mirror of
https://github.com/bevyengine/bevy
synced 2024-12-21 02:23:08 +00:00
015f2c69ca
# 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(); } } ```
81 lines
2.8 KiB
Rust
81 lines
2.8 KiB
Rust
//! This example illustrates how to use logs in bevy.
|
|
|
|
use bevy::{log::once, prelude::*};
|
|
|
|
fn main() {
|
|
App::new()
|
|
.add_plugins(DefaultPlugins.set(bevy::log::LogPlugin {
|
|
// Uncomment this to override the default log settings:
|
|
// level: bevy::log::Level::TRACE,
|
|
// filter: "wgpu=warn,bevy_ecs=info".to_string(),
|
|
..default()
|
|
}))
|
|
.add_systems(Startup, setup)
|
|
.add_systems(Update, log_system)
|
|
.add_systems(Update, log_once_system)
|
|
.add_systems(Update, panic_on_p)
|
|
.run();
|
|
}
|
|
|
|
fn setup(mut commands: Commands) {
|
|
commands.spawn(Camera2d);
|
|
commands.spawn((
|
|
Text::new("Press P to panic"),
|
|
Node {
|
|
position_type: PositionType::Absolute,
|
|
top: Val::Px(12.0),
|
|
left: Val::Px(12.0),
|
|
..default()
|
|
},
|
|
));
|
|
}
|
|
|
|
fn panic_on_p(keys: Res<ButtonInput<KeyCode>>) {
|
|
if keys.just_pressed(KeyCode::KeyP) {
|
|
panic!("P pressed, panicking");
|
|
}
|
|
}
|
|
|
|
fn log_system() {
|
|
// here is how you write new logs at each "log level" (in "least important" to "most important"
|
|
// order)
|
|
trace!("very noisy");
|
|
debug!("helpful for debugging");
|
|
info!("helpful information that is worth printing by default");
|
|
warn!("something bad happened that isn't a failure, but thats worth calling out");
|
|
error!("something failed");
|
|
|
|
// by default, trace and debug logs are ignored because they are "noisy"
|
|
// you can control what level is logged by setting up the LogPlugin
|
|
// alternatively you can set the log level via the RUST_LOG=LEVEL environment variable
|
|
// ex: RUST_LOG=trace, RUST_LOG=info,bevy_ecs=warn
|
|
// the format used here is super flexible. check out this documentation for more info:
|
|
// https://docs.rs/tracing-subscriber/*/tracing_subscriber/filter/struct.EnvFilter.html
|
|
}
|
|
|
|
fn log_once_system() {
|
|
// The 'once' variants of each log level are useful when a system is called every frame,
|
|
// but we still wish to inform the user only once. In other words, use these to prevent spam :)
|
|
|
|
trace_once!("one time noisy message");
|
|
debug_once!("one time debug message");
|
|
info_once!("some info which is printed only once");
|
|
warn_once!("some warning we wish to call out only once");
|
|
error_once!("some error we wish to report only once");
|
|
|
|
for i in 0..10 {
|
|
info_once!("logs once per call site, so this works just fine: {}", i);
|
|
}
|
|
|
|
// you can also use the `once!` macro directly,
|
|
// in situations where you want to do something expensive only once
|
|
// within the context of a continuous system.
|
|
once!({
|
|
info!("doing expensive things");
|
|
let mut a: u64 = 0;
|
|
for i in 0..100000000 {
|
|
a += i;
|
|
}
|
|
info!("result of some expensive one time calculation: {}", a);
|
|
});
|
|
}
|