A frame layout that is aware of taps but doesn't intercept touch events from children

TapAwareFrameLayout.kt

package com.example.ui.views

import android.content.Context
import android.util.AttributeSet
import android.view.GestureDetector
import android.view.MotionEvent
import android.widget.FrameLayout


typealias TapListener = () -> Unit
typealias EventAwareTapListener = (MotionEvent) -> Unit


class TapAwareFrameLayout @JvmOverloads constructor(
        context: Context,
        attrs: AttributeSet? = null,
        defStyleAttr: Int = 0
) : FrameLayout(context, attrs, defStyleAttr) {
    var tapListener : TapListener? = null
    var longTapListener: EventAwareTapListener? = null

    val gestureDetector = GestureDetector(context, object : GestureDetector.SimpleOnGestureListener() {
        override fun onSingleTapConfirmed(e: MotionEvent?): Boolean {
            tapListener?.invoke()
            return super.onSingleTapConfirmed(e)
        }

        override fun onLongPress(e: MotionEvent?) {
            println("TAPAWARE onLongPress")
            e?.let {
                longTapListener?.invoke(it)
            }
            super.onLongPress(e)
        }
    })

    override fun onInterceptTouchEvent(event: MotionEvent?): Boolean {
        if (listeningToTouchEvents()) {
            gestureDetector.onTouchEvent(event)

        }
        return super.onInterceptTouchEvent(event)
    }

    override fun onTouchEvent(event: MotionEvent?): Boolean {
        val listeningToTouchEvents = listeningToTouchEvents()
        if (listeningToTouchEvents) {
            gestureDetector.onTouchEvent(event)
        }
        return super.onTouchEvent(
                event) || (event?.action == MotionEvent.ACTION_DOWN && listeningToTouchEvents)
    }


    private fun listeningToTouchEvents()  = tapListener != null || longTapListener != null
}