Source Code
use gpui::{
Application, Background, Bounds, ColorSpace, Context, MouseDownEvent, Path, PathBuilder,
PathStyle, Pixels, Point, Render, StrokeOptions, Window, WindowOptions, canvas, div,
linear_color_stop, linear_gradient, point, prelude::*, px, quad, rgb, size,
};
struct PaintingViewer {
default_lines: Vec<(Path<Pixels>, Background)>,
background_quads: Vec<(Bounds<Pixels>, Background)>,
lines: Vec<Vec<Point<Pixels>>>,
start: Point<Pixels>,
dashed: bool,
_painting: bool,
}
impl PaintingViewer {
fn new(_window: &mut Window, _cx: &mut Context<Self>) -> Self {
let mut lines = vec![];
// Black squares beneath transparent paths.
let background_quads = vec![
(
Bounds {
origin: point(px(70.), px(70.)),
size: size(px(40.), px(40.)),
},
gpui::black().into(),
),
(
Bounds {
origin: point(px(170.), px(70.)),
size: size(px(40.), px(40.)),
},
gpui::black().into(),
),
(
Bounds {
origin: point(px(270.), px(70.)),
size: size(px(40.), px(40.)),
},
gpui::black().into(),
),
(
Bounds {
origin: point(px(370.), px(70.)),
size: size(px(40.), px(40.)),
},
gpui::black().into(),
),
(
Bounds {
origin: point(px(450.), px(50.)),
size: size(px(80.), px(80.)),
},
gpui::black().into(),
),
];
// 50% opaque red path that extends across black quad.
let mut builder = PathBuilder::fill();
builder.move_to(point(px(50.), px(50.)));
builder.line_to(point(px(130.), px(50.)));
builder.line_to(point(px(130.), px(130.)));
builder.line_to(point(px(50.), px(130.)));
builder.close();
let path = builder.build().unwrap();
let mut red = rgb(0xFF0000);
red.a = 0.5;
lines.push((path, red.into()));
// 50% opaque blue path that extends across black quad.
let mut builder = PathBuilder::fill();
builder.move_to(point(px(150.), px(50.)));
builder.line_to(point(px(230.), px(50.)));
builder.line_to(point(px(230.), px(130.)));
builder.line_to(point(px(150.), px(130.)));
builder.close();
let path = builder.build().unwrap();
let mut blue = rgb(0x0000FF);
blue.a = 0.5;
lines.push((path, blue.into()));
// 50% opaque green path that extends across black quad.
let mut builder = PathBuilder::fill();
builder.move_to(point(px(250.), px(50.)));
builder.line_to(point(px(330.), px(50.)));
builder.line_to(point(px(330.), px(130.)));
builder.line_to(point(px(250.), px(130.)));
builder.close();
let path = builder.build().unwrap();
let mut green = rgb(0x00FF00);
green.a = 0.5;
lines.push((path, green.into()));
// 50% opaque black path that extends across black quad.
let mut builder = PathBuilder::fill();
builder.move_to(point(px(350.), px(50.)));
builder.line_to(point(px(430.), px(50.)));
builder.line_to(point(px(430.), px(130.)));
builder.line_to(point(px(350.), px(130.)));
builder.close();
let path = builder.build().unwrap();
let mut black = rgb(0x000000);
black.a = 0.5;
lines.push((path, black.into()));
// Two 50% opaque red circles overlapping - center should be darker red
let mut builder = PathBuilder::fill();
let center = point(px(530.), px(85.));
let radius = px(30.);
builder.move_to(point(center.x + radius, center.y));
builder.arc_to(
point(radius, radius),
px(0.),
false,
false,
point(center.x - radius, center.y),
);
builder.arc_to(
point(radius, radius),
px(0.),
false,
false,
point(center.x + radius, center.y),
);
builder.close();
let path = builder.build().unwrap();
let mut red1 = rgb(0xFF0000);
red1.a = 0.5;
lines.push((path, red1.into()));
let mut builder = PathBuilder::fill();
let center = point(px(570.), px(85.));
let radius = px(30.);
builder.move_to(point(center.x + radius, center.y));
builder.arc_to(
point(radius, radius),
px(0.),
false,
false,
point(center.x - radius, center.y),
);
builder.arc_to(
point(radius, radius),
px(0.),
false,
false,
point(center.x + radius, center.y),
);
builder.close();
let path = builder.build().unwrap();
let mut red2 = rgb(0xFF0000);
red2.a = 0.5;
lines.push((path, red2.into()));
// draw a Rust logo
let mut builder = lyon::path::Path::svg_builder();
lyon::extra::rust_logo::build_logo_path(&mut builder);
// move down the Path
let mut builder: PathBuilder = builder.into();
builder.translate(point(px(10.), px(200.)));
builder.scale(0.9);
let path = builder.build().unwrap();
lines.push((path, gpui::black().into()));
// draw a lightening bolt ⚡
let mut builder = PathBuilder::fill();
builder.add_polygon(
&[
point(px(150.), px(300.)),
point(px(200.), px(225.)),
point(px(200.), px(275.)),
point(px(250.), px(200.)),
],
false,
);
let path = builder.build().unwrap();
lines.push((path, rgb(0x1d4ed8).into()));
// draw a ⭐
let mut builder = PathBuilder::fill();
builder.move_to(point(px(350.), px(200.)));
builder.line_to(point(px(370.), px(260.)));
builder.line_to(point(px(430.), px(260.)));
builder.line_to(point(px(380.), px(300.)));
builder.line_to(point(px(400.), px(360.)));
builder.line_to(point(px(350.), px(320.)));
builder.line_to(point(px(300.), px(360.)));
builder.line_to(point(px(320.), px(300.)));
builder.line_to(point(px(270.), px(260.)));
builder.line_to(point(px(330.), px(260.)));
builder.line_to(point(px(350.), px(200.)));
let path = builder.build().unwrap();
lines.push((
path,
linear_gradient(
180.,
linear_color_stop(rgb(0xFACC15), 0.7),
linear_color_stop(rgb(0xD56D0C), 1.),
)
.color_space(ColorSpace::Oklab),
));
// draw linear gradient
let square_bounds = Bounds {
origin: point(px(450.), px(200.)),
size: size(px(200.), px(80.)),
};
let height = square_bounds.size.height;
let horizontal_offset = height;
let vertical_offset = px(30.);
let mut builder = PathBuilder::fill();
builder.move_to(square_bounds.bottom_left());
builder.curve_to(
square_bounds.origin + point(horizontal_offset, vertical_offset),
square_bounds.origin + point(px(0.0), vertical_offset),
);
builder.line_to(square_bounds.top_right() + point(-horizontal_offset, vertical_offset));
builder.curve_to(
square_bounds.bottom_right(),
square_bounds.top_right() + point(px(0.0), vertical_offset),
);
builder.line_to(square_bounds.bottom_left());
let path = builder.build().unwrap();
lines.push((
path,
linear_gradient(
180.,
linear_color_stop(gpui::blue(), 0.4),
linear_color_stop(gpui::red(), 1.),
),
));
// draw a pie chart
let center = point(px(96.), px(96.));
let pie_center = point(px(775.), px(255.));
let segments = [
(
point(px(871.), px(255.)),
point(px(747.), px(163.)),
rgb(0x1374e9),
),
(
point(px(747.), px(163.)),
point(px(679.), px(263.)),
rgb(0xe13527),
),
(
point(px(679.), px(263.)),
point(px(754.), px(349.)),
rgb(0x0751ce),
),
(
point(px(754.), px(349.)),
point(px(854.), px(310.)),
rgb(0x209742),
),
(
point(px(854.), px(310.)),
point(px(871.), px(255.)),
rgb(0xfbc10a),
),
];
for (start, end, color) in segments {
let mut builder = PathBuilder::fill();
builder.move_to(start);
builder.arc_to(center, px(0.), false, false, end);
builder.line_to(pie_center);
builder.close();
let path = builder.build().unwrap();
lines.push((path, color.into()));
}
// draw a wave
let options = StrokeOptions::default()
.with_line_width(1.)
.with_line_join(lyon::path::LineJoin::Bevel);
let mut builder = PathBuilder::stroke(px(1.)).with_style(PathStyle::Stroke(options));
builder.move_to(point(px(40.), px(420.)));
for i in 1..50 {
builder.line_to(point(
px(40.0 + i as f32 * 10.0),
px(420.0 + (i as f32 * 10.0).sin() * 40.0),
));
}
let path = builder.build().unwrap();
lines.push((path, gpui::green().into()));
Self {
default_lines: lines.clone(),
background_quads,
lines: vec![],
start: point(px(0.), px(0.)),
dashed: false,
_painting: false,
}
}
fn clear(&mut self, cx: &mut Context<Self>) {
self.lines.clear();
cx.notify();
}
}
fn button(
text: &str,
cx: &mut Context<PaintingViewer>,
on_click: impl Fn(&mut PaintingViewer, &mut Context<PaintingViewer>) + 'static,
) -> impl IntoElement {
div()
.id(text.to_string())
.child(text.to_string())
.bg(gpui::black())
.text_color(gpui::white())
.active(|this| this.opacity(0.8))
.flex()
.px_3()
.py_1()
.on_click(cx.listener(move |this, _, _, cx| on_click(this, cx)))
}
impl Render for PaintingViewer {
fn render(&mut self, _: &mut Window, cx: &mut Context<Self>) -> impl IntoElement {
let default_lines = self.default_lines.clone();
let background_quads = self.background_quads.clone();
let lines = self.lines.clone();
let dashed = self.dashed;
div()
.bg(gpui::white())
.size_full()
.p_4()
.flex()
.flex_col()
.child(
div()
.flex()
.gap_2()
.justify_between()
.items_center()
.child("Mouse down any point and drag to draw lines (Hold on shift key to draw straight lines)")
.child(
div()
.flex()
.gap_x_2()
.child(button(
if dashed { "Solid" } else { "Dashed" },
cx,
move |this, _| this.dashed = !dashed,
))
.child(button("Clear", cx, |this, cx| this.clear(cx))),
),
)
.child(
div()
.size_full()
.child(
canvas(
move |_, _, _| {},
move |_, _, window, _| {
// First draw background quads
for (bounds, color) in background_quads.iter() {
window.paint_quad(quad(
*bounds,
px(0.),
*color,
px(0.),
gpui::transparent_black(),
Default::default(),
));
}
// Then draw the default paths on top
for (path, color) in default_lines {
window.paint_path(path, color);
}
for points in lines {
if points.len() < 2 {
continue;
}
let mut builder = PathBuilder::stroke(px(1.));
if dashed {
builder = builder.dash_array(&[px(4.), px(2.)]);
}
for (i, p) in points.into_iter().enumerate() {
if i == 0 {
builder.move_to(p);
} else {
builder.line_to(p);
}
}
if let Ok(path) = builder.build() {
window.paint_path(path, gpui::black());
}
}
},
)
.size_full(),
)
.on_mouse_down(
gpui::MouseButton::Left,
cx.listener(|this, ev: &MouseDownEvent, _, _| {
this._painting = true;
this.start = ev.position;
let path = vec![ev.position];
this.lines.push(path);
}),
)
.on_mouse_move(cx.listener(|this, ev: &gpui::MouseMoveEvent, _, cx| {
if !this._painting {
return;
}
let is_shifted = ev.modifiers.shift;
let mut pos = ev.position;
// When holding shift, draw a straight line
if is_shifted {
let dx = pos.x - this.start.x;
let dy = pos.y - this.start.y;
if dx.abs() > dy.abs() {
pos.y = this.start.y;
} else {
pos.x = this.start.x;
}
}
if let Some(path) = this.lines.last_mut() {
path.push(pos);
}
cx.notify();
}))
.on_mouse_up(
gpui::MouseButton::Left,
cx.listener(|this, _, _, _| {
this._painting = false;
}),
),
)
}
}
fn main() {
Application::new().run(|cx| {
cx.open_window(
WindowOptions {
focus: true,
..Default::default()
},
|window, cx| cx.new(|cx| PaintingViewer::new(window, cx)),
)
.unwrap();
cx.on_window_closed(|cx| {
cx.quit();
})
.detach();
cx.activate(true);
});
}