import com.facebook.react.uimanager.events.TouchEventType; //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,
      TouchEventType.CANCEL,
      androidEvent,
      mGestureStartTime,
      mTargetCoordinates[0],
      mTargetCoordinates[1],
      mTouchEventCoalescingKeyHelper));
}
 

import com.facebook.react.uimanager.events.TouchEventType; //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.uimanager.events.TouchEventType; //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,
      TouchEventType.CANCEL,
      androidEvent,
      mTargetCoordinates[0],
      mTargetCoordinates[1],
      mTouchEventCoalescingKeyHelper));
}
 

import com.facebook.react.uimanager.events.TouchEventType; //导入依赖的package包/类
private void dispatchCancelEvent(MotionEvent androidEvent) {
  // 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;
  }

  EventDispatcher eventDispatcher = mReactInstanceManager.getCurrentReactContext()
      .getNativeModule(UIManagerModule.class)
      .getEventDispatcher();

  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.uimanager.events.TouchEventType; //导入依赖的package包/类
private void dispatch(MotionEvent ev, TouchEventType type) {
    ev.offsetLocation(getAbsoluteLeft(this), getAbsoluteTop(this));
    mEventDispatcher.dispatchEvent(
        TouchEvent.obtain(
            mTargetTag,
            type,
            ev,
            mGestureStartTime,
            ev.getX(),
            ev.getY(),
            mTouchEventCoalescingKeyHelper));
}
 

import com.facebook.react.uimanager.events.TouchEventType; //导入依赖的package包/类
private void handleTouchEvent(MotionEvent ev) {
    int action = ev.getAction() & MotionEvent.ACTION_MASK;
    if (action == MotionEvent.ACTION_DOWN) {
        mGestureStartTime = ev.getEventTime();
        dispatch(ev, TouchEventType.START);
    } else if (mTargetTag == -1) {
        // All the subsequent action types are expected to be called after ACTION_DOWN thus target
        // is supposed to be set for them.
        Log.e(
            "error",
            "Unexpected state: received touch event but didn't get starting ACTION_DOWN for this " +
                "gesture before");
    } else if (action == MotionEvent.ACTION_UP) {
        // End of the gesture. We reset target tag to -1 and expect no further event associated with
        // this gesture.
        dispatch(ev, TouchEventType.END);
        mTargetTag = -1;
        mGestureStartTime = TouchEvent.UNSET;
    } else if (action == MotionEvent.ACTION_MOVE) {
        // Update pointer position for current gesture
        dispatch(ev, TouchEventType.MOVE);
    } else if (action == MotionEvent.ACTION_POINTER_DOWN) {
        // New pointer goes down, this can only happen after ACTION_DOWN is sent for the first pointer
        dispatch(ev, TouchEventType.START);
    } else if (action == MotionEvent.ACTION_POINTER_UP) {
        // Exactly onw of the pointers goes up
        dispatch(ev, TouchEventType.END);
    } else if (action == MotionEvent.ACTION_CANCEL) {
        dispatchCancelEvent(ev);
        mTargetTag = -1;
        mGestureStartTime = TouchEvent.UNSET;
    } else {
        Log.w(
            "IGNORE",
            "Warning : touch event was ignored. Action=" + action + " Target=" + mTargetTag);
    }
}
 

import com.facebook.react.uimanager.events.TouchEventType; //导入依赖的package包/类
private void dispatchCancelEvent(MotionEvent ev) {
    // 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) {
        Log.w(
            "error",
            "Can't cancel already finished gesture. Is a child View trying to start a gesture from " +
                "an UP/CANCEL event?");
        return;
    }

    dispatch(ev, TouchEventType.CANCEL);
}
 

import com.facebook.react.uimanager.events.TouchEventType; //导入依赖的package包/类
static Map getBubblingEventTypeConstants() {
  return MapBuilder.builder()
      .put(
          "topChange",
          MapBuilder.of(
              "phasedRegistrationNames",
              MapBuilder.of("bubbled", "onChange", "captured", "onChangeCapture")))
      .put(
          "topSelect",
          MapBuilder.of(
              "phasedRegistrationNames",
              MapBuilder.of("bubbled", "onSelect", "captured", "onSelectCapture")))
      .put(
          TouchEventType.START.getJSEventName(),
          MapBuilder.of(
              "phasedRegistrationNames",
              MapBuilder.of(
                  "bubbled",
                  "onTouchStart",
                  "captured",
                  "onTouchStartCapture")))
      .put(
          TouchEventType.MOVE.getJSEventName(),
          MapBuilder.of(
              "phasedRegistrationNames",
              MapBuilder.of(
                  "bubbled",
                  "onTouchMove",
                  "captured",
                  "onTouchMoveCapture")))
      .put(
          TouchEventType.END.getJSEventName(),
          MapBuilder.of(
              "phasedRegistrationNames",
              MapBuilder.of(
                  "bubbled",
                  "onTouchEnd",
                  "captured",
                  "onTouchEndCapture")))
      .build();
}