tachyonfx 0.25.0

A ratatui library for creating shader-like effects in TUIs.
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

use alloc::boxed::Box;

use ratatui_core::{buffer::Buffer, layout::Rect};

use crate::{effect::Effect, shader::Shader, CellFilter, ColorSpace, Duration, EffectTimer};

/// A shader that wraps another effect and ensures it runs exactly once before reporting
/// completion.
///
/// This shader is particularly useful for zero-duration effects that need to be included
/// in sequences or parallel compositions. Without this wrapper, zero-duration effects
/// would be skipped entirely in such compositions.
///
/// The wrapped effect will execute once, regardless of its completion status, after which
/// the RunOnce shader will report completion.
#[derive(Clone, Debug)]
pub(crate) struct RunOnce {
    effect: Effect,
    has_run: bool,
}

impl RunOnce {
    pub(crate) fn new(effect: Effect) -> Self {
        Self { effect, has_run: false }
    }
}

impl Shader for RunOnce {
    fn name(&self) -> &'static str {
        "run_once"
    }

    fn process(&mut self, duration: Duration, buf: &mut Buffer, area: Rect) -> Option<Duration> {
        if !self.has_run {
            self.has_run = true;
            self.effect.process(duration, buf, area)
        } else {
            None
        }
    }

    fn done(&self) -> bool {
        self.has_run
    }

    fn clone_box(&self) -> Box<dyn Shader> {
        Box::new(self.clone())
    }

    fn area(&self) -> Option<Rect> {
        self.effect.area()
    }

    fn set_area(&mut self, area: Rect) {
        self.effect.set_area(area);
    }

    fn filter(&mut self, strategy: CellFilter) {
        self.effect.filter(strategy);
    }

    fn reverse(&mut self) {
        self.effect.reverse();
    }

    fn timer_mut(&mut self) -> Option<&mut EffectTimer> {
        None
    }

    fn cell_filter(&self) -> Option<&CellFilter> {
        self.effect.cell_filter()
    }

    fn reset(&mut self) {
        self.has_run = false;
        self.effect.reset();
    }

    fn color_space(&self) -> ColorSpace {
        self.effect.color_space()
    }

    fn set_color_space(&mut self, color_space: ColorSpace) {
        self.effect.set_color_space(color_space);
    }

    #[cfg(feature = "dsl")]
    fn to_dsl(&self) -> Result<crate::dsl::EffectExpression, crate::dsl::DslError> {
        use crate::dsl::EffectExpression;
        let nested = self.effect.to_dsl()?;
        EffectExpression::parse(&format!("fx::run_once({nested})"))
    }
}

#[cfg(test)]
mod tests {
    use crate::fx;

    #[test]
    fn test_run_once_execution() {
        let mut effect = fx::run_once(fx::consume_tick());
        let mut buf =
            ratatui_core::buffer::Buffer::empty(ratatui_core::layout::Rect::new(0, 0, 10, 10));
        let area = ratatui_core::layout::Rect::new(0, 0, 10, 10);

        // Should not be done initially
        assert!(!effect.done());

        // After first process, should be done
        effect.process(crate::Duration::from_millis(16), &mut buf, area);
        assert!(effect.done());

        // Subsequent processes should not change state
        effect.process(crate::Duration::from_millis(16), &mut buf, area);
        assert!(effect.done());
    }

    #[test]
    fn test_run_once_reset() {
        let mut effect = fx::run_once(fx::consume_tick());
        let mut buf =
            ratatui_core::buffer::Buffer::empty(ratatui_core::layout::Rect::new(0, 0, 10, 10));
        let area = ratatui_core::layout::Rect::new(0, 0, 10, 10);

        // Run once
        effect.process(crate::Duration::from_millis(16), &mut buf, area);
        assert!(effect.done());

        // Reset and verify it can run again
        effect.reset();
        assert!(!effect.done());

        effect.process(crate::Duration::from_millis(16), &mut buf, area);
        assert!(effect.done());
    }

    #[cfg(feature = "dsl")]
    #[test]
    fn test_run_once_dsl() {
        let dsl = fx::run_once(fx::consume_tick())
            .to_dsl()
            .unwrap()
            .to_string();

        assert_eq!(dsl, "fx::run_once(fx::consume_tick())");
    }

    #[cfg(feature = "dsl")]
    #[test]
    fn test_run_once_dsl_roundtrip() {
        use crate::dsl::EffectDsl;

        let dsl = EffectDsl::new();
        let result = dsl
            .compiler()
            .compile("fx::run_once(fx::consume_tick())");

        assert!(result.is_ok());
        let effect = result.unwrap();
        assert_eq!(effect.name(), "run_once");
    }
}