bevy/examples/ui/grid.rs
UkoeHB c2c19e5ae4
Text rework (#15591)
**Ready for review. Examples migration progress: 100%.**

# Objective

- Implement https://github.com/bevyengine/bevy/discussions/15014

## Solution

This implements [cart's
proposal](https://github.com/bevyengine/bevy/discussions/15014#discussioncomment-10574459)
faithfully except for one change. I separated `TextSpan` from
`TextSpan2d` because `TextSpan` needs to require the `GhostNode`
component, which is a `bevy_ui` component only usable by UI.

Extra changes:
- Added `EntityCommands::commands_mut` that returns a mutable reference.
This is a blocker for extension methods that return something other than
`self`. Note that `sickle_ui`'s `UiBuilder::commands` returns a mutable
reference for this reason.

## Testing

- [x] Text examples all work.

---

## Showcase

TODO: showcase-worthy

## Migration Guide

TODO: very breaking

### Accessing text spans by index

Text sections are now text sections on different entities in a
hierarchy, Use the new `TextReader` and `TextWriter` system parameters
to access spans by index.

Before:
```rust
fn refresh_text(mut query: Query<&mut Text, With<TimeText>>, time: Res<Time>) {
    let text = query.single_mut();
    text.sections[1].value = format_time(time.elapsed());
}
```

After:
```rust
fn refresh_text(
    query: Query<Entity, With<TimeText>>,
    mut writer: UiTextWriter,
    time: Res<Time>
) {
    let entity = query.single();
    *writer.text(entity, 1) = format_time(time.elapsed());
}
```

### Iterating text spans

Text spans are now entities in a hierarchy, so the new `UiTextReader`
and `UiTextWriter` system parameters provide ways to iterate that
hierarchy. The `UiTextReader::iter` method will give you a normal
iterator over spans, and `UiTextWriter::for_each` lets you visit each of
the spans.

---------

Co-authored-by: ickshonpe <david.curthoys@googlemail.com>
Co-authored-by: Carter Anderson <mcanders1@gmail.com>
2024-10-09 18:35:36 +00:00

219 lines
9.9 KiB
Rust

//! Demonstrates how CSS Grid layout can be used to lay items out in a 2D grid
use bevy::{color::palettes::css::*, prelude::*};
fn main() {
App::new()
.add_plugins(DefaultPlugins.set(WindowPlugin {
primary_window: Some(Window {
resolution: [800., 600.].into(),
title: "Bevy CSS Grid Layout Example".to_string(),
..default()
}),
..default()
}))
.add_systems(Startup, spawn_layout)
.run();
}
fn spawn_layout(mut commands: Commands, asset_server: Res<AssetServer>) {
let font = asset_server.load("fonts/FiraSans-Bold.ttf");
commands.spawn(Camera2d);
// Top-level grid (app frame)
commands
.spawn(NodeBundle {
style: Style {
// Use the CSS Grid algorithm for laying out this node
display: Display::Grid,
// Make node fill the entirety of its parent (in this case the window)
width: Val::Percent(100.0),
height: Val::Percent(100.0),
// Set the grid to have 2 columns with sizes [min-content, minmax(0, 1fr)]
// - The first column will size to the size of its contents
// - The second column will take up the remaining available space
grid_template_columns: vec![GridTrack::min_content(), GridTrack::flex(1.0)],
// Set the grid to have 3 rows with sizes [auto, minmax(0, 1fr), 20px]
// - The first row will size to the size of its contents
// - The second row take up remaining available space (after rows 1 and 3 have both been sized)
// - The third row will be exactly 20px high
grid_template_rows: vec![
GridTrack::auto(),
GridTrack::flex(1.0),
GridTrack::px(20.),
],
..default()
},
background_color: BackgroundColor(Color::WHITE),
..default()
})
.with_children(|builder| {
// Header
builder
.spawn(NodeBundle {
style: Style {
display: Display::Grid,
// Make this node span two grid columns so that it takes up the entire top tow
grid_column: GridPlacement::span(2),
padding: UiRect::all(Val::Px(6.0)),
..default()
},
..default()
})
.with_children(|builder| {
spawn_nested_text_bundle(builder, font.clone(), "Bevy CSS Grid Layout Example");
});
// Main content grid (auto placed in row 2, column 1)
builder
.spawn(NodeBundle {
style: Style {
// Make the height of the node fill its parent
height: Val::Percent(100.0),
// Make the grid have a 1:1 aspect ratio meaning it will scale as an exact square
// As the height is set explicitly, this means the width will adjust to match the height
aspect_ratio: Some(1.0),
// Use grid layout for this node
display: Display::Grid,
// Add 24px of padding around the grid
padding: UiRect::all(Val::Px(24.0)),
// Set the grid to have 4 columns all with sizes minmax(0, 1fr)
// This creates 4 exactly evenly sized columns
grid_template_columns: RepeatedGridTrack::flex(4, 1.0),
// Set the grid to have 4 rows all with sizes minmax(0, 1fr)
// This creates 4 exactly evenly sized rows
grid_template_rows: RepeatedGridTrack::flex(4, 1.0),
// Set a 12px gap/gutter between rows and columns
row_gap: Val::Px(12.0),
column_gap: Val::Px(12.0),
..default()
},
background_color: BackgroundColor(Color::srgb(0.25, 0.25, 0.25)),
..default()
})
.with_children(|builder| {
// Note there is no need to specify the position for each grid item. Grid items that are
// not given an explicit position will be automatically positioned into the next available
// grid cell. The order in which this is performed can be controlled using the grid_auto_flow
// style property.
item_rect(builder, ORANGE);
item_rect(builder, BISQUE);
item_rect(builder, BLUE);
item_rect(builder, CRIMSON);
item_rect(builder, AQUA);
item_rect(builder, ORANGE_RED);
item_rect(builder, DARK_GREEN);
item_rect(builder, FUCHSIA);
item_rect(builder, TEAL);
item_rect(builder, ALICE_BLUE);
item_rect(builder, CRIMSON);
item_rect(builder, ANTIQUE_WHITE);
item_rect(builder, YELLOW);
item_rect(builder, DEEP_PINK);
item_rect(builder, YELLOW_GREEN);
item_rect(builder, SALMON);
});
// Right side bar (auto placed in row 2, column 2)
builder
.spawn(NodeBundle {
style: Style {
display: Display::Grid,
// Align content towards the start (top) in the vertical axis
align_items: AlignItems::Start,
// Align content towards the center in the horizontal axis
justify_items: JustifyItems::Center,
// Add 10px padding
padding: UiRect::all(Val::Px(10.)),
// Add an fr track to take up all the available space at the bottom of the column so that the text nodes
// can be top-aligned. Normally you'd use flexbox for this, but this is the CSS Grid example so we're using grid.
grid_template_rows: vec![GridTrack::auto(), GridTrack::auto(), GridTrack::fr(1.0)],
// Add a 10px gap between rows
row_gap: Val::Px(10.),
..default()
},
background_color: BackgroundColor(BLACK.into()),
..default()
})
.with_children(|builder| {
builder.spawn((Text::new("Sidebar"),
TextStyle {
font: font.clone(),
..default()
},
));
builder.spawn((Text::new("A paragraph of text which ought to wrap nicely. A paragraph of text which ought to wrap nicely. A paragraph of text which ought to wrap nicely. A paragraph of text which ought to wrap nicely. A paragraph of text which ought to wrap nicely. A paragraph of text which ought to wrap nicely. A paragraph of text which ought to wrap nicely."),
TextStyle {
font: font.clone(),
font_size: 13.0,
..default()
},
));
builder.spawn(NodeBundle::default());
});
// Footer / status bar
builder.spawn(NodeBundle {
style: Style {
// Make this node span two grid column so that it takes up the entire bottom row
grid_column: GridPlacement::span(2),
..default()
},
background_color: BackgroundColor(WHITE.into()),
..default()
});
// Modal (absolutely positioned on top of content - currently hidden: to view it, change its visibility)
builder.spawn(NodeBundle {
visibility: Visibility::Hidden,
style: Style {
position_type: PositionType::Absolute,
margin: UiRect {
top: Val::Px(100.),
bottom: Val::Auto,
left: Val::Auto,
right: Val::Auto,
},
width: Val::Percent(60.),
height: Val::Px(300.),
max_width: Val::Px(600.),
..default()
},
background_color: BackgroundColor(Color::WHITE.with_alpha(0.8)),
..default()
});
});
}
/// Create a coloured rectangle node. The node has size as it is assumed that it will be
/// spawned as a child of a Grid container with `AlignItems::Stretch` and `JustifyItems::Stretch`
/// which will allow it to take its size from the size of the grid area it occupies.
fn item_rect(builder: &mut ChildBuilder, color: Srgba) {
builder
.spawn(NodeBundle {
style: Style {
display: Display::Grid,
padding: UiRect::all(Val::Px(3.0)),
..default()
},
background_color: BackgroundColor(BLACK.into()),
..default()
})
.with_children(|builder| {
builder.spawn(NodeBundle {
background_color: BackgroundColor(color.into()),
..default()
});
});
}
fn spawn_nested_text_bundle(builder: &mut ChildBuilder, font: Handle<Font>, text: &str) {
builder.spawn((
Text::new(text),
TextStyle {
font,
color: Color::BLACK,
..default()
},
));
}