Android - Constraint layout - How to align a view centered over edge of other view?

Question

I want to build a layout like this:

Inside the constraint layout there is an Image View which acts like a banner, then there is a Card that is center aligned wi

Answer 1

Try this:

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.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"
    android:orientation="vertical"
    android:padding="20dp">

    <android.support.v7.widget.CardView
        android:id="@+id/card_1"
        android:layout_width="0dp"
        android:layout_height="200dp"
        android:layout_marginLeft="8dp"
        android:layout_marginRight="8dp"
        android:layout_marginTop="8dp"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <android.support.v7.widget.CardView
        android:id="@+id/card_2"
        android:layout_width="100dp"
        android:layout_height="100dp"
        android:layout_marginBottom="8dp"
        android:layout_marginLeft="8dp"
        android:layout_marginRight="8dp"
        android:layout_marginTop="0dp"
        app:cardBackgroundColor="#69F"
        app:layout_constraintBottom_toBottomOf="@+id/card_1"
        app:layout_constraintLeft_toLeftOf="@+id/card_1"
        app:layout_constraintRight_toRightOf="@+id/card_1"
        app:layout_constraintTop_toBottomOf="@+id/card_1" />

</android.support.constraint.ConstraintLayout>

Explanation :- This works because of these four lines

Following lines sets the blue CardView centered on the bottom edge of White CardView.

<!-- top constraint is set to bottom of White CardView -->
app:layout_constraintTop_toBottomOf="@+id/card_1"

<!-- bottom constraint is set to bottom of White CardView -->
app:layout_constraintBottom_toBottomOf="@+id/card_1"

Following lines set the blue CardView centered horizontally

<!-- left constraint is set to left of White CardView -->
app:layout_constraintLeft_toLeftOf="@+id/card_1"

<!-- right constraint is set to right of White CardView -->
app:layout_constraintRight_toRightOf="@+id/card_1"

Answer 2

try below:

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.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"
    android:fitsSystemWindows="true"
    app:layout_collapseMode="parallax">


    <ImageView
        android:id="@+id/imageView_jobBackdrop_jobDetails"
        android:layout_width="match_parent"
        android:layout_height="175dp"
        android:fitsSystemWindows="true"
        android:scaleType="centerCrop"
        android:background="@android:color/white"
        app:layout_collapseMode="parallax"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <ImageView
        android:id="@+id/imageView2"
        android:layout_width="match_parent"
        android:layout_height="60dp"
        android:layout_marginBottom="8dp"
        android:layout_marginEnd="8dp"
        android:layout_marginStart="8dp"
        android:background="@android:color/black"
        app:layout_constraintBottom_toBottomOf="@+id/imageView_jobBackdrop_jobDetails"
        app:layout_constraintEnd_toEndOf="@+id/imageView_jobBackdrop_jobDetails"
        app:layout_constraintStart_toStartOf="@+id/imageView_jobBackdrop_jobDetails"
        app:layout_constraintTop_toBottomOf="@+id/imageView_jobBackdrop_jobDetails"  />

    <ImageView
        android:id="@+id/imageView3"
        android:layout_width="75dp"
        android:layout_height="75dp"
        android:layout_marginBottom="8dp"
        android:layout_marginEnd="8dp"
        android:background="@android:color/darker_gray"
        app:layout_constraintBottom_toTopOf="@+id/imageView2"
        app:layout_constraintEnd_toEndOf="@+id/imageView2"
        app:layout_constraintStart_toStartOf="@+id/imageView2"
        app:layout_constraintTop_toTopOf="@+id/imageView2"  />


</android.support.constraint.ConstraintLayout>