CODEWITHSUNDEEP
androidandroid-viewmodel
David
David

Reputation: 4817

Is it ok to save complex object with activity reference in Android ViewModel?

I'm using a lib that uses an interface I pass by to communicate with the calling activity, the problem is once I rotate the device the new instance of the activity wouldn't receive the callback anymore. I was thinking in saving an instance of this lib in a AndroidViewModel, would I get a memory issue doing so because the instance of the lib references my activity?

Causes problem when rotating:

public class MainActivity implements Lib.Callback
    {
        private Lib mLib;

        @Override
        public void onCreate ( final Bundle savedInstanceState){
            mLib = new Lib(this);
        }

        @Override
        protected void callback() {
          ...
        }
    }

Makes it better if I put "mLib" in an AndroidViewModel? Or is there a better alternative for such a case?

Upvotes: 0

Views: 139

Answers (2)

Yavor Mitev
Yavor Mitev

Reputation: 1508

If you do so you will leak the Activity. And you still will have only the old instance. Not the new one. Implement the callback for example in the ViewModel and then expose some LiveData from the ViewModel which the Activity can observe. It will work on device rotation.

Upvotes: 1

Abu Yousuf
Abu Yousuf

Reputation: 6107

Would I get a memory issue doing so because the instance of the lib references my activity?

Saving lib reference in ViewModel will cause memory leak for your scenario.As your lib has reference of Activity, when you rotate your phone that lib will hold a reference of your old activity.

Upvotes: 0

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