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.
Related
I need to add an artificial pause before my AI plays its turn on the tic tac toe board. However, when I try to use something like Thread.sleep, in the location where I have the comment, the entire onClick function lags. What I mean by lagging is that the ((Button) v).setText("0") does not set the button text to 0 for the amount of time I use the sleep function and the moment that the timer is up, everything happens immediately. It is like the lag happens in the beginning of the function rather than the middle where the comment is. Is there anyway to address this problem or explain why the sleep function isn't lagging where it is suppose to be?
public void onClick(View v) {
if(!((Button) v).getText().toString().equals("")){
return;
}
((Button) v).setText("0");
turn();
// Need a pause before tictacAI does anything
tictacAI("0", "X").setText("X");
turn();
if(won){
resetBoard();
won = false;
}
}
When using Thread.sleep in onClick, you are actually blocking the entire UI Thread, This will prevent Android Framework redraw your view, so your change to View's property will not be displayed.
In order to delay the execution, you should use View.postDelayed, which will post your action to a message queue and execute it later.
public void onClick(View v) {
if(!((Button) v).getText().toString().equals("")){
return;
}
((Button) v).setText("0");
turn();
// Need a pause before tictacAI does anything
v.postDelayed(new Runnable() {
#Override
public void run() {
tictacAI("0", "X").setText("X");
turn();
if(won){
resetBoard();
won = false;
}
}
}, 1000L); //wait 1 second
}
If you are using Java 1.8, you can use lambda instead of anonymous class.
Another note:
this Runnable will not be garbage collected until executed, so a long interval may cause your entire view leaked, which is very bad. Consider using View.removeCallbacks when this callback is not needed anymore(like activity's onDestroy, for example)
I have made the beginning of what will be a pretty cool wear app, for now it is just a metronome that vibrates on the tempo the user selects.
My problem is that when you exit the app or when the screen goes into "ambient mode" the vibration keeps going, which is great, but when you open the app again it opens a new "instance" (or however you say that) of the app so the vibration tempo previously selected keeps vibrating and when you select a new one you basically have 2 tempos vibrating.
Maybe this has something to do with the fact that I use a new Thread for the timing and that Thread keeps running. Is there a way to prevent this? Thank you!
public void buttonTempoOnClick(final View v) {
Running = !Running;
Button button = (Button) v;
Thread Timer = new Thread(new Runnable() {
public void run() {
while (Running == true) {
vibrate(150);
try {
Thread.sleep(60000 / Tempo);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
});
Timer.start();
(vibrate refers to a void I created in the class, which works.)
public void vibrate(int duration){
Vibrator vibrator = (Vibrator) getSystemService(Context.VIBRATOR_SERVICE);
vibrator.vibrate(duration);
}
Edit: I already have a public boolean Running that is false by default, when the "start' button is pressed it toggles the boolean and starts a new threat with a while(Running == true) loop in it. Stopping the vibration by pressing the button one more time works like a charm.
Try setting a variable in the class managing the thread, like
boolean isTempoOn = true;
In your main activity, in the onResume() function, check if it's already running. If so, don't start again.
Perhaps posting the applicable portion of code will help.
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;
}
I have written a function to create a splash screen with a 5 second timeout for my app.
The code works fine, but when the timeout reaches zero and I want to redirect to my main activity, the app crashes with the following error:
Only the original thread that created a view hierarchy can touch its views.
So I looked around a bit and someone suggested nesting this inside my function. It seems like a good Idea, but now methods like sleep / stop won't work.
My code is below, I can provide more / explain more in details if it isn't clear enough just let me know. Thanks for the help.
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
showSplashScreen();
}
protected boolean _active = true;
protected int _splashTime = 5000; // Splash screen is 5 seconds
public void showSplashScreen() {
setContentView(R.layout.splash_layout);
// Thread splashThread = new Thread() {
runOnUiThread(new Runnable() {
#Override
public void run() {
try {
int waited = 0;
while (_active && (waited < _splashTime)) {
Thread.sleep(100);
if (_active) {
waited += 100;
}
}
} catch (InterruptedException e) {
// do nothing
} finally {
showApplication();
}
}
});
}
Probably not what you want to hear, but you should never put a splash screen on your mobile app. With the exception of games, when people use a mobile app they want to get in, do what ever it is they need to do, and get out. If you make that process take longer, people are just going to get frustrated with you app. You should probably reconsider just not using a splash screen.
This will perform sleep on the UI thread. That's never a good idea.
Why not something like this?
new Handler().postDelayed(new Runnable() {
public void run() {
// start application ...
}
}, _splashTime);
But this answer has a good point. Displaying a splash screen for 5 seconds can be very annoying.
I believe you want AsyncTask for this. The method called on completion of the task will be called on your UI thread, making modifying UI elements much easier.
Use a Handler to post an event to the UI thread that will remove the splash.
Code should be something like...
splash.show()
new Handler().postDelayed(
new Runnable() {
void run() {
splash.remove();
},
delayTime);
I suggest you to make new activity for your spalsh screen, show it in a regular way (with startActivityForResult) and place in it such code (in it, not in your main activity):
new Handler().postDelayed( new Runnable()
{
public void run()
{ finish(); }
}, 5000 );
Also you can handle in this new activity click events for giving opportunity to user to close it faster, tapping on it.
I am trying to create a simple exception handler which will help me debug the application. Right now, when I have an exception I am forced to connect with Eclipse debugger merely to see the exception details.
To avoid that I've used setUncaughtExceptionHandler to handle any unhandled exception and display a Toast on the exception. Unfortunately, that doesn't work.
public class TicTacToe extends Activity {
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Thread.currentThread().setUncaughtExceptionHandler(new UncaughtExceptionHandler() {
#Override
public void uncaughtException(Thread thread, Throwable ex) {
Toast.makeText(TicTacToe.this, "TOAST", Toast.LENGTH_LONG).show();
}
});
setContentView(R.layout.main);
Button continueButton = (Button) findViewById(R.id.cell01);
continueButton.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
int i = 5;
i = 5 / 0;
Toast.makeText(TicTacToe.this, "BUTTON", Toast.LENGTH_LONG).show();
}
});
}
}
Essentially I made a form with a single button, pressing on which, it would throw a devision-by-zero exception. However, pressing the button doesn't cause the global toast handler to show. Instead, the button stays orange (pressed) and nothing happens.
Needless to say, if I comment out i = 5 / 0; I see the toast that says that a button was pressed.
Two questions:
1) Why isn't the toast showing in the UncaughtExceptionHandler body? How do cause it to show?
2) Is there an alternative/better way for global exception handling? I guess I could install aLogCat on the android simulator and simply log the uncaught exception, it seems, however, less comfortable - I will need to be switching applications just to see exception details.
Thanks!
It is possible. You need to do it inside another thread
Then it should be like this
Thread.currentThread().setUncaughtExceptionHandler(new UncaughtExceptionHandler() {
#Override
public void uncaughtException(Thread thread, Throwable ex) {
new Thread() {
#Override
public void run() {
Looper.prepare();
Toast.makeText(TicTacToe.this, "TOAST", toast.LENGTH_LONG).show();
Looper.loop();
}
}.start();
}
});
You're not seeing anything because the exception happened on your UI thread and the stack unrolled all the way. So there is no more Looper and there is no support there that is used to display the Toast. If you want to display the exception information on screen you'll most likely need to start another Activity in another process.
There is also a problem with your UncaughtExceptionHandler. You really should keep a reference to the old one and call it at the end of uncaughtException this allows the system to display the Force Close button.
I know it's an old question but I hope I can save someone from frustration and wasting time.
Qberticus is right, you can't start an Activity on the same process, but you can kill the current process and have android run it in a new one:
Intent intent = new Intent(myContext, AnotherActivity.class);
intent.putExtra("error", errorReport.toString());
myContext.startActivity(intent);
android.os.Process.killProcess(android.os.Process.myPid());
System.exit(10);
refer to this page for an awesome working example: