# transformed method Null safety

- Matrix4? transform

Transforms the event from the global coordinate space into the coordinate space of an event receiver.

The coordinate space of the event receiver is described by `transform`

. A
null value for `transform`

is treated as the identity transformation.

The resulting event will store the base event as original, delegates
most properties to original, except for localPosition and localDelta,
which are calculated based on `transform`

on first use and cached.

The method may return the same object instance if for example the transformation has no effect on the event. Otherwise, the resulting event will be a subclass of, but not exactly, the original event class (e.g. PointerDownEvent.transformed may return a subclass of PointerDownEvent).

Transforms are not commutative, and are based on original events.
If this method is called on a transformed event, the provided `transform`

will override (instead of multiplied onto) the existing `transform`

and
used to calculate the new localPosition and localDelta.

## Implementation

```
@override
PointerPanZoomStartEvent transformed(Matrix4? transform) {
if (transform == null || transform == this.transform) {
return this;
}
return _TransformedPointerPanZoomStartEvent(original as PointerPanZoomStartEvent? ?? this, transform);
}
```