ReactNative For Android 框架启动核心路径剖析

/**
 * ReactRootView.java
 */
public void startReactApplication(
    ReactInstanceManager reactInstanceManager,
    String moduleName,
    @Nullable Bundle launchOptions) {
  UiThreadUtil.assertOnUiThread();

  mReactInstanceManager = reactInstanceManager;
  mJSModuleName = moduleName;
  mLaunchOptions = launchOptions;

  if (!mReactInstanceManager.hasStartedCreatingInitialContext()) {
    mReactInstanceManager.createReactContextInBackground();
  }

  if (mWasMeasured && mIsAttachedToWindow) {
    mReactInstanceManager.attachMeasuredRootView(this);
    mIsAttachedToInstance = true;
    getViewTreeObserver().addOnGlobalLayoutListener(getKeyboardListener());
  } else {
    mAttachScheduled = true;
  }
}

/**
 * ReactInstanceManagerImpl.java
 */
private void recreateReactContextInBackgroundFromBundleFile() {
  recreateReactContextInBackground(
      new JSCJavaScriptExecutor.Factory(),
      JSBundleLoader.createFileLoader(mApplicationContext, mJSBundleFile));
}

/**
 * ReactInstanceManagerImpl.java
 */
private void recreateReactContextInBackground(
    JavaScriptExecutor.Factory jsExecutorFactory,
    JSBundleLoader jsBundleLoader) {

  ReactContextInitParams initParams =
      new ReactContextInitParams(jsExecutorFactory, jsBundleLoader);
  if (!mIsContextInitAsyncTaskRunning) {

    ReactContextInitAsyncTask initTask = new ReactContextInitAsyncTask();
    initTask.execute(initParams);
    mIsContextInitAsyncTaskRunning = true;
  } else {
    mPendingReactContextInitParams = initParams;
  }
}

/**
 * ReactInstanceManagerImpl$ReactContextInitAsynTask.java
 */
private final class ReactContextInitAsyncTask extends
    AsyncTask<ReactContextInitParams, Void, Result<ReactApplicationContext>> {
  @Override
  protected void onPreExecute() {
    if (mCurrentReactContext != null) {
      tearDownReactContext(mCurrentReactContext);
      mCurrentReactContext = null;
    }
  }

  @Override
  protected Result<ReactApplicationContext> doInBackground(ReactContextInitParams... params) {
    Assertions.assertCondition(params != null && params.length > 0 && params[0] != null);
    try {
      JavaScriptExecutor jsExecutor = params[0].getJsExecutorFactory().create();
      return Result.of(createReactContext(jsExecutor, params[0].getJsBundleLoader()));
    } catch (Exception e) {
      // Pass exception to onPostExecute() so it can be handled on the main thread
      return Result.of(e);
    }
  }

  @Override
  protected void onPostExecute(Result<ReactApplicationContext> result) {
    try {
      setupReactContext(result.get());
    } catch (Exception e) {
      mDevSupportManager.handleException(e);
    } finally {
      mIsContextInitAsyncTaskRunning = false;
    }

    // Handle enqueued request to re-initialize react context.
    if (mPendingReactContextInitParams != null) {
      recreateReactContextInBackground(
          mPendingReactContextInitParams.getJsExecutorFactory(),
          mPendingReactContextInitParams.getJsBundleLoader());
      mPendingReactContextInitParams = null;
    }
  }
}

/**
 * ReactInstanceManagerImpl.java
 *
 * @return instance of {@link ReactContext} configured a {@link CatalystInstance} set
 */
private ReactApplicationContext createReactContext(
    JavaScriptExecutor jsExecutor,
    JSBundleLoader jsBundleLoader) {
  
  mSourceUrl = jsBundleLoader.getSourceUrl();
  NativeModuleRegistry.Builder nativeRegistryBuilder = new NativeModuleRegistry.Builder();
  JavaScriptModulesConfig.Builder jsModulesBuilder = new JavaScriptModulesConfig.Builder();

  ReactApplicationContext reactContext = new ReactApplicationContext(mApplicationContext);
  if (mUseDeveloperSupport) {
    reactContext.setNativeModuleCallExceptionHandler(mDevSupportManager);
  }
  
  CoreModulesPackage coreModulesPackage =
        new CoreModulesPackage(this, mBackBtnHandler, mUIImplementationProvider);
  processPackage(coreModulesPackage, reactContext, nativeRegistryBuilder, jsModulesBuilder);
  
  for (ReactPackage reactPackage : mPackages) {
      processPackage(reactPackage, reactContext, nativeRegistryBuilder, jsModulesBuilder);
  }
  
  nativeModuleRegistry = nativeRegistryBuilder.build();
  javaScriptModulesConfig = jsModulesBuilder.build();

  NativeModuleCallExceptionHandler exceptionHandler = mNativeModuleCallExceptionHandler != null
      ? mNativeModuleCallExceptionHandler
      : mDevSupportManager;
  CatalystInstanceImpl.Builder catalystInstanceBuilder = new CatalystInstanceImpl.Builder()
      .setReactQueueConfigurationSpec(ReactQueueConfigurationSpec.createDefault())
      .setJSExecutor(jsExecutor)
      .setRegistry(nativeModuleRegistry)
      .setJSModulesConfig(javaScriptModulesConfig)
      .setJSBundleLoader(jsBundleLoader)
      .setNativeModuleCallExceptionHandler(exceptionHandler);
  
  CatalystInstance catalystInstance= catalystInstanceBuilder.build();
  if (mBridgeIdleDebugListener != null) {
    catalystInstance.addBridgeIdleDebugListener(mBridgeIdleDebugListener);
  }
  reactContext.initializeWithInstance(catalystInstance);
  catalystInstance.runJSBundle();
  
  return reactContext;
}

/**
 *  CatalystInstanceImpl.java
 */
private CatalystInstanceImpl(
    final ReactQueueConfigurationSpec ReactQueueConfigurationSpec,
    final JavaScriptExecutor jsExecutor,
    final NativeModuleRegistry registry,
    final JavaScriptModulesConfig jsModulesConfig,
    final JSBundleLoader jsBundleLoader,
    NativeModuleCallExceptionHandler nativeModuleCallExceptionHandler) {
  mReactQueueConfiguration = ReactQueueConfigurationImpl.create(
      ReactQueueConfigurationSpec,
      new NativeExceptionHandler());
  mBridgeIdleListeners = new CopyOnWriteArrayList<>();
  mJavaRegistry = registry;
  mJSModuleRegistry = new JavaScriptModuleRegistry(CatalystInstanceImpl.this, jsModulesConfig);
  mJSBundleLoader = jsBundleLoader;
  mNativeModuleCallExceptionHandler = nativeModuleCallExceptionHandler;
  mTraceListener = new JSProfilerTraceListener();

  try {
    mBridge = mReactQueueConfiguration.getJSQueueThread().callOnQueue(
        new Callable<ReactBridge>() {
          @Override
          public ReactBridge call() throws Exception {
            Systrace.beginSection(Systrace.TRACE_TAG_REACT_JAVA_BRIDGE, "initializeBridge");
            try {
              return initializeBridge(jsExecutor, jsModulesConfig);
            } finally {
              Systrace.endSection(Systrace.TRACE_TAG_REACT_JAVA_BRIDGE);
            }
          }
        }).get();
  } catch (Exception t) {
    throw new RuntimeException("Failed to initialize bridge", t);
  }
}

/**
 *  CatalystInstanceImpl.java
 */
private ReactBridge initializeBridge(
    JavaScriptExecutor jsExecutor,
    JavaScriptModulesConfig jsModulesConfig) {

  ReactBridge bridge = new ReactBridge(jsExecutor, new NativeModulesReactCallback(),
      mReactQueueConfiguration.getNativeModulesQueueThread());
  
  Systrace.beginSection(Systrace.TRACE_TAG_REACT_JAVA_BRIDGE, "setBatchedBridgeConfig");
  bridge.setGlobalVariable(
      "__fbBatchedBridgeConfig",
      buildModulesConfigJSONProperty(mJavaRegistry, jsModulesConfig));
  bridge.setGlobalVariable(
      "__RCTProfileIsProfiling",
    
  return bridge;
}

/**
 *  CatalystInstanceImpl.java
 */
public void runJSBundle() {
  try {
    mJSBundleHasLoaded = mReactQueueConfiguration.getJSQueueThread().callOnQueue(
        new Callable<Boolean>() {
          @Override
          public Boolean call() throws Exception {
            incrementPendingJSCalls();
            try {
              mJSBundleLoader.loadScript(mBridge);
              Systrace.registerListener(mTraceListener);
            } catch (JSExecutionException e) {
              mNativeModuleCallExceptionHandler.handleException(e);
            } finally {
              Systrace.endSection(Systrace.TRACE_TAG_REACT_JAVA_BRIDGE);
            }
            return true;
          }
        }).get();
  } catch (Exception t) {
    throw new RuntimeException(t);
  }
}

/**
 * ReactInstanceManagerImpl.java
 */
@Override
public void attachMeasuredRootView(ReactRootView rootView) {
  UiThreadUtil.assertOnUiThread();
  if(mIsNeedDetachView){
    Log.d(ReactConstants.QZONE_REACT_SRC_TAG,"attachMeasuredRootView do add");
    mAttachedRootViews.add(rootView);
    // If react context is being created in the background, JS application will be started
    // automatically when creation completes, as root view is part of the attached root view list.
    if (!mIsContextInitAsyncTaskRunning && mCurrentReactContext != null) {
      attachMeasuredRootViewToInstance(rootView, mCurrentReactContext.getCatalystInstance());
    }
  }else{
    Log.d(ReactConstants.QZONE_REACT_SRC_TAG,"attachMeasuredRootView do nothing");
  }

}

/**
 * ReactInstanceManagerImpl.java
 */
private void attachMeasuredRootViewToInstance(
    ReactRootView rootView,
    CatalystInstance catalystInstance) {

  rootView.removeAllViews();
  rootView.setId(View.NO_ID);

  UIManagerModule uiManagerModule = catalystInstance.getNativeModule(UIManagerModule.class);
  int rootTag = uiManagerModule.addMeasuredRootView(rootView);
  @Nullable Bundle launchOptions = rootView.getLaunchOptions();
  WritableMap initialProps = launchOptions != null
      ? Arguments.fromBundle(launchOptions)
      : Arguments.createMap();
  String jsAppModuleName = rootView.getJSModuleName();

  WritableNativeMap appParams = new WritableNativeMap();
  appParams.putDouble("rootTag", rootTag);
  appParams.putMap("initialProps", initialProps);
  catalystInstance.getJSModule(AppRegistry.class).runApplication(jsAppModuleName, appParams);
}

/**
* AppRegistry.js
*/
runApplication: function(appKey: string, appParameters: any): void {
  console.log(
    'Running application "' + appKey + '" with appParams: ' +
    JSON.stringify(appParameters) + '. ' +
    '__DEV__ === ' + String(__DEV__) +
    ', development-level warning are ' + (__DEV__ ? 'ON' : 'OFF') +
    ', performance optimizations are ' + (__DEV__ ? 'OFF' : 'ON')
  );
  invariant(
    runnables[appKey] && runnables[appKey].run,
    'Application ' + appKey + ' has not been registered. This ' +
    'is either due to a require() error during initialization ' +
    'or failure to call AppRegistry.registerComponent.'
  );
  runnables[appKey].run(appParameters);
},