InvertViewLayout.kt

package com.davidmedenjak.overlappinginvertview

import android.content.Context
import android.graphics.*
import android.util.AttributeSet
import android.view.View
import android.widget.FrameLayout


class InvertViewLayout(context: Context, attrs: AttributeSet? = null) : FrameLayout(context, attrs) {
    lateinit var backgroundView: View
    lateinit var overlay: View
    lateinit var bitmap: Bitmap

    val inversePaint: Paint = Paint()
    val rectPaint: Paint = Paint().apply {
        isAntiAlias = true
        color = Color.RED
    }

    init {
        // https://stackoverflow.com/q/5941926/1837367
        val mx = floatArrayOf(-1.0f, 0.0f, 0.0f, 1.0f, 0.0f, 0.0f, -1.0f, 0.0f, 1.0f, 0.0f, 0.0f, 0.0f, -1.0f, 1.0f, 0.0f, 1.0f, 1.0f, 1.0f, 1.0f, 0.0f)
        val cm = ColorMatrix(mx)

        inversePaint.colorFilter = ColorMatrixColorFilter(cm)

    }

    override fun onLayout(changed: Boolean, left: Int, top: Int, right: Int, bottom: Int) {
        super.onLayout(changed, left, top, right, bottom)
        backgroundView = getChildAt(0)
        overlay = getChildAt(1)

        bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888)
    }

    override fun drawChild(canvas: Canvas, child: View, drawingTime: Long): Boolean {
        if (child !== overlay) {
            return super.drawChild(canvas, child, drawingTime)
        }

        val overlayCanvas = Canvas(bitmap)
        val result = super.drawChild(overlayCanvas, child, drawingTime)

        canvas.save()
        canvas.clipRect(backgroundView.left, backgroundView.top, backgroundView.right, backgroundView.bottom)
        canvas.drawBitmap(bitmap, 0F, 0F, inversePaint)
        canvas.restore()

        canvas.save()
        canvas.clipOutRect(backgroundView.left, backgroundView.top, backgroundView.right, backgroundView.bottom)
        canvas.drawBitmap(bitmap, 0F, 0F, null)
        canvas.restore()
        return result
    }

}

layout.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.davidmedenjak.overlappinginvertview.MainActivity">

    <com.davidmedenjak.overlappinginvertview.InvertViewLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="#999999">

        <View
            android:layout_width="100dp"
            android:layout_height="100dp"
            android:layout_marginStart="50dp"
            android:layout_marginTop="50dp"
            android:background="@android:color/black"/>

        <TextView
            style="@style/TextAppearance.AppCompat.Display1"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginStart="0sp"
            android:layout_marginTop="100dp"
            android:text="Hello World!"
            android:textColor="@android:color/black"
            android:textSize="50sp"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintLeft_toLeftOf="parent"
            app:layout_constraintRight_toRightOf="parent"
            app:layout_constraintTop_toTopOf="parent"/>

    </com.davidmedenjak.overlappinginvertview.InvertViewLayout>
</android.support.constraint.ConstraintLayout>