Retrieve Object From Listener

Question

Hello.

So the scenario here is that I have an activity that has an ArrayList that I want to display in a DialogFragment. I used an interface to deliver the data from the activity to the DialogFragment:

@Override
    public void addListClickListener(View v, ArrayList<ListObject> objects, ListsAdapter adapter) {
        mObjects = objects; //Delivering the data to the fragment
        mListsAdapter = adapter;
        mNewListFragment.setListener(mListener5);
        mNewListFragment.setListener1(mListener6);
        mTodoListsFragment.dismiss();
        mNewListFragment.show(getSupportFragmentManager(), NEW_LIST_FRAGMENT);
    }

Then in my fragment I display, or at least try to, the data from the interface to the ListAdapter:

   public interface AddListClickListener {
        void addListClickListener(View v, ArrayList<ListObject> objects, ListsAdapter adapter);
    }

   mAddListImage.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                mListener.addListClickListener(v, mObjects, mListsAdapter);
            }
        });

   protected void RecyclerViewSetup() {
        mListsAdapter = new ListsAdapter(mListener1, mListener2, getActivity(), mObjects);
        mListsAdapter.registerAdapterDataObserver(new RecyclerView.AdapterDataObserver() {
            @Override
            public void onChanged() {
                super.onChanged();
            }

            @Override
            public void onItemRangeChanged(int positionStart, int itemCount) {
                super.onItemRangeChanged(positionStart, itemCount);
            }

            @Override
            public void onItemRangeChanged(int positionStart, int itemCount, Object payload) {
                super.onItemRangeChanged(positionStart, itemCount, payload);
            }

            @Override
            public void onItemRangeInserted(int positionStart, int itemCount) {
                super.onItemRangeInserted(positionStart, itemCount);
            }

            @Override
            public void onItemRangeRemoved(int positionStart, int itemCount) {
                super.onItemRangeRemoved(positionStart, itemCount);
            }

            @Override
            public void onItemRangeMoved(int fromPosition, int toPosition, int itemCount) {
                super.onItemRangeMoved(fromPosition, toPosition, itemCount);
            }
        });

        RecyclerView.LayoutManager layoutManager = new LinearLayoutManager(getActivity());
        mRecyclerView.setLayoutManager(layoutManager);
        mRecyclerView.setHasFixedSize(true);
        mRecyclerView.setAdapter(mListsAdapter);
        checkAdapterIsEmpty();

However, I also need to define the mObjects array in the fragment without recreating itself every time the user opens the DialogFragment. How would I do this?

Thank you.

Answer 1 · 2017-01-10T19:32:35Z

January 10, 2017 7:32pm

Hey Diego! You could try making the ArrayList static in your Activity. Just make sure it gets populated before you launch the DialogFragment.

Answer 2 · 2017-01-18T02:29:27Z

January 18, 2017 2:29am

I think there are two ways you could do this:

(Option 1) One way is to send the ArrayList as an argument to your Fragment, and retrieve it in the Fragment. However, to do this you will have to make the object in your ArrayList parcelable. To make your object Parcelable, take a look at this helpful guide to do that http://guides.codepath.com/android/Using-Parcelable. Once your object is Parcelable all you need to do is send it to the Fragment as an argument. For example:
In your Activity:

Bundle args = new Bundle();  
args.putParcelableArrayList("key", mObjects);   
mNewListFragment.setArguments(args);  
...

In your Fragment:

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        ...
        ArrayList<ListObject> mObjects = new ArrayList<>();
        Bundle args = getArguments();
        if(args != null) {
           mObjects = args.getParcelableArrayList("key");
        }
        ...
}

(Option 2) I created a small Android utility class that provides a simple way to pass objects between Fragments and Activities. It works pretty much in the same way as you would use Intent Extras to pass a String between Activities. The link to it is (https://gist.github.com/kkuivi/161f254374a4007ae6014f67ae45789e). To use it, first copy the class into your project and then:
In your Activity

ReferenceMap.getInstance().putObjectReference(NEW_FRAGMENT.class, "myKey", mObjects);

In your fragment

@Override 
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        ...
        ArrayList<ListObject> mObjects = new ArrayList<>();
        ReferenceMap.ReferenceList refList = ReferenceMap.getInstance().getReferenceList(this);
        if(refList != null) {
           mObject = (ObjectType) refList.get("myKey");
        }
        ...
}  

@Override  
public void onStop(){
   ReferenceMap.getInstance().releaseRefList(this);
   super.onStop();
}

Let me know if this helps

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Diego Marrs

Diego Marrs

Retrieve Object From Listener

2 Answers

Ben Deitch

Ben Deitch

Diego Marrs

Diego Marrs

Ben Deitch

Ben Deitch

Diego Marrs

Diego Marrs

Ben Deitch

Ben Deitch

Diego Marrs

Diego Marrs

Ben Deitch

Ben Deitch

Diego Marrs

Diego Marrs

Diego Marrs

Diego Marrs

Ben Deitch

Ben Deitch

Diego Marrs

Diego Marrs

Elikem Kuivi

Elikem Kuivi