class App : Application() {
    override fun onCreate() {
        super.onCreate()
        StrictModeToaster.setup(applicationContext)
    }
}

package com.example.myapp

import android.content.Context
import android.content.pm.ApplicationInfo
import android.os.Handler
import android.os.Looper
import android.os.StrictMode
import android.os.strictmode.Violation
import android.widget.Toast
import java.util.concurrent.ExecutorService
import java.util.concurrent.Executors

/**
 * StrictMode utility to show a violation message as a toast.
 * To enable the StrictMode, just call [setup] at the beginning of the application.
 */
object StrictModeToaster {
    // To show a toast
    private val mainThreadHandler by lazy {
        Handler(Looper.getMainLooper())
    }
    private lateinit var appContext: Context

    // To handle violation messages
    private val workerThreadExecutor: ExecutorService by lazy {
        Executors.newSingleThreadExecutor()
    }
    private val vmViolationListener by lazy {
        StrictMode.OnVmViolationListener(::showViolationName)
    }
    private val threadViolationListener by lazy {
        StrictMode.OnThreadViolationListener(::showViolationName)
    }

    /**
     * Starts handling strict mode violation messages.
     * This method must be called as soon as possible after launching the app.
     */
    fun setup(context: Context) {
        // Enable the strict mode only when the debuggable flag is true
        if (context.applicationInfo.flags and ApplicationInfo.FLAG_DEBUGGABLE == 0) {
            return
        }

        appContext = context.applicationContext
        StrictMode.setThreadPolicy(
            StrictMode.ThreadPolicy.Builder()
                .detectAll()
                .penaltyLog()
                .penaltyListener(workerThreadExecutor, threadViolationListener)
                .build()
        )
        StrictMode.setVmPolicy(
            StrictMode.VmPolicy.Builder()
                .detectAll()
                .penaltyLog()
                .penaltyListener(workerThreadExecutor, vmViolationListener)
                .build()
        )
    }

    /**
     * Shows the [violation] name with a Toast.
     */
    private fun showViolationName(violation: Violation) {
        val message: String = violation.javaClass.simpleName
        mainThreadHandler.post {
            Toast.makeText(appContext, message, Toast.LENGTH_LONG).show()
        }
    }