[Android] Add onUserLeaveHint support to ReactActivityDelegate

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/ReactActivity.java

@@ -105,6 +105,12 @@ public void onNewIntent(Intent intent) {
     }
   }
 
+  @Override
+  public void onUserLeaveHint() {
+    super.onUserLeaveHint();
+    mDelegate.onUserLeaveHint();
+  }
+
   @Override
   public void requestPermissions(
       String[] permissions, int requestCode, PermissionListener listener) {

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/ReactActivityDelegate.java

@@ -123,6 +123,10 @@ protected void loadApp(String appKey) {
     getPlainActivity().setContentView(mReactDelegate.getReactRootView());
   }
 
+  protected void onUserLeaveHint() {
+    mReactDelegate.onUserLeaveHint();
+  }
+
   protected void onPause() {
     mReactDelegate.onHostPause();
   }

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/ReactDelegate.java

@@ -99,6 +99,16 @@ public void onHostResume() {
     }
   }
 
+  public void onUserLeaveHint() {
+    if (ReactFeatureFlags.enableBridgelessArchitecture) {
+      mReactHost.onHostLeaveHint(mActivity);
+    } else {
+      if (getReactNativeHost().hasInstance()) {
+        getReactNativeHost().getReactInstanceManager().onUserLeaveHint(mActivity);
+      }
+    }
+  }
+
   public void onHostPause() {
     if (ReactFeatureFlags.enableBridgelessArchitecture) {
       mReactHost.onHostPause(mActivity);

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/ReactHost.kt

@@ -57,6 +57,9 @@ interface ReactHost {
   /** To be called when the host activity is resumed. */
   fun onHostResume(activity: Activity?)
 
+  /** To be called when the host activity is about to go into the background as the result of user choice. */
+  fun onHostLeaveHint(activity: Activity?)
+
   /** To be called when the host activity is paused. */
   fun onHostPause(activity: Activity?)
 

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/ReactInstanceManager.java

@@ -585,6 +585,38 @@ public void onHostPause() {
     moveToBeforeResumeLifecycleState();
   }
 
+  /**
+   * This method should be called from {@link Activity#onUserLeaveHint()}. It notifies all
+   * listening modules that the user is about to leave the activity. The passed Activity is has to
+   * be the current Activity.
+   *
+   * @param activity the activity being backgrounded as a result of user action
+   */
+  @ThreadConfined(UI)
+  public void onUserLeaveHint(@Nullable Activity activity) {
+    if (mRequireActivity) {
+      Assertions.assertCondition(mCurrentActivity != null);
+    }
+
+    if (mCurrentActivity != null) {
+      Assertions.assertCondition(
+        activity == mCurrentActivity,
+        "Called onUserLeaveHint on an activity that is not the current activity, this is incorrect! "
+          + "Current activity: "
+          + mCurrentActivity.getClass().getSimpleName()
+          + " "
+          + "Leaving activity: "
+          + activity.getClass().getSimpleName());
+
+      UiThreadUtil.assertOnUiThread();
+
+      ReactContext currentContext = getCurrentReactContext();
+      if (currentContext != null) {
+        currentContext.onUserLeaveHint(activity);
+      }
+    }
+  }
+
   /**
    * Call this from {@link Activity#onPause()}. This notifies any listening modules so they can do
    * any necessary cleanup. The passed Activity is the current Activity being paused. This will

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/bridge/ActivityEventListener.java

@@ -22,4 +22,7 @@ public interface ActivityEventListener {
 
   /** Called when a new intent is passed to the activity */
   void onNewIntent(Intent intent);
+
+  /** Called when host activity receives an {@link Activity#onUserLeaveHint()} call. */
+  default void onUserLeaveHint(Activity activity) {};
 }

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/bridge/ReactContext.java

@@ -314,6 +314,19 @@ public void onHostResume(@Nullable Activity activity) {
     ReactMarker.logMarker(ReactMarkerConstants.ON_HOST_RESUME_END);
   }
 
+  @ThreadConfined(UI)
+  public void onUserLeaveHint(@Nullable Activity activity) {
+    ReactMarker.logMarker(ReactMarkerConstants.ON_USER_LEAVE_HINT_START);
+    for (ActivityEventListener listener : mActivityEventListeners) {
+      try {
+        listener.onUserLeaveHint(activity);
+      } catch (RuntimeException e) {
+        handleException(e);
+      }
+    }
+    ReactMarker.logMarker(ReactMarkerConstants.ON_USER_LEAVE_HINT_END);
+  }
+
   @ThreadConfined(UI)
   public void onNewIntent(@Nullable Activity activity, Intent intent) {
     UiThreadUtil.assertOnUiThread();

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/bridge/ReactMarkerConstants.java

@@ -52,6 +52,8 @@ public enum ReactMarkerConstants {
   INITIALIZE_MODULE_END,
   ON_HOST_RESUME_START,
   ON_HOST_RESUME_END,
+  ON_USER_LEAVE_HINT_START,
+  ON_USER_LEAVE_HINT_END,
   ON_HOST_PAUSE_START,
   ON_HOST_PAUSE_END,
   CONVERT_CONSTANTS_START,

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/runtime/ReactHostImpl.java

@@ -286,6 +286,18 @@ public void onHostResume(final @Nullable Activity activity) {
     mReactLifecycleStateManager.moveToOnHostResume(currentContext, getCurrentActivity());
   }
 
+  @ThreadConfined(UI)
+  @Override
+  public void onHostLeaveHint(final @Nullable Activity activity) {
+    final String method = "onUserLeaveHint(activity)";
+    log(method);
+
+    ReactContext currentContext = getCurrentReactContext();
+    if (currentContext != null) {
+      currentContext.onUserLeaveHint(activity);
+    }
+  }
+
   @ThreadConfined(UI)
   @Override
   public void onHostPause(final @Nullable Activity activity) {