ConstraintLayout max width percentage

Question

I've been experimenting with ConstraintLayout, is there a way to set the max width of a view to a percentage of the parent (and a height of match constraint and dimension ratio of 1:1)?

Here is the code without using max width:

<?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="wrap_content">

   <FrameLayout
      android:id="@+id/frameLayout3"
      android:layout_width="0dp"
      android:layout_height="259dp"
      android:layout_marginEnd="8dp"
      android:layout_marginStart="8dp"
      android:background="@android:color/black"
      app:layout_constraintEnd_toEndOf="parent"
      app:layout_constraintHorizontal_bias="0.0"
      app:layout_constraintStart_toEndOf="@+id/imageView"
      app:layout_constraintTop_toTopOf="parent"/>

   <ImageView
      android:id="@+id/imageView"
      android:layout_width="0dp"
      android:layout_height="0dp"
      android:src="@android:drawable/ic_menu_add"
      app:layout_constraintBottom_toBottomOf="@+id/frameLayout3"
      app:layout_constraintDimensionRatio="1:1"
      app:layout_constraintStart_toStartOf="parent"
      app:layout_constraintTop_toTopOf="parent"
      app:layout_constraintWidth_percent="0.3"/>

</android.support.constraint.ConstraintLayout>

This is the result:

Tablet:

Phone:

Solution 1

I achieved the max width percentage using two attributes:

app:layout_constraintWidth_max="wrap"
app:layout_constraintWidth_percent="0.4" 

Example:

<TextView
    android:id="@+id/textView2"
    android:layout_width="0dp"
    android:layout_height="wrap_content"
    android:layout_marginStart="8dp"
    android:layout_marginTop="8dp"
    android:text="Helo world"
    android:textAlignment="viewStart"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintWidth_max="wrap"
    app:layout_constraintWidth_percent="0.4" />

The text width will increase to 40% of parent and then wrap if the content exceeds that.

Solution 2

If I'm understanding your problem right then You're almost there. I think you're giving frameLayout static height that's why it is not giving the appropriate result on tablet.. because you set the height according to phone preview. What you need to do is make the height of frameLayout relative to imageView.. so when imageView grows in size the frameLayout also grows with it.

I think you should do 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="wrap_content">

    <ImageView
        android:id="@+id/imageView"
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:src="@android:drawable/ic_menu_add"
        app:layout_constraintDimensionRatio="1:1"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintWidth_percent="0.3" />    

    <FrameLayout
        android:id="@+id/frameLayoutTwo"
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:background="@android:color/black"
        app:layout_constraintBottom_toBottomOf="@+id/imageView"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toEndOf="@+id/imageView"
        app:layout_constraintTop_toTopOf="parent" /> 

</android.support.constraint.ConstraintLayout>

I checked and this gives the same result in phone and tablet. Correct me if I misunderstood your problem.

Comments

[fiipi]

This is a great tip. That worked, and should be the accepted answer.

[Sergey Grishin]

@thomson-varghese, I've tried your answer, but I've not received correct result/ Maybe, I've done something wrong. Can you check my code, please and write, how to set max width as percentage of parent, but just "regular" width should be like wrap_content: 1) first variant , when text is to long, and width should be as % from parent 2) second variant, when width shoundn't be so huge, jast wrap_content My code

[momvart]

nice job! could you please explain what does layout_constraintWidth_max="wrap" actually mean?

[Michał Ziobro]

does not work when such textview is placed in vertical Flow when it obscures view being above and below

[user924]

but if taken space is less than 0.4 pct, it still will be minimum matched 0.4 pct

[David Ibrahim]

it doesn't wrap if the text is in multiple lines

[z3ntu]

Works great, except when android:text="" the view takes up the maximum % of the width, even though I want it to be 0dp (or at least close to it). My workaround is setting a space instead of an empty string when that would be set.

[reavcn]

Very useful, worked for me! Remember to set 0dp on both views in the horizontal chain and set the chain style to spread_inside

[RoShan Shan]

Thanks @reavcn, it should be horizontal chain for both view. if not, it always set the width 0.4