Property Animation: 概要、ObjectAnimatorとValueAnimator

import android.animation.ObjectAnimator
import android.view.View

// ObjectAnimator for translationX
val animator = ObjectAnimator.ofFloat(
    myView,
    "translationX",
    0f,
    300f
).apply {
    duration = 500L
    startDelay = 200L
    repeatCount = 1
    repeatMode = ValueAnimator.REVERSE
    interpolator = FastOutSlowInInterpolator()
    start()
}

// ObjectAnimatorとカスタムTypeEvaluator（色）
import android.animation.ObjectAnimator
import android.animation.ArgbEvaluator
import android.graphics.Color

val colorAnim = ObjectAnimator.ofObject(
    myView,
    "backgroundColor",
    ArgbEvaluator(),
    Color.BLUE,
    Color.RED
).apply {
    duration = 1000L
    repeatCount = ValueAnimator.INFINITE
    repeatMode = ValueAnimator.REVERSE
    start()
}

// 複数のプロパティを同時にアニメーション化
val scaleXAnim = ObjectAnimator.ofFloat(myView, "scaleX", 1f, 1.5f)
val scaleYAnim = ObjectAnimator.ofFloat(myView, "scaleY", 1f, 1.5f)
val alphaAnim = ObjectAnimator.ofFloat(myView, "alpha", 1f, 0.5f)

import android.animation.ValueAnimator
import android.view.animation.LinearInterpolator

"> ValueAnimator: ロード進捗アニメーション
val valueAnimator = ValueAnimator.ofFloat(0f, 100f).apply {
    duration = 2000L
    interpolator = LinearInterpolator()
    repeatCount = ValueAnimator.INFINITE

    addUpdateListener { animator ->
        val progress = animator.animatedValue as Float
        progressBar.progress = progress.toInt()
        progressText.text = "${progress.toInt()}%"
    }

    addListener(object : AnimatorListenerAdapter() {
        override fun onAnimationRepeat(animation: Animator) {
            Log.d("Anim", "Progress animation restarted")
        }
    })
    start()
}

// ValueAnimator.ofObjectとPointEvaluator
import android.animation.ValueAnimator
import android.graphics.PointF
import android.animation.PointFEvaluator

val pointAnim = ValueAnimator.ofObject(
    PointFEvaluator(),
    PointF(0f, 0f),
    PointF(300f, 500f)
).apply {
    duration = 1000L
    addUpdateListener { animator ->
        val point = animator.animatedValue as PointF
        movingView.x = point.x
        movingView.y = point.y
    }
    start()
}

import android.animation.AnimatorSet
import android.animation.ObjectAnimator

// AnimatorSet: 順次および並列アニメーション
val fadeIn = ObjectAnimator.ofFloat(myView, "alpha", 0f, 1f)
val slideUp = ObjectAnimator.ofFloat(myView, "translationY", 100f, 0f)
val bounce = ObjectAnimator.ofFloat(myView, "scaleX", 1f, 1.1f, 1f)

val animatorSet = AnimatorSet().apply {
    // 並列: fadeIn + slideUp
    play(fadeIn).with(slideUp)
    "> 後: 200msの遅延付きbounce
    play(bounce).after(200L)

    duration = 400L
    interpolator = FastOutSlowInInterpolator()
    addListener(object : AnimatorListenerAdapter() {
        override fun onAnimationEnd(animation: Animator) {
            Log.d("Anim", "Set completed")
        }
    })
    start()
}

import android.animation.ObjectAnimator
import android.view.animation.BounceInterpolator
import android.view.animation.OvershootInterpolator
import android.view.animation.AnticipateOvershootInterpolator

// BounceInterpolator — 最後にバウンス効果
val bounceAnim = ObjectAnimator.ofFloat(myView, "translationY", 0f, -50f).apply {
    duration = 600L
    interpolator = BounceInterpolator()
    start()
}

// AnticipateOvershoot — 引き戻し、その後オーバーシュート
val anticipateAnim = ObjectAnimator.ofFloat(myView, "scaleX", 1f, 1.3f).apply {
    duration = 500L
    interpolator = AnticipateOvershootInterpolator(2.0f)
    start()
}

// ProgressStateクラスのカスタムTypeEvaluator
data class ProgressState(val progress: Float, val color: Int)

class ProgressEvaluator : TypeEvaluator<ProgressState> {
    override fun evaluate(
        fraction: Float,
        startValue: ProgressState,
        endValue: ProgressState
    ): ProgressState {
        val progress = startValue.progress + fraction * (endValue.progress - startValue.progress)
        val color = ArgbEvaluator().evaluate(
            fraction, startValue.color, endValue.color
        ) as Int
        return ProgressState(progress, color)
    }
}

"> PropertyValuesHolder — 最大限のパフォーマンス
val pvh1 = PropertyValuesHolder.ofFloat("scaleX", 1f, 1.5f)
val pvh2 = PropertyValuesHolder.ofFloat("scaleY", 1f, 1.5f)
val pvhAnim = ObjectAnimator.ofPropertyValuesHolder(myView, pvh1, pvh2).apply {
    duration = 300L
    start()
}