Move lifecycle to activity plugin

README.md

@@ -31,7 +31,6 @@ The bootstrapper for WebView-based Android apps.
 - [Google Sign-In](#google-sign-in-plugin)
 - [HTTPS](#https-plugin)
 - [Keyboard](#keyboard-plugin)
-- [Lifecycle](#lifecycle-plugin)
 - [Network](#network-plugin)
 - [Notifications](#notifications-plugin)
 - [Permissions](#permissions-plugin)
@@ -75,9 +74,7 @@ instance that would be responsible for event marshalling:
 ```kotlin
 import org.racehorse.EventBridge
 
-val eventBridge = EventBridge(webView)
-
-eventBridge.enable()
+val eventBridge = EventBridge(webView).also { enable() }
 ```
 
 Racehorse uses a [Greenrobot EventBus](https://greenrobot.org/eventbus) to deliver events to subscribers, so bridge must
@@ -351,15 +348,23 @@ class ShowToastEvent(val message: String) : WebEvent
 [`ActivityManager`](https://smikhalevski.github.io/racehorse/interfaces/racehorse.ActivityManager.html) starts
 activities and provides info about the activity that renders the WebView.
 
-1. Initialize the plugin in your Android app:
+1. Add Lifecycle dependency to your Android app:
+
+```kotlin
+dependencies {
+    implementation("androidx.lifecycle:lifecycle-process:2.6.2")
+}
+```
+
+2. Initialize the plugin in your Android app:
 
 ```kotlin
 import org.racehorse.ActivityPlugin
 
-EventBus.getDefault().register(ActivityPlugin(activity))
+EventBus.getDefault().register(ActivityPlugin().also { enable() })
 ```
 
-2. Start the activity, for example to open settings app and navigate user to the notification settings:
+3. Start a new activity. For example, here's how to open Settings app and navigate user to the notification settings:
 
 ```ts
 import { activityManager, Intent } from 'racehorse';
@@ -373,6 +378,34 @@ activityManager.startActivity({
 });
 ```
 
+4. Synchronously read the status of the current activity or subscribe to its changes:
+
+```ts
+import { activityManager, ActivityState } from 'racehorse';
+
+activityManager.getActivityState();
+// ⮕ ActivityState.BACKGROUND
+
+activityManager.subscribe(state => {
+  // React to activity state changes
+});
+
+activityManager.subscribe('foreground', () => {
+  // React to activity entering foreground
+});
+```
+
+If you are using React, then refer to
+[`useActivityState`](https://smikhalevski.github.io/racehorse/functions/_racehorse_react.useActivityState.html) hook
+that re-renders a component when activity state changes.
+
+```tsx
+import { useActivityState } from '@racehorse/react';
+
+const state = useActivityState();
+// ⮕ ActivityState.BACKGROUND
+```
+
 # Asset loader plugin
 
 Asset loader plugin requires [WebView events](#webview-events) to be enabled.
@@ -1010,48 +1043,6 @@ status.height;
 // ⮕ 630
 ```
 
-# Lifecycle plugin
-
-[`LifecycleManager`](https://smikhalevski.github.io/racehorse/interfaces/racehorse.LifecycleManager.html) enables
-lifecycle state monitoring.
-
-1. Add Lifecycle dependency to your Android app:
-
-```kotlin
-dependencies {
-    implementation("androidx.lifecycle:lifecycle-process:2.6.2")
-}
-```
-
-2. Initialize the plugin in your Android app:
-
-```kotlin
-import org.racehorse.LifecyclePlugin
-
-val lifecyclePlugin = LifecyclePlugin()
-
-EventBus.getDefault().register(lifecyclePlugin)
-
-lifecyclePlugin.enable()
-```
-
-3. Synchronously read the lifecycle state or subscribe to its changes:
-
-```ts
-import { lifecycleManager, LifecycleState } from 'racehorse';
-
-lifecycleManager.getLifecycleState();
-// ⮕ LifecycleState.STARTED
-
-lifecycleManager.subscribe(state => {
-  // React to lifecycle state changes
-});
-
-lifecycleManager.subscribe('pause', () => {
-  // React to app being paused
-});
-```
-
 # Network plugin
 
 [`NetworkManager`](https://smikhalevski.github.io/racehorse/interfaces/racehorse.NetworkManager.html) enables network

android/example/build.gradle.kts

@@ -59,7 +59,7 @@ dependencies {
     implementation("org.greenrobot:eventbus:3.3.1")
     implementation("com.google.code.gson:gson:2.10.1")
 
-    // LifecyclePlugin
+    // ActivityPlugin
     implementation("androidx.lifecycle:lifecycle-process:2.6.2")
 
     // AssetLoaderPlugin

android/example/src/main/java/com/example/MainActivity.kt

@@ -57,7 +57,7 @@ class MainActivity : AppCompatActivity() {
         eventBus.register(HttpsPlugin())
         eventBus.register(networkPlugin)
         eventBus.register(KeyboardPlugin(this))
-        eventBus.register(ActivityPlugin(this))
+        eventBus.register(ActivityPlugin(this).apply { enable() })
         eventBus.register(DeepLinkPlugin())
         eventBus.register(PermissionsPlugin(this))
         eventBus.register(NotificationsPlugin(this))
@@ -66,7 +66,6 @@ class MainActivity : AppCompatActivity() {
         eventBus.register(FacebookSharePlugin(this))
         eventBus.register(BiometricPlugin(this))
         eventBus.register(BiometricEncryptedStoragePlugin(this, File(filesDir, "biometric_storage")))
-        eventBus.register(LifecyclePlugin().apply { enable() })
         eventBus.register(ToastPlugin(this))
 
         @Suppress("DEPRECATION")

android/racehorse/build.gradle.kts

@@ -79,7 +79,7 @@ dependencies {
     compileOnly("org.greenrobot:eventbus:3.3.1")
     compileOnly("com.google.code.gson:gson:2.10.1")
 
-    // LifecyclePlugin
+    // ActivityPlugin
     compileOnly("androidx.lifecycle:lifecycle-process:2.6.2")
 
     // AssetLoaderPlugin

android/racehorse/src/main/java/org/racehorse/ActivityPlugin.kt

@@ -2,6 +2,9 @@ package org.racehorse
 
 import android.app.Activity
 import androidx.activity.ComponentActivity
+import androidx.lifecycle.Lifecycle
+import androidx.lifecycle.LifecycleEventObserver
+import org.greenrobot.eventbus.EventBus
 import org.greenrobot.eventbus.Subscribe
 import org.racehorse.utils.SerializableIntent
 import org.racehorse.utils.launchActivity
@@ -10,6 +13,12 @@ import java.io.Serializable
 
 class ActivityInfo(val packageName: String) : Serializable
 
+class ActivityStateChangedEvent(val activityState: Int) : NoticeEvent
+
+class GetActivityStateEvent : RequestEvent() {
+    class ResultEvent(val activityState: Int) : ResponseEvent()
+}
+
 class GetActivityInfoEvent : RequestEvent() {
     class ResultEvent(val activityInfo: ActivityInfo) : ResponseEvent()
 }
@@ -31,11 +40,47 @@ class StartActivityForResultEvent(val intent: SerializableIntent) : RequestEvent
 }
 
 /**
- * Opens URL in an external app.
+ * Launches activities for various intents, and provides info about the current activity.
  *
  * @param activity The activity that launches the intent to open a URL.
+ * @param eventBus The event bus to which events are posted.
  */
-open class ActivityPlugin(private val activity: ComponentActivity) {
+open class ActivityPlugin(
+    private val activity: ComponentActivity,
+    private val eventBus: EventBus = EventBus.getDefault()
+) {
+
+    companion object {
+        private const val BACKGROUND = 0
+        private const val FOREGROUND = 1
+        private const val ACTIVE = 2
+    }
+
+    private val lifecycleListener = LifecycleEventObserver { _, event ->
+        when (event.targetState) {
+            Lifecycle.State.CREATED -> eventBus.post(ActivityStateChangedEvent(BACKGROUND))
+            Lifecycle.State.STARTED -> eventBus.post(ActivityStateChangedEvent(FOREGROUND))
+            Lifecycle.State.RESUMED -> eventBus.post(ActivityStateChangedEvent(ACTIVE))
+            else -> {}
+        }
+    }
+
+    open fun enable() = activity.lifecycle.addObserver(lifecycleListener)
+
+    open fun disable() = activity.lifecycle.removeObserver(lifecycleListener)
+
+    @Subscribe
+    open fun onGetActivityState(event: GetActivityStateEvent) {
+        event.respond(
+            GetActivityStateEvent.ResultEvent(
+                when (activity.lifecycle.currentState) {
+                    Lifecycle.State.INITIALIZED, Lifecycle.State.CREATED, Lifecycle.State.DESTROYED -> BACKGROUND
+                    Lifecycle.State.STARTED -> FOREGROUND
+                    Lifecycle.State.RESUMED -> ACTIVE
+                }
+            )
+        )
+    }
 
     @Subscribe
     open fun onGetActivityInfo(event: GetActivityInfoEvent) {

web/example/src/App.tsx

@@ -17,13 +17,11 @@ import { FacebookShareExample } from './examples/FacebookShareExample';
 import { DownloadExample } from './examples/DownloadExample';
 import { BiometricExample } from './examples/BiometricExample';
 import { BiometricEncryptedStorageExample } from './examples/BiometricEncryptedStorageExample';
-import { LifecycleExample } from './examples/LifecycleExample';
 
 export function App() {
   return (
     <>
       <ToastExample />
-      <LifecycleExample />
       <BiometricExample />
       <BiometricEncryptedStorageExample />
       <DownloadExample />

web/example/src/examples/ActivityExample.tsx

@@ -1,17 +1,41 @@
-import React, { useState } from 'react';
-import { activityManager, ActivityResult, Intent, permissionsManager } from 'racehorse';
+import React, { useEffect, useState } from 'react';
+import { activityManager, ActivityResult, ActivityState, Intent, permissionsManager } from 'racehorse';
 import { FormattedJSON } from '../components/FormattedJSON';
+import { useActivityState } from '@racehorse/react';
+
+const activityStateLabel = {
+  [ActivityState.BACKGROUND]: '🔴 Background',
+  [ActivityState.FOREGROUND]: '🟡 Foreground',
+  [ActivityState.ACTIVE]: '🟢 Active',
+} as const;
 
 export function ActivityExample() {
+  const activityState = useActivityState();
   const [activityInfo] = useState(activityManager.getActivityInfo);
   const [contactActivityResult, setContactActivityResult] = useState<ActivityResult | null>();
 
+  useEffect(
+    () =>
+      activityManager.subscribe(activityState => {
+        console.log(activityStateLabel[activityState]);
+      }),
+    []
+  );
+
   return (
     <>
       <h2>{'Activity'}</h2>
 
-      {'Activity info: '}
-      <FormattedJSON value={activityInfo} />
+      <p>{'Activity state: ' + activityStateLabel[activityState]}</p>
+
+      <p>
+        <i>{'Open WebView console to observe activity state changes'}</i>
+      </p>
+
+      <p>
+        {'Activity info: '}
+        <FormattedJSON value={activityInfo} />
+      </p>
 
       <p>
         <button