Pin a view to bottom of screen in BottomSheetDialog Fragment

Question

I've used BottomSheetDialogFragment in my project and I've designed it as below:

Target: I'm going to stick the bottom menu of BottomSheetDialog to bottom of the screen, in either mode collapse and expand.

So in BottomSheetDialog layout, I used RelativeLayout for parent and "layout_alignParentBottom" for menu container, As below:

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/bottomSheetContainer"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="center_horizontal"
app:behavior_hideable="true"
app:behavior_peekHeight="0dp"
app:layout_behavior="android.support.design.widget.BottomSheetBehavior"
tools:context=".MyBottomSheetDialogFragment">

<RelativeLayout
    android:id="@+id/topSection"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_alignParentTop="true">
    ....
</RelativeLayout>

<android.support.v4.widget.NestedScrollView
    android:id="@+id/descriptionContainer"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_below="@id/topSection">
    ....
</android.support.v4.widget.NestedScrollView>

<HorizontalScrollView
    android:id="@+id/iconsContainer"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_alignParentBottom="true">
    ....
</HorizontalScrollView>
</RelativeLayout>

But the dialogue is as follows:

As you can see, the bottom menu is not visible at first.

Can someone help me to solve this problem?

Answer 1

To solve this, several things came to my mind when I tried, but I did not succeed.

But this finally solved for me by this way:

For collapse mode, I set the bottomSheetBehavior's peekHeight to 1/3 of the screen (with the following code):

    View bottomSheetContainer = dialog.findViewById(R.id.bottomSheetContainer);
    View parent = (View) bottomSheetContainer.getParent();
    CoordinatorLayout.LayoutParams params = (CoordinatorLayout.LayoutParams) parent.getLayoutParams();
    BottomSheetBehavior bottomSheetBehavior = (BottomSheetBehavior) params.getBehavior();
    View inflatedView = View.inflate(getContext(), R.layout.word_details_bottom_sheet, null);
    inflatedView.measure(0, 0);
    int screenHeight = getActivity().getResources().getDisplayMetrics().heightPixels;

    if (bottomSheetBehavior != null) {
        bottomSheetBehavior.setPeekHeight(screenHeight /3);
    }

So I decided to do it:

1- for collapse mode: bottomSheet container's height = bottomSheetBehavior's peekHeight

2- for expand mode: bottomSheet container's height = full screen Height

So I wrote the following code (full code):

WordDetailsBottomSheet.java

public class WordDetailsBottomSheet extends BottomSheetDialogFragment {

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

@NotNull
@Override
public Dialog onCreateDialog(Bundle savedInstanceState) {
    BottomSheetDialog dialog = new BottomSheetDialog(getActivity(), 0);
    dialog.setContentView(R.layout.word_details_bottom_sheet);

    View bottomSheetContainer = dialog.findViewById(R.id.bottomSheetContainer);
    View parent = (View) bottomSheetContainer.getParent();
    CoordinatorLayout.LayoutParams params = (CoordinatorLayout.LayoutParams) parent.getLayoutParams();
    BottomSheetBehavior bottomSheetBehavior = (BottomSheetBehavior) params.getBehavior();
    View inflatedView = View.inflate(getContext(), R.layout.word_details_bottom_sheet, null);
    inflatedView.measure(0, 0);
    int screenHeight = getActivity().getResources().getDisplayMetrics().heightPixels;
    int statusBarHeight = getStatusBarHeight();

    if (bottomSheetBehavior != null) {
        bottomSheetBehavior.setPeekHeight(screenHeight / BOTTOM_SHEET_PEEK_HEIGHT_PERCENT);
        bottomSheetContainer.getLayoutParams().height = bottomSheetBehavior.getPeekHeight();
    }

    bottomSheetBehavior.setBottomSheetCallback(new BottomSheetBehavior.BottomSheetCallback() {
        @Override
        public void onStateChanged(@NonNull View view, int newState) {
            switch (newState) {
                case BottomSheetBehavior.STATE_EXPANDED:
                    bottomSheetContainer.getLayoutParams().height = screenHeight-statusBarHeight;
                    break;
                case BottomSheetBehavior.STATE_COLLAPSED:
                    bottomSheetContainer.getLayoutParams().height = bottomSheetBehavior.getPeekHeight();
                    break;
                case BottomSheetBehavior.STATE_HIDDEN:
                    dismiss();
                    break;
                default:
                    break;
            }
        }

        @Override
        public void onSlide(@NonNull View view, float slideOffset) {
        }
    });

    return dialog;
}

public int getStatusBarHeight() {
    int result = 0;
    int resourceId = getResources().getIdentifier("status_bar_height", "dimen", "android");
    if (resourceId > 0) {
        result = getResources().getDimensionPixelSize(resourceId);
    }
    return result;
    }
}

word_details_bottom_sheet.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/bottomSheetContainer"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="center_horizontal"
app:behavior_hideable="true"
app:behavior_peekHeight="0dp"
app:layout_behavior="android.support.design.widget.BottomSheetBehavior"
tools:context=".MyBottomSheetDialogFragment">

<RelativeLayout
android:id="@+id/topSection"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentTop="true">
....
</RelativeLayout>

<android.support.v4.widget.NestedScrollView
android:id="@+id/descriptionContainer"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_below="@id/topSection">
....
</android.support.v4.widget.NestedScrollView>

<HorizontalScrollView
android:id="@+id/iconsContainer"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true">
....
</HorizontalScrollView>
</RelativeLayout>

In the xml file, things that matter are:

1- parent id (android:id="@+id/bottomSheetContainer")

2- iconsContainer align (android:layout_alignParentBottom="true")