Adjust recycler view height when persistent bottom sheet is expanded

Question

I have a persistent bottom sheet (which is basically a button) and a recycler view both contained in a CoordinatorLayout.

When the bottom sheet is expanded, I do not want it to obscure the recycler view. I am able to achieve this by setting app:layout_insetEdge="bottom" in the bottom sheet and app:layout_dodgeInsetEdges="bottom" in the recycler view respectively.

However, since the recycler view's height is set to android:layout_height="match_parent", its top partly moves out of the screen when the bottom sheet is expanded.

Instead, I want the recycler view to adjust its height dynamically occording to the height of the bottom sheet so it does not move out of the screen anymore. How can I achieve that?

Here is the complete layout:

<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout 
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

<android.support.v7.widget.RecyclerView
    android:id="@+id/recycler_view"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:nestedScrollingEnabled="false"
    app:layout_dodgeInsetEdges="bottom" />

<Button
    android:id="@+id/bottom_sheet"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:text="@string/update_all"
    android:foreground="?attr/selectableItemBackground"
    android:background="@drawable/angled_button"
    app:behavior_hideable="false"
    app:behavior_peekHeight="0dp"
    app:layout_insetEdge="bottom"
    app:layout_behavior="android.support.design.widget.BottomSheetBehavior" />

</android.support.design.widget.CoordinatorLayout>

Edit: Screenshots added

Without the bottom sheet everything looks fine.

With the bottom sheet expanded the recycler view is not completely visible anymore.

Edit 2: GIF added

Answer 1

Faced the same issue recently, didn't find a better way than to remove app:layout_dodgeInsetEdges="bottom" and use padding instead. This is how it can be achieved:

Kotlin:

val rv = findViewById<RecyclerView>(R.id.recycler_view))
val behavior = BottomSheetBehavior.from(findViewById<Button>(R.id.bottom_sheet))
behavior.setBottomSheetCallback(object : BottomSheetBehavior.BottomSheetCallback(){
    override fun onSlide(bottomSheet: View, offset: Float) {
        rv.setPadding(0, 0, 0, (bottomSheet.height * offset).toInt())
    }

    override fun onStateChanged(bottomSheet: View, newState: Int){}
})

Java:

RecyclerView rv = (RecyclerView) findViewById(R.id.recycler_view); 
BottomSheetBehavior behavior = BottomSheetBehavior.from(findViewById(R.id.bottom_sheet));
behavior.setBottomSheetCallback(new BottomSheetBehavior.BottomSheetCallback() {
    @Override
    public void onStateChanged(@NonNull View bottomSheet, int newState) {
    }

    @Override
    public void onSlide(@NonNull View bottomSheet, float slideOffset) {
        rv.setPadding(0, 0, 0, (int)(slidingView.getHeight() * offset));
    }
});

Pros:

• No overlapping on screen, neither with Toolbar nor with BottomSheet button;
• Doesn't break move-up functionality for FAB;
• RecyclerView scrolling can be done along with sliding up the BottomSheet;

Cons:

• Not pure XML, coding required;
• Additional changes are required to keep original padding (but still possible and relatively easy to do)

Answer 2

Nikita's accepted answer has the right idea, but has two problems :

• The proposed padding formula is only correct when the bottom sheet is fully expanded, because the slideOffset provided as argument to the onSlide callback is proportional to the difference between the peek height and the full height of the bottom sheet, not just to its full height

• Padding doesn't apply to a recyclerview's fast scrollbar, which continues to extend beneath the bottom sheet. Margin, on the other hand, behaves as intended.

Here is a Kotlin implementation that takes those two corrections into account :

val behavior = BottomSheetBehavior.from(constraintLayout)
behavior.setBottomSheetCallback(object : BottomSheetCallback() {

    override fun onSlide(bottomSheet: View, slideOffset: Float) {
        val margin = behavior.peekHeight + (bottomSheet.height - behavior.peekHeight) * slideOffset
        recyclerview.updateLayoutParams<FrameLayout.LayoutParams> { bottomMargin = margin.toInt() }
    }

    override fun onStateChanged(bottomSheet: View, newState: Int) { /* Nothing to do */ }
})

The type of LayoutParams referenced should be changed according to the parent of the RecyclerView in your own layout.

Please note that the RecyclerView's bottom margin should be set to the bottom sheet's peek height in the layout xml, in order to get the right layout when the activity loads, before any sliding has occurred.

The above example is for a bottom sheet that isn't hideable, which means the slideOffset argument only goes from 0 to 1. For a hideable bottom sheet, another formula should be used when the slideOffset is between -1 and 0 : behavior.peekHeight * (1 + slideOffset)