android - ConstraintLayout from bottom to top

Question

I have layout like this:

<androidx.constraintlayout.widget.ConstraintLayout
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">

<androidx.fragment.app.FragmentContainerView
    android:id="@+id/container"
    android:layout_width="match_parent"
    android:layout_height="0dp"
    android:background="@color/colorPrimary"
    android:minHeight="300dp"
    app:layout_constraintBottom_toTopOf="@+id/recyclerView"
    app:layout_constraintHeight_min="300dp"
    app:layout_constraintTop_toTopOf="parent" />

<androidx.recyclerview.widget.RecyclerView
    android:id="@+id/recyclerView"
    android:layout_width="match_parent"
    android:layout_height="0dp"
    app:layout_constraintBottom_toBottomOf="parent" />

</androidx.constraintlayout.widget.ConstraintLayout>

FragmentContainerView and RecyclerView have dynamic sizes, and FragmentContainerView should not be less than 300dp and fit all available spase. RecyclerView should be on the bottom and can contains from 1 to 20 items. Current solution works ok only for case RecyclerView contains few items, but for other case it overlaps FragmentContainerView. Is it possible to align RecyclerView to bottom but restrict max size to have free space = 300dp at the top?

Answer 1

I think you need to do:

• Add app:layout_constraintTop_toBottomOf="@id/container" to the RecyclerView
• Remove app:layout_constraintBottom_toTopOf="@+id/recyclerView" From the FragmentContainerView

This will make the FragmentContainerView height not restricted to the height of the RecyclerView .. and Make the RecyclerView height limited between the bottom of the FragmentContainerView & the bottom of the parent.