# Objective
Define a framework for handling keyboard focus and bubbled keyboard
events, as discussed in #15374.
## Solution
Introduces a new crate, `bevy_input_focus`. This crate provides:
* A resource for tracking which entity has keyboard focus.
* Methods for getting and setting keyboard focus.
* Event definitions for triggering bubble-able keyboard input events to
the focused entity.
* A system for dispatching keyboard input events to the focused entity.
This crate does *not* provide any integration with UI widgets, or
provide functions for
tab navigation or gamepad-based focus navigation, as those are typically
application-specific.
## Testing
Most of the code has been copied from a different project, one that has
been well tested. However, most of what's in this module consists of
type definitions, with relatively small amounts of executable code. That
being said, I expect that there will be substantial bikeshedding on the
design, and I would prefer to hold off writing tests until after things
have settled.
I think that an example would be appropriate, however I'm waiting on a
few other pending changes to Bevy before doing so. In particular, I can
see a simple example with four buttons, with focus navigation between
them, and which can be triggered by the keyboard.
@alice-i-cecile
ea33fc04ab