rgx 0.9.0

A 2D graphics toolkit for rust
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178

use std::ops::{ControlFlow, Deref};
use std::{env, fmt};

use crate::ui::canvas::*;
use crate::ui::*;

/// Widget pod. Wraps all widgets, making them smart.
pub struct Pod<T, W> {
    pub id: WidgetId,
    pub size: Size,
    pub offset: Offset,
    pub hot: bool,
    pub active: bool,

    widget: W,
    data: PhantomData<T>,
}

impl<T, W: Widget<T>> Pod<T, W> {
    pub fn new(widget: W) -> Self {
        Self {
            id: WidgetId::next(),
            size: Size::ZERO,
            offset: Offset::ZERO,
            hot: false,
            active: false,
            widget,
            data: PhantomData,
        }
    }

    fn context<'a>(&self, parent: &'a Context<'_>) -> Context<'a> {
        parent.offset(self.offset).hot(self.hot).active(self.active)
    }

    fn bounds(&self) -> Rect<f32> {
        Rect::origin(self.size)
    }

    fn transform(&self) -> Transform {
        Transform::translate(self.offset)
    }
}

impl<T, W: Widget<T>> fmt::Display for Pod<T, W> {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        write!(f, "{}#{}", self.display(), self.id)
    }
}

impl<T, W: Widget<T>> Widget<T> for Pod<T, W> {
    fn layout(&mut self, parent: Size, ctx: &LayoutCtx<'_>, data: &T, env: &Env) -> Size {
        self.size = self.widget.layout(parent, ctx, data, env);
        self.size
    }

    fn paint(&mut self, mut canvas: Canvas<'_>, data: &T) {
        self.widget.paint(canvas.transform(self.transform()), data);

        if env::var("DEBUG").is_ok() {
            canvas.paint(
                Rectangle::new(self.offset, self.size)
                    .stroke(1., Rgba8::GREEN.alpha(0x44))
                    .fill(Rgba8::GREEN.alpha(if self.hot { 0x22 } else { 0x11 })),
            );
        }
    }

    fn update(&mut self, ctx: &Context<'_>, data: &T) {
        self.widget.update(&self.context(ctx), data)
    }

    fn cursor(&self) -> Option<&'static str> {
        self.widget.cursor()
    }

    fn event(&mut self, event: &WidgetEvent, ctx: &Context<'_>, data: &mut T) -> ControlFlow<()> {
        let ctx = self.context(ctx);

        match event {
            WidgetEvent::MouseEnter => {
                let contains =
                    self.bounds().contains(ctx.cursor) && self.widget.contains(ctx.cursor);

                if contains {
                    self.hot = true;
                    self.widget.event(&WidgetEvent::MouseEnter, &ctx, data)
                } else {
                    ControlFlow::Continue(())
                }
            }
            WidgetEvent::MouseExit => {
                if self.hot {
                    self.hot = false;
                    self.widget.event(&WidgetEvent::MouseExit, &ctx, data)
                } else {
                    ControlFlow::Continue(())
                }
            }
            WidgetEvent::MouseMove(point) => {
                let cursor = point.untransform(self.transform());
                let contains = self.bounds().contains(cursor) && self.widget.contains(cursor);

                if contains {
                    // If the widget wasn't hot before, we send a `MouseEnter`.
                    if self.hot {
                        self.widget
                            .event(&WidgetEvent::MouseMove(cursor), &ctx, data)
                    } else {
                        self.hot = true;
                        self.widget.event(&WidgetEvent::MouseEnter, &ctx, data)
                    }
                } else if self.hot {
                    self.hot = false;
                    self.widget.event(&WidgetEvent::MouseExit, &ctx, data)
                } else {
                    ControlFlow::Continue(())
                }
            }
            WidgetEvent::MouseDown(_) => {
                // Only propagate event if hot.
                if self.hot {
                    self.active = true;
                    self.widget.event(event, &ctx, data)
                } else {
                    ControlFlow::Continue(())
                }
            }
            WidgetEvent::MouseUp(_) => {
                // Only propagate event if active.
                if self.active {
                    // It may look wrong that we're setting active to `false`
                    // here while telling our widget that we're active, but
                    // it's not!
                    self.active = false;
                    self.widget.event(event, &ctx, data)
                } else {
                    ControlFlow::Continue(())
                }
            }
            _ => self.widget.event(event, &ctx, data),
        }
    }

    fn lifecycle(
        &mut self,
        lifecycle: &WidgetLifecycle<'_>,
        ctx: &Context<'_>,
        data: &T,
        env: &Env,
    ) {
        self.widget.lifecycle(lifecycle, ctx, data, env)
    }

    fn frame(&mut self, surfaces: &Surfaces, data: &mut T) {
        self.widget.frame(surfaces, data);
    }

    fn contains(&self, point: Point) -> bool {
        self.widget.contains(point - self.offset)
    }

    fn type_name(&self) -> &'static str {
        self.widget.type_name()
    }

    fn display(&self) -> String {
        self.widget.display()
    }
}

impl<T, W> Deref for Pod<T, W> {
    type Target = W;

    fn deref(&self) -> &Self::Target {
        &self.widget
    }
}