bevy/examples/ui/overflow.rs
ickshonpe 09df19bcad
Split UI Overflow by axis (#8095)
# Objective

Split the UI overflow enum so that overflow can be set for each axis
separately.

## Solution

Change `Overflow` from an enum to a struct with `x` and `y`
`OverflowAxis` fields, where `OverflowAxis` is an enum with `Clip` and
`Visible` variants. Modify `update_clipping` to calculate clipping for
each axis separately. If only one axis is clipped, the other axis is
given infinite bounds.

<img width="642" alt="overflow"
src="https://user-images.githubusercontent.com/27962798/227592983-568cf76f-7e40-48c4-a511-43c886f5e431.PNG">

---

## Changelog
* Split the UI overflow implementation so overflow can be set for each
axis separately.
* Added the enum `OverflowAxis` with `Clip` and `Visible` variants.
* Changed `Overflow` to a struct with `x` and `y` fields of type
`OverflowAxis`.
* `Overflow` has new methods `visible()` and `hidden()` that replace its
previous `Clip` and `Visible` variants.
* Added `Overflow` helper methods `clip_x()` and `clip_y()` that return
a new `Overflow` value with the given axis clipped.
* Modified `update_clipping` so it calculates clipping for each axis
separately. If a node is only clipped on a single axis, the other axis
is given `-f32::INFINITY` to `f32::INFINITY` clipping bounds.


## Migration Guide

The `Style` property `Overflow` is now a struct with `x` and `y` fields,
that allow for per-axis overflow control.

Use these helper functions to replace the variants of `Overflow`:
* Replace `Overflow::Visible` with  `Overflow::visible()`
* Replace `Overflow::Hidden` with `Overflow::clip()`
2023-04-17 22:23:52 +00:00

100 lines
4 KiB
Rust

//! Simple example demonstrating overflow behavior.
use bevy::{prelude::*, winit::WinitSettings};
fn main() {
App::new()
.add_plugins(DefaultPlugins)
// Only run the app when there is user input. This will significantly reduce CPU/GPU use.
.insert_resource(WinitSettings::desktop_app())
.add_systems(Startup, setup)
.run();
}
fn setup(mut commands: Commands, asset_server: Res<AssetServer>) {
commands.spawn(Camera2dBundle::default());
let text_style = TextStyle {
font: asset_server.load("fonts/FiraMono-Medium.ttf"),
font_size: 20.0,
color: Color::WHITE,
};
let image = asset_server.load("branding/icon.png");
commands
.spawn(NodeBundle {
style: Style {
align_items: AlignItems::Center,
justify_content: JustifyContent::Center,
size: Size::width(Val::Percent(100.)),
..Default::default()
},
background_color: Color::ANTIQUE_WHITE.into(),
..Default::default()
})
.with_children(|parent| {
for overflow in [
Overflow::visible(),
Overflow::clip_x(),
Overflow::clip_y(),
Overflow::clip(),
] {
parent
.spawn(NodeBundle {
style: Style {
flex_direction: FlexDirection::Column,
align_items: AlignItems::Center,
margin: UiRect::horizontal(Val::Px(25.)),
..Default::default()
},
..Default::default()
})
.with_children(|parent| {
let label = format!("{overflow:#?}");
parent
.spawn(NodeBundle {
style: Style {
padding: UiRect::all(Val::Px(10.)),
margin: UiRect::bottom(Val::Px(25.)),
..Default::default()
},
background_color: Color::DARK_GRAY.into(),
..Default::default()
})
.with_children(|parent| {
parent.spawn(TextBundle {
text: Text::from_section(label, text_style.clone()),
..Default::default()
});
});
parent
.spawn(NodeBundle {
style: Style {
size: Size::all(Val::Px(100.)),
padding: UiRect {
left: Val::Px(25.),
top: Val::Px(25.),
..Default::default()
},
overflow,
..Default::default()
},
background_color: Color::GRAY.into(),
..Default::default()
})
.with_children(|parent| {
parent.spawn(ImageBundle {
image: UiImage::new(image.clone()),
style: Style {
min_size: Size::all(Val::Px(100.)),
..Default::default()
},
background_color: Color::WHITE.into(),
..Default::default()
});
});
});
}
});
}