# d3fc-pointer

Very simple component which emits an event to indicate the current mouse or touch position over a selection. Useful for implementing uni-directional data flow in a visualisation and not a lot else.

[Main D3FC package](https://github.com/d3fc/d3fc)

## Installing

```bash
npm install @d3fc/d3fc-pointer
```

## API Reference

<a name="pointer" href="#pointer">#</a> fc.**pointer**()

Constructs a new pointer component instance.

<a name="pointer_on" href="#pointer_on">#</a> *pointer*.**on**(*typenames*[, *callback*])

This component dispatches `point` events. The sole argument to the event handler is an array. If the mouse or touch interaction is over the selection then the array will contain a single object representing the co-ordinate (e.g. `{ x: 10, y: 10 }`). If the mouse or touch interaction is not over the selection then the array will be empty.

See [d3-dispatch's `on`](https://github.com/d3/d3-dispatch#dispatch_on) for a full description.