Struct Command 

pub struct Command { /* private fields */ }

An application operation shared by buttons, menus, toolbars, and direct callers (docs/commands.md): one id, one title, one availability, one handler, presented through button, menu_item and toolbar_item.

Built with Command::new in the scope that owns it. Clones share the handler and reactive sources. Builders configure a copy, not existing presentations. Invocation after the owning scope’s disposal is a no-op. This is a UI-thread value, not a global registry or a native edit role.

use day_pieces::prelude::*;
use day_reactive::Signal;

let count = Signal::new(0);
let add = Command::new(day_core::id!(add), "Add one", move || count.update(|n| *n += 1))
    .enabled(move || count.get() < 3);
assert!(add.invoke());
assert_eq!(count.get(), 1);

Implementations

impl Command

pub fn new<M>( id: ElementId, label: impl IntoText<M>, action: impl Fn() + 'static, ) -> Command

A command with its default presentation id, its title (the same sources as a button: a literal, a localized text, a signal, a closure) and its synchronous handler. Availability is checked before the handler is called. Captures the current reactive scope as the command’s owner.

pub fn enabled<M>(self, enabled: impl IntoReactive<bool, M>) -> Self

Availability shared by every presentation and checked again on every invocation.

pub fn checked<M>(self, checked: impl IntoReactive<bool, M>) -> Self

Optional check state. The handler owns mutations; invoking never flips this itself.

pub fn icon(self, symbol: Symbol) -> Self

pub fn image(self, name: impl Into<ImageName>) -> Self

pub fn shortcut(self, shortcut: Shortcut) -> Self

Menu accelerator metadata. Only installing a menu entry installs the shortcut.

pub fn id(&self) -> &str

pub fn label(&self) -> String

Current title, with tracked reads for reactive presentation builders.

pub fn is_enabled(&self) -> bool

pub fn is_checked(&self) -> Option<bool>

pub fn invoke(&self) -> bool

Run if still available. Returns whether the handler ran, not whether its work succeeded. Reads are untracked; invoking inside an effect does not subscribe it to the handler.

pub fn button(&self) -> Decorated<Button>

A live button with this command’s default id, title, icon, availability, and handler. A push button does not draw a check mark. Add presentation styling as usual.

pub fn menu_item(&self) -> MenuEntry

A live menu entry: its title, availability and check mark follow the command, and the menu it sits in re-lowers when they change. Invocation always rechecks availability.

pub fn toolbar_item(&self) -> ToolbarEntry

Snapshot for a derived toolbar: .toolbar(move || vec![command.toolbar_item()]). Checked commands draw a toggle; the handler remains the sole owner of its state. Reactive builders refresh titles/checks; availability also gets a targeted live binding.

Trait Implementations

impl Clone for Command

fn clone(&self) -> Command

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.