bevy/examples/testbed/ui.rs
ickshonpe 1a18c9f87b
UI Debug Overlay show_hidden and show_clipped options (#17097)
# Objective

The UI debug overlay draws an outline for every UI node even if it is
invisible or clipped.
Disable debug outlines for hidden and clipped nodes by default and add
options to renable them if needed.

## Solution

* Add `show_hidden` and `show_clipped` fields to `UiDebugOptions`:
```rust
    /// Show outlines for non-visible UI nodes
    pub show_hidden: bool,
    /// Show outlines for clipped sections of UI nodes
    pub show_clipped: bool,
```

* Only extract debug outlines for hidden and clipped UI nodes if the
respective field in `UiDebugOptions` is set to `true`.

## Testing

Also added some extra features to the `testbed_ui` example that
demonstrate the new options:

cargo run --example testbed_ui --features "bevy_ui_debug"

<img width="641" alt="show-hidden-and-clipped"
src="https://github.com/user-attachments/assets/16a68600-170c-469e-a3c7-f7dae411dc40"
/>
2025-01-02 18:43:14 +00:00

437 lines
19 KiB
Rust

//! This example illustrates the various features of Bevy UI.
use std::f32::consts::PI;
use accesskit::{Node as Accessible, Role};
use bevy::{
a11y::AccessibilityNode,
color::palettes::{basic::LIME, css::DARK_GRAY},
input::mouse::{MouseScrollUnit, MouseWheel},
picking::hover::HoverMap,
prelude::*,
ui::widget::NodeImageMode,
};
fn main() {
let mut app = App::new();
app.add_plugins(DefaultPlugins)
.add_systems(Startup, setup)
.add_systems(Update, update_scroll_position);
#[cfg(feature = "bevy_ui_debug")]
app.add_systems(Update, toggle_debug_overlay);
app.run();
}
fn setup(mut commands: Commands, asset_server: Res<AssetServer>) {
// Camera
commands.spawn((Camera2d, IsDefaultUiCamera, BoxShadowSamples(6)));
// root node
commands
.spawn(Node {
width: Val::Percent(100.0),
height: Val::Percent(100.0),
justify_content: JustifyContent::SpaceBetween,
..default()
})
.insert(PickingBehavior::IGNORE)
.with_children(|parent| {
// left vertical fill (border)
parent
.spawn((
Node {
width: Val::Px(200.),
border: UiRect::all(Val::Px(2.)),
..default()
},
BackgroundColor(Color::srgb(0.65, 0.65, 0.65)),
))
.with_children(|parent| {
// left vertical fill (content)
parent
.spawn((
Node {
width: Val::Percent(100.),
flex_direction: FlexDirection::Column,
padding: UiRect::all(Val::Px(5.)),
row_gap: Val::Px(5.),
..default()
},
BackgroundColor(Color::srgb(0.15, 0.15, 0.15)),
Visibility::Visible,
))
.with_children(|parent| {
// text
parent.spawn((
Text::new("Text Example"),
TextFont {
font: asset_server.load("fonts/FiraSans-Bold.ttf"),
font_size: 25.0,
..default()
},
// Because this is a distinct label widget and
// not button/list item text, this is necessary
// for accessibility to treat the text accordingly.
Label,
));
#[cfg(feature = "bevy_ui_debug")]
{
// Debug overlay text
parent.spawn((
Text::new("Press Space to toggle debug outlines."),
TextFont {
font: asset_server.load("fonts/FiraSans-Bold.ttf"),
..default()
},
Label,
));
parent.spawn((
Text::new("V: toggle UI root's visibility"),
TextFont {
font: asset_server.load("fonts/FiraSans-Bold.ttf"),
font_size: 12.,
..default()
},
Label,
));
parent.spawn((
Text::new("S: toggle outlines for hidden nodes"),
TextFont {
font: asset_server.load("fonts/FiraSans-Bold.ttf"),
font_size: 12.,
..default()
},
Label,
));
parent.spawn((
Text::new("C: toggle outlines for clipped nodes"),
TextFont {
font: asset_server.load("fonts/FiraSans-Bold.ttf"),
font_size: 12.,
..default()
},
Label,
));
}
#[cfg(not(feature = "bevy_ui_debug"))]
parent.spawn((
Text::new("Try enabling feature \"bevy_ui_debug\"."),
TextFont {
font: asset_server.load("fonts/FiraSans-Bold.ttf"),
..default()
},
Label,
));
});
});
// right vertical fill
parent
.spawn(Node {
flex_direction: FlexDirection::Column,
justify_content: JustifyContent::Center,
align_items: AlignItems::Center,
width: Val::Px(200.),
..default()
})
.with_children(|parent| {
// Title
parent.spawn((
Text::new("Scrolling list"),
TextFont {
font: asset_server.load("fonts/FiraSans-Bold.ttf"),
font_size: 21.,
..default()
},
Label,
));
// Scrolling list
parent
.spawn((
Node {
flex_direction: FlexDirection::Column,
align_self: AlignSelf::Stretch,
height: Val::Percent(50.),
overflow: Overflow::scroll_y(),
..default()
},
BackgroundColor(Color::srgb(0.10, 0.10, 0.10)),
))
.with_children(|parent| {
// List items
for i in 0..25 {
parent
.spawn((
Text(format!("Item {i}")),
TextFont {
font: asset_server.load("fonts/FiraSans-Bold.ttf"),
..default()
},
Label,
AccessibilityNode(Accessible::new(Role::ListItem)),
))
.insert(PickingBehavior {
should_block_lower: false,
..default()
});
}
});
});
parent
.spawn(Node {
left: Val::Px(210.),
bottom: Val::Px(10.),
position_type: PositionType::Absolute,
..default()
})
.with_children(|parent| {
parent
.spawn((
Node {
width: Val::Px(200.0),
height: Val::Px(200.0),
border: UiRect::all(Val::Px(20.)),
flex_direction: FlexDirection::Column,
justify_content: JustifyContent::Center,
..default()
},
BorderColor(LIME.into()),
BackgroundColor(Color::srgb(0.8, 0.8, 1.)),
))
.with_children(|parent| {
parent.spawn((
ImageNode::new(asset_server.load("branding/bevy_logo_light.png")),
// Uses the transform to rotate the logo image by 45 degrees
Transform::from_rotation(Quat::from_rotation_z(0.25 * PI)),
BorderRadius::all(Val::Px(10.)),
Outline {
width: Val::Px(2.),
offset: Val::Px(4.),
color: DARK_GRAY.into(),
},
));
});
});
let shadow_style = ShadowStyle {
color: Color::BLACK.with_alpha(0.5),
blur_radius: Val::Px(2.),
x_offset: Val::Px(10.),
y_offset: Val::Px(10.),
..default()
};
// render order test: reddest in the back, whitest in the front (flex center)
parent
.spawn(Node {
width: Val::Percent(100.0),
height: Val::Percent(100.0),
position_type: PositionType::Absolute,
align_items: AlignItems::Center,
justify_content: JustifyContent::Center,
..default()
})
.insert(PickingBehavior::IGNORE)
.with_children(|parent| {
parent
.spawn((
Node {
width: Val::Px(100.0),
height: Val::Px(100.0),
..default()
},
BackgroundColor(Color::srgb(1.0, 0.0, 0.)),
BoxShadow::from(shadow_style),
))
.with_children(|parent| {
parent.spawn((
Node {
// Take the size of the parent node.
width: Val::Percent(100.0),
height: Val::Percent(100.0),
position_type: PositionType::Absolute,
left: Val::Px(20.),
bottom: Val::Px(20.),
..default()
},
BackgroundColor(Color::srgb(1.0, 0.3, 0.3)),
BoxShadow::from(shadow_style),
));
parent.spawn((
Node {
width: Val::Percent(100.0),
height: Val::Percent(100.0),
position_type: PositionType::Absolute,
left: Val::Px(40.),
bottom: Val::Px(40.),
..default()
},
BackgroundColor(Color::srgb(1.0, 0.5, 0.5)),
BoxShadow::from(shadow_style),
));
parent.spawn((
Node {
width: Val::Percent(100.0),
height: Val::Percent(100.0),
position_type: PositionType::Absolute,
left: Val::Px(60.),
bottom: Val::Px(60.),
..default()
},
BackgroundColor(Color::srgb(0.0, 0.7, 0.7)),
BoxShadow::from(shadow_style),
));
// alpha test
parent.spawn((
Node {
width: Val::Percent(100.0),
height: Val::Percent(100.0),
position_type: PositionType::Absolute,
left: Val::Px(80.),
bottom: Val::Px(80.),
..default()
},
BackgroundColor(Color::srgba(1.0, 0.9, 0.9, 0.4)),
BoxShadow::from(ShadowStyle {
color: Color::BLACK.with_alpha(0.3),
..shadow_style
}),
));
});
});
// bevy logo (flex center)
parent
.spawn(Node {
width: Val::Percent(100.0),
position_type: PositionType::Absolute,
justify_content: JustifyContent::Center,
align_items: AlignItems::FlexStart,
..default()
})
.with_children(|parent| {
// bevy logo (image)
parent
.spawn((
ImageNode::new(asset_server.load("branding/bevy_logo_dark_big.png"))
.with_mode(NodeImageMode::Stretch),
Node {
width: Val::Px(500.0),
height: Val::Px(125.0),
margin: UiRect::top(Val::VMin(5.)),
..default()
},
))
.with_children(|parent| {
// alt text
// This UI node takes up no space in the layout and the `Text` component is used by the accessibility module
// and is not rendered.
parent.spawn((
Node {
display: Display::None,
..default()
},
Text::new("Bevy logo"),
));
});
});
// four bevy icons demonstrating image flipping
parent
.spawn(Node {
width: Val::Percent(100.0),
height: Val::Percent(100.0),
position_type: PositionType::Absolute,
justify_content: JustifyContent::Center,
align_items: AlignItems::FlexEnd,
column_gap: Val::Px(10.),
padding: UiRect::all(Val::Px(10.)),
..default()
})
.insert(PickingBehavior::IGNORE)
.with_children(|parent| {
for (flip_x, flip_y) in
[(false, false), (false, true), (true, true), (true, false)]
{
parent.spawn((
ImageNode {
image: asset_server.load("branding/icon.png"),
flip_x,
flip_y,
..default()
},
Node {
// The height will be chosen automatically to preserve the image's aspect ratio
width: Val::Px(75.),
..default()
},
));
}
});
});
}
#[cfg(feature = "bevy_ui_debug")]
// The system that will enable/disable the debug outlines around the nodes
fn toggle_debug_overlay(
input: Res<ButtonInput<KeyCode>>,
mut debug_options: ResMut<UiDebugOptions>,
mut root_node_query: Query<&mut Visibility, (With<Node>, Without<Parent>)>,
) {
info_once!("The debug outlines are enabled, press Space to turn them on/off");
if input.just_pressed(KeyCode::Space) {
// The toggle method will enable the debug overlay if disabled and disable if enabled
debug_options.toggle();
}
if input.just_pressed(KeyCode::KeyS) {
// Toggle debug outlines for nodes with `ViewVisibility` set to false.
debug_options.show_hidden = !debug_options.show_hidden;
}
if input.just_pressed(KeyCode::KeyC) {
// Toggle outlines for clipped UI nodes.
debug_options.show_clipped = !debug_options.show_clipped;
}
if input.just_pressed(KeyCode::KeyV) {
for mut visibility in root_node_query.iter_mut() {
// Toggle the UI root node's visibility
visibility.toggle_inherited_hidden();
}
}
}
/// Updates the scroll position of scrollable nodes in response to mouse input
pub fn update_scroll_position(
mut mouse_wheel_events: EventReader<MouseWheel>,
hover_map: Res<HoverMap>,
mut scrolled_node_query: Query<&mut ScrollPosition>,
keyboard_input: Res<ButtonInput<KeyCode>>,
) {
for mouse_wheel_event in mouse_wheel_events.read() {
let (mut dx, mut dy) = match mouse_wheel_event.unit {
MouseScrollUnit::Line => (mouse_wheel_event.x * 20., mouse_wheel_event.y * 20.),
MouseScrollUnit::Pixel => (mouse_wheel_event.x, mouse_wheel_event.y),
};
if keyboard_input.pressed(KeyCode::ShiftLeft) || keyboard_input.pressed(KeyCode::ShiftRight)
{
std::mem::swap(&mut dx, &mut dy);
}
for (_pointer, pointer_map) in hover_map.iter() {
for (entity, _hit) in pointer_map.iter() {
if let Ok(mut scroll_position) = scrolled_node_query.get_mut(*entity) {
scroll_position.offset_x -= dx;
scroll_position.offset_y -= dy;
}
}
}
}
}