debugHandleEvent method

bool debugHandleEvent(
  1. PointerEvent event,
  2. HitTestEntry<HitTestTarget> entry
)
inherited

Implements the debugPaintPointersEnabled debugging feature.

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

class RenderFoo extends RenderBox {
  // ...

  @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;
}