Current Animation Assignment

AnimationActivity.kt

package com.amohnacs.currentapplication

import android.animation.*
import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import android.view.View
import android.view.animation.AlphaAnimation
import android.view.animation.Animation
import android.view.animation.Animation.INFINITE
import androidx.core.animation.addListener

class AnimationActivity : AppCompatActivity() {

    private lateinit var blackFadeView: View
    private lateinit var purpleConstrictFadeOutView: View
    private lateinit var gradientConstrictFadeInView: View
    private lateinit var blackExpandView: View

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        blackFadeView = findViewById(R.id.black_background)
        purpleConstrictFadeOutView = findViewById(R.id.purple_circle)
        gradientConstrictFadeInView = findViewById(R.id.gradient_circle)
        blackExpandView = findViewById(R.id.black_circle)

        val gradientRotate = ObjectAnimator.ofFloat(
            gradientConstrictFadeInView,
            "rotation",
            0f,
            360f
        ).apply {
            duration = 4000
            addListener ( object : AnimatorListenerAdapter() {
                override fun onAnimationEnd(animation: Animator?) {
                    start()
                }
            })
        }
        val fadoutBlack = ObjectAnimator.ofFloat(
            blackFadeView,
            "alpha",
            1f,
            0f
        ).apply {
            duration = 1600
        }
        val purpleConstrictX = ObjectAnimator.ofFloat(
            purpleConstrictFadeOutView,
            "scaleX",
            1f,
            0.15f
        ).apply {
            duration = 4000
        }
        val purpleConstrictY = ObjectAnimator.ofFloat(
            purpleConstrictFadeOutView,
            "scaleY",
            1f,
            0.1f
        ).apply {
            duration = 4000
        }
        val purpleFadOut = ObjectAnimator.ofFloat(
            purpleConstrictFadeOutView,
            "alpha",
            1f,
            0f
        ).apply {
            duration = 1600
        }
        val gradientConstrictX = ObjectAnimator.ofFloat(
            gradientConstrictFadeInView,
            "scaleX",
            1f,
            0.15f
        ).apply {
            duration = 4000
        }
        val gradientConstrictY = ObjectAnimator.ofFloat(
            gradientConstrictFadeInView,
            "scaleY",
            1f,
            0.1f
        ).apply {
            duration = 4000
        }
        val blackExpandX = ObjectAnimator.ofFloat(
            blackExpandView,
            "scaleX",
            0f,
            0.14f
        ).apply {
            duration = 4000
        }
        val blackExpandY = ObjectAnimator.ofFloat(
            blackExpandView,
            "scaleY",
            0f,
            0.09f
        ).apply {
            duration = 4000
            addListener ( object : AnimatorListenerAdapter() {
                override fun onAnimationEnd(animation: Animator?) {
                    gradientRotate.start()
                }
            })
        }
        AnimatorSet().apply {
            play(fadoutBlack)
                .with(purpleConstrictX)
                .with(purpleConstrictY)
                .with(purpleFadOut)
                .with(gradientConstrictX)
                .with(gradientConstrictY)
                .with(blackExpandX)
                .with(blackExpandY)
            start()
        }
    }
}