ConstraintLayout View size - ratio with parent

Question

I'm learning how to use ConstraintLayout. I want to make menu with 4 element.

• Elements should be centered in parent

• Elements should be size 1:5 of parent height (ratio 1:1 - square)

I have made something like 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"
    android:layout_width="match_parent"
    android:layout_height="match_parent">


    <android.support.constraint.Guideline
        android:id="@+id/split"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:orientation="horizontal"
        app:layout_constraintGuide_percent="0.6" />

    <android.support.constraint.ConstraintLayout
        android:id="@+id/tiles_container"
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:layout_marginBottom="8dp"
        android:layout_marginEnd="8dp"
        android:layout_marginStart="8dp"
        android:layout_marginTop="8dp"
        android:background="@color/colorPrimary"
        app:layout_constraintBottom_toTopOf="@+id/split"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="1.0"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="0.0">

        <android.support.constraint.Guideline
            android:id="@+id/container_v"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:orientation="horizontal"
            app:layout_constraintGuide_percent="0.5" />

        <android.support.constraint.Guideline
            android:id="@+id/container_h"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:orientation="vertical"
            app:layout_constraintGuide_percent="0.5" />

        <ImageView
            android:id="@+id/tile_1"
            android:layout_width="@dimen/tile_size"
            android:layout_height="@dimen/tile_size"
            android:layout_marginBottom="@dimen/tile_margin"
            android:layout_marginEnd="@dimen/tile_margin"
            app:layout_constraintBottom_toTopOf="@+id/container_v"
            app:layout_constraintEnd_toStartOf="@+id/container_h"
            app:srcCompat="@mipmap/ic_launcher" />

        <ImageView
            android:id="@+id/tile_2"
            android:layout_width="@dimen/tile_size"
            android:layout_height="@dimen/tile_size"
            android:layout_marginBottom="@dimen/tile_margin"
            android:layout_marginStart="@dimen/tile_margin"
            app:layout_constraintBottom_toTopOf="@+id/container_v"
            app:layout_constraintStart_toStartOf="@+id/container_h"
            app:srcCompat="@mipmap/ic_launcher" />

        <ImageView
            android:id="@+id/tile_3"
            android:layout_width="@dimen/tile_size"
            android:layout_height="@dimen/tile_size"
            android:layout_marginTop="@dimen/tile_margin"
            android:layout_marginEnd="@dimen/tile_margin"
            app:layout_constraintEnd_toStartOf="@+id/container_h"
            app:layout_constraintTop_toTopOf="@+id/container_v"
            app:srcCompat="@mipmap/ic_launcher" />

        <ImageView
            android:id="@+id/tile_4"
            android:layout_width="@dimen/tile_size"
            android:layout_height="@dimen/tile_size"
            android:layout_marginTop="@dimen/tile_margin"
            android:layout_marginStart="@dimen/tile_margin"
            app:layout_constraintStart_toStartOf="@+id/container_h"
            app:layout_constraintTop_toTopOf="@+id/container_v"
            app:srcCompat="@mipmap/ic_launcher" />


    </android.support.constraint.ConstraintLayout>


</android.support.constraint.ConstraintLayout>

Unfortunately, I had to hardcode Images width and height. Is it possible to set size of child based on ratio with parent (like in Xcode)

Answer 1

You should never nest a ConstraintLayout inside another one. You should always maintain a flat layout hierarchy.

The "1.1.0-beta3" release of ConstraintLayout allows the usage of percentage dimensions and many more cool features.

Just set the "layout_constraintHeight_default" attribute to "percent" (to use percentage units), and set the percentage using "layout_constraintHeight_percent". (width related attributes are available too)

Here's the solution using Guidelines:

<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:id="@+id/parent"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#caf">

    <android.support.constraint.Guideline
        android:id="@+id/guideline_ver"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:orientation="vertical"
        app:layout_constraintGuide_percent=".5" />

    <android.support.constraint.Guideline
        android:id="@+id/guideline_hor"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:orientation="horizontal"
        app:layout_constraintGuide_percent=".5" />

    <View
        android:id="@+id/topLeft"
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:layout_margin="4dp"
        android:background="#fff"
        app:layout_constraintBottom_toTopOf="@+id/guideline_hor"
        app:layout_constraintDimensionRatio="h,1:1"
        app:layout_constraintHeight_default="percent"
        app:layout_constraintHeight_percent=".2"
        app:layout_constraintRight_toLeftOf="@+id/guideline_ver" />

    <View
        android:id="@+id/topRight"
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:layout_margin="4dp"
        android:background="#fff"
        app:layout_constraintBottom_toTopOf="@+id/guideline_hor"
        app:layout_constraintDimensionRatio="h,1:1"
        app:layout_constraintHeight_default="percent"
        app:layout_constraintHeight_percent=".2"
        app:layout_constraintLeft_toRightOf="@+id/guideline_ver" />

    <View
        android:id="@+id/bottomLeft"
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:layout_margin="4dp"
        android:background="#fff"
        app:layout_constraintDimensionRatio="h,1:1"
        app:layout_constraintHeight_default="percent"
        app:layout_constraintHeight_percent=".2"
        app:layout_constraintRight_toLeftOf="@+id/guideline_ver"
        app:layout_constraintTop_toBottomOf="@+id/guideline_hor" />

    <View
        android:id="@+id/bottomRight"
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:layout_margin="4dp"
        android:background="#fff"
        app:layout_constraintDimensionRatio="h,1:1"
        app:layout_constraintHeight_default="percent"
        app:layout_constraintHeight_percent=".2"
        app:layout_constraintLeft_toRightOf="@+id/guideline_ver"
        app:layout_constraintTop_toBottomOf="@+id/guideline_hor" />

</android.support.constraint.ConstraintLayout>

Hope this helps!