Set shape as ImageView background to get top corners rounded

Question

I'm trying to build a layout with a ConstraintLayout with rounded corners inside a ScrollView. At the top of the layout I want to place an image that should have the top corners rounded (to match the layout corners) and the bottom corners straight.

Following the suggestions I found in this StackOverflow question here's my code:

<androidx.constraintlayout.widget.ConstraintLayout 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:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity"
    android:orientation="vertical">

    <ScrollView
        android:id="@+id/scroll_layout"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_weight="7.5"
        android:background="@color/darkModePrimary">

        <androidx.constraintlayout.widget.ConstraintLayout
            android:layout_marginLeft="16dp"
            android:layout_marginRight="16dp"
            android:layout_marginTop="16dp"
            android:layout_width="match_parent"
            android:background="@drawable/layout_bg"
            android:layout_height="wrap_content">

            <ImageView
                android:background="@drawable/layout_bg"
                android:src="@drawable/house_medium"
                android:id="@+id/house_image"
                android:layout_width="match_parent"
                android:layout_height="200dp"
                android:scaleType="fitXY"
                app:layout_constraintRight_toRightOf="parent"
                app:layout_constraintLeft_toLeftOf="parent"
                app:layout_constraintTop_toTopOf="parent"/>

            <TextView
                android:layout_marginTop="32dp"
                android:gravity="center"
                app:layout_constraintLeft_toLeftOf="parent"
                app:layout_constraintRight_toRightOf="parent"
                app:layout_constraintTop_toBottomOf="@id/house_image"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:text="Some text"
                android:textSize="24sp"/>

        </androidx.constraintlayout.widget.ConstraintLayout>

    </ScrollView>

</androidx.constraintlayout.widget.ConstraintLayout>

This is the xml file where I define the shape for the background of the ConstraintLayout

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android">
    <solid android:color="@android:color/white"/>
    <corners android:radius="10dp"/>
    <padding
        android:left="0dp"
        android:top="0dp"
        android:right="0dp"
        android:bottom="0dp" />
</shape>

If I set this shape as the background of both the Constraint Layout and the ImageView, I get - as expected - an image with all four rounded corners, as shown here.

I've tried to create another shape to use as background of the image, like this:

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android">
    <solid android:color="@android:color/white"/>
    <corners android:bottomRightRadius="0dp"
        android:bottomLeftRadius="0dp"
        android:topLeftRadius="10dp"
        android:topRightRadius="10dp"/>
    <padding
        android:left="0dp"
        android:top="0dp"
        android:right="0dp"
        android:bottom="0dp"/>
</shape>

But when I set it as background of the ImageView I don't get what I want, all four corners of the image are now straight

What am I doing wrong?

Answer 1

To make it working just set outline to your card container layout in code.

• In layout xml add id to card container:

    <androidx.constraintlayout.widget.ConstraintLayout
        android:id="@+id/card"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginLeft="16dp"
        android:layout_marginTop="16dp"
        android:layout_marginRight="16dp"
        android:background="@drawable/layout_bg"
        android:elevation="4dp">
  

• In your MainActivity onCreate:

  override fun onCreate(savedInstanceState: Bundle?) {
       super.onCreate(savedInstanceState)
       setContentView(R.layout.activity_main)
  
       card.clipToOutline = true
       card.outlineProvider = ViewOutlineProvider.BACKGROUND
  }
  

Result: