Dismiss indefinite Snackbar depending on touch action and touch point

Hide Snackbar when user touches anywhere except it's bounds

package com.example.abusik.snackbarhideontap

import android.graphics.Point
import android.graphics.Rect
import android.os.Bundle
import android.support.design.widget.Snackbar
import android.support.v7.app.AppCompatActivity
import android.view.MotionEvent
import android.view.View
import kotlinx.android.synthetic.main.activity_main.coordinator_layout
import kotlinx.android.synthetic.main.activity_main.toolbar

class MainActivity : AppCompatActivity() {

    private var snackbar: Snackbar? = null

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
        setSupportActionBar(toolbar)

        // show indefinite snackbar
        snackbar = Snackbar.make(coordinator_layout, "Hello world!", Snackbar.LENGTH_INDEFINITE).apply {
            addCallback(object : BaseTransientBottomBar.BaseCallback<Snackbar>() {
                override fun onDismissed(transientBottomBar: Snackbar?, event: Int) {
                    super.onDismissed(transientBottomBar, event)
                    /**
                     * Set [snackbar] to null for [MainActivity.dispatchTouchEvent] to perform better
                     */
                    if (transientBottomBar == snackbar) {
                        snackbar = null
                    }
                }
            })
            show()
        }
    }

    /**
     * On each touch event:
     * Check is [snackbar] present and displayed
     * and dismiss it if user touched anywhere outside it's bounds
     */
    override fun dispatchTouchEvent(ev: MotionEvent): Boolean {
        // dismiss shown snackbar if user tapped anywhere outside snackbar
        snackbar?.takeIf { it.isShown }?.run {
            val touchPoint = Point(Math.round(ev.rawX), Math.round(ev.rawY))
            if (!isPointInsideViewBounds(view, touchPoint)) {
                dismiss()
                snackbar = null // set snackbar to null to prevent this block being executed twice
            }
        }

        // call super
        return super.dispatchTouchEvent(ev)
    }

    /**
     * Defines bounds of displayed view and check is it contains [Point]
     * @param view View to define bounds
     * @param point Point to check inside bounds
     * @return `true` if view bounds contains point, `false` - otherwise
     */
    private fun isPointInsideViewBounds(view: View, point: Point): Boolean = Rect().run {
        // get view rectangle
        view.getDrawingRect(this)

        // apply offset
        IntArray(2).also { locationOnScreen ->
            view.getLocationOnScreen(locationOnScreen)
            offset(locationOnScreen[0], locationOnScreen[1])
        }

        // check is rectangle contains point
        contains(point.x, point.y)
    }
}

Great approach!

A good adjustment might be to just consider a started pressed gesture with action MotionEvent.ACTION_DOWN. Otherwise, the block is called several times for further events.

class MainActivity : AppCompatActivity() {

    ....

    override fun dispatchTouchEvent(ev: MotionEvent): Boolean {
        snackbar?.takeIf { it.isShown }?.run {
            if (MotionEvent.ACTION_DOWN == ev.action) {
                val point = Point(Math.round(ev.rawX), Math.round(ev.rawY))
                if (!point.isInsideViewBounds(view)) {
                    dismiss()
                }
            }
        }
        return super.dispatchTouchEvent(ev)
    }
}