AnimatedVectorProgressActivity.kt

package com.tagakov.avdplayground

import android.animation.Animator
import android.animation.AnimatorSet
import android.animation.ValueAnimator
import android.os.Bundle
import android.os.Handler
import android.support.graphics.drawable.AnimatedVectorDrawableCompat
import android.support.v7.app.AppCompatActivity
import android.widget.ImageView

class AnimatedVectorProgressActivity : AppCompatActivity() {

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
        val avd = findViewById<ImageView>(R.id.img).drawable as AnimatedVectorDrawableCompat

        //avd.start()

        val realAnimator = getInternalAnimator(avd)

        val handler = Handler()
        var time = 0
        val runnable = object : Runnable {
            override fun run() {
                if (realAnimator.setPlayTime(time.toLong())) {
                    time += 16
                    avd.invalidateSelf()
                    handler.postDelayed(this, 16 * 1)
                }
            }
        }
        runnable.run()

    }

    private fun getInternalAnimator(animatable: AnimatedVectorDrawableCompat): Animator {
        val mAnimatedVectorStateField = animatable.javaClass.getDeclaredField("mAnimatedVectorState")
        mAnimatedVectorStateField.isAccessible = true

        val mAnimatedVectorState = mAnimatedVectorStateField.get(animatable)
        val mAnimatorSetField = mAnimatedVectorState.javaClass.getDeclaredField("mAnimatorSet")
        mAnimatorSetField.isAccessible = true

        return mAnimatorSetField.get(mAnimatedVectorState) as Animator
    }

    private fun Animator.setPlayTime(time: Long): Boolean {
        val adjustedTime = time - startDelay
        if (adjustedTime >= 0) {
            if (this is AnimatorSet) {
                return childAnimations.any { it.setPlayTime(adjustedTime) }
            } else {
                val valueAnimator = this as ValueAnimator
                if (valueAnimator.repeatCount == ValueAnimator.INFINITE || valueAnimator.duration * valueAnimator.repeatCount >= adjustedTime) {
                    valueAnimator.currentPlayTime = adjustedTime
                    return true
                }
            }
        }
        return false
    }
}