ID of the back arrow drawable in the ActionBar in programming side

Issue

I am searching for default drawable of back arrow. In this question showed how to get it in xml. But I am searching for using in programming side (java/kotlin).

I want to use this drawable id in code like:

ContextCompat.getDrawable(context, homeAsUpIndicatorId);

Solution

Create the drawable and pass the drawable id to the function. For example, I create a vector drawable called arrow_back.xml.

<?xml version="1.0" encoding="utf-8"?>
    <vector xmlns:android="http://schemas.android.com/apk/res/android"
        android:width="24dp"
        android:height="24dp"
        android:viewportWidth="24.0"
        android:viewportHeight="24.0"
        android:autoMirrored="true">
        <path
            android:pathData="M20,11L7.8,11l5.6,-5.6L12,4l-8,8l8,8l1.4,-1.4L7.8,13L20,13L20,11z"
            android:fillColor="#fff"/>
    </vector>

Note: the drawable that homeAsUpIndicatorId is referencing has a private modifier, so you can't access it directly. However, the above code was copied from the vector drawable with little modification.

I will pass the id to the getDrawable() function like this.

ContextCompat.getDrawable(context, R.drawable.arrow_back);

EDIT: Do the following to get the drawable from homeAsUpIndicatorId:

    TypedArray a = getTheme().obtainStyledAttributes(R.style.AppTheme, new int[] {R.attr.homeAsUpIndicator});
    int attributeResourceId = a.getResourceId(0, 0);
    ContextCompat.getDrawable(context, attributeResourceId);
    a.recycle()

Answered By - devmike01