Files
oak-gpui/gpui/src/elements/event_handler.rs
T
2021-03-09 21:00:51 -07:00

70 lines
1.9 KiB
Rust

use super::try_rect;
use crate::{
geometry::vector::Vector2F, AfterLayoutContext, AppContext, Element, Event, EventContext,
LayoutContext, MutableAppContext, PaintContext, SizeConstraint,
};
use std::cell::RefCell;
pub struct EventHandler {
child: Box<dyn Element>,
mouse_down: Option<RefCell<Box<dyn FnMut(&mut EventContext, &AppContext) -> bool>>>,
origin: Option<Vector2F>,
}
impl EventHandler {
pub fn new(child: Box<dyn Element>) -> Self {
Self {
child,
mouse_down: None,
origin: None,
}
}
pub fn on_mouse_down<F>(mut self, callback: F) -> Self
where
F: 'static + FnMut(&mut EventContext, &AppContext) -> bool,
{
self.mouse_down = Some(RefCell::new(Box::new(callback)));
self
}
}
impl Element for EventHandler {
fn layout(
&mut self,
constraint: SizeConstraint,
ctx: &mut LayoutContext,
app: &AppContext,
) -> Vector2F {
self.child.layout(constraint, ctx, app)
}
fn after_layout(&mut self, ctx: &mut AfterLayoutContext, app: &mut MutableAppContext) {
self.child.after_layout(ctx, app);
}
fn paint(&mut self, origin: Vector2F, ctx: &mut PaintContext, app: &AppContext) {
self.origin = Some(origin);
self.child.paint(origin, ctx, app);
}
fn size(&self) -> Option<Vector2F> {
self.child.size()
}
fn dispatch_event(&self, event: &Event, ctx: &mut EventContext, app: &AppContext) -> bool {
match event {
Event::LeftMouseDown { position, .. } => {
if let Some(callback) = self.mouse_down.as_ref() {
let rect = try_rect(self.origin, self.size()).unwrap();
if rect.contains_point(*position) {
return callback.borrow_mut()(ctx, app);
}
}
false
}
_ => false,
}
}
}