Files
iris/core/src/event/controller.rs
T
2026-09-10 18:49:03 -04:00

292 lines
8.5 KiB
Rust

use crate::{
ActiveData, WidgetId,
util::{HashMap, HashSet},
};
use std::any::{Any, TypeId};
#[derive(Clone, Copy, Debug, Eq, PartialEq, Hash)]
pub struct ControllerId {
host: WidgetId,
kind: TypeId,
}
impl ControllerId {
pub fn host(self) -> WidgetId {
self.host
}
pub fn is<C: 'static>(self) -> bool {
self.kind == TypeId::of::<C>()
}
}
#[derive(Clone, Copy, Debug, Eq, PartialEq)]
pub enum Command {
Copy,
SelectAll,
Escape,
}
#[derive(Debug, Eq, PartialEq)]
pub enum CommandResult {
Unused,
Used,
Copy(String),
}
pub trait ControllerValue: Any {
fn into_any(self: Box<Self>) -> Box<dyn Any>;
}
impl<T: Any> ControllerValue for T {
fn into_any(self: Box<Self>) -> Box<dyn Any> {
self
}
}
pub trait Controller<Rsc>: ControllerValue {
fn command(&mut self, _command: Command, _rsc: &mut Rsc) -> CommandResult {
CommandResult::Unused
}
fn blocks_prior_input(&self) -> bool {
false
}
}
pub struct ControllerManager<Rsc> {
by_widget: HashMap<WidgetId, HashMap<TypeId, Box<dyn Controller<Rsc>>>>,
parents: HashMap<WidgetId, Option<WidgetId>>,
borrowed: HashSet<ControllerId>,
removed_while_borrowed: HashSet<WidgetId>,
command_target: Option<ControllerId>,
command_target_revision: u64,
command_boundary: Option<WidgetId>,
}
impl<Rsc> Default for ControllerManager<Rsc> {
fn default() -> Self {
Self {
by_widget: Default::default(),
parents: Default::default(),
borrowed: Default::default(),
removed_while_borrowed: Default::default(),
command_target: None,
command_target_revision: 0,
command_boundary: None,
}
}
}
impl<Rsc: 'static> ControllerManager<Rsc> {
#[track_caller]
pub fn register<C: Controller<Rsc>>(&mut self, host: WidgetId, controller: C) {
let kind = TypeId::of::<C>();
let id = ControllerId { host, kind };
assert!(
!self.borrowed.contains(&id),
"a controller cannot be replaced while it is handling input"
);
assert!(
!self.removed_while_borrowed.contains(&host),
"a controller cannot be attached to a removed widget"
);
let old = self
.by_widget
.entry(host)
.or_default()
.insert(kind, Box::new(controller));
assert!(
old.is_none(),
"a widget cannot have two controllers of type {}",
std::any::type_name::<C>()
);
}
pub fn id<C: Controller<Rsc>>(&self, host: WidgetId) -> Option<ControllerId> {
let kind = TypeId::of::<C>();
self.by_widget
.get(&host)?
.contains_key(&kind)
.then_some(ControllerId { host, kind })
}
pub fn nearest_id<C: Controller<Rsc>>(&self, mut origin: WidgetId) -> Option<ControllerId> {
let kind = TypeId::of::<C>();
loop {
let candidate = ControllerId { host: origin, kind };
assert!(
!self.borrowed.contains(&candidate),
"a controller cannot re-enter itself while it is handling input"
);
if let Some(id) = self.id::<C>(origin) {
return Some(id);
}
origin = self.parents.get(&origin).copied().flatten()?;
}
}
pub fn path_to<C: Controller<Rsc>>(
&self,
mut origin: WidgetId,
) -> Option<(ControllerId, Vec<WidgetId>)> {
let mut path = Vec::new();
loop {
path.push(origin);
if let Some(id) = self.id::<C>(origin) {
return Some((id, path));
}
origin = self.parents.get(&origin).copied().flatten()?;
}
}
pub fn draw(&mut self, active: &ActiveData) {
self.parents.insert(active.id, active.parent);
}
pub fn undraw(&mut self, active: &ActiveData) {
self.parents.remove(&active.id);
}
pub fn take<C: Controller<Rsc>>(&mut self, id: ControllerId) -> Option<C> {
if id.kind != TypeId::of::<C>() {
return None;
}
assert!(
!self.borrowed.contains(&id),
"a controller cannot re-enter itself while it is handling input"
);
let boxed = self.by_widget.get_mut(&id.host)?.remove(&id.kind)?;
self.borrowed.insert(id);
let boxed = boxed.into_any();
boxed.downcast().ok().map(|boxed| *boxed)
}
pub fn put<C: Controller<Rsc>>(&mut self, id: ControllerId, controller: C) {
debug_assert_eq!(id.kind, TypeId::of::<C>());
assert!(
self.borrowed.remove(&id),
"restored an unborrowed controller"
);
if self.finish_removed_host(id.host) {
return;
}
let old = self
.by_widget
.entry(id.host)
.or_default()
.insert(id.kind, Box::new(controller));
debug_assert!(old.is_none(), "a controller was re-entered while borrowed");
}
fn take_dyn(&mut self, id: ControllerId) -> Option<Box<dyn Controller<Rsc>>> {
assert!(
!self.borrowed.contains(&id),
"a controller cannot re-enter itself while it is handling input"
);
let controller = self.by_widget.get_mut(&id.host)?.remove(&id.kind)?;
self.borrowed.insert(id);
Some(controller)
}
fn put_dyn(&mut self, id: ControllerId, controller: Box<dyn Controller<Rsc>>) {
assert!(
self.borrowed.remove(&id),
"restored an unborrowed controller"
);
if self.finish_removed_host(id.host) {
return;
}
let old = self
.by_widget
.entry(id.host)
.or_default()
.insert(id.kind, controller);
debug_assert!(old.is_none(), "a controller was re-entered while borrowed");
}
pub fn set_command_target(&mut self, target: Option<ControllerId>) {
self.command_target = target;
self.command_target_revision = self.command_target_revision.wrapping_add(1);
}
pub fn command_target(&self) -> Option<ControllerId> {
self.command_target
}
pub fn command_target_blocks_input(&self) -> bool {
let Some(id) = self.command_target else {
return false;
};
self.by_widget
.get(&id.host)
.and_then(|controllers| controllers.get(&id.kind))
.is_some_and(|controller| controller.blocks_prior_input())
}
pub(crate) fn command_target_revision(&self) -> u64 {
self.command_target_revision
}
pub(crate) fn command_boundary(&self) -> Option<WidgetId> {
self.command_boundary
}
pub(crate) fn is_below(&self, mut widget: WidgetId, ancestor: WidgetId) -> bool {
loop {
let Some(parent) = self.parents.get(&widget).copied().flatten() else {
return false;
};
if parent == ancestor {
return true;
}
widget = parent;
}
}
pub(crate) fn set_command_boundary(&mut self, boundary: Option<WidgetId>) {
self.command_boundary = boundary;
}
pub fn remove(&mut self, host: WidgetId) {
self.by_widget.remove(&host);
self.parents.remove(&host);
if self.borrowed.iter().any(|id| id.host == host) {
self.removed_while_borrowed.insert(host);
}
if self.command_target.is_some_and(|id| id.host == host) {
self.command_target = None;
}
}
pub(crate) fn take_command_target(
&mut self,
) -> Option<(ControllerId, Box<dyn Controller<Rsc>>)> {
let id = self.command_target?;
match self.take_dyn(id) {
Some(controller) => Some((id, controller)),
None => {
self.command_target = None;
None
}
}
}
pub(crate) fn restore(&mut self, id: ControllerId, controller: Box<dyn Controller<Rsc>>) {
self.put_dyn(id, controller);
}
/// Returns true when a host disappeared during its controller callback,
/// in which case restoring the temporarily extracted value would revive
/// state belonging to a dead widget generation.
fn finish_removed_host(&mut self, host: WidgetId) -> bool {
if !self.removed_while_borrowed.contains(&host) {
return false;
}
if !self.borrowed.iter().any(|id| id.host == host) {
self.removed_while_borrowed.remove(&host);
}
true
}
}