> For the complete documentation index, see [llms.txt](https://asrob-uc3m.gitbook.io/robotdevastation-developer-manual/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://asrob-uc3m.gitbook.io/robotdevastation-developer-manual/robotdevastation/managers/input-management/listening-to-events.md).

# Listening to Events

When a class needs to receive input events, such as keypresses, it must implement the `InputEventListener` interface. Once registered in the `InputManager`, it will receive input events each time the user generates them.

## InputEventListener

This interface has the following functions, that are called when the corresponding event is triggered in the `InputManager`:

* `onKeyDown()`: called when a key is pressed, the event passed stores the key that triggered the event.
* `onKeyUp()`: called when a key is released, the event passed stores the key that triggered the event.
* `onWindowEvent()`: called when a window event happens, the event passed stores the event type and information.

## MockInputEventListener

Implements the following functions to extract information about received input events:

* `getNumKeyDownPresses()`: returns the number of key down events received.
* `getNumKeyUpPresses()`: returns the number of key up events received.
* `getNumWindowEvents()`: returns the number of window events received.
* `clear()`: clears all events received.
* `getStoredKeyUpPresses()`: returns a vector of key down events received.
* `getStoredKeyDownPresses()`: returns a vector of key up events received.
* `getStoredWindowEvents()`: returns a vector of window events received.