feat(app): Add pause and resume event listeners

app/README.md

@@ -77,6 +77,8 @@ const checkAppLaunchUrl = async () => {
 * [`getLaunchUrl()`](#getlaunchurl)
 * [`minimizeApp()`](#minimizeapp)
 * [`addListener('appStateChange', ...)`](#addlistenerappstatechange)
+* [`addListener('pause', ...)`](#addlistenerpause)
+* [`addListener('resume', ...)`](#addlistenerresume)
 * [`addListener('appUrlOpen', ...)`](#addlistenerappurlopen)
 * [`addListener('appRestoredResult', ...)`](#addlistenerapprestoredresult)
 * [`addListener('backButton', ...)`](#addlistenerbackbutton)
@@ -171,7 +173,12 @@ Only available for Android.
 addListener(eventName: 'appStateChange', listenerFunc: StateChangeListener) => Promise<PluginListenerHandle> & PluginListenerHandle
 ```
 
-Listen for changes in the App's active state (whether the app is in the foreground or background)
+Listen for changes in the app or the activity states.
+
+On iOS it's fired when the native [UIApplication.willResignActiveNotification](https://developer.apple.com/documentation/uikit/uiapplication/1622973-willresignactivenotification) and
+[UIApplication.didBecomeActiveNotification](https://developer.apple.com/documentation/uikit/uiapplication/1622953-didbecomeactivenotification) events get fired.
+On Android it's fired when the Capacitor's Activity [onResume](https://developer.android.com/reference/android/app/Activity#onResume()) and [onStop](https://developer.android.com/reference/android/app/Activity#onStop()) methods gets called.
+On Web it's fired when the document's visibilitychange gets fired.
 
 | Param              | Type                                                                |
 | ------------------ | ------------------------------------------------------------------- |
@@ -185,6 +192,55 @@ Listen for changes in the App's active state (whether the app is in the foregrou
 --------------------
 
 
+### addListener('pause', ...)
+
+```typescript
+addListener(eventName: 'pause', listenerFunc: () => void) => Promise<PluginListenerHandle> & PluginListenerHandle
+```
+
+Listen for when the app or the activity are paused.
+
+On iOS it's fired when the native [UIApplication.didEnterBackgroundNotification](https://developer.apple.com/documentation/uikit/uiapplication/1623071-didenterbackgroundnotification) event gets fired.
+On Android it's fired when the Capacitor's Activity [onPause](https://developer.android.com/reference/android/app/Activity#onPause()) method gets called.
+On Web it's fired when the document's visibilitychange gets fired and document.hidden is true.
+
+| Param              | Type                       |
+| ------------------ | -------------------------- |
+| **`eventName`**    | <code>'pause'</code>       |
+| **`listenerFunc`** | <code>() =&gt; void</code> |
+
+**Returns:** <code>Promise&lt;<a href="#pluginlistenerhandle">PluginListenerHandle</a>&gt; & <a href="#pluginlistenerhandle">PluginListenerHandle</a></code>
+
+**Since:** 4.1.0
+
+--------------------
+
+
+### addListener('resume', ...)
+
+```typescript
+addListener(eventName: 'resume', listenerFunc: () => void) => Promise<PluginListenerHandle> & PluginListenerHandle
+```
+
+Listen for when the app or activity are resumed.
+
+On iOS it's fired when the native [UIApplication.willEnterForegroundNotification](https://developer.apple.com/documentation/uikit/uiapplication/1622944-willenterforegroundnotification) event gets fired.
+On Android it's fired when the Capacitor's Activity [onResume](https://developer.android.com/reference/android/app/Activity#onResume()) method gets called,
+but only after resume has fired first.
+On Web it's fired when the document's visibilitychange gets fired and document.hidden is false.
+
+| Param              | Type                       |
+| ------------------ | -------------------------- |
+| **`eventName`**    | <code>'resume'</code>      |
+| **`listenerFunc`** | <code>() =&gt; void</code> |
+
+**Returns:** <code>Promise&lt;<a href="#pluginlistenerhandle">PluginListenerHandle</a>&gt; & <a href="#pluginlistenerhandle">PluginListenerHandle</a></code>
+
+**Since:** 4.1.0
+
+--------------------
+
+
 ### addListener('appUrlOpen', ...)
 
 ```typescript

app/android/src/main/java/com/capacitorjs/plugins/app/AppPlugin.java

@@ -21,6 +21,9 @@ public class AppPlugin extends Plugin {
     private static final String EVENT_URL_OPEN = "appUrlOpen";
     private static final String EVENT_STATE_CHANGE = "appStateChange";
     private static final String EVENT_RESTORED_RESULT = "appRestoredResult";
+    private static final String EVENT_PAUSE = "pause";
+    private static final String EVENT_RESUME = "resume";
+    private boolean hasPausedEver = false;
 
     public void load() {
         bridge
@@ -132,6 +135,21 @@ protected void handleOnNewIntent(Intent intent) {
         notifyListeners(EVENT_URL_OPEN, ret, true);
     }
 
+    @Override
+    protected void handleOnPause() {
+        super.handleOnPause();
+        hasPausedEver = true;
+        notifyListeners(EVENT_PAUSE, null);
+    }
+
+    @Override
+    protected void handleOnResume() {
+        super.handleOnResume();
+        if (hasPausedEver) {
+            notifyListeners(EVENT_RESUME, null);
+        }
+    }
+
     @Override
     protected void handleOnDestroy() {
         unsetAppListeners();

app/ios/Plugin/AppPlugin.swift

@@ -19,6 +19,14 @@ public class AppPlugin: CAPPlugin {
             ])
         })
 
+        observers.append(NotificationCenter.default.addObserver(forName: UIApplication.didEnterBackgroundNotification, object: nil, queue: OperationQueue.main) { [weak self] (_) in
+            self?.notifyListeners("pause", data: nil)
+        })
+
+        observers.append(NotificationCenter.default.addObserver(forName: UIApplication.willEnterForegroundNotification, object: nil, queue: OperationQueue.main) { [weak self] (_) in
+            self?.notifyListeners("resume", data: nil)
+        })
+
     }
 
     deinit {

app/src/definitions.ts

@@ -172,7 +172,12 @@ export interface AppPlugin {
   minimizeApp(): Promise<void>;
 
   /**
-   * Listen for changes in the App's active state (whether the app is in the foreground or background)
+   * Listen for changes in the app or the activity states.
+   *
+   * On iOS it's fired when the native [UIApplication.willResignActiveNotification](https://developer.apple.com/documentation/uikit/uiapplication/1622973-willresignactivenotification) and
+   * [UIApplication.didBecomeActiveNotification](https://developer.apple.com/documentation/uikit/uiapplication/1622953-didbecomeactivenotification) events get fired.
+   * On Android it's fired when the Capacitor's Activity [onResume](https://developer.android.com/reference/android/app/Activity#onResume()) and [onStop](https://developer.android.com/reference/android/app/Activity#onStop()) methods gets called.
+   * On Web it's fired when the document's visibilitychange gets fired.
    *
    * @since 1.0.0
    */
@@ -181,6 +186,35 @@ export interface AppPlugin {
     listenerFunc: StateChangeListener,
   ): Promise<PluginListenerHandle> & PluginListenerHandle;
 
+  /**
+   * Listen for when the app or the activity are paused.
+   *
+   * On iOS it's fired when the native [UIApplication.didEnterBackgroundNotification](https://developer.apple.com/documentation/uikit/uiapplication/1623071-didenterbackgroundnotification) event gets fired.
+   * On Android it's fired when the Capacitor's Activity [onPause](https://developer.android.com/reference/android/app/Activity#onPause()) method gets called.
+   * On Web it's fired when the document's visibilitychange gets fired and document.hidden is true.
+   *
+   * @since 4.1.0
+   */
+  addListener(
+    eventName: 'pause',
+    listenerFunc: () => void,
+  ): Promise<PluginListenerHandle> & PluginListenerHandle;
+
+  /**
+   * Listen for when the app or activity are resumed.
+   *
+   * On iOS it's fired when the native [UIApplication.willEnterForegroundNotification](https://developer.apple.com/documentation/uikit/uiapplication/1622944-willenterforegroundnotification) event gets fired.
+   * On Android it's fired when the Capacitor's Activity [onResume](https://developer.android.com/reference/android/app/Activity#onResume()) method gets called,
+   * but only after resume has fired first.
+   * On Web it's fired when the document's visibilitychange gets fired and document.hidden is false.
+   *
+   * @since 4.1.0
+   */
+  addListener(
+    eventName: 'resume',
+    listenerFunc: () => void,
+  ): Promise<PluginListenerHandle> & PluginListenerHandle;
+
   /**
    * Listen for url open events for the app. This handles both custom URL scheme links as well
    * as URLs your app handles (Universal Links on iOS and App Links on Android)

app/src/web.ts

@@ -38,5 +38,10 @@ export class AppWeb extends WebPlugin implements AppPlugin {
     };
 
     this.notifyListeners('appStateChange', data);
+    if (document.hidden) {
+      this.notifyListeners('pause', null);
+    } else {
+      this.notifyListeners('resume', null);
+    }
   };
 }