# Objective
Because we want to be able to support more notification options in the
future (in addition to just using registered one-shot systems), the
`Option<SystemId>` notifications have been changed to a new enum,
`Callback`.
@alice-i-cecile
# Objective
When dragging the slider thumb the thumb is only highlighted while the
pointer is hovering the widget. If the pointer moves off the widget
during a drag the thumb reverts to its normal unhovered colour.
## Solution
Query for `CoreSliderDragState` in the slider update systems and set the
lighter color if the thumb is dragged or hovered.
Click to focus is now a global observer.
# Objective
Previously, the "click to focus" behavior was implemented in each
individual headless widget, producing redundant logic.
## Solution
The new scheme is to have a global observer which looks for pointer down
events and triggers an `AcquireFocus` event on the target. This event
bubbles until it finds an entity with `TabIndex`, and then focuses it.
## Testing
Tested the changes using the various examples that have focusable
widgets. (This will become easier to test when I add focus ring support
to the examples, but that's for another day. For now you just have to
know which keys to press.)
## Migration
This change is backwards-compatible. People who want the new behavior
will need to install the new plugin.
# Objective
This is part of the "core widgets" effort:
https://github.com/bevyengine/bevy/issues/19236.
## Solution
This adds the "core checkbox" widget type.
## Testing
Tested using examples core_widgets and core_widgets_observers.
Note to reviewers: I reorganized the code in the examples, so the diffs
are large because of code moves.
# Objective
This is part of the "core widgets" effort: #19236.
## Solution
This PR adds the "core slider" widget to the collection.
## Testing
Tested using examples `core_widgets` and `core_widgets_observers`.
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Co-authored-by: ickshonpe <david.curthoys@googlemail.com>
# Objective
#19366 implemented core button widgets, which included the `Depressed`
state component.
`Depressed` was chosen instead of `Pressed` to avoid conflict with the
`Pointer<Pressed>` event, but it is problematic and awkward in many
ways:
- Using the word "depressed" for such a high-traffic type is not great
due to the obvious connection to "depressed" as in depression.
- "Depressed" is not what I would search for if I was looking for a
component like this, and I'm not aware of any other engine or UI
framework using the term.
- `Depressed` is not a very natural pair to the `Pointer<Pressed>`
event.
- It might be because I'm not a native English speaker, but I have very
rarely heard someone say "a button is depressed". Seeing it, my mind
initially goes from "depression??" to "oh, de-pressed, meaning released"
and definitely not "is pressed", even though that *is* also a valid
meaning for it.
A related problem is that the current `Pointer<Pressed>` and
`Pointer<Released>` event names use a different verb tense than all of
our other observer events such as `Pointer<Click>` or
`Pointer<DragStart>`. By fixing this and renaming `Pressed` (and
`Released`), we can then use `Pressed` instead of `Depressed` for the
state component.
Additionally, the `IsHovered` and `IsDirectlyHovered` components added
in #19366 use an inconsistent naming; the other similar components don't
use an `Is` prefix. It also makes query filters like `Has<IsHovered>`
and `With<IsHovered>` a bit more awkward.
This is partially related to Cart's [picking concept
proposal](https://gist.github.com/cart/756e48a149db2838028be600defbd24a?permalink_comment_id=5598154).
## Solution
- Rename `Pointer<Pressed>` to `Pointer<Press>`
- Rename `Pointer<Released>` to `Pointer<Release>`
- Rename `Depressed` to `Pressed`
- Rename `IsHovered` to `Hovered`
- Rename `IsDirectlyHovered` to `DirectlyHovered`
# Objective
Part of #19236
## Solution
Adds a new `bevy_core_widgets` crate containing headless widget
implementations. This PR adds a single `CoreButton` widget, more widgets
to be added later once this is approved.
## Testing
There's an example, ui/core_widgets.
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Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
