if you want more info, but just treat this like I am saving something into the cloud)
currentUser.put("somethingBoolean", false);
currentUser.saveInBackground(new SaveCallback(){
#Override
public void done(ParseException e) { //once data has been put into the cloud
progressDialog.dismiss();//dismiss the dialog
supportInvalidateOptionsMenu();//refreshes the options menu
}
});
return true;
so looks something like this
case R.id.menu_roll_call_opt_in:
progressDialog = ProgressDialog.show(CruiseDetailRollCallActivity.this, "", "Loading...", true);//set up & show progress dialog
//saveing something into Parse -- (a database online, check Parse.com if you want more info, but just treat this like I am saving something into the cloud)
currentUser.put("somethingBoolean", false);
currentUser.saveInBackground(new SaveCallback(){
#Override
public void done(ParseException e) { //once data has been put into the cloud
progressDialog.dismiss();//dismiss the dialog
supportInvalidateOptionsMenu();//refreshes the options menu
}
});
return true;
I'm making a little game and in it I have to check if a value is zero every second. When it is zero the game should stop and show a dialog instead.
As from now the game never ever shoud work until the app is reinstalled.
So, I have an timer with an timertask which executes a runOnUiThread.
Timer:
private void update(){
Timer timer = new Timer();
timer.schedule(new TimerTask(){
#Override
public void run() {
onChange();
}
},0,(1000* getResources().getInteger(R.integer.remove_speed_inSecond)));
}
runOnUiThread: (with try/catch to catch the exeption at this point but i want to fix and not just ignore it.)
private void onChange(){
runOnUiThread(new Runnable() {
#Override
public void run() {
try{
checkupifexpire();
}
catch (Exception ex) {
}
}
});
}
The Method where i show the dialog:
private void checkupifexpire() {
if(eat == 0 || drink == 0 || wash == 0 || care == 0){
dialog = new Dialog(this, android.R.style.Theme_Black_NoTitleBar_Fullscreen);
dialog.setOnCancelListener(new DialogInterface.OnCancelListener()
{
#Override
public void onCancel(DialogInterface dialog)
{
GameEngine.this.finish();
}
});
dialog.setContentView(R.layout.activity_rip);
dialog.show();
}
}
Always when I press the back button or just the home button then the App crashes.
Any Idea how to fix this?
So, the logcat tells us that is crashes on line 306 of GameEngine.java, in the method checkupifexpire, which looks like it is the dialog.show() line.
I'm not 100% sure, but from what you've said, it would seem to me that when back or home is pressed, the app will lose its UI thread. This means that checkuponexpire cannot do what it does.
To solve your crash problem, there are three obvious options:
You could use onPause in your main activity to catch when the app loses the screen. At this point you need to either stop the timer, or switch it to using Toast to communicate information.
Only use Toast in checkuponexpire
Decide that when the back or home is pressed the game is over anyway and cancel the Timer.
To Actually get the dialog, it may also be helpful to change the context you use to create the dialog with. Although it should be used sparingly, it may be that getApplicationContext() is what you need here (possibly this.getApplicationContext()).
Thanks to Neil Townsend and WELLCZECH. :)
My problem was the Lifecycles.
Mostly i had the App running in the onCreat() and had no onStart() method.
Just didn't know that thies methods were as much important as they are.
Also i didn't need a dialog shown. Instead i just have to start a new activity and cancel the old one.
The example is pretty straightforward: i want to let the user know about what the app is doing by just showing a text (canvas.drawText()). Then, my first message appears, but not the other ones. I mean, i have a "setText" method but it doesn't updates.
onCreate(Bundle bundle) {
super.onCreate(bundle);
setContentView(splash); // splash is the view class
loadResources();
splash.setText("this");
boundWebService();
splash.setText("that"):
etc();
splash.setText("so on");
}
The view's text drawing works by doing just a drawText in onDraw();, so setText changes the text but doesn't show it.
Someone recommended me replacing the view with a SurfaceView, but it would be alot of trouble for just a couple of updates, SO... how the heck can i update the view dinamically at runtime?
It should be quite simple, just showing a text for say 2 seconds and then the main thread doing his stuff and then updating the text...
Thanks!
Update:
I tried implementing handler.onPost(), but is the same story all over again. Let me put you the code:
public class ThreadViewTestActivity extends Activity {
Thread t;
Splash splash;
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
splash = new Splash(this);
t = new Thread(splash);
t.start();
splash.setTextow("OA");
try { Thread.sleep(4000); } catch (InterruptedException e) { }
splash.setTextow("LALA");
}
}
And:
public class Splash implements Runnable {
Activity activity;
final Handler myHandler = new Handler();
public Splash(Activity activity) {
this.activity=activity;
}
#Override
public void run() {
// TODO Auto-generated method stub
}
public synchronized void setTextow(final String textow) {
// Wrap DownloadTask into another Runnable to track the statistics
myHandler.post(new Runnable() {
#Override
public void run() {
TextView t = (TextView)activity.findViewById(R.id.testo);
t.setText(textow);
t.invalidate();
}
});
}
}
Although splash is in other thread, i put a sleep on the main thread, i use the handler to manage UI and everything, it doesn't changes a thing, it only shows the last update.
I haven't hit this yet, but I think the usual pattern is to do lengthy initialization in a background thread, and use Handler.post() to update the UI. See http://developer.android.com/reference/android/widget/ProgressBar.html for a different, but possibly related, example.
Also see this answer, especially the first paragraph:
The problem is most likely that you
are running the splash screen (some
sort of Dialog such as ProgressDialog
I assume) in the same thread as all
the work being done. This will keep
the view of the splash screen from
being updated, which can keep it from
even getting displayed to the screen.
You need to display the splash screen,
kick off an instance of AsyncTask to
go download all your data, then hide
the splash screen once the task is
complete.
Update (based on your update and your comment): You are not supposed to update the UI in any thread except the one where your Activity is created. Why is it impossible for you to load your resources in a background thread?
First: onCreate is executed on main UI thread of application so no UI updates until you leave it. Basically you need one thread to execute long running tasks and some mechanism to push updates into the UI.
Most usual approach is to extend AsyncTask see this link for further info
i suppose that your view is an extended view and you call onDraw for drawing the view, so, maybe the view isn´t 'refresh' their state, so try this
onCreate(Bundle bundle) {
setContentView(splash); // splash is the view class
loadResources();
splash.setText("this");
splash.invalidate();
boundWebService();
splash.setText("that"):
splash.invalidate();
etc();
splash.setText("so on");
splash.invalidate();
}
I need a popup dialog to be shown when i get a message from different thread but the dialog should be not dependent on Activity i.e, it should display the dialog wherever the screen focus is.
Can it be done? Because the dialog is handled per Activity, I thought of using a service but again it would be one more thread added and I want to avoid that.
Any other options available?
If you're trying to ask how to show a dialog when your activity is not the focused activity on the user's phone then try using Notifications instead. Popping up a dialog over a different application interrupts the user when they may be doing something else. From the Android UI guidelines:
Use the notification system — don't
use dialog boxes in place of
notifications
If your background service needs to
notify a user, use the standard
notification system — don't use a
dialog or toast to notify them. A
dialog or toast would immediately take
focus and interrupt the user, taking
focus away from what they were doing:
the user could be in the middle of
typing text the moment the dialog
appears and could accidentally act on
the dialog. Users are used to dealing
with notifications and can pull down
the notification shade at their
convenience to respond to your
message.
A guide to create notifications is here: http://developer.android.com/guide/topics/ui/notifiers/notifications.html
Alternative solution :
AlertDialog dialog;
//add this to your code
dialog = builder.create();
Window window = dialog.getWindow();
WindowManager.LayoutParams lp = window.getAttributes();
lp.token = mInputView.getWindowToken();
lp.type = WindowManager.LayoutParams.TYPE_APPLICATION_ATTACHED_DIALOG;
window.setAttributes(lp);
window.addFlags(WindowManager.LayoutParams.FLAG_ALT_FOCUSABLE_IM);
//end addons
alert.show();
if I understand you correctly you could use a base class for all of your activities
public abstract class BaseActivity extends Activity{
protected static BaseActivity current_context = null;
#override
protected void onPause(){
current_context = null;
super.onPause();
}
#override
protected void onResume(){
current_context = this;
super.onResume();
}
public static void showDialog(/*your parameters*/){
//show nothing, if no activity has focus
if(current_context == null)return;
current_context.runOnUiThread(new Runnable() {
#override
public void run(){
AlertDialog.Builder builder =
new AlertDialog.Builder(current_context);
//your dialog initialization
builder.show();
}
});
}
}
in your thread show your dialog with BaseActivity.showDialog(..) But this approach doesn't work if you want to show your dialog on top of any activity of the target device.