BottomSheetDialogFragment - How to set expanded height (or min top offset)

Question

I create a BottomSheetDialogFragment and I want to adjust it's maximum expanded height. How can I do that? I can retrieve the BottomSheetBehaviour but all I can find is a setter for the peek height but nothing for the expanded height.

public class DialogMediaDetails extends BottomSheetDialogFragment
{
    @Override
    public void setupDialog(Dialog dialog, int style)
    {
        super.setupDialog(dialog, style);
        View view = View.inflate(getContext(), R.layout.dialog_media_details, null);
        dialog.setContentView(view);

        ...

        View bottomSheet = dialog.findViewById(R.id.design_bottom_sheet);
        BottomSheetBehavior behavior = BottomSheetBehavior.from(bottomSheet);
        behavior.setPeekHeight(...);
        // how to set maximum expanded height???? Or a minimum top offset?

    }
}

EDIT

Why do I need that? Because I show a BottomSheet Dialog in a full screen activity and it looks bad if the BottomSheet leaves a space on top...

Answer 1

The height is being wrapped because of the inflated view is added to the FrameLayout which has layout_height=wrap_content. See FrameLayout (R.id.design_bottom_sheet) at https://github.com/dandar3/android-support-design/blob/master/res/layout/design_bottom_sheet_dialog.xml.

The class below makes the bottom sheet full screen, background transparent and fully expanded to the top.

public class FullScreenBottomSheetDialogFragment extends BottomSheetDialogFragment {


    @CallSuper
    @Override
    public void onViewCreated(View view, @Nullable Bundle savedInstanceState) {
        super.onViewCreated(view, savedInstanceState);
        ButterKnife.bind(this, view);
    }


    @Override
    public void onStart() {
        super.onStart();
        Dialog dialog = getDialog();

        if (dialog != null) {
            View bottomSheet = dialog.findViewById(R.id.design_bottom_sheet);
            bottomSheet.getLayoutParams().height = ViewGroup.LayoutParams.MATCH_PARENT;
        }
        View view = getView();
        view.post(() -> {
            View parent = (View) view.getParent();
            CoordinatorLayout.LayoutParams params = (CoordinatorLayout.LayoutParams) (parent).getLayoutParams();
            CoordinatorLayout.Behavior behavior = params.getBehavior();
            BottomSheetBehavior bottomSheetBehavior = (BottomSheetBehavior) behavior;
            bottomSheetBehavior.setPeekHeight(view.getMeasuredHeight());
            ((View)bottomSheet.getParent()).setBackgroundColor(Color.TRANSPARENT)

        });
    }

}

--- EDIT Aug 30, 2018 --- I realized a year later that the background was coloured on a wrong view. This dragged the background along with the content while a user was dragging the dialog. I fixed it so that the parent view of the bottom sheet is coloured.