Get state of activity (paused / resumed)

Question

I am using a LoaderManager to get some data and when it finishes a child fragment should be shown. In some cases this happens when the activity is already in paused state and can not perform the fragment transaction.

Is there a way to get the current state of the activity (seems to have a mResume flag)? Or do I have to maintain my own boolean?

Answer 1

The new Architecture Components allow you to do it with:

this.getLifecycle().getCurrentState()

Answer 2

A quick look in the Activity source code indicates that the Activity class does keep track on the resume state with the member mResumed. But since mResume is not public and isResumed() is hidden, we can't use them.

You can have a simple solution to provide you with that information for all your classes. Simply create a base Activity class that store the state. For example:

public class ActivityBase extends Activity {

    private boolean mIsResumed = false;

    @Override
    public void onResume() {
        super.onResume()
        mIsResumed = true;
    }

    @Override
    public void onPaused() {
        super.onPaused()
        mIsResumed = false;
    }

    public boolean isResumed() {
        return mIsResumed
    }

}

Simply extend this class with your class:

public class MyActivity extends ActivityBase {

    private void onLoadDone() {
        if (isResumed()) {
            // Show the fragment
        }
    }

}