Bottom sheet doesn't expand as expected

Question

I'm working with Bottom Sheet and Recyclerview.

My expectation is converting the layout manager of RecyclerView from List to Grid.

However, when I changed the LayoutManager, the bottom sheet doesn't show fullscreen anymore.

Here is the Gif:

https://media.giphy.com/media/26FeSME9RKKfIQIPS/giphy.gif

Main Activity:

private BottomSheetBehavior bottomSheetBehavior;


@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_sliding_up_panel);

    ListHorizontalFragment fragment = new ListHorizontalFragment();
    FragmentTransaction transaction = getFragmentManager().beginTransaction();
    transaction.add(R.id.containerFragment, fragment).commit();

    View bottomSheet = findViewById(R.id.bottom_sheet);

    DisplayMetrics displayMetrics = new DisplayMetrics();
    getWindowManager().getDefaultDisplay().getMetrics(displayMetrics);
    int height = displayMetrics.heightPixels;


    bottomSheetBehavior = BottomSheetBehavior.from(bottomSheet);
    bottomSheetBehavior.setBottomSheetCallback(new BottomSheetBehavior.BottomSheetCallback() {
        @Override
        public void onStateChanged(@NonNull View bottomSheet, int newState) {
            if (newState == BottomSheetBehavior.STATE_COLLAPSED) {
                final float scale = getResources().getDisplayMetrics().density;
                int pixels = (int) (200 * scale + 0.5f);
                bottomSheetBehavior.setPeekHeight(pixels);
                fragment.changeLayoutManagerToHorizontal();
            }
            if (newState == BottomSheetBehavior.STATE_EXPANDED) {
                fragment.changeLayoutManagerToGrid();
                bottomSheet.setMinimumHeight(height);
            }

        }

        @Override
        public void onSlide(@NonNull View bottomSheet, float slideOffset) {

        }
    });


}

Fragment to display items:

 private RecyclerView recyclerView;
private RecyclerViewAdapter adapter;
private ArrayList<Integer> colors = new ArrayList<>();

public ListHorizontalFragment() {
    // Required empty public constructor
}


@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    // Inflate the layout for this fragment
    View view = inflater.inflate(R.layout.fragment_list_horizontal, container, false);
    recyclerView = (RecyclerView) view.findViewById(R.id.horizontalRecyclerView);


    List<Integer> lstColor = new ArrayList<>();
    lstColor.add(R.color.actionbar_blue);
    lstColor.add(R.color.black);
    lstColor.add(R.color.dark_blue);
    lstColor.add(R.color.common_action_bar_splitter);
    lstColor.add(R.color.red);
    lstColor.add(R.color.yellow);
    lstColor.add(R.color.green);
    lstColor.add(R.color.pitch_blue);

    colors.addAll(lstColor);

    changeLayoutManagerToHorizontal();
    return view;
}

public void changeLayoutManagerToHorizontal() {
    recyclerView.setAdapter(null);
    LinearLayoutManager linearLayoutManager = new LinearLayoutManager(getActivity(), LinearLayoutManager.HORIZONTAL, false);
    recyclerView.setLayoutManager(linearLayoutManager);
    adapter = new RecyclerViewAdapter(colors, getActivity());
    recyclerView.setAdapter(adapter);
}

public void changeLayoutManagerToGrid() {
    recyclerView.setAdapter(null);
    recyclerView.setLayoutManager(new GridLayoutManager(getActivity(), 3));
    adapter = new RecyclerViewAdapter(colors, getActivity());
    recyclerView.setAdapter(adapter);
}

The layout of bottom sheet:

 <RelativeLayout
    android:orientation="vertical"
    android:id="@+id/bottom_sheet"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    app:behavior_peekHeight="300dp"
    android:background="@android:color/holo_orange_light"
    app:layout_behavior="android.support.design.widget.BottomSheetBehavior"
    >
    <FrameLayout
        android:layout_centerInParent="true"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:id="@+id/containerFragment"/>
</RelativeLayout>

When I expended the bottom sheet, it supposed to be fullscreen. But somehow it doesn't work like I expected

Answer 1

You should make new fragment that extends BottomSheetDialogFragment and override its methods

    @Override
        public void setupDialog(final Dialog dialog, int style) {
          //initialize your view here
}

and call your action from this callback

    private BottomSheetBehavior.BottomSheetCallback mBottomSheetBehaviorCallback = new BottomSheetBehavior.BottomSheetCallback() {

            @Override
            public void onStateChanged(@NonNull View bottomSheet, int newState) {
             //your code     
            }

            @Override
            public void onSlide(@NonNull View bottomSheet, float slideOffset) {
            //your code
           }
        };

then from your activity initialize this Bottom sheet fragment.

for more detail check this tutorial http://www.truiton.com/2016/07/android-bottom-sheet-example/ Hope this help.