ZIm/crates/gpui/src/app/action.rs
2023-02-24 09:39:21 -08:00

131 lines
3.8 KiB
Rust

use std::any::{Any, TypeId};
pub trait Action: 'static {
fn id(&self) -> TypeId;
fn namespace(&self) -> &'static str;
fn name(&self) -> &'static str;
fn as_any(&self) -> &dyn Any;
fn boxed_clone(&self) -> Box<dyn Action>;
fn eq(&self, other: &dyn Action) -> bool;
fn qualified_name() -> &'static str
where
Self: Sized;
fn from_json_str(json: &str) -> anyhow::Result<Box<dyn Action>>
where
Self: Sized;
}
impl std::fmt::Debug for dyn Action {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
f.debug_struct("dyn Action")
.field("namespace", &self.namespace())
.field("name", &self.name())
.finish()
}
}
/// Define a set of unit struct types that all implement the `Action` trait.
///
/// The first argument is a namespace that will be associated with each of
/// the given action types, to ensure that they have globally unique
/// qualified names for use in keymap files.
#[macro_export]
macro_rules! actions {
($namespace:path, [ $($name:ident),* $(,)? ]) => {
$(
#[derive(Clone, Debug, Default, PartialEq, Eq)]
pub struct $name;
$crate::__impl_action! {
$namespace,
$name,
fn from_json_str(_: &str) -> $crate::anyhow::Result<Box<dyn $crate::Action>> {
Ok(Box::new(Self))
}
}
)*
};
}
/// Implement the `Action` trait for a set of existing types.
///
/// The first argument is a namespace that will be associated with each of
/// the given action types, to ensure that they have globally unique
/// qualified names for use in keymap files.
#[macro_export]
macro_rules! impl_actions {
($namespace:path, [ $($name:ident),* $(,)? ]) => {
$(
$crate::__impl_action! {
$namespace,
$name,
fn from_json_str(json: &str) -> $crate::anyhow::Result<Box<dyn $crate::Action>> {
Ok(Box::new($crate::serde_json::from_str::<Self>(json)?))
}
}
)*
};
}
/// Implement the `Action` trait for a set of existing types that are
/// not intended to be constructed via a keymap file, but only dispatched
/// internally.
#[macro_export]
macro_rules! impl_internal_actions {
($namespace:path, [ $($name:ident),* $(,)? ]) => {
$(
$crate::__impl_action! {
$namespace,
$name,
fn from_json_str(_: &str) -> $crate::anyhow::Result<Box<dyn $crate::Action>> {
Err($crate::anyhow::anyhow!("internal action"))
}
}
)*
};
}
#[doc(hidden)]
#[macro_export]
macro_rules! __impl_action {
($namespace:path, $name:ident, $from_json_fn:item) => {
impl $crate::action::Action for $name {
fn namespace(&self) -> &'static str {
stringify!($namespace)
}
fn name(&self) -> &'static str {
stringify!($name)
}
fn qualified_name() -> &'static str {
concat!(
stringify!($namespace),
"::",
stringify!($name),
)
}
fn id(&self) -> std::any::TypeId {
std::any::TypeId::of::<$name>()
}
fn as_any(&self) -> &dyn std::any::Any {
self
}
fn boxed_clone(&self) -> Box<dyn $crate::Action> {
Box::new(self.clone())
}
fn eq(&self, other: &dyn $crate::Action) -> bool {
if let Some(other) = other.as_any().downcast_ref::<Self>() {
self == other
} else {
false
}
}
$from_json_fn
}
};
}