Android: How can I get the current foreground activity (from a service)?

Question

Is there a native android way to get a reference to the currently running Activity from a service?

I have a service running on the background, and I would like to update my current Activity when an event occurs (in the service). Is there a easy way to do that (like the one I suggested above)?

Answer 1

Update: this no longer works with other apps' activities as of Android 5.0

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Here's a good way to do it using the activity manager. You basically get the runningTasks from the activity manager. It will always return the currently active task first. From there you can get the topActivity.

Example here

There's an easy way of getting a list of running tasks from the ActivityManager service. You can request a maximum number of tasks running on the phone, and by default, the currently active task is returned first.

Once you have that you can get a ComponentName object by requesting the topActivity from your list.

Here's an example.

    ActivityManager am = (ActivityManager) this.getSystemService(ACTIVITY_SERVICE);
    List<ActivityManager.RunningTaskInfo> taskInfo = am.getRunningTasks(1);
    Log.d("topActivity", "CURRENT Activity ::" + taskInfo.get(0).topActivity.getClassName());
    ComponentName componentInfo = taskInfo.get(0).topActivity;
    componentInfo.getPackageName();

You will need the following permission on your manifest:

<uses-permission android:name="android.permission.GET_TASKS"/>