Improve state guarantees in bezier_tool

This commit is contained in:
Héctor Ramón Jiménez 2020-01-11 00:40:27 +01:00
parent dd5edbc6ee
commit e879982cfd

View File

@ -25,26 +25,41 @@ mod bezier {
use std::sync::Arc;
pub struct Bezier<'a, Message> {
pending_points: &'a [Point],
state: &'a mut State,
curves: &'a [Curve],
// [from, to, ctrl]
bezier_points: &'a [[Point; 3]],
on_click: Box<dyn Fn(Point) -> Message>,
on_click: Box<dyn Fn(Curve) -> Message>,
}
#[derive(Debug, Clone, Copy)]
pub struct Curve {
from: Point,
to: Point,
control: Point,
}
#[derive(Default)]
pub struct State {
pending: Option<Pending>,
}
enum Pending {
One { from: Point },
Two { from: Point, to: Point },
}
impl<'a, Message> Bezier<'a, Message> {
pub fn new<F>(
bezier_points: &'a [[Point; 3]],
pending_points: &'a [Point],
state: &'a mut State,
curves: &'a [Curve],
on_click: F,
) -> Self
where
F: 'static + Fn(Point) -> Message,
F: 'static + Fn(Curve) -> Message,
{
assert!(pending_points.len() < 3);
Self {
bezier_points,
pending_points,
state,
curves,
on_click: Box::new(on_click),
}
}
@ -102,40 +117,40 @@ mod bezier {
)
.unwrap();
for pts in self.bezier_points {
for curve in self.curves {
path_builder.move_to(lyon::math::Point::new(
pts[0].x + bounds.x,
pts[0].y + bounds.y,
curve.from.x + bounds.x,
curve.from.y + bounds.y,
));
path_builder.quadratic_bezier_to(
lyon::math::Point::new(
pts[2].x + bounds.x,
pts[2].y + bounds.y,
curve.control.x + bounds.x,
curve.control.y + bounds.y,
),
lyon::math::Point::new(
pts[1].x + bounds.x,
pts[1].y + bounds.y,
curve.to.x + bounds.x,
curve.to.y + bounds.y,
),
);
}
match self.pending_points.len() {
0 => {}
1 => {
match self.state.pending {
None => {}
Some(Pending::One { from }) => {
path_builder.move_to(lyon::math::Point::new(
self.pending_points[0].x + bounds.x,
self.pending_points[0].y + bounds.y,
from.x + bounds.x,
from.y + bounds.y,
));
path_builder.line_to(lyon::math::Point::new(
cursor_position.x,
cursor_position.y,
));
}
2 => {
Some(Pending::Two { from, to }) => {
path_builder.move_to(lyon::math::Point::new(
self.pending_points[0].x + bounds.x,
self.pending_points[0].y + bounds.y,
from.x + bounds.x,
from.y + bounds.y,
));
path_builder.quadratic_bezier_to(
lyon::math::Point::new(
@ -143,14 +158,11 @@ mod bezier {
cursor_position.y,
),
lyon::math::Point::new(
self.pending_points[1].x + bounds.x,
self.pending_points[1].y + bounds.y,
to.x + bounds.x,
to.y + bounds.y,
),
);
}
_ => {
unreachable!();
}
}
let mut tessellator = StrokeTessellator::new();
@ -197,21 +209,45 @@ mod bezier {
_clipboard: Option<&dyn Clipboard>,
) {
let bounds = layout.bounds();
if bounds.contains(cursor_position) {
match event {
Event::Mouse(input::mouse::Event::Input { state, .. }) => {
if state == input::ButtonState::Pressed
&& bounds.contains(cursor_position)
{
messages.push((self.on_click)(Point::new(
Event::Mouse(input::mouse::Event::Input {
state: input::ButtonState::Pressed,
..
}) => {
let new_point = Point::new(
cursor_position.x - bounds.x,
cursor_position.y - bounds.y,
)));
);
match self.state.pending {
None => {
self.state.pending =
Some(Pending::One { from: new_point });
}
Some(Pending::One { from }) => {
self.state.pending = Some(Pending::Two {
from,
to: new_point,
});
}
Some(Pending::Two { from, to }) => {
self.state.pending = None;
messages.push((self.on_click)(Curve {
from,
to,
control: new_point,
}));
}
}
}
_ => {}
}
}
}
}
impl<'a, Message> Into<Element<'a, Message, Renderer>> for Bezier<'a, Message>
where
@ -228,7 +264,6 @@ use iced::{
button, Align, Button, Color, Column, Container, Element, Length, Sandbox,
Settings, Text,
};
use iced_native::Point;
pub fn main() {
Example::run(Settings::default())
@ -236,14 +271,14 @@ pub fn main() {
#[derive(Default)]
struct Example {
bezier_points: Vec<[Point; 3]>,
pending_points: Vec<Point>,
bezier: bezier::State,
curves: Vec<bezier::Curve>,
button_state: button::State,
}
#[derive(Debug, Clone, Copy)]
enum Message {
AddPoint(Point),
AddCurve(bezier::Curve),
Clear,
}
@ -260,20 +295,12 @@ impl Sandbox for Example {
fn update(&mut self, message: Message) {
match message {
Message::AddPoint(point) => {
self.pending_points.push(point);
if self.pending_points.len() == 3 {
self.bezier_points.push([
self.pending_points[0],
self.pending_points[1],
self.pending_points[2],
]);
self.pending_points.clear();
}
Message::AddCurve(curve) => {
self.curves.push(curve);
}
Message::Clear => {
self.bezier_points.clear();
self.pending_points.clear();
self.bezier = bezier::State::default();
self.curves.clear();
}
}
}
@ -289,9 +316,9 @@ impl Sandbox for Example {
.size(50),
)
.push(Bezier::new(
self.bezier_points.as_slice(),
self.pending_points.as_slice(),
Message::AddPoint,
&mut self.bezier,
self.curves.as_slice(),
Message::AddCurve,
))
.push(
Button::new(&mut self.button_state, Text::new("Clear"))