Files
oak-gpui/crates/gpui/src/elements/mouse_event_handler.rs
T
2022-05-26 20:00:01 -06:00

151 lines
4.0 KiB
Rust

use std::{any::TypeId, rc::Rc};
use super::Padding;
use crate::{
geometry::{
rect::RectF,
vector::{vec2f, Vector2F},
},
platform::CursorStyle,
scene::CursorRegion,
DebugContext, Element, ElementBox, Event, EventContext, LayoutContext, MouseRegion, MouseState,
PaintContext, RenderContext, SizeConstraint, View,
};
use serde_json::json;
pub struct MouseEventHandler {
child: ElementBox,
tag: TypeId,
id: usize,
cursor_style: Option<CursorStyle>,
mouse_down_handler: Option<Rc<dyn Fn(Vector2F, &mut EventContext)>>,
click_handler: Option<Rc<dyn Fn(Vector2F, usize, &mut EventContext)>>,
drag_handler: Option<Rc<dyn Fn(Vector2F, &mut EventContext)>>,
padding: Padding,
}
impl MouseEventHandler {
pub fn new<Tag, V, F>(id: usize, cx: &mut RenderContext<V>, render_child: F) -> Self
where
Tag: 'static,
V: View,
F: FnOnce(MouseState, &mut RenderContext<V>) -> ElementBox,
{
Self {
id,
tag: TypeId::of::<Tag>(),
child: render_child(cx.mouse_state::<Tag>(id), cx),
cursor_style: None,
mouse_down_handler: None,
click_handler: None,
drag_handler: None,
padding: Default::default(),
}
}
pub fn with_cursor_style(mut self, cursor: CursorStyle) -> Self {
self.cursor_style = Some(cursor);
self
}
pub fn on_mouse_down(
mut self,
handler: impl Fn(Vector2F, &mut EventContext) + 'static,
) -> Self {
self.mouse_down_handler = Some(Rc::new(handler));
self
}
pub fn on_click(
mut self,
handler: impl Fn(Vector2F, usize, &mut EventContext) + 'static,
) -> Self {
self.click_handler = Some(Rc::new(handler));
self
}
pub fn on_drag(mut self, handler: impl Fn(Vector2F, &mut EventContext) + 'static) -> Self {
self.drag_handler = Some(Rc::new(handler));
self
}
pub fn with_padding(mut self, padding: Padding) -> Self {
self.padding = padding;
self
}
fn hit_bounds(&self, bounds: RectF) -> RectF {
RectF::from_points(
bounds.origin() - vec2f(self.padding.left, self.padding.top),
bounds.lower_right() + vec2f(self.padding.right, self.padding.bottom),
)
.round_out()
}
}
impl Element for MouseEventHandler {
type LayoutState = ();
type PaintState = ();
fn layout(
&mut self,
constraint: SizeConstraint,
cx: &mut LayoutContext,
) -> (Vector2F, Self::LayoutState) {
(self.child.layout(constraint, cx), ())
}
fn paint(
&mut self,
bounds: RectF,
visible_bounds: RectF,
_: &mut Self::LayoutState,
cx: &mut PaintContext,
) -> Self::PaintState {
if let Some(style) = self.cursor_style {
cx.scene.push_cursor_region(CursorRegion {
bounds: self.hit_bounds(bounds),
style,
});
}
cx.scene.push_mouse_region(MouseRegion {
view_id: cx.current_view_id(),
tag: self.tag,
region_id: self.id,
bounds,
hover: None,
click: self.click_handler.clone(),
mouse_down: self.mouse_down_handler.clone(),
drag: self.drag_handler.clone(),
});
self.child.paint(bounds.origin(), visible_bounds, cx);
}
fn dispatch_event(
&mut self,
event: &Event,
_: RectF,
_: RectF,
_: &mut Self::LayoutState,
_: &mut Self::PaintState,
cx: &mut EventContext,
) -> bool {
self.child.dispatch_event(event, cx)
}
fn debug(
&self,
_: RectF,
_: &Self::LayoutState,
_: &Self::PaintState,
cx: &DebugContext,
) -> serde_json::Value {
json!({
"type": "MouseEventHandler",
"child": self.child.debug(cx),
})
}
}