import com.facebook.react.common.SystemClock; //导入依赖的package包/类
@Override
protected void addEventEmitters(
        final ThemedReactContext reactContext,
        final RCTSwipeRefreshLayout view) {
    view.setOnEvTouchListener(
            new RCTSwipeRefreshLayout.OnEvTouchListener() {
                @Override
                public void onSwipe(int movement) {
                    reactContext.getNativeModule(UIManagerModule.class).getEventDispatcher()
                            .dispatchEvent(new TouchEvent(view.getId(), SystemClock.nanoTime(), movement));
                }

                @Override
                public void onSwipeRefresh() {
                    reactContext.getNativeModule(UIManagerModule.class).getEventDispatcher()
                            .dispatchEvent(new TouchUpEvent(view.getId(), SystemClock.nanoTime()));
                }

            });
}
 

import com.facebook.react.common.SystemClock; //导入依赖的package包/类
/**
 * Get the current position. This can return almost immediately if the location is cached or
 * request an update, which might take a while.
 *
 * @param options map containing optional arguments: timeout (millis), maximumAge (millis) and
 *        highAccuracy (boolean)
 */
@ReactMethod
public void getCurrentPosition(
    ReadableMap options,
    final Callback success,
    Callback error) {
  LocationOptions locationOptions = LocationOptions.fromReactMap(options);

  try {
    LocationManager locationManager =
        (LocationManager) getReactApplicationContext().getSystemService(Context.LOCATION_SERVICE);
    String provider = getValidProvider(locationManager, locationOptions.highAccuracy);
    if (provider == null) {
      error.invoke(PositionError.buildError(
              PositionError.PERMISSION_DENIED,
              "No location provider available."));
      return;
    }
    Location location = locationManager.getLastKnownLocation(provider);
    if (location != null &&
        SystemClock.currentTimeMillis() - location.getTime() < locationOptions.maximumAge) {
      success.invoke(locationToMap(location));
      return;
    }
    new SingleUpdateRequest(locationManager, provider, locationOptions.timeout, success, error)
        .invoke();
  } catch (SecurityException e) {
    throwLocationPermissionMissing(e);
  }
}
 

import com.facebook.react.common.SystemClock; //导入依赖的package包/类
@Override
public void onSelectionChanged(int start, int end) {
  // Android will call us back for both the SELECTION_START span and SELECTION_END span in text
  // To prevent double calling back into js we cache the result of the previous call and only
  // forward it on if we have new values
  if (mPreviousSelectionStart != start || mPreviousSelectionEnd != end) {
    mEventDispatcher.dispatchEvent(
        new ReactTextInputSelectionEvent(
            mReactEditText.getId(),
            SystemClock.nanoTime(),
            start,
            end
        )
    );

    mPreviousSelectionStart = start;
    mPreviousSelectionEnd = end;
  }
}
 

import com.facebook.react.common.SystemClock; //导入依赖的package包/类
@Override
protected void onScrollChanged(int l, int t, int oldl, int oldt) {
  super.onScrollChanged(l, t, oldl, oldt);

  ((ReactContext) getContext()).getNativeModule(UIManagerModule.class).getEventDispatcher()
      .dispatchEvent(ScrollEvent.obtain(
              getId(),
              SystemClock.nanoTime(),
              ScrollEventType.SCROLL,
              0, /* offsetX = 0, horizontal scrolling only */
              calculateAbsoluteOffset(),
              getWidth(),
              ((ReactListAdapter) getAdapter()).getTotalChildrenHeight(),
              getWidth(),
              getHeight()));
}
 

import com.facebook.react.common.SystemClock; //导入依赖的package包/类
@Override
public void onReceivedError(
    WebView webView,
    int errorCode,
    String description,
    String failingUrl) {
  super.onReceivedError(webView, errorCode, description, failingUrl);
  mLastLoadFailed = true;

  // In case of an error JS side expect to get a finish event first, and then get an error event
  // Android WebView does it in the opposite way, so we need to simulate that behavior
  emitFinishEvent(webView, failingUrl);

  WritableMap eventData = createWebViewEvent(webView, failingUrl);
  eventData.putDouble("code", errorCode);
  eventData.putString("description", description);

  dispatchEvent(
      webView,
      new TopLoadingErrorEvent(webView.getId(), SystemClock.nanoTime(), eventData));
}
 

import com.facebook.react.common.SystemClock; //导入依赖的package包/类
@Override
public void onPageScrollStateChanged(int state) {
  String pageScrollState;
  switch (state) {
    case SCROLL_STATE_IDLE:
      pageScrollState = "idle";
      break;
    case SCROLL_STATE_DRAGGING:
      pageScrollState = "dragging";
      break;
    case SCROLL_STATE_SETTLING:
      pageScrollState = "settling";
      break;
    default:
      throw new IllegalStateException("Unsupported pageScrollState");
  }
  mEventDispatcher.dispatchEvent(
    new PageScrollStateChangedEvent(getId(), SystemClock.nanoTime(), pageScrollState));
}
 

import com.facebook.react.common.SystemClock; //导入依赖的package包/类
@Override
protected void addEventEmitters(final ThemedReactContext reactContext, final ReactToolbar view) {
  final EventDispatcher mEventDispatcher = reactContext.getNativeModule(UIManagerModule.class)
      .getEventDispatcher();
  view.setNavigationOnClickListener(
      new View.OnClickListener() {
        @Override
        public void onClick(View v) {
          mEventDispatcher.dispatchEvent(
              new ToolbarClickEvent(view.getId(), SystemClock.nanoTime(), -1));
        }
      });

  view.setOnMenuItemClickListener(
      new ReactToolbar.OnMenuItemClickListener() {
        @Override
        public boolean onMenuItemClick(MenuItem menuItem) {
          mEventDispatcher.dispatchEvent(
              new ToolbarClickEvent(
                  view.getId(),
                  SystemClock.nanoTime(),
                  menuItem.getOrder()));
          return true;
        }
      });
}
 

import com.facebook.react.common.SystemClock; //导入依赖的package包/类
private static void emitScrollEvent(ViewGroup scrollView, ScrollEventType scrollEventType) {
  View contentView = scrollView.getChildAt(0);

  if (contentView == null) {
    return;
  }

  ReactContext reactContext = (ReactContext) scrollView.getContext();
  reactContext.getNativeModule(UIManagerModule.class).getEventDispatcher().dispatchEvent(
      ScrollEvent.obtain(
          scrollView.getId(),
          SystemClock.nanoTime(),
          scrollEventType,
          scrollView.getScrollX(),
          scrollView.getScrollY(),
          contentView.getWidth(),
          contentView.getHeight(),
          scrollView.getWidth(),
          scrollView.getHeight()));
}
 

import com.facebook.react.common.SystemClock; //导入依赖的package包/类
private void dispatchCancelEvent(MotionEvent androidEvent, EventDispatcher eventDispatcher) {
  // This means the gesture has already ended, via some other CANCEL or UP event. This is not
  // expected to happen very often as it would mean some child View has decided to intercept the
  // touch stream and start a native gesture only upon receiving the UP/CANCEL event.
  if (mTargetTag == -1) {
    FLog.w(
      ReactConstants.TAG,
      "Can't cancel already finished gesture. Is a child View trying to start a gesture from " +
        "an UP/CANCEL event?");
    return;
  }

  Assertions.assertCondition(
    !mChildIsHandlingNativeGesture,
    "Expected to not have already sent a cancel for this gesture");
  Assertions.assertNotNull(eventDispatcher).dispatchEvent(
    TouchEvent.obtain(
      mTargetTag,
      SystemClock.nanoTime(),
      TouchEventType.CANCEL,
      androidEvent,
      mTargetCoordinates[0],
      mTargetCoordinates[1]));
}
 

import com.facebook.react.common.SystemClock; //导入依赖的package包/类
@Override
public void onPageScrollStateChanged(int state) {
    String pageScrollState;
    switch (state) {
        case SCROLL_STATE_IDLE:
            pageScrollState = "idle";
            break;
        case SCROLL_STATE_DRAGGING:
            pageScrollState = "dragging";
            break;
        case SCROLL_STATE_SETTLING:
            pageScrollState = "settling";
            break;
        default:
            throw new IllegalStateException("Unsupported pageScrollState");
    }
    mEventDispatcher.dispatchEvent(
            new PageScrollStateChangedEvent(getId(), SystemClock.nanoTime(), pageScrollState));
}
 

import com.facebook.react.common.SystemClock; //导入依赖的package包/类
@Override
protected void onScrollChanged(int l, int t, int oldl, int oldt) {
    super.onScrollChanged(l, t, oldl, oldt);

    if (mOnScrollDispatchHelper.onScrollChanged(l, t)) {
        getReactContext().getNativeModule(UIManagerModule.class).getEventDispatcher()
                .dispatchEvent(ScrollEvent.obtain(
                        getId(),
                        ScrollEventType.SCROLL,
                        0, /* offsetX = 0, horizontal scrolling only */
                        computeVerticalScrollOffset(),
                        mOnScrollDispatchHelper.getXFlingVelocity(),
                        mOnScrollDispatchHelper.getYFlingVelocity(),
                        getWidth(),
                        computeVerticalScrollRange(),
                        getWidth(),
                        getHeight()));
    }

    final int firstIndex = ((LinearLayoutManager) getLayoutManager()).findFirstVisibleItemPosition();
    final int lastIndex = ((LinearLayoutManager) getLayoutManager()).findLastVisibleItemPosition();

    if (firstIndex != mFirstVisibleIndex || lastIndex != mLastVisibleIndex) {
        getReactContext().getNativeModule(UIManagerModule.class).getEventDispatcher()
                .dispatchEvent(new VisibleItemsChangeEvent(
                        getId(),
                        SystemClock.nanoTime(),
                        firstIndex,
                        lastIndex));

        mFirstVisibleIndex = firstIndex;
        mLastVisibleIndex = lastIndex;
    }
}
 

import com.facebook.react.common.SystemClock; //导入依赖的package包/类
@Override
protected void addEventEmitters(
        final ThemedReactContext reactContext,
        final RCTLazyLoadView view) {
    view.setOnEvChangeListener(
            new OnEvChangeListener() {
                @Override
                public void onWindowVisibilityChange( boolean hiddenState) {
                    reactContext.getNativeModule(UIManagerModule.class).getEventDispatcher()
                            .dispatchEvent(new WindowVisibilityChangeEvent(view.getId(), SystemClock.nanoTime(), hiddenState));
                }

            });
}
 

import com.facebook.react.common.SystemClock; //导入依赖的package包/类
@Override
public void run() {
  if (mCancelled) {
    return;
  }

  long frameTimeMillis = mFrameStartTime / 1000000;
  long timeSinceBoot = SystemClock.uptimeMillis();
  long frameTimeElapsed = timeSinceBoot - frameTimeMillis;
  long time = SystemClock.currentTimeMillis();
  long absoluteFrameStartTime = time - frameTimeElapsed;

  if (FRAME_DURATION_MS - (float) frameTimeElapsed < IDLE_CALLBACK_FRAME_DEADLINE_MS) {
    return;
  }

  mIdleCallbackContextsToCall.clear();
  synchronized (mIdleCallbackGuard) {
    mIdleCallbackContextsToCall.addAll(mSendIdleEventsExecutorTokens);
  }

  for (ExecutorToken context : mIdleCallbackContextsToCall) {
    getReactApplicationContext().getJSModule(context, JSTimersExecution.class)
        .callIdleCallbacks(absoluteFrameStartTime);
  }

  mCurrentIdleCallbackRunnable = null;
}
 

import com.facebook.react.common.SystemClock; //导入依赖的package包/类
private void stepChoreographerFrame() {
  ChoreographerCompat.FrameCallback callback = mPostFrameCallbackHandler.getAndResetFrameCallback();
  ChoreographerCompat.FrameCallback idleCallback = mIdlePostFrameCallbackHandler.getAndResetFrameCallback();

  mCurrentTimeNs += FRAME_TIME_NS;
  when(SystemClock.uptimeMillis()).thenReturn(mCurrentTimeNs / 1000000);
  if (callback != null) {
    callback.doFrame(mCurrentTimeNs);
  }

  if (idleCallback != null) {
    idleCallback.doFrame(mCurrentTimeNs);
  }
}
 

import com.facebook.react.common.SystemClock; //导入依赖的package包/类
@Test
public void testIdleCallback() {
  mTiming.onHostResume();
  mTiming.setSendIdleEvents(mExecutorTokenMock, true);

  stepChoreographerFrame();
  verify(mJSTimersMock).callIdleCallbacks(SystemClock.currentTimeMillis());
}
 

import com.facebook.react.common.SystemClock; //导入依赖的package包/类
/**
 * Get the current position. This can return almost immediately if the location is cached or
 * request an update, which might take a while.
 *
 * @param options map containing optional arguments: timeout (millis), maximumAge (millis) and
 *        highAccuracy (boolean)
 */
@ReactMethod
public void getCurrentPosition(
    ReadableMap options,
    final Callback success,
    Callback error) {
  LocationOptions locationOptions = LocationOptions.fromReactMap(options);

  try {
    LocationManager locationManager =
        (LocationManager) getReactApplicationContext().getSystemService(Context.LOCATION_SERVICE);
    String provider = getValidProvider(locationManager, locationOptions.highAccuracy);
    if (provider == null) {
      emitError(PositionError.PERMISSION_DENIED, "No location provider available.");
      return;
    }
    Location location = locationManager.getLastKnownLocation(provider);
    if (location != null &&
        SystemClock.currentTimeMillis() - location.getTime() < locationOptions.maximumAge) {
      success.invoke(locationToMap(location));
      return;
    }
    new SingleUpdateRequest(locationManager, provider, locationOptions.timeout, success, error)
        .invoke();
  } catch (SecurityException e) {
    throwLocationPermissionMissing(e);
  }
}
 

import com.facebook.react.common.SystemClock; //导入依赖的package包/类
@Override
public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
  ReactContext reactContext = (ReactContext) buttonView.getContext();
  reactContext.getNativeModule(UIManagerModule.class).getEventDispatcher().dispatchEvent(
      new ReactSwitchEvent(
          buttonView.getId(),
          SystemClock.nanoTime(),
          isChecked));
}
 

import com.facebook.react.common.SystemClock; //导入依赖的package包/类
private void onTotalChildrenHeightChange(int newTotalChildrenHeight) {
  if (mSendContentSizeChangeEvents) {
    ((ReactContext) getContext()).getNativeModule(UIManagerModule.class).getEventDispatcher()
        .dispatchEvent(new ContentSizeChangeEvent(
                getId(),
                SystemClock.nanoTime(),
                getWidth(),
                newTotalChildrenHeight));
  }
}
 

import com.facebook.react.common.SystemClock; //导入依赖的package包/类
@Override
protected void addEventEmitters(
    final ThemedReactContext reactContext,
    final ReactSwipeRefreshLayout view) {
  view.setOnRefreshListener(
      new OnRefreshListener() {
        @Override
        public void onRefresh() {
          reactContext.getNativeModule(UIManagerModule.class).getEventDispatcher()
              .dispatchEvent(new RefreshEvent(view.getId(), SystemClock.nanoTime()));
        }
      });
}
 

import com.facebook.react.common.SystemClock; //导入依赖的package包/类
@Override
public void onPageStarted(WebView webView, String url, Bitmap favicon) {
  super.onPageStarted(webView, url, favicon);
  mLastLoadFailed = false;

  dispatchEvent(
      webView,
      new TopLoadingStartEvent(
          webView.getId(),
          SystemClock.nanoTime(),
          createWebViewEvent(webView, url)));
}