Finishing multiple activities to resume an old one in stack? - android

I need to finish multiple activities in stack and resume an old one. For example,
There are four activities in stack Act1, Act2, Act3 and Act4. On some event in Act4, I need to finish Act4, Act3 and Act2 to resume Act1.
I tried using Intet.FLAG_ACTIVITY_CLEAR_TOP but it's recreating the activity which is not my requirement.
Advance thanks for suggestions.

You have used Clear_top, it will clear all the activities and bring act1 to front, but, onNewIntent method will be called of you activity, you can perform any task you want in that, after activity starts again.
Or, you can use flag FLAG_ACTIVITY_REORDER_TO_FRONT with your intent, it will do:
FLAG_ACTIVITY_REORDER_TO_FRONT do this:If set in an Intent passed to Context.startActivity(), this flag will cause the launched activity to be brought to the front of its task's history stack if it is already running.
FLAG_ACTIVITY_CLEAR_TOP will do: If set, and the activity being launched is already running in the current task, then instead of launching a new instance of that activity, all of the other activities on top of it will be closed and this Intent will be delivered to the (now on top) old activity as a new Intent.
for more information on flags look
http://developer.android.com/reference/android/content/Intent.html

There are four activities in stack Act1, Act2, Act3 and Act4. On some
event in Act4, I need to finish Act4, Act3 and Act2 to resume Act1.
Do this:
Intent intent = new Intent(Act4.this, Act1.class);
intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(intent);
finish();

use android:launchMode,will be ok.
<Act1
...
android:launchMode="singleTask">

Related

How to set no History for all Activities

My Android Application is based on four Activities. The last activity starts an Intent Service and set itself to background.
Before I sent the last Activity to background I would like to remove all four Activities from backstack history
I tried already to set the no history = true attribute for the activities. This causes errors when I use startActivityForResult, so I need a different solution
I don't really think there is an "good" way to do this, I would try something like this:
First create a SelfClosingActivity which only job is to close itself after opening:
public void onCreate(Bundle savedInstanceState()) {
super.onCreate(savedInstanceState);
finish();
}
When you want to close all the Activities (after you start your IntentService I guess) run the SelfClosingActivity and add flags to clear the current stack.
Intent intent = new Intent(this, SelfClosingActivity.class);
intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TASK);
intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
startActivity(intent);
This will clear the current stack before opening SelfClosingActivity and SelfClosingActivity will close itself leaving the stack completely empty.
FLAG_ACTIVITY_CLEAR_TOP | FLAG_ACTIVITY_NEW_TASK will do what you want.
FLAG_ACTIVITY_CLEAR_TOP
Added in API level 1 int FLAG_ACTIVITY_CLEAR_TOP If set, and the
activity being launched is already running in the current task, then
instead of launching a new instance of that activity, all of the other
activities on top of it will be closed and this Intent will be
delivered to the (now on top) old activity as a new Intent.
For example, consider a task consisting of the activities: A, B, C, D.
If D calls startActivity() with an Intent that resolves to the
component of activity B, then C and D will be finished and B receive
the given Intent, resulting in the stack now being: A, B.
This launch mode can also be used to good effect in conjunction with
FLAG_ACTIVITY_NEW_TASK: if used to start the root activity of a task,
it will bring any currently running instance of that task to the
foreground, and then clear it to its root state. This is especially
useful, for example, when launching an activity from the notification
manager.
Refer to Tasks and Back Stack for more info

How to come back to First activity without its onCreate() called

I have 3 activity . Activity A ,Activity B, Activity C.
This is the flow A->B->C.
Now i want to come to activity A from C .(i.e C->A) without getting its onCreate() called of Activity A.
so far my code is:But it will call onCreate() of ActivityA.
I want to call Restart().
Intent intent=new Intent(ActivityC.this,ActivityA.class);
intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(intent);
finish();
Two cases:
If you want to keep other activities live and just want to bring A to front, just use intent flag FLAG_ACTIVITY_REORDER_TO_FRONT.
If you don't want to clear all activities and want existing instance of A at top, then use intent flags FLAG_ACTIVITY_CLEAR_TOP and FLAG_ACTIVITY_SINGLE_TOP.
Note : If you use only FLAG_ACTIVITY_CLEAR_TOP, then onCreate will be called.
Keep android:launchMode="singleTask" in manifest at activity declaretion
An Activity with singleTask launchMode is allowed to have only one instance in the system
If instance already exists, i will not call 'onCreate' it will call 'onNewIntent' method.
See http://androidsrc.net/android-activity-launch-mode-example/ for better understand about launch modes.
Although setting the launch mode to singleTask will work, use of that launch mode is discouraged. The documentation for launch mode indicates singleTask is "not recommended for general use".
The desired behavior can be achieved using Intent flags FLAG_ACTIVITY_CLEAR_TOP and FLAG_ACTIVITY_SINGLE_TOP:
Intent intent=new Intent(ActivityC.this,ActivityA.class);
intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP | Intent.FLAG_ACTIVITY_SINGLE_TOP);
startActivity(intent);
finish();
Activity A will not be recreated and will receive the intent via onNewIntent().
Use SingleTask launch mode for Activity A.
New intent will be delivered to existing instance.

How to keep layout and its data

I need your help, I have 2 activities A and B where A is the main activity.
Now B starts the activities from A using startActivityForResult() and from B when I finish it will go back to activity A.
This works fine but the actual purpose was like the Gmail application when you go back from B to A and then start activity B again from A, then A need to start activity with its last screen as i left it.
For example: from inbox->label->draft in gmail how to achieve this to keep data/layout as it is.
Maybe android:launchMode="singleInstance" on activity A and B will get it done?
How to switch Activity from 2 activities without losing its data and current state of data
Ok I have got solution that when every time start your application that time only activity will be created and view and put in stack so the next time you start again this activity just open from background so the activity will available in stack and just brought to front using start activity
From A to start ActivityB
Intent intent = new Intent(context,ActivityB.class);
intent.addFlags(Intent.FLAG_ACTIVITY_LAUNCHED_FROM_HISTORY);
intent.addFlags(Intent.FLAG_ACTIVITY_BROUGHT_TO_FRONT);
intent.addFlags(Intent.FLAG_ACTIVITY_REORDER_TO_FRONT);
startActivity(intent);
Now for start ActivityA from ActivityB
Intent intent = new Intent(getInstance(), ActivityA.class);
intent.addFlags(Intent.FLAG_ACTIVITY_BROUGHT_TO_FRONT);
intent.addFlags(Intent.FLAG_ACTIVITY_LAUNCHED_FROM_HISTORY);
intent.addFlags(Intent.FLAG_ACTIVITY_REORDER_TO_FRONT);
startActivity(intent);
It just brought front while activity start and put the current activity into background

FLAG_ACTIVITY_CLEAR_TOP calls onCreate() instead of onResume()

So I have an abstract class extended through the entire app that overrides the back key to reorder Activity A to the front (With the flag).
So, it would be:
A > B > anywhere, and the back key should bring me back to A
I'm using the FLAG_ACTIVITY_CLEAR_TOP, but it is entirely refreshing A for some reason and I don't want that.
So: Flag_activity_clear_top is reloading the onCreate() rather than onResume(). What gives?
If you want the activity to just be brought to the top without restarting it set the launchMode of the activity to singleTop in the manifest. You will receive a call to onNewIntent when the activity is being brought to the top. onNewIntent is called before onResume. If you only want this behavior for the specific intent you can add the FLAG_ACTIVITY_SINGLE_TOP(in addition to FLAG_ACTIVITY_CLEAR_TOP) to the intent with the addFlags call instead of the manifest.
Intent intent = new Intent(CurrentActivity.this, ActivityNeedOnTop.class);
intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP | Intent.FLAG_ACTIVITY_SINGLE_TOP);
startActivity(intent);
CurrentActivity.this.finish();
From the API docs for FLAG_ACTIVITY_CLEAR_TOP
For example, consider a task consisting of the activities:
A, B, C, D. If D calls startActivity() with an Intent that
resolves to the component of activity B, then C and D
will be finished and B receive the given Intent,
resulting in the stack now being: A, B.
**The currently running instance of activity B in the above example
will either receive the new intent you are starting here in its
onNewIntent() method, or be itself finished and restarted with the new intent.**
So I think your activity is itself finished and restarted.

How to finish all child activities from parent in android [duplicate]

I'm new to android. Actually one handler is running in Home Activity A for every 30 sec to check the net connection.
If I'm went to activity C by A->B->C, If there in no net connection at that time, then i want to close Activity B and C, then want to show message box in Activity A.
But My problem is My handler is running for every 30 sec in Home Activity A. But If i was in Activity C or some other Activity how to find which activity is my Application currently focussed now. Then i want to finish those child activities and want to show Home Activity A I have some 9 child activities in Activity B.
I heard about using "FLAG_ACTIVITY_CLEAR_TOP" . I used the code as follows in the handler in Home activity A itself. But got error.
Intent intent = new Intent( ctx, Homepage.class );
intent.setFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP |
Intent.FLAG_ACTIVITY_CLEAR_TOP);
ctx.startActivity( intent );
Here Homepage.class is my Home Activity A and i set that activity in manifest file as
android:launchMode="singleTop"
Please help!
You can start Activity A and close all other activities.
You have to create new intent and add flag FLAG_ACTIVITY_CLEAR_TOP
Intent activityA = new Intent(context, ActivityA.class);
activityA.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
context.StartActivity(activityA);
this will close all activities that are in the stack and are at the top of activity A
When calling Acitivity C, call finish in activity B , when calling Activity A from C , call finish() in activity C !
You can use, According to me two ways,
If you start an activity using startActivityForResult, then you can call finish() in this new Activity when you're done with it and it will return control to the activity that started it.
OR otherwise, May be I am wrong,
Call finish inside onStop 'override method'.
make a uniform resultCode for closing child activities. Eg. you make 911 (should be int) as your resultCode. If you want your Activity to finish and go back directly to parent Activity, you set the resultCode to 911:
setResult(911); finish();
In every child activity, you override the onActivityResult and check if the resultCode is 911. If yes, then call the setResult(911); finish(); until you get back to your parent activity. Hope this helps!
For example, if you want to start intentB, you can do following in old activity:
Intent intentB = new Intent();
intentB.setClass(XYZ.this, abc.class);
intentB.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(intentB);

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