DialogFragment with fixed header, scrollable body and fixed footer

Question

I want to show a dialog with a title (header), body (content) and accept button (footer). I want header and footer to be visible even if content is longer than the screen height. If this is the case, I want body to be scrollable so that it can shrink. Here is what I tried, scrollView gets all the dialog space, no header and no footer is shown:

<?xml version="1.0" encoding="utf-8"?>
<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="wrap_content"
    android:fillViewport="true"
    android:minWidth="300dp">

    <TextView
        android:id="@+id/title"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:background="@android:color/darker_gray"
        android:text="Title"
        app:layout_constraintBottom_toTopOf="@+id/bodyContainer"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <ScrollView
        android:id="@+id/bodyContainer"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        app:layout_constraintBottom_toTopOf="@+id/buttonContainer"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/title">

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:orientation="vertical">

            <TextView
                android:id="@+id/text"
                android:layout_width="match_parent"
                android:layout_height="1500dp"
                android:text="Long text" />
        </LinearLayout>
    </ScrollView>

    <LinearLayout
        android:id="@+id/buttonContainer"
        android:layout_width="0dp"
        android:layout_height="30dp"
        android:background="@android:color/darker_gray"
        android:orientation="vertical"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/bodyContainer" />

</androidx.constraintlayout.widget.ConstraintLayout>

Answer 1

When your ScrollView's height is set to wrap_content the constraints will not limit the dimension if it gets too big to satisfy them. To fix this and enforce the top and bottom constraints, set app:layout_constrainedHeight="true" for your ScrollView.