# Objective
Fix https://github.com/bevyengine/bevy/issues/19617
# Solution
Add newlines before all impl blocks.
I suspect that at least some of these will be objectionable! If there's
a desired Bevy style for this then I'll update the PR. If not then we
can just close it - it's the work of a single find and replace.
# Objective
Minimal effort to address feedback here:
https://github.com/bevyengine/bevy/pull/19345#discussion_r2107844018
more thoroughly.
## Solution
- Remove hardcoded label string comparisons and make more use of the new
enum added during review
- Resist temptation to let this snowball this into a huge refactor
- Maybe come back later for a few other small improvements
## Testing
`cargo run --example box_shadow`
# Objective
- Addresses the previous example's lack of visual appeal and clarity. It
was missing labels for clear distinction of the shadow settings used on
each of the shapes. The suggestion in the linked issue was to either
just visually update and add labels or to collapse example to a single
node with adjustable settings.
- Fixes#19240
## Solution
- Replace the previous static example with a single, central node with
adjustable settings as per issue suggestion.
- Implement button-based setting adjustments. Unfortunately slider
widgets don't seem available yet and I didn't want to further bloat the
example.
- Improve overall aesthetics of the example -- although color pallette
could still be improved. flat gray tones are probably not the best
choice as a contrast to the shadow, but the white border does help in
that aspect.
- Dynamically recolor shadows for visual clarity when increasing shadow
count.
- Add Adjustable Settings:
- Shape selection
- Shadow X/Y offset, blur, spread, and count
- Add Reset button to restore default settings
The disadvantage of this solution is that the old example code would
have probably been easier to digest as the new example is quite bloated
in comparison. Alternatively I could also just implement labels and fix
aesthetics of the old example without adding functionality for
adjustable settings, _but_ I personally feel like interactive examples
are more engaging to users.
## Testing
- Did you test these changes? If so, how? `cargo run --example
box_shadow` and functionality of all features of the example.
- Are there any parts that need more testing? Not that I am aware of.
- How can other people (reviewers) test your changes? Is there anything
specific they need to know? Not really, it should be pretty
straightforward just running the new example and testing the feats.
---
## Showcase


---------
Co-authored-by: ickshonpe <david.curthoys@googlemail.com>
# Objective
allow specifying the left/top/right/bottom border colors separately for
ui elements
fixes#14773
## Solution
- change `BorderColor` to
```rs
pub struct BorderColor {
pub left: Color,
pub top: Color,
pub right: Color,
pub bottom: Color,
}
```
- generate one ui node per distinct border color, set flags for the
active borders
- render only the active borders
i chose to do this rather than adding multiple colors to the
ExtractedUiNode in order to minimize the impact for the common case
where all border colors are the same.
## Testing
modified the `borders` example to use separate colors:

the behaviour is a bit weird but it mirrors html/css border behaviour.
---
## Migration:
To keep the existing behaviour, just change `BorderColor(color)` into
`BorderColor::all(color)`.
---------
Co-authored-by: ickshonpe <david.curthoys@googlemail.com>
# Objective
The `UiBoxShadowSamples` resource should be renamed to
`BoxShadowSamples` so it matches the `BoxShadow` component.
## Migration Guide
`UiBoxShadowSamples` has been renamed to `BoxShadowSamples`
# Objective
Add support for multiple box shadows on a single `Node`.
## Solution
* Rename `BoxShadow` to `ShadowStyle` and remove its `Component` derive.
* Create a new `BoxShadow` component that newtypes a `Vec<ShadowStyle>`.
* Add a `new` constructor method to `BoxShadow` for single shadows.
* Change `extract_shadows` to iterate through a list of shadows per
node.
Render order is determined implicitly from the order of the shadows
stored in the `BoxShadow` component, back-to-front.
Might be more efficient to use a `SmallVec<[ShadowStyle; 1]>` for the
list of shadows but not sure if the extra friction is worth it.
## Testing
Added a node with four differently coloured shadows to the `box_shadow`
example.
---
## Showcase
```
cargo run --example box_shadow
```
<img width="460" alt="four-shadow"
src="https://github.com/user-attachments/assets/2f728c47-33b4-42e1-96ba-28a774b94b24">
## Migration Guide
Bevy UI now supports multiple shadows per node. A new struct
`ShadowStyle` is used to set the style for each shadow. And the
`BoxShadow` component is changed to a tuple struct wrapping a vector
containing a list of `ShadowStyle`s. To spawn a node with a single
shadow you can use the `new` constructor function:
```rust
commands.spawn((
Node::default(),
BoxShadow::new(
Color::BLACK.with_alpha(0.8),
Val::Percent(offset.x),
Val::Percent(offset.y),
Val::Percent(spread),
Val::Px(blur),
)
));
```
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
# Objective
Continue improving the user experience of our UI Node API in the
direction specified by [Bevy's Next Generation Scene / UI
System](https://github.com/bevyengine/bevy/discussions/14437)
## Solution
As specified in the document above, merge `Style` fields into `Node`,
and move "computed Node fields" into `ComputedNode` (I chose this name
over something like `ComputedNodeLayout` because it currently contains
more than just layout info. If we want to break this up / rename these
concepts, lets do that in a separate PR). `Style` has been removed.
This accomplishes a number of goals:
## Ergonomics wins
Specifying both `Node` and `Style` is now no longer required for
non-default styles
Before:
```rust
commands.spawn((
Node::default(),
Style {
width: Val::Px(100.),
..default()
},
));
```
After:
```rust
commands.spawn(Node {
width: Val::Px(100.),
..default()
});
```
## Conceptual clarity
`Style` was never a comprehensive "style sheet". It only defined "core"
style properties that all `Nodes` shared. Any "styled property" that
couldn't fit that mold had to be in a separate component. A "real" style
system would style properties _across_ components (`Node`, `Button`,
etc). We have plans to build a true style system (see the doc linked
above).
By moving the `Style` fields to `Node`, we fully embrace `Node` as the
driving concept and remove the "style system" confusion.
## Next Steps
* Consider identifying and splitting out "style properties that aren't
core to Node". This should not happen for Bevy 0.15.
---
## Migration Guide
Move any fields set on `Style` into `Node` and replace all `Style`
component usage with `Node`.
Before:
```rust
commands.spawn((
Node::default(),
Style {
width: Val::Px(100.),
..default()
},
));
```
After:
```rust
commands.spawn(Node {
width: Val::Px(100.),
..default()
});
```
For any usage of the "computed node properties" that used to live on
`Node`, use `ComputedNode` instead:
Before:
```rust
fn system(nodes: Query<&Node>) {
for node in &nodes {
let computed_size = node.size();
}
}
```
After:
```rust
fn system(computed_nodes: Query<&ComputedNode>) {
for computed_node in &computed_nodes {
let computed_size = computed_node.size();
}
}
```
# Objective
UI box shadow support
Adds a new component `BoxShadow`:
```rust
pub struct BoxShadow {
/// The shadow's color
pub color: Color,
/// Horizontal offset
pub x_offset: Val,
/// Vertical offset
pub y_offset: Val,
/// Horizontal difference in size from the occluding uninode
pub spread_radius: Val,
/// Blurriness of the shadow
pub blur_radius: Val,
}
```
To use `BoxShadow`, add the component to any Bevy UI node and a shadow
will be drawn beneath that node.
Also adds a resource `BoxShadowSamples` that can be used to adjust the
shadow quality.
#### Notes
* I'm not super happy with the field names. Maybe we need a `struct Size
{ width: Val, height: Val }` type or something.
* The shader isn't very optimised but I don't see that it's too
important for now as the number of shadows being rendered is not going
to be massive most of the time. I think it's more important to get the
API and geometry correct with this PR.
* I didn't implement an inset property, it's not essential and can
easily be added in a follow up.
* Shadows are only rendered for uinodes, not for images or text.
* Batching isn't supported, it would need out-of-the-scope-of-this-pr
changes to the way the UI handles z-ordering for it to be effective.
# Showcase
```cargo run --example box_shadow -- --samples 4```
<img width="391" alt="br" src="https://github.com/user-attachments/assets/4e8add96-dc93-46e0-9e35-d995eb0943ad">
```cargo run --example box_shadow -- --samples 10```
<img width="391" alt="s10"
src="https://github.com/user-attachments/assets/ecb384c9-4012-4cd6-9dea-5180904bf28e">