bevy/examples/ui/borders.rs
Carter Anderson 015f2c69ca
Merge Style properties into Node. Use ComputedNode for computed properties. (#15975)
# 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();
    }
}
```
2024-10-18 22:25:33 +00:00

304 lines
9.1 KiB
Rust

//! Example demonstrating bordered UI nodes
use bevy::{color::palettes::css::*, prelude::*};
fn main() {
App::new()
.add_plugins(DefaultPlugins)
.add_systems(Startup, setup)
.run();
}
fn setup(mut commands: Commands) {
commands.spawn(Camera2d);
let root = commands
.spawn((
Node {
margin: UiRect::all(Val::Px(25.0)),
align_self: AlignSelf::Stretch,
justify_self: JustifySelf::Stretch,
flex_wrap: FlexWrap::Wrap,
justify_content: JustifyContent::FlexStart,
align_items: AlignItems::FlexStart,
align_content: AlignContent::FlexStart,
..default()
},
BackgroundColor(Color::srgb(0.25, 0.25, 0.25)),
))
.id();
let root_rounded = commands
.spawn((
Node {
margin: UiRect::all(Val::Px(25.0)),
align_self: AlignSelf::Stretch,
justify_self: JustifySelf::Stretch,
flex_wrap: FlexWrap::Wrap,
justify_content: JustifyContent::FlexStart,
align_items: AlignItems::FlexStart,
align_content: AlignContent::FlexStart,
..default()
},
BackgroundColor(Color::srgb(0.25, 0.25, 0.25)),
))
.id();
// labels for the different border edges
let border_labels = [
"None",
"All",
"Left",
"Right",
"Top",
"Bottom",
"Horizontal",
"Vertical",
"Top Left",
"Bottom Left",
"Top Right",
"Bottom Right",
"Top Bottom Right",
"Top Bottom Left",
"Top Left Right",
"Bottom Left Right",
];
// all the different combinations of border edges
// these correspond to the labels above
let borders = [
UiRect::default(),
UiRect::all(Val::Px(10.)),
UiRect::left(Val::Px(10.)),
UiRect::right(Val::Px(10.)),
UiRect::top(Val::Px(10.)),
UiRect::bottom(Val::Px(10.)),
UiRect::horizontal(Val::Px(10.)),
UiRect::vertical(Val::Px(10.)),
UiRect {
left: Val::Px(20.),
top: Val::Px(10.),
..Default::default()
},
UiRect {
left: Val::Px(10.),
bottom: Val::Px(20.),
..Default::default()
},
UiRect {
right: Val::Px(20.),
top: Val::Px(10.),
..Default::default()
},
UiRect {
right: Val::Px(10.),
bottom: Val::Px(10.),
..Default::default()
},
UiRect {
right: Val::Px(10.),
top: Val::Px(20.),
bottom: Val::Px(10.),
..Default::default()
},
UiRect {
left: Val::Px(10.),
top: Val::Px(10.),
bottom: Val::Px(10.),
..Default::default()
},
UiRect {
left: Val::Px(20.),
right: Val::Px(10.),
top: Val::Px(10.),
..Default::default()
},
UiRect {
left: Val::Px(10.),
right: Val::Px(10.),
bottom: Val::Px(20.),
..Default::default()
},
];
for (label, border) in border_labels.into_iter().zip(borders) {
let inner_spot = commands
.spawn((
Node {
width: Val::Px(10.),
height: Val::Px(10.),
..default()
},
BackgroundColor(YELLOW.into()),
))
.id();
let border_node = commands
.spawn((
Node {
width: Val::Px(50.),
height: Val::Px(50.),
border,
margin: UiRect::all(Val::Px(20.)),
align_items: AlignItems::Center,
justify_content: JustifyContent::Center,
..default()
},
BackgroundColor(MAROON.into()),
BorderColor(RED.into()),
Outline {
width: Val::Px(6.),
offset: Val::Px(6.),
color: Color::WHITE,
},
))
.add_child(inner_spot)
.id();
let label_node = commands
.spawn((
Text::new(label),
TextFont {
font_size: 9.0,
..Default::default()
},
))
.id();
let container = commands
.spawn(Node {
flex_direction: FlexDirection::Column,
align_items: AlignItems::Center,
..default()
})
.add_children(&[border_node, label_node])
.id();
commands.entity(root).add_child(container);
}
for (label, border) in border_labels.into_iter().zip(borders) {
let inner_spot = commands
.spawn((
Node {
width: Val::Px(10.),
height: Val::Px(10.),
..default()
},
BorderRadius::MAX,
BackgroundColor(YELLOW.into()),
))
.id();
let non_zero = |x, y| x != Val::Px(0.) && y != Val::Px(0.);
let border_size = |x, y| if non_zero(x, y) { f32::MAX } else { 0. };
let border_radius = BorderRadius::px(
border_size(border.left, border.top),
border_size(border.right, border.top),
border_size(border.right, border.bottom),
border_size(border.left, border.bottom),
);
let border_node = commands
.spawn((
Node {
width: Val::Px(50.),
height: Val::Px(50.),
border,
margin: UiRect::all(Val::Px(20.)),
align_items: AlignItems::Center,
justify_content: JustifyContent::Center,
..default()
},
BackgroundColor(MAROON.into()),
BorderColor(RED.into()),
border_radius,
Outline {
width: Val::Px(6.),
offset: Val::Px(6.),
color: Color::WHITE,
},
))
.add_child(inner_spot)
.id();
let label_node = commands
.spawn((
Text::new(label),
TextFont {
font_size: 9.0,
..Default::default()
},
))
.id();
let container = commands
.spawn(Node {
flex_direction: FlexDirection::Column,
align_items: AlignItems::Center,
..default()
})
.add_children(&[border_node, label_node])
.id();
commands.entity(root_rounded).add_child(container);
}
let border_label = commands
.spawn((
Node {
margin: UiRect {
left: Val::Px(25.0),
right: Val::Px(25.0),
top: Val::Px(25.0),
bottom: Val::Px(0.0),
},
..default()
},
BackgroundColor(Color::srgb(0.25, 0.25, 0.25)),
))
.with_children(|builder| {
builder.spawn((
Text::new("Borders"),
TextFont {
font_size: 20.0,
..Default::default()
},
));
})
.id();
let border_rounded_label = commands
.spawn((
Node {
margin: UiRect {
left: Val::Px(25.0),
right: Val::Px(25.0),
top: Val::Px(25.0),
bottom: Val::Px(0.0),
},
..default()
},
BackgroundColor(Color::srgb(0.25, 0.25, 0.25)),
))
.with_children(|builder| {
builder.spawn((
Text::new("Borders Rounded"),
TextFont {
font_size: 20.0,
..Default::default()
},
));
})
.id();
commands
.spawn((
Node {
margin: UiRect::all(Val::Px(25.0)),
flex_direction: FlexDirection::Column,
align_self: AlignSelf::Stretch,
justify_self: JustifySelf::Stretch,
flex_wrap: FlexWrap::Wrap,
justify_content: JustifyContent::FlexStart,
align_items: AlignItems::FlexStart,
align_content: AlignContent::FlexStart,
..default()
},
BackgroundColor(Color::srgb(0.25, 0.25, 0.25)),
))
.add_child(border_label)
.add_child(root)
.add_child(border_rounded_label)
.add_child(root_rounded);
}