Margin/Padding in percentage in XML

Question

I am new in android development. I want to set margin & padding in Xml,not in dp or px but in percentage. Is there any way to do this?

Answer 1

it is not possible, though You better do it by taking width and height of screen like below in your java code, and

 Display display = getWindowManager().getDefaultDisplay(); 
 int width = display.getWidth();
 int height = display.getHeight();

then calculate your margin from screen size, and set it by

  setmargin(int x) //method of view/layout.

this way you can set margin depending on the screen size not fixed for all screen, and basically it is like setting in percentage but from Java code.

Answer 2

It became possible with Guidelines introduced in ConstraintLayout.

Here's the example of TextView placed at 60% of screen width and 25% of screen height:

<?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">

    <TextView
        android:id="@+id/textView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="TextView"
        app:layout_constraintLeft_toLeftOf="@+id/guideline1"
        app:layout_constraintTop_toTopOf="@+id/guideline2" />

    <android.support.constraint.Guideline
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/guideline1"
        android:orientation="vertical"
        app:layout_constraintGuide_percent="0.6" />

    <android.support.constraint.Guideline
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/guideline2"
        android:orientation="horizontal"
        app:layout_constraintGuide_percent="0.25" />

</android.support.constraint.ConstraintLayout>