FitsystemWindow with FrameLayout!

FitWindowFrameLayout.kt

package com.airweb.waw.wawmusicplayer.ui.widgets

import android.content.Context
import android.support.v4.view.ViewCompat
import android.support.v4.view.WindowInsetsCompat
import android.util.AttributeSet
import android.view.View
import android.view.ViewGroup
import android.widget.FrameLayout


/**
 * Use for fragment that make [FrameLayout] can be system awared. by their children.
 * @see <https://stackoverflow.com/a/47349880/3979479>
 */
class FitWindowFrameLayout : FrameLayout {
    constructor(context: Context) : this(context, null)
    constructor(context: Context, attrs: AttributeSet?) : this(context, attrs, 0)
    constructor(context: Context, attrs: AttributeSet?, defStyleAttr: Int) : super(context,
        attrs,
        defStyleAttr) {
        setOnHierarchyChangeListener(object : ViewGroup.OnHierarchyChangeListener {
            override fun onChildViewAdded(parent: View, child: View) {
                ViewCompat.requestApplyInsets(this@FitWindowFrameLayout)
            }

            override fun onChildViewRemoved(parent: View, child: View) {
                ViewCompat.requestApplyInsets(this@FitWindowFrameLayout)
            }
        })
        ViewCompat.setOnApplyWindowInsetsListener(this) { v, insets ->
            val childCount = childCount
            for (index in 0 until childCount) {
                ViewCompat.dispatchApplyWindowInsets(getChildAt(index), WindowInsetsCompat(insets))
            }
            return@setOnApplyWindowInsetsListener insets
        }
    }
    
}