MainActivity.kt

TLDR

This file contains the code for the MainActivity class, which is an Android activity. The activity is responsible for initializing and managing the user interface elements, event listeners, and functionality of the main activity screen in the application.

Methods

There are no methods in this file.

Classes

MainActivity

The MainActivity class is an Android activity that represents the main screen of the application. It extends the Activity class and is responsible for initializing the user interface, handling user interactions, and managing the lifecycle of the activity.

Some notable features of the MainActivity class include:

• In the onCreate method, it sets the content view to the layout defined in main_activity.xml.
• It initializes various views and buttons and sets click listeners for them.
• It handles the creation and handling of leaked views, dialogs, services, receivers, and animations.
• It contains a nested NoOpBroadcastReceiver class that extends BroadcastReceiver and overrides the onReceive method to do nothing.
• In the onDestroy method, if leakyReceiver is true, it registers a dummy NoOpBroadcastReceiver with no intent filter after a delay of 500 milliseconds.

/*
 * Copyright (C) 2015 Square, Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.example.leakcanary

import android.animation.ObjectAnimator
import android.animation.ValueAnimator
import android.app.Activity
import android.app.AlertDialog
import android.content.BroadcastReceiver
import android.content.Context
import android.content.Intent
import android.content.IntentFilter
import android.os.Bundle
import android.os.Handler
import android.os.Looper
import android.os.SystemClock
import android.view.View
import android.widget.Button
import java.util.concurrent.atomic.AtomicReference
import kotlin.concurrent.thread
import kotlin.random.Random
import leakcanary.AppWatcher

class MainActivity : Activity() {

  private var leakyReceiver = false

  override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    setContentView(R.layout.main_activity)

    val app = application as ExampleApplication
    findViewById<Button>(R.id.recreate_activity_button).setOnClickListener { recreate() }
    findViewById<Button>(R.id.leak_activity_button).setOnClickListener {
      val leakedView = findViewById<View>(R.id.helper_text)
      when (Random.nextInt(4)) {
        // Leak from application class
        0 -> app.leakedViews.add(leakedView)
        // Leak from Kotlin object singleton
        1 -> LeakingSingleton.leakedViews.add(leakedView)
        2 -> {
          // Leak from local variable on thread
          val ref = AtomicReference(this)
          thread(name = "Leaking local variables") {
            val activity = ref.get()
            ref.set(null)
            while (true) {
              print(activity)
              SystemClock.sleep(1000)
            }
          }
        }
        // Leak from thread fields
        else -> LeakingThread.thread.leakedViews.add(leakedView)
      }
    }
    findViewById<Button>(R.id.show_dialog_button).setOnClickListener {
      AlertDialog.Builder(this)
        .setTitle("Leaky dialog")
        .setPositiveButton("Dismiss and leak dialog") { dialog, _ ->
          app.leakedDialogs += dialog as AlertDialog
        }
        .show()
    }
    findViewById<Button>(R.id.start_service_button).setOnClickListener {
      startService(Intent(this, LeakingService::class.java))
    }
    findViewById<Button>(R.id.leak_receiver_button).setOnClickListener {
      leakyReceiver = true
      recreate()
    }
    findViewById<Button>(R.id.message_leak_button).setOnClickListener {
      val leaky = Any()
      AppWatcher.objectWatcher.expectWeaklyReachable(leaky, "Repeated Message")
      @Suppress("unused")
      class LeakyReschedulingRunnable(private val leaky: Any) : Runnable {
        private val handler = Handler(Looper.getMainLooper())
        override fun run() {
          handler.postDelayed(this, 1000)
        }
      }
      LeakyReschedulingRunnable(leaky).run()
    }
    findViewById<Button>(R.id.infinite_animator).setOnClickListener { view ->
      ObjectAnimator.ofFloat(view, View.ALPHA, 0.1f, 0.2f).apply {
        duration = 100
        repeatMode = ValueAnimator.REVERSE
        repeatCount = ValueAnimator.INFINITE
        start()
      }
    }
    findViewById<Button>(R.id.finish_activity).setOnClickListener { view ->
      finish()
    }
  }

  class NoOpBroadcastReceiver : BroadcastReceiver() {
    override fun onReceive(
      context: Context,
      intent: Intent
    ) = Unit
  }

  override fun onDestroy() {
    super.onDestroy()
    if (leakyReceiver) {
      Handler().postDelayed({
        registerReceiver(NoOpBroadcastReceiver(), IntentFilter())
      }, 500)
    }
  }
}