Understanding Android's VectorDrawable properties

Question

I need help understanding some of the properties of VectorDrawable that is defined by XML.

When i import a new vector asset using Android Studio, It generates something like:

<vector xmlns:android="http://schemas.android.com/apk/res/android"
    android:width="24dp"
    android:height="24dp"
    android:viewportHeight="24.0"
    android:viewportWidth="24.0">

    <path 
        android:fillColor="#000000"
        android:pathData="M3,17.25V21h3.75L17.81,9.94l-3.75,-3.75L3,17.25zM20.71,7.04c0.39,-0.39 0.39,-1.02 0,-1.41l-2.34,-2.34c-0.39,-0.39 -1.02,-0.39 -1.41,0l-1.83,1.83 3.75,3.75 1.83,-1.83z" />
</vector>

By default the width, height, viewportHeight and viewportWidth are being set to some default Material design value.

Since we are dealing with vectors and not pixel images. My questions are:

• why is it required to set a size (width, height, etc)?
• If i need to use the same vector xml for multiple sizes, how to override this 24dp value without creating multiple vector xml's which of course defeats the whole purpose!

Answer 1

Adding @dimen in xml vector gives error Error:Error: Width (0) and height (0) cannot be <= 0