C++ Touch::Identifier方法代码示例

Touch*
nsDOMTouchList::IdentifiedTouch(int32_t aIdentifier) const
{
    for (uint32_t i = 0; i < mPoints.Length(); ++i) {
        Touch* point = mPoints[i];
        if (point && point->Identifier() == aIdentifier) {
            return point;
        }
    }
    return nullptr;
}

/* static */
void PointerEventHandler::ProcessPointerCaptureForTouch(
    WidgetTouchEvent* aEvent) {
  if (!ShouldGeneratePointerEventFromTouch(aEvent)) {
    return;
  }

  for (uint32_t i = 0; i < aEvent->mTouches.Length(); ++i) {
    Touch* touch = aEvent->mTouches[i];
    if (!TouchManager::ShouldConvertTouchToPointer(touch, aEvent)) {
      continue;
    }
    PointerCaptureInfo* info = GetPointerCaptureInfo(touch->Identifier());
    if (!info || info->mPendingContent == info->mOverrideContent) {
      continue;
    }
    WidgetPointerEvent event(aEvent->IsTrusted(), eVoidEvent, aEvent->mWidget);
    InitPointerEventFromTouch(&event, aEvent, touch, i == 0);
    CheckPointerCaptureState(&event);
  }
}

bool
TouchManager::PreHandleEvent(WidgetEvent* aEvent,
                             nsEventStatus* aStatus,
                             bool& aTouchIsNew,
                             bool& aIsHandlingUserInput,
                             nsCOMPtr<nsIContent>& aCurrentEventContent)
{
  switch (aEvent->mMessage) {
    case eTouchStart: {
      aIsHandlingUserInput = true;
      WidgetTouchEvent* touchEvent = aEvent->AsTouchEvent();
      // if there is only one touch in this touchstart event, assume that it is
      // the start of a new touch session and evict any old touches in the
      // queue
      if (touchEvent->mTouches.Length() == 1) {
        WidgetTouchEvent::AutoTouchArray touches;
        AppendToTouchList(&touches);
        for (uint32_t i = 0; i < touches.Length(); ++i) {
          EvictTouchPoint(touches[i]);
        }
      }
      // Add any new touches to the queue
      for (uint32_t i = 0; i < touchEvent->mTouches.Length(); ++i) {
        Touch* touch = touchEvent->mTouches[i];
        int32_t id = touch->Identifier();
        if (!sCaptureTouchList->Get(id, nullptr)) {
          // If it is not already in the queue, it is a new touch
          touch->mChanged = true;
        }
        touch->mMessage = aEvent->mMessage;
        TouchInfo info = { touch, GetNonAnonymousAncestor(touch->mTarget) };
        sCaptureTouchList->Put(id, info);
      }
      break;
    }
    case eTouchMove: {
      // Check for touches that changed. Mark them add to queue
      WidgetTouchEvent* touchEvent = aEvent->AsTouchEvent();
      WidgetTouchEvent::TouchArray& touches = touchEvent->mTouches;
      bool haveChanged = false;
      for (int32_t i = touches.Length(); i; ) {
        --i;
        Touch* touch = touches[i];
        if (!touch) {
          continue;
        }
        int32_t id = touch->Identifier();
        touch->mMessage = aEvent->mMessage;

        TouchInfo info;
        if (!sCaptureTouchList->Get(id, &info)) {
          touches.RemoveElementAt(i);
          continue;
        }
        RefPtr<Touch> oldTouch = info.mTouch;
        if (!touch->Equals(oldTouch)) {
          touch->mChanged = true;
          haveChanged = true;
        }

        nsCOMPtr<EventTarget> targetPtr = oldTouch->mTarget;
        if (!targetPtr) {
          touches.RemoveElementAt(i);
          continue;
        }
        nsCOMPtr<nsINode> targetNode(do_QueryInterface(targetPtr));
        if (!targetNode->IsInComposedDoc()) {
          targetPtr = do_QueryInterface(info.mNonAnonymousTarget);
        }
        touch->SetTarget(targetPtr);

        info.mTouch = touch;
        // info.mNonAnonymousTarget is still valid from above
        sCaptureTouchList->Put(id, info);
        // if we're moving from touchstart to touchmove for this touch
        // we allow preventDefault to prevent mouse events
        if (oldTouch->mMessage != touch->mMessage) {
          aTouchIsNew = true;
        }
      }
      // is nothing has changed, we should just return
      if (!haveChanged) {
        if (aTouchIsNew) {
          // however, if this is the first touchmove after a touchstart,
          // it is special in that preventDefault is allowed on it, so
          // we must dispatch it to content even if nothing changed. we
          // arbitrarily pick the first touch point to be the "changed"
          // touch because firing an event with no changed events doesn't
          // work.
          for (uint32_t i = 0; i < touchEvent->mTouches.Length(); ++i) {
            if (touchEvent->mTouches[i]) {
              touchEvent->mTouches[i]->mChanged = true;
              break;
            }
          }
        } else {
          return false;
        }
      }
      break;
//.........这里部分代码省略.........