# Objective
This PR continues the work of `bevy_input_focus` by adding a pluggable
tab navigation framework.
As part of this work, `FocusKeyboardEvent` now propagates to the window
after exhausting all ancestors.
## Testing
Unit tests and manual tests.
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Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
# Objective
I was curious to use the newly created `bevy_input_focus`, but I found
some issues with it
- It was only implementing traits for `World`.
- Lack of tests
- `is_focus_within` logic was incorrect.
## Solution
This PR includes some improvements to the `bevy_input_focus` crate:
- Add new `IsFocusedHelper` that doesn't require access to `&World`. It
implements `IsFocused`
- Remove `IsFocused` impl for `DeferredWorld`. Since it already
implements `Deref<Target=World>` it was just duplication of code.
- impl `SetInputFocus` for `Commands`. There was no way to use
`SetFocusCommand` directly. This allows it.
- The `is_focus_within` logic has been fixed to check descendants.
Previously it was checking if any of the ancestors had focus which is
not correct according to the documentation.
- Added a bunch of unit tests to verify the logic of the crate.
## Testing
- Did you test these changes? If so, how? Yes, running newly added unit
tests.
---
This adds a few minor items which were left out of the previous PR:
- Added synchronization from bevy_input_focus to bevy_a11y.
- Initialize InputFocusVisible resource.
- Make `input_focus` available from `bevy` module.
I've tested this using VoiceOver on Mac OS. It works, but it needs
considerable polish.
# 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
