I am executing maswebview class and I would like to finish only this activity. I tried maswebview.this.finish() but when executed, app is been closed. Then if I set a new view for the tab content, it is loaded properly and webviewmas dissapears but just for a while, then appears again fitting fullscreen. How to finish maswebview completely? ThanK you
public void onClick(View arg0)
{
/*
Intent intent = getIntent();
intent.addFlags(Intent.FLAG_ACTIVITY_TASK_ON_HOME);
startActivityForResult(intent, 1);
Intent intentmas = new Intent (maswebview.this, mas.class);
intentmas.setFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP);
intentmas.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
intentmas.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
intentmas.addFlags(Intent.FLAG_ACTIVITY_NO_HISTORY);
View vista = getLocalActivityManager().startActivity("maswb", intentmas).getDecorView();
setContentView(vista); */
maswebview.this.finish();
Do you have any other activities of your app in the stack by the time you call finish()? If you don't, you'll want to start the desired activity instead of finishing the current one.
But actually it seems to me that you're trying to accomplish something that can be done simpler. Can you provide more info on the task at hand and your app structure you're trying to go about it with?
From what you said, it seems like you have tabbed UI and you're trying to show a webview in one of the tabs, then hide it.
First, I don't see why you want the webview in a separate activity. Seems to me you could just have it in layout of one of the tabs and just call setVisibility(GONE) to hide it.
Second - and this is important - looks like you're trying to implement tabs the old way - TabWidget, TabHost, etc. Since Honeycomb has been released, there's much more convenient way to implement tabbed UI - Action Bar Tabs and Fragments - that approach is much more convenient and will render your webview problems obsolete: there's a thing called WebViewFragment which is basically a WebView but smarter - it will handle its own lifecycle with minimum effort required from you (i.e. pause when removed, resume when added). It will take some effort to study up on Fragments, but it's well worth it. You can get Fragments API for pre-Honeycomb android sdks as a static library - it's called android-support-v4 and you can download it in Android SDK Manager.
Are you calling "maswebview.this.finish();" before the new Activity is started?
Also if you want to just start this new activity without having the old activity in existence then you can add android:nohistory="true" to your manifest.xml. This will cause the current activity to be the only activity in the queue.
See HERE
You need to provide a little more information for us to better understand what exactly is going on.
I hope this helps.
Try following code
#Override
public void onBackPressed() {
if(childView != null && parentLayout.getChildCount()==2){
childView.stopLoading();
parentLayout.removeViewAt(parentLayout.getChildCount()-1);
if(webView.getVisibility() == View.GONE)
webView.setVisibility(View.VISIBLE);
}else{
super.onBackPressed();
}
Do you have a parent activity which is launching this one? If yes make sure you don't call finish() after launching maswebview, that way the parent activity will remain in the stack. Once maswebview would exit, onResume would be called for your parent activity.
Related
I am developing an Android app in which I want to check if the user has minimized the application or just come from another activity.
In detail, if the user have started another app, went to the home screen or locked the screen, I want to show the activity where the user will enter the password to access the app. But where or how to check this exactly?
https://developer.android.com/guide/components/activities/activity-lifecycle.html
I was trying onResume() but according to documentation onResume() can be fired if the user’s navigating to another activity and coming back.
I'm not very clear on what you are trying to achieve.
The life cycle diagram is quite clear if you are wondering which lifecycle method it would hit when something happens.
Basically, it's the same to minimise the app and go to another activity. But if you are referring to coming from another activity in your own app, you can distinguish your own activity by adding extra information to the intent you use.
Basically, it's like this:
Intent intent = new Intent(FirstActivity.this,SecondActivity.class);
intent.putExtra(key,value);
startActivity(intent);
And in your SecondActivity, you can always retrieve that data like this:
Bundle bundle = getIntent().getExtras();
if ( bundle != null && bundle.containsKey(key) ) {
value = bundle.getInt(key); // not nessecarily getInt(), you should use according to your value type
// use the value to tell if it is from your own app
} else {
// it is not from your own app
}
You can use this mechanism combined with the lifecycle methods. For example, if you use the latter code in your onCreate() method, then whenever the Activity is created, if will check who creates it, which sounds like your what you might want.
As soon as your activity becomes visible it will call OnStart() and as soon as it is ready for the interaction(such as touch ,click etc event). it calls onResume, at this stage your app is running and it is completely in foreground. When your activity start another activity or a dialog box then it calls onPause it means activity is visible but user can not interact with the Activity UI. in case we start another Activity which completely hides the previous activity then its onStop method is called
onPause: Called when another activity comes into the foreground.
onStop: Called when that other activity is completely visible.
onResume: Called when your activity is navigated back to from the onPause state.
Maybe your app was already in the onStop state, so then it would call onRestart.
I am currently developing a game with the android development enviornment. And for the past couple of months I've been dealing with a nasty OOM error. My first problem was that I was placing my drawables in the wrong folder (Drawable-xhdpi in drawable folder). But now, the OOM error eventually happens as you go through the game.
It is a rpg, basically compoed of menus in activity layouts with animations and things. and I've tried everything I could to fix it. I've tried the unbindDrawables method:
unbindDrawables(View view) {
if (view.getBackground() != null) {
view.getBackground().setCallback(null);
}
if (view instanceof ViewGroup) {
for (int i = 0; i < ((ViewGroup) view).getChildCount(); i++) {
unbindDrawables(((ViewGroup) view).getChildAt(i));
}
((ViewGroup) view).removeAllViews();
}
}
which does help a lot, but it does not fix the issue. And I cannot use any of the bitmap.factory options or anything, since I load my images through xml in my drawables folder. My images aren't that big by the way, as activities have a background of 720x1280, with some smaller images, and the most total images I'll have on screen at a time is around 8.
So this lead me to think that I may have a memory leak. I did ALOT of research, and I found out that use this(the activity context) will cause a leak, and I should use the application context. However, If I make the switch, there is almost no difference.
So I used MAT to figure out what was going on, and most of my memory is going to byte[], android.graphics.bitmap. And if I drill down to find the cause of this, it seems that java.ref.finalizer is causing all of the retained memory in the VM.
The only reason I could think this is happening, is because whenever I start a new activity I use,
Intent fight = new Intent(this, StartScreen.class);
//add this flag to remove all previous activities
fight.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(fight);
finish();
which opens a new activity, but closes the one we were just in. So, I'm guessing the bitmaps are not being recycled correctly whenever I finish an activity? or is closing and starting activities like this bad for memory?
I've been on Google all day trying to find the solution to this problem and I can't find it. Any soulutions are appreciated, thank you for reading this!
P.S if you would like to see any snippets of my logcat or code or anything, I am more than happy to post it.
P.S P.S My game has about 10-12 different activities I switch between. For example If I have activities A,B,C I open A, Open B close A, Open C close B, open B close C, open A close B.
EDIT: As request about my activities. Usually it is a menu, and when you press a button, that activity finishes, and then moves into another activity. Or buttons will do some math for things like selling, or doing damage to an enemy. One thing about my activity architecture, is that since I am closing every activity as I go to a new one, when I go back to the ones I closed, I am re-creating them. So I don't know if the old activities I finished still have memory in the VM that over time causes the Out Of Memory error, since it all builds up and keeps expanding. I explained My call for a new activity above. And the intent flag closes all past activities (if there are any) in the stack.
EDIT EDIT: As per request my oncreate and onDestroy:
OnCreate:
#Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_start_screen);
//setting fonts
//a function that binds views by findview by Id and then sets their typeface
setFont();
//set up the music service
//connects the app to the background music service
playMusic();
//aquire wakelock
getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
}
OnDestroy:
#Override
public void onDestroy()
{
super.onDestroy();
//unbinds the service
unbindService(musicConnection);
//unbind drawables (function above)
unbindDrawables((LinearLayout) findViewById(R.id.container));
}
you should destroy the activities that you don't need anymore it takes place in the memory. or if you dont want your user/player to go back to the recent activity you should finish the activity. and if you will notice. if you dont finish the activity and press the back button several times it is layered.
second you mentioned that it is a game. in android programming you need to consider your bitmap resources so to avoid getting an OOM error in your game make use of sprite sheet it will save a lot of memory and usage of bitmaps in your application. i encountered those kind of situation and bitmaps mainly causes the OOM error.
I will say it depends. but with your problem your answer is right here
Quick quote from the site
Note: In most cases, you should not explicitly finish an activity using these methods.
As discussed in the following section about the activity lifecycle,the Android
system manages the life of an activity for you, so you do not need to finish your own
activities. Calling these methods could adversely affect the expected user experience
and should only be used when you absolutely do not want the user to return to this
instance of the activity.
Read for more info
well i get you lucidly now, but im thinking of what you are tryna do here, so y dont you use FragmentActivity for B and C.. So, Activity A opens B..B is opened as fragment but works like activity-(thats fragmentActivity), and opens C which is most likely a Fragment..which i think would be perfect for your situation..
for more info about FragmentActivity click Here
no more activities back and forth.. and its gonna work like an activity..
In my application when i click the back button it passes through all the activities that i open them previously , i used the public void onBackPressed() method to make the back button back to the activity that i want as follow
public void onBackPressed()
{
startActivity(new Intent("com.MyDiet.Main"));
Tracker.this.finish();
}
is that true and safe way to code the back button ? how i can prevent the application from passing through all the previous opened activities when the back button is pressed ? and how i can make the application exit when i click the back button in the main activity?
In your application, and in ALL android applications, unless it's critical not to pass through unneeded steps (such as login if you're already logged in), it's VERY important not to override Android standard behaviour. Users normally complain about Android apps not having a common behaviour or style guideline.
Anyway, yeah, you can just override onBackPressed on all your activities and do whatever you want. But just don't.
This approach isn't good, because you're polluting the activity stack of your application
Example:
current stack: MainAct -> Act2 -> Act3 (we're in activity 3)
With your code above, when you press back, the stack now looks as follows:
MainAct -> Act2 -> MainAct
Because you ended Act3 and launched a NEW main activity, which may be not what you wanted.
To achieve what you want (Get back to main when the current activity is over) you need to work on the intermediate activities: In the example above, when from Act2 you call startActivity("Act3"), you should call "this.finish()". Therefore you don't have to override "onBackPressed()" of activity 3: simply the default value will terminate Act3 and the next activity in the stack will be MainAct
MainAct -> A2 (A2 launches A3 and then calls this.finish())
MainAct -> A3 (user now press back)
MainAct (the mainactivity is now on top)
To summarize, you don't have to override onBackPressed, you just have to correctly manage the lifecycle of the activity between the main one and the current one.
Generally speaking it's not recommended to make things work like user doesn't expect and that is considered as very bad practice. That's why it is not good to start activity from overriden onBackPressed().
When user press back by default activity will finish and one from back stack will be displayed. You as developer will (by writing code) decide which one is that. You can do it this way but later (or for somebody else) it will be a bit messy and difficult to find this unusual place for code which is starting other activity.
So..It would be useful to read about activity lifecycle and back stack to get impression how it works and understand terminology better.
If you want one of your activity not to stay on back stack you can add in manifest file file android:noHistory="true" for that activity.
Same thing you can achieve from code by adding appropriate flag to intent when you start activity: Intent.FLAG_ACTIVITY_NO_HISTORY
When user "go away" from ActivityOne (started using intent or defined in manifest like described), to new ActivityTwo and then press back, it will not go to ActivityOne because it will not be on back stack. Using this you can precisely control navigation through your activities.
More flags are available for use, but I guess this is what you wanted to achieve.
Hope you will find my answer useful. Cheers..
You can use a lot of tricks to exit your complet application for my part i use this start a intent and then from the androidmanifest i choose the category to home and than close the current activity such would be your mainactivity !
public void onBackPressed() {
Intent intent = new Intent(Intent.ACTION_MAIN);
intent.addCategory(Intent.CATEGORY_HOME);
intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
startActivity(intent);
finish();
}
My application shows an alert that the user must respond to before continuing to do other things. I'm trying to figure out the best way to implement this. Using an Activity for the alert isn't quite working.
In my current implementation, the alert is activity (A). When another activity from the same package is started and onStop is called, it starts itself again using FLAG_ACTIVITY_REORDER_TO_FRONT so that it's always at the top of the stack. This works as described, unless Activity A uses Theme.Dialog or Theme.Translucent.
Modified log:
Activity A created
Activity A started
Activity A resumed
Activity A paused
Activity B created
Activity B started
Activity B resumed
Activity B gains window focus
Activity A stopped
Top activity in stack is Activity B, so Activity A relaunches itself
Activity B paused
Activity A started
Activity A resumed
The top activity in the stack should be Activity A, however Activity B remains in the foreground.
Another implementation detail: my application is not for a phone, so I'm not concerned with a back button finishing the activity or interactions with other apps. Still, I agree that on principle I should prevent such problems anyway, so in my code I check whether the activity that has come in front is from the same package (i.e. from our code base). This should work around the theoretical problem of interfering with other apps.
Is there a way to bring Activity A into focus? I understand that this is unusual behavior, but it is necessary for Activity A to remain in the foreground until it is deliberately finished.
I'm also open to suggestions about a completely different and better approach!
FWIW, I'm running 2.2.
(Cross-posted from http://groups.google.com/group/android-developers/browse_thread/thread/d46fd7d59abe15a0, where we got no response.)
You can't do this. Please don't do this. The activity at the top of the stack is the one that has input focus. What you are trying to do fundamentally breaks the user interaction that is supposed to happen.
What you are doing is generally considered by the platform to be an abuse of it, and Android has increasingly been doing things to prevent applications like this from causing harm.
Well, here's what I had in mind:
public class ActivityA extends Activity
{
...
public void onStop() {
super.onStop();
finish();
Intent i = new Intent();
i.setClass(getApplicationContext(), ActivityA.class);
startActivity(i);
}
}
ActivityA is finished in onStop() and started again right away. You might have to check issues regarding device rotation, but this approach should work.
Having window focus means that activity B is still in its visible lifetime, since it has on top the activity A which has a translucent bg or is dialog-like.
Having the window focus doesn't mean that activity B is on the foreground. They are different things.
If you don't want this, then don't use those two themes.
I came to do the eternal question, which so far have not found a solution, I searched on the internet the same problem but found a final solution to this problem.
when I have 2 activities open and I pull the 'Home Button' and then press the shortcut for my application, it shows me again the first activity (the launcher activity), and then to return to the activity that was displayed, I have to press the back button.
what is the solution to this problem?
I want to press the shortcut of my application (after having left my application by pressing the Home Button) show me the last activity was displayed, instead it shows me the first activity (activity launcher).
Thanks in advance.
That is the expected behavior. The launcher will launch the Activity with the filter android.intent.action.MAIN.
There are ways to work around it, though. A very simple one is to have a boolean flag mRunning that you will set to true upon launch. If true, then on the onStart() method you start an intent to launch your second Activity; if false, then go on with setContentView().
If you have several activities to go back to, then a feasible approach is to save the current activity in SharedPreferences and launch it the same way.
Alternatively, your main Activity may be just an entry Activity whose only job is to start the last Activity used.
EDIT: I found this duplicate question: How to make an android app return to the last open activity when relaunched? that has a much better ansewr than mine.
Your application is still running in the background when you press the home button. finish() the activity when you press the Home button if you want to go back.
Depending on whether or not your main activity is ever launched by another activity, or only the application icon, you can use a much simpler solution. If your main activity is only launched by the application icon, you can use isTaskRoot() to check if your main activity is being launched as a fresh start to the application, or if the user is returning and the main activity is being laid on top of other activities that you wish to display instead.
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if (! isTaskRoot()) {
finish();
} else {
...
}
}
You can use startActivityForResult replace for startActivity when you want to open another Activity.