Struct Circle Copy item path

70    fn event(&mut self, ctx: &mut EventCtx, ev: &Event, data: &mut Vector<Circle>, _env: &Env) {
71        if let Event::MouseDown(ev) = ev {
72            if ev.mods.shift() {
73                data.push_back(Circle {
74                    pos: ev.pos,
75                    time: Instant::now(),
76                });
77            } else if ev.mods.ctrl() {
78                data.retain(|c| {
79                    if (c.pos - ev.pos).hypot() > RADIUS {
80                        true
81                    } else {
82                        ctx.request_paint_rect(kurbo::Circle::new(c.pos, RADIUS).bounding_box());
83                        false
84                    }
85                });
86            } else {
87                // Move the circle to a new location, invalidating the old locations. The new location
88                // will be invalidated during AnimFrame.
89                for c in data.iter() {
90                    ctx.request_paint_rect(kurbo::Circle::new(c.pos, RADIUS).bounding_box());
91                }
92                data.clear();
93                data.push_back(Circle {
94                    pos: ev.pos,
95                    time: Instant::now(),
96                });
97            }
98            ctx.request_anim_frame();
99        } else if let Event::AnimFrame(_) = ev {
100            for c in &*data {
101                ctx.request_paint_rect(kurbo::Circle::new(c.pos, RADIUS).bounding_box());
102            }
103            if !data.is_empty() {
104                ctx.request_anim_frame();
105            }
106        }
107    }
108
109    fn lifecycle(
110        &mut self,
111        _ctx: &mut LifeCycleCtx,
112        _ev: &LifeCycle,
113        _data: &Vector<Circle>,
114        _env: &Env,
115    ) {
116    }
117
118    fn update(
119        &mut self,
120        _ctx: &mut UpdateCtx,
121        _old: &Vector<Circle>,
122        _new: &Vector<Circle>,
123        _env: &Env,
124    ) {
125    }
126
127    fn layout(
128        &mut self,
129        _ctx: &mut LayoutCtx,
130        bc: &BoxConstraints,
131        _data: &Vector<Circle>,
132        _env: &Env,
133    ) -> Size {
134        bc.max()
135    }
136
137    fn paint(&mut self, ctx: &mut PaintCtx, data: &Vector<Circle>, _env: &Env) {
138        ctx.with_save(|ctx| {
139            let rect = ctx.size().to_rect();
140            ctx.clip(rect);
141            ctx.fill(rect, &Color::WHITE);
142            let now = Instant::now();
143            for c in data {
144                let color =
145                    Color::BLACK.with_alpha(now.duration_since(c.time).as_secs_f64().cos().abs());
146                ctx.fill(kurbo::Circle::new(c.pos, RADIUS), &color);
147            }
148        });
149    }

62fn build_root_widget() -> impl Widget<HelloState> {
63    // Draw red circle, and two semi-transparent rectangles
64    let circle_and_rects = Painter::new(|ctx, _data, _env| {
65        let boundaries = ctx.size().to_rect();
66        let center = (boundaries.width() / 2., boundaries.height() / 2.);
67        let circle = Circle::new(center, center.0.min(center.1));
68        ctx.fill(circle, &Color::RED);
69
70        let rect1 = Rect::new(0., 0., boundaries.width() / 2., boundaries.height() / 2.);
71        ctx.fill(rect1, &Color::rgba8(0x0, 0xff, 0, 125));
72
73        let rect2 = Rect::new(
74            boundaries.width() / 2.,
75            boundaries.height() / 2.,
76            boundaries.width(),
77            boundaries.height(),
78        );
79        ctx.fill(rect2, &Color::rgba8(0x0, 0x0, 0xff, 125));
80    });
81
82    // This textbox modifies the label, idea here is to test that the background
83    // invalidation works when you type to the textbox
84    let textbox = TextBox::new()
85        .with_placeholder("Type to test clearing")
86        .with_text_size(18.0)
87        .lens(HelloState::name)
88        .fix_width(250.);
89
90    let label = Label::new(|data: &HelloState, _env: &Env| {
91        if data.name.is_empty() {
92            "Text: ".to_string()
93        } else {
94            format!("Text: {}!", data.name)
95        }
96    })
97    .with_text_color(Color::RED)
98    .with_text_size(32.0);
99
100    Flex::column()
101        .with_flex_child(circle_and_rects.expand().controller(DragController), 10.0)
102        .with_spacer(4.0)
103        .with_child(textbox)
104        .with_spacer(4.0)
105        .with_child(label)
106}

31fn build_app() -> impl Widget<()> {
32    let gradient = LinearGradient::new(
33        UnitPoint::TOP_LEFT,
34        UnitPoint::BOTTOM_RIGHT,
35        (DARKER_GREY, LIGHTER_GREY),
36    );
37
38    // a custom background
39    let polka_dots = Painter::new(|ctx, _, _| {
40        let bounds = ctx.size().to_rect();
41        let dot_diam = bounds.width().max(bounds.height()) / 20.;
42        let dot_spacing = dot_diam * 1.8;
43        for y in 0..((bounds.height() / dot_diam).ceil() as usize) {
44            for x in 0..((bounds.width() / dot_diam).ceil() as usize) {
45                let x_offset = (y % 2) as f64 * (dot_spacing / 2.0);
46                let x = x as f64 * dot_spacing + x_offset;
47                let y = y as f64 * dot_spacing;
48                let circ = Circle::new((x, y), dot_diam / 2.0);
49                let purp = Color::rgb(1.0, 0.22, 0.76);
50                ctx.fill(circ, &purp);
51            }
52        }
53    });
54
55    Flex::column()
56        .with_flex_child(
57            Flex::row()
58                .with_flex_child(
59                    Label::new("top left")
60                        .center()
61                        .border(DARK_GREY, 4.0)
62                        .padding(10.0),
63                    1.0,
64                )
65                .with_flex_child(
66                    Label::new("top right")
67                        .center()
68                        .background(DARK_GREY)
69                        .padding(10.0),
70                    1.0,
71                ),
72            1.0,
73        )
74        .with_flex_child(
75            Flex::row()
76                .with_flex_child(
77                    Label::new("bottom left")
78                        .center()
79                        .background(gradient)
80                        .rounded(10.0)
81                        .padding(10.0),
82                    1.0,
83                )
84                .with_flex_child(
85                    Label::new("bottom right")
86                        .center()
87                        .border(LIGHTER_GREY, 4.0)
88                        .background(polka_dots)
89                        .rounded(10.0)
90                        .padding(10.0),
91                    1.0,
92                ),
93            1.0,
94        )
95}