debugHandleEvent method

bool debugHandleEvent (PointerEvent event, HitTestEntry entry)

Implements the debugPaintPointersEnabled debugging feature.

RenderBox subclasses that implement handleEvent should call debugHandleEvent from their handleEvent method, as follows:

@override
void handleEvent(PointerEvent event, HitTestEntry entry) {
  assert(debugHandleEvent(event, entry));
  // ... handle the event ...
}

If you call this for a PointerDownEvent, make sure you also call it for the corresponding PointerUpEvent or PointerCancelEvent.

Implementation 

bool debugHandleEvent(PointerEvent event, HitTestEntry entry) {
  assert(() {
    if (debugPaintPointersEnabled) {
      if (event is PointerDownEvent) {
        _debugActivePointers += 1;
      } else if (event is PointerUpEvent || event is PointerCancelEvent) {
        _debugActivePointers -= 1;
      }
      markNeedsPaint();
    }
    return true;
  }());
  return true;
}