Struct druid::Command

pub struct Command {
    pub selector: Selector,
    // some fields omitted
}

An arbitrary command.

A Command consists of a Selector, that indicates what the command is, and an optional argument, that can be used to pass arbitrary data.

One-shot and reusable Commands

Commands come in two varieties, 'reusable' and 'one-shot'.

Regular commands are created with Command::new, and their argument objects may be accessed repeatedly, via Command::get_object.

One-shot commands are intended for cases where an object should only be used once; an example would be if you have some resource that cannot be cloned, and you wish to send it to another widget.

Examples

use druid::{Command, Selector};

let selector = Selector::new("process_rows");
let rows = vec![1, 3, 10, 12];
let command = Command::new(selector, rows);

assert_eq!(command.get_object(), Ok(&vec![1, 3, 10, 12]));

Fields

selector: Selector

The command's Selector.

Methods

impl Command

pub fn new(selector: Selector, arg: impl Any) -> Self

Create a new Command with an argument. If you do not need an argument, Selector implements Into<Command>.

pub fn one_shot(selector: Selector, arg: impl Any) -> Self

Create a new 'one-shot' Command.

Unlike those created with Command::new, one-shot commands cannot be reused; their argument is consumed when it is accessed, via take_object.

pub fn get_object<T: Any>(&self) -> Result<&T, ArgumentError>

Return a reference to this Command's object, if it has one.

This only works for 'reusable' commands; it does not work for commands created with one_shot.

pub fn take_object<T: Any>(&self) -> Result<Box<T>, ArgumentError>

Attempt to take the object of a one-shot command.

Trait Implementations

impl Clone for Command

fn clone(&self) -> Command

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for Command

fn fmt(&self, f: &mut Formatter) -> Result

Formats the value using the given formatter.

impl From<Selector> for Command

fn from(selector: Selector) -> Command

Performs the conversion.