feat: add back press intercept

crates/ability/src/app.rs

@@ -159,11 +159,13 @@ impl OpenHarmonyAppInner {
 }
 
 type EventLoop = Arc<RefCell<Option<Box<dyn FnMut(Event) + Sync + Send>>>>;
+type BackPressInterceptor = Arc<RefCell<Option<Box<dyn FnMut() -> bool + Sync + Send>>>>;
 
 #[derive(Clone)]
 pub struct OpenHarmonyApp {
     pub(crate) inner: Arc<RwLock<OpenHarmonyAppInner>>,
     pub(crate) event_loop: EventLoop,
+    pub(crate) back_press_interceptor: BackPressInterceptor,
     pub(crate) ime: Arc<RefCell<Option<IME>>>,
     is_keyboard_show: Arc<Mutex<bool>>,
 }
@@ -212,6 +214,8 @@ impl OpenHarmonyApp {
             #[allow(clippy::arc_with_non_send_sync)]
             event_loop: Arc::new(RefCell::new(None)),
             #[allow(clippy::arc_with_non_send_sync)]
+            back_press_interceptor: Arc::new(RefCell::new(None)),
+            #[allow(clippy::arc_with_non_send_sync)]
             ime: Arc::new(RefCell::new(None)),
             is_keyboard_show: Arc::new(Mutex::new(false)),
         }
@@ -369,6 +373,18 @@ impl OpenHarmonyApp {
         self.event_loop.replace(Some(static_handler));
         HAS_EVENT.store(true, std::sync::atomic::Ordering::SeqCst);
     }
+
+    /// Register back press interceptor. Return `true` to intercept back action, `false` to pass through.
+    pub fn on_back_press_intercept<'a, F: FnMut() -> bool + 'a>(&self, interceptor: F) {
+        let static_handler = unsafe {
+            std::mem::transmute::<
+                Box<dyn FnMut() -> bool + 'a>,
+                Box<dyn FnMut() -> bool + 'static + Sync + Send>,
+            >(Box::new(interceptor))
+        };
+
+        self.back_press_interceptor.replace(Some(static_handler));
+    }
 }
 
 impl Default for OpenHarmonyApp {

crates/ability/src/lifecycle.rs

@@ -20,6 +20,7 @@ pub struct EnvironmentCallback<'a> {
 pub struct WindowStageEventCallback<'a> {
     pub on_window_stage_create: Function<'a, (), ()>,
     pub on_window_stage_destroy: Function<'a, (), ()>,
+    pub on_back_press_intercept: Function<'a, (), bool>,
     pub on_ability_create: Function<'a, (), ()>,
     pub on_ability_destroy: Function<'a, (), ()>,
     pub on_ability_save_state: Function<'a, (), ()>,
@@ -199,6 +200,18 @@ pub fn create_lifecycle_handle<'a>(
             Ok(())
         })?;
 
+    let on_back_press_intercept_app = app.clone();
+    let on_back_press_intercept =
+        env.create_function_from_closure("on_back_press_intercept", move |_ctx| {
+            let intercept = on_back_press_intercept_app
+                .back_press_interceptor
+                .borrow_mut()
+                .as_mut()
+                .map(|h| h())
+                .unwrap_or(true);
+            Ok(intercept)
+        })?;
+
     let on_ability_create_app = app.clone();
     let on_ability_create = env.create_function_from_closure("on_ability_create", move |_ctx| {
         if let Some(ref mut h) = *on_ability_create_app.event_loop.borrow_mut() {
@@ -261,6 +274,7 @@ pub fn create_lifecycle_handle<'a>(
         window_stage_event_callback: WindowStageEventCallback {
             on_window_stage_create,
             on_window_stage_destroy,
+            on_back_press_intercept,
             on_ability_create,
             on_ability_destroy,
             on_ability_save_state,

rust_ability/AppScope/resources/base/element/string.json

@@ -5,4 +5,4 @@
       "value": "rust_ability"
     }
   ]
-}
+}

rust_ability/AppScope/resources/base/media/layered_image.json

@@ -1,7 +1,6 @@
 {
-  "layered-image":
-  {
-    "background" : "$media:background",
-    "foreground" : "$media:foreground"
+  "layered-image": {
+    "background": "$media:background",
+    "foreground": "$media:foreground"
   }
 }

rust_ability/ability_rust/src/main/ets/ability/RustAbility.ets

@@ -91,4 +91,9 @@ export class RustAbility extends UIAbility {
     wantParam[STATE_KEY] = ret as string;
     return AbilityConstant.OnSaveResult.RECOVERY_AGREE;
   }
+
+  onBackPress(): boolean {
+    const intercept = this.lifecycle?.windowStageEventCallback.onBackPressIntercept();
+    return intercept ?? true;
+  }
 }

rust_ability/ability_rust/src/main/ets/ability/type.ets

@@ -18,6 +18,7 @@ export interface KeyboardCallback {
 export interface WindowStageEventCallback {
   onWindowStageCreate: () => void;
   onWindowStageDestroy: () => void;
+  onBackPressIntercept: () => boolean;
   onAbilityCreate: (arg: string) => void;
   onAbilityDestroy: () => void;
   onAbilitySaveState: () => string;

rust_ability/ability_rust/src/main/ets/webview/DefaultWebview.ets

@@ -109,15 +109,12 @@ export class RustWebviewNodeController extends NodeController {
       return getCookies(url) as string;
     };
     const loadUrl = (url: string, header?: Record<string, string>) => {
-      const headers = Object.keys((header || {}) as Record<string, string>).reduce(
-        (t, i) => {
-          if (!!header![i]) {
-            t.push({ headerKey: i, headerValue: header![i] });
-          }
-          return t;
-        },
-        [] as Array<WebHeader>,
-      );
+      const headers = Object.keys((header || {}) as Record<string, string>).reduce((t, i) => {
+        if (!!header![i]) {
+          t.push({ headerKey: i, headerValue: header![i] });
+        }
+        return t;
+      }, [] as Array<WebHeader>);
       controller.loadUrl(url, headers);
     };
 

rust_ability/ability_rust/src/main/resources/base/element/string.json

@@ -5,4 +5,4 @@
       "value": "page from package"
     }
   ]
-}
+}

rust_ability/ability_rust/src/main/resources/en_US/element/string.json

@@ -5,4 +5,4 @@
       "value": "page from package"
     }
   ]
-}
+}

rust_ability/ability_rust/src/main/resources/zh_CN/element/string.json

@@ -5,4 +5,4 @@
       "value": "page from package"
     }
   ]
-}
+}

rust_ability/entry/src/main/resources/base/element/float.json

@@ -5,4 +5,4 @@
       "value": "50fp"
     }
   ]
-}
+}

rust_ability/entry/src/main/resources/base/media/layered_image.json

@@ -1,7 +1,6 @@
 {
-  "layered-image":
-  {
-    "background" : "$media:background",
-    "foreground" : "$media:foreground"
+  "layered-image": {
+    "background": "$media:background",
+    "foreground": "$media:foreground"
   }
 }

rust_ability/entry/src/main/resources/base/profile/main_pages.json

@@ -2,4 +2,4 @@
   "src": [
     "pages/Index"
   ]
-}
+}

rust_example/xcomponent_example/src/lib.rs

@@ -13,6 +13,7 @@ use openharmony_ability_derive::ability;
 static INNER_APP: LazyLock<RwLock<Option<OpenHarmonyApp>>> = LazyLock::new(|| RwLock::new(None));
 static PERMISSION_REQUESTED: AtomicBool = AtomicBool::new(false);
 static MAIN_THREAD_DEMO_REQUESTED: AtomicBool = AtomicBool::new(false);
+static BACK_PRESS_INTERCEPT_ENABLED: AtomicBool = AtomicBool::new(true);
 
 #[napi_derive_ohos::napi]
 pub async fn demo_request_permission_from_main_thread() -> Result<Vec<i32>> {
@@ -42,10 +43,24 @@ pub async fn demo_request_permission_from_main_thread() -> Result<Vec<i32>> {
     Ok(codes)
 }
 
+#[napi_derive_ohos::napi]
+pub fn toggle_back_press_intercept() -> bool {
+    let current = BACK_PRESS_INTERCEPT_ENABLED.load(Ordering::SeqCst);
+    let next = !current;
+    BACK_PRESS_INTERCEPT_ENABLED.store(next, Ordering::SeqCst);
+    hilog_info!(format!("back press intercept set to: {}", next).as_str());
+    next
+}
+
 #[ability]
 fn openharmony_app(app: OpenHarmonyApp) {
     INNER_APP.write().unwrap().replace(app.clone());
     let permission_app = app.clone();
+    app.on_back_press_intercept(|| {
+        let intercept = BACK_PRESS_INTERCEPT_ENABLED.load(Ordering::SeqCst);
+        hilog_info!(format!("on_back_press_intercept => {}", intercept).as_str());
+        intercept
+    });
 
     app.run_loop(move |types| match types {
         Event::SurfaceCreate => {

webview_example/AppScope/resources/base/element/string.json

@@ -5,4 +5,4 @@
       "value": "webview_example"
     }
   ]
-}
+}

webview_example/AppScope/resources/base/media/layered_image.json

@@ -1,7 +1,6 @@
 {
-  "layered-image":
-  {
-    "background" : "$media:background",
-    "foreground" : "$media:foreground"
+  "layered-image": {
+    "background": "$media:background",
+    "foreground": "$media:foreground"
   }
 }

webview_example/entry/src/main/resources/base/element/float.json

@@ -5,4 +5,4 @@
       "value": "50fp"
     }
   ]
-}
+}

webview_example/entry/src/main/resources/base/media/layered_image.json

@@ -1,7 +1,6 @@
 {
-  "layered-image":
-  {
-    "background" : "$media:background",
-    "foreground" : "$media:foreground"
+  "layered-image": {
+    "background": "$media:background",
+    "foreground": "$media:foreground"
   }
 }

webview_example/entry/src/main/resources/base/profile/main_pages.json

@@ -2,4 +2,4 @@
   "src": [
     "pages/Index"
   ]
-}
+}

xcomponent_example/AppScope/resources/base/element/string.json

@@ -5,4 +5,4 @@
       "value": "example"
     }
   ]
-}
+}

xcomponent_example/entry/src/main/ets/pages/Index.ets

@@ -1,21 +1,32 @@
 import { DefaultXComponent } from "@ohos-rs/ability";
-import { demoRequestPermissionFromMainThread } from "libxcomponent_example.so";
+import {
+  demoRequestPermissionFromMainThread,
+  toggleBackPressIntercept,
+} from "libxcomponent_example.so";
 
 @Entry
 @Component
 struct Index {
-  private permissionDemoCalled: boolean = false;
+  @State interceptEnabled: boolean = true;
 
   async handleClick() {
     const re: number[] = await demoRequestPermissionFromMainThread();
     console.log(`${re}`);
   }
 
+  handleToggleBackIntercept() {
+    this.interceptEnabled = toggleBackPressIntercept();
+    console.log(`backPressIntercept=${this.interceptEnabled}`);
+  }
+
   build() {
     Row() {
       Column() {
-        Button()
+        Button("request permission demo")
           .onClick(() => this.handleClick())
+        Button(this.interceptEnabled ? "back intercept: ON" : "back intercept: OFF")
+          .onClick(() => this.handleToggleBackIntercept())
+        Text("Swipe back to test intercept behavior.")
         DefaultXComponent()
       }.width("100%")
     }.height("100%");

xcomponent_example/entry/src/main/resources/base/media/layered_image.json

@@ -1,7 +1,6 @@
 {
-  "layered-image":
-  {
-    "background" : "$media:background",
-    "foreground" : "$media:foreground"
+  "layered-image": {
+    "background": "$media:background",
+    "foreground": "$media:foreground"
   }
 }

xcomponent_example/entry/src/main/resources/base/profile/main_pages.json

@@ -2,4 +2,4 @@
   "src": [
     "pages/Index"
   ]
-}
+}