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Android - Bring an activity to the front from application class

I am trying to bring an activity to the front. I found many questions similar to this but none of them actually works.
I always hold a reference to the current activity in a variable in application class. While the application is running in the background (after onPause fires), if any message arrives, I need to bring the same activity to the front and display the message. The only way I got it worked is..
Intent i = new Intent(mCurrentActivity, JoboffersActivity.class);
i.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
i.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(i);
The issue I have got with this, is that it recreates the activity which I wanted to avoid. I tried singleInstance and singleTask both in the manifest. If I do not add FLAG_ACTIVITY_CLEAR_TOP, on back key press it takes me to the previous instance of the same activity. Even if I add sigleInstance it creates two instances of the same activity. If I do not add FLAG_ACTIVITY_NEW_TASK then it shows an error Calling startActivity() from outside of an Activity context requires the FLAG_ACTIVITY_NEW_TASK flag

Try to add another flag FLAG_ACTIVITY_SINGLE_TOP to your intent.
According to Android documentation, combination of this 2 flags:
i.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP | Intent.FLAG_ACTIVITY_SINGLE_TOP);
brings the current instance of Activity to the front.
http://developer.android.com/reference/android/content/Intent.html#FLAG_ACTIVITY_CLEAR_TOP

How to start a new Intent that will clear all other activities?

To lay it out as simply as possible. My user enters the app through Activity A. They "login" and then Activity B is started, and Activity A is finished using finish() so that the users can't get back to the login screen by pressing back from Activity B. Now in Activity B, they move to Activity C, and in activity C, I want them to start a new intent that will start activity A, but "kill"/"finish" all other activities. The only way I can think of doing this is using an Intent Flag. so far I've come up with:
Intent intent = new Intent(getActivity(), ActivityA.class);
intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_WHEN_TASK_RESET|Intent.FLAG_ACTIVITY_RESET_TASK_IF_NEEDED);
startActivity(intent);
But the code above doesn't work. I still see that my app had a savedInstanceState in Activity B. Hence something like CLEAR_TASK won't work for me case.
EDIT: Also, is there an easy way to tell have many "tasks" your app has opened currently?
Note: There seems to be other flags that may help, but they were added in API 11, and I need to support API 10.
Flag combos I've tried:
Doesn't work
intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_WHEN_TASK_RESET|Intent.FLAG_ACTIVITY_RESET_TASK_IF_NEEDED);
Doesn't work
intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TOP);

You need to use IntentCompat. like
import android.support.v4.content.IntentCompat;
intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK |IntentCompat.FLAG_ACTIVITY_CLEAR_TASK);

Check whether the below answer helps you:
http://www.hrupin.com/2011/10/how-to-finish-all-activities-in-your-android-application-through-simple-call

History Stack of activity clear in android

I need to clear the back history of activities.
I have 5 Activities.
In the first 4 activities I have to make the back button go to and fro with data filled in all the screens. But as I proceed on 5th screen I need to reset the back history and start intent with new stack. So that after i press back in my 5th screen app should exit. I tried using launchMode , Nohistory and Flags such as NEW_TASK , CLEAR_TOP, CLEAR_TASK but still unable to achieve this. Please help me. Suggest me how to achieve this.

In your comments you suggested that you've tried using flags like:
Intent i = new Intent(MainActivity.this,SecondActivity.Class);
i.addFlags(android.flags.FLAG_CLEAR_TOP | FLAG_NEW_TASK | FLAG_CLEAR_TASK)
But instead try using them like:
Intent intent = new Intent(MainActivity.this,SecondActivity.Class);
intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP|Intent.FLAG_ACTIVITY_NEW_TASK|Intent.FLAG_ACTIVITY_CLEAR_TASK);

Multiple Instances of an Activity

I am trying to show the user information on incoming-call screen, whenever there is an incoming-call. So I have a broadcast receiver listening to incoming calls, which starts the intent service, which subsequently starts an activity (with Theme Dialog).
Now, whenever there is an incoming-call, my activity dialog pops up and shows as intended.
Problem: When the activity dialog is already on the screen and incoming-call happens, there is no new activity dialog with new information. I guess that whenever there is an instance, Android does not creates the new one. So it seems like my problem is "creating multiple instances of an activity".
Please note that I am starting an activity from an intent service using FLAG_NEW_TASK.

Google Doc says :
FLAG_ACTIVITY_NEW_TASK
"When using this flag, if a task is already running for the activity
you are now starting, then a new activity will not be started;
instead, the current task will simply be brought to the front of the
screen with the state it was last in."
So, if you want to start a new fresh activity then simply not use this flag only, you should use it with FLAG_ACTIVITY_CLEAR_TASK for the desired result.
For Example:
// Sets the Activity to start in a new, empty task
notifyIntent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK |
Intent.FLAG_ACTIVITY_CLEAR_TASK);
If the above solution is not what you needed, then have a look at
android:launchMode attribute, declare this attribute with the desired options (i.e. as per your need) in activity tag of manifest file.
Hope this will solve the problem.

Use flag FLAG_ACTIVITY_MULTIPLE_TASK which according to the documentation :
Used in conjunction with FLAG_ACTIVITY_NEW_TASK to disable the behavior of bringing an existing task to the foreground. When set, a new task is always started to host the Activity for the Intent, regardless of whether there is already an existing task running the same thing.
Using this flag along with FLAG_ACTIVITY_NEW_TASK will cause each activity instance to be created as a separate task and thus you can have different dialog pop ups.

Simply add following flags to your Intent .
intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK
| Intent.FLAG_ACTIVITY_EXCLUDE_FROM_RECENTS
| Intent.FLAG_ACTIVITY_MULTIPLE_TASK);

single instance of an activity in android

I know single instance can be achived by setting android:launchMode="singleInstance" in menifest file. but i want to do it on run time . I think it can be achived by setting FLAG but not sure witch one.. plzz help me.. thanks in advance.

In general you can use a combination of Intent.FLAG_ACTIVITY_SINGLE_TOP, Intent.FLAG_ACTIVITY_CLEAR_TOP, Intent.FLAG_ACTIVITY_REORDER_TO_FRONT and Intent.FLAG_ACTIVITY_NEW_TASK to accomplish what you want. However, which one (or ones) to use depends on the situation you have.

This is what u are looking for
Intent intent= new Intent(context, YourActivity.class);
intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_SINGLE_TOP);
UPDATE: android:launchMode="singleInstance" may also be needed in Manifest

singleInstance specifies that the launched or recycled activity will be created on a new or existing task, and no other activities can be stacked on top of it. The system will ensure any activities started from it are put on other tasks.
1 task and 1 activity.
There is no intent flag that I know of that will prevent further activities launched by your activity without having to specify flags in all of your new activity's created intents.
So the answer is this is not possible.
Previous posted answers imitate how this will look, but the behavior goes against the specification.

you can achieve singleInstance behaviour with this flags Intent.FLAG_ACTIVITY_MULTIPLE_TASK, Intent.FLAG_ACTIVITY_NEW_TASK