> For the complete documentation index, see [llms.txt](https://nostramap-doc.fatos.biz/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://nostramap-doc.fatos.biz/fatos-api/map/map-control/on-off.md).
# On/Off
## on / off
Adds or removes a listener for a specific event on a given layer.
```
// Adds a listener
mapInstance.on(type, layerId, listener);
// Removes a listener
mapInstance.off(type, layerId, listener);
```
### Parameter
| Parameter | Description | Type |
| ------------------ | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | -------- |
| type | specifies which event to listen to. | String |
| *Supported types:* | "mouseup", "mousedown", "click", "dblclick", "mousemove", "mouseenter", "mouseleave, "mouseover", "mouseout", "contextmenu", "touchstart", touchend" or "touchcancel". "mouseenter" and "mouseover" events are triggered when the cursor enters a visible portion of the specified layer or map canvas from outside and vice versa for "mouseleave" and "mouseout". | |
| layerId (Optional) | ID of a style layer. Only layer that matches the given parameter will trigger the event listener. | String |
| listener | A callback function that detects the event and triggers further procedures. | Function |
#### Example(Javascript + HTML)
```javascript
Map Event
```
---
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