expand delegate, item in recyclerview #view

ExpandDelegate.kt

// Example
fun expandAdapterDelegate() = adapterDelegateLayoutContainer<ExpandedItem, DisplayableItem>(R.layout.item_expanded) {

    llArrowContainer.setOnClickListener {
        val isExpand = !item.isExpanded
        item.isExpanded = isExpand
        expandText(isExpand, ivArrow, llTextContainer)
    }

    bind {
        tvNumber.text = item.number.toString()
        expandText(item.isExpanded, ivArrow, llTextContainer, 0L)
    }
}

fun expandText(isExpanded: Boolean, ivArrow: ImageView, llContainer: LinearLayout, duration: Long = 300L){
    if (!isExpanded) {
        if (ivArrow.rotation != 360f) {
            ivArrow.rotate(duration, 180f, 360f)
        }
        collapse(llContainer, duration)
    } else {
        if (ivArrow.rotation != 180f) {
            ivArrow.rotate(duration, 360f, 180f)

        }
        expand(llContainer, duration)
    }

}

data class ExpandedItem(var isExpanded: Boolean = false, val number: Int): DisplayableItem

ext.kt

object Extension {


    fun View.rotate(duration: Long, from: Float, to: Float) {
        val rotation = ObjectAnimator.ofFloat(this, "rotation", from, to)
        rotation.duration = duration
        rotation.start()
    }

    fun View.animateAlpha(visibility: Int, duration: Long) {
        setVisibility(visibility)
        val startValue: Float
        val endValue: Float

        when (visibility){
            View.GONE, View.INVISIBLE -> { startValue = 1f; endValue = 0f }
            View.VISIBLE -> { startValue = 0f; endValue = 1f }
            else -> { startValue = 0f; endValue = 1f}
        }

        val anim = ObjectAnimator.ofFloat(this, "alpha", startValue, endValue)
        anim.duration = duration
        anim.start()
    }


    fun View.slideToBottom(duration: Long) {
        val animate = TranslateAnimation(0f, 0f, 0f, this.height.toFloat())
        animate.duration = duration
        animate.fillAfter = true
        this.startAnimation(animate)
        this.visibility = View.GONE
    }

    fun View.slideToTop(duration: Long) {
        val animate = TranslateAnimation(0f, 0f, this.height.toFloat(), 0f)
        animate.duration = duration
        animate.fillAfter = true
        this.startAnimation(animate)
        this.visibility = View.VISIBLE
    }

    fun expand(v: View, duration: Long) {
        val matchParentMeasureSpec = View.MeasureSpec.makeMeasureSpec((v.parent as View).width, View.MeasureSpec.EXACTLY)
        val wrapContentMeasureSpec = View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED)
        v.measure(matchParentMeasureSpec, wrapContentMeasureSpec)
        val targetHeight = v.measuredHeight

        // Older versions of android (pre API 21) cancel animations for views with a height of 0.
        v.layoutParams.height = 1
        v.visibility = View.VISIBLE
        val a = object : Animation() {
            override fun applyTransformation(interpolatedTime: Float, t: Transformation) {
                v.layoutParams.height = if (interpolatedTime == 1f)
                    ViewGroup.LayoutParams.WRAP_CONTENT
                else
                    (targetHeight * interpolatedTime).toInt()
                v.requestLayout()
            }

            override fun willChangeBounds(): Boolean {
                return true
            }
        }

        // Expansion speed of 1dp/ms
        a.duration = duration
        v.startAnimation(a)
    }

    fun collapse(v: View, duration: Long) {
        val initialHeight = v.measuredHeight

        val a = object : Animation() {
            override fun applyTransformation(interpolatedTime: Float, t: Transformation) {
                if (interpolatedTime == 1f) {
                    v.visibility = View.GONE
                } else {
                    v.layoutParams.height = initialHeight - (initialHeight * interpolatedTime).toInt()
                    v.requestLayout()
                }
            }

            override fun willChangeBounds(): Boolean {
                return true
            }
        }

        // Collapse speed of 1dp/ms
        a.duration = duration
        v.startAnimation(a)
    }
}

MainListAdapter.kt

class MainListAdapter(activity: Activity) : ListDelegationAdapter<List<DisplayableItem>>(
    AdvertisementAdapterDelegate(activity),
    catAdapterDelegate(),
    DogAdapterDelegate(activity),
    GeckoAdapterDelegate(activity),
    SnakeListItemAdapterDelegate(activity),
    expandedAdapterDelegate()
)