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
179
180
181
182
183
184
185
186
187
188

pub use euclid::Rect;

use crate::geometry::Length;
use crate::scaled::Scaled;

#[derive(PartialEq, Clone, Debug)]
pub enum Size {
    Inner,
    Percentage(Length),
    Pixels(Length),
    DynamicCalculations(Vec<DynamicCalculation>),
    Fill,
    RootPercentage(Length),
}

impl Default for Size {
    fn default() -> Self {
        Self::Inner
    }
}

impl Size {
    pub fn pretty(&self) -> String {
        match self {
            Size::Inner => "auto".to_string(),
            Size::Pixels(s) => format!("{}", s.get()),
            Size::DynamicCalculations(calcs) => format!(
                "calc({})",
                calcs
                    .iter()
                    .map(|c| c.to_string())
                    .collect::<Vec<String>>()
                    .join(" ")
            ),
            Size::Percentage(p) => format!("{}%", p.get()),
            Size::Fill => "fill".to_string(),
            Size::RootPercentage(p) => format!("{}% of root", p.get()),
        }
    }

    pub fn eval(
        &self,
        parent_value: f32,
        available_parent_value: f32,
        parent_margin: f32,
        root_value: f32,
    ) -> Option<f32> {
        match self {
            Size::Pixels(px) => Some(px.get() + parent_margin),
            Size::Percentage(per) => Some(parent_value / 100.0 * per.get()),
            Size::DynamicCalculations(calculations) => {
                Some(run_calculations(calculations, parent_value))
            }
            Size::Fill => Some(available_parent_value),
            Size::RootPercentage(per) => Some(root_value / 100.0 * per.get()),
            _ => None,
        }
    }

    #[allow(clippy::too_many_arguments)]
    pub fn min_max(
        &self,
        value: f32,
        parent_value: f32,
        available_parent_value: f32,
        single_margin: f32,
        margin: f32,
        minimum: &Self,
        maximum: &Self,
        root_value: f32,
    ) -> f32 {
        let value = self
            .eval(parent_value, available_parent_value, margin, root_value)
            .unwrap_or(value + margin);

        let minimum_value = minimum
            .eval(parent_value, available_parent_value, margin, root_value)
            .map(|v| v + single_margin);
        let maximum_value = maximum.eval(parent_value, available_parent_value, margin, root_value);

        let mut final_value = value;

        if let Some(minimum_value) = minimum_value {
            if minimum_value > final_value {
                final_value = minimum_value;
            }
        }

        if let Some(maximum_value) = maximum_value {
            if final_value > maximum_value {
                final_value = maximum_value
            }
        }

        final_value
    }
}

impl Scaled for Size {
    fn scale(&mut self, scale_factor: f32) {
        match self {
            Size::Pixels(s) => *s *= scale_factor,
            Size::DynamicCalculations(calcs) => {
                calcs.iter_mut().for_each(|calc| calc.scale(scale_factor));
            }
            _ => (),
        }
    }
}

#[derive(Copy, Clone, Debug, PartialEq)]
pub enum DynamicCalculation {
    Sub,
    Mul,
    Div,
    Add,
    Percentage(f32),
    Pixels(f32),
}

impl Scaled for DynamicCalculation {
    fn scale(&mut self, scale_factor: f32) {
        if let DynamicCalculation::Pixels(s) = self {
            *s *= scale_factor;
        }
    }
}

impl std::fmt::Display for DynamicCalculation {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        match self {
            DynamicCalculation::Sub => f.write_str("-"),
            DynamicCalculation::Mul => f.write_str("*"),
            DynamicCalculation::Div => f.write_str("/"),
            DynamicCalculation::Add => f.write_str("+"),
            DynamicCalculation::Percentage(p) => f.write_fmt(format_args!("{p}%")),
            DynamicCalculation::Pixels(s) => f.write_fmt(format_args!("{s}")),
        }
    }
}

/// Calculate some chained operations with a given value.
/// This value could be for example the width of a node's parent area.
pub fn run_calculations(calcs: &[DynamicCalculation], value: f32) -> f32 {
    let mut prev_number: Option<f32> = None;
    let mut prev_op: Option<DynamicCalculation> = None;

    let mut calc_with_op = |val: f32, prev_op: Option<DynamicCalculation>| {
        if let Some(op) = prev_op {
            match op {
                DynamicCalculation::Sub => {
                    prev_number = Some(prev_number.unwrap() - val);
                }
                DynamicCalculation::Add => {
                    prev_number = Some(prev_number.unwrap() + val);
                }
                DynamicCalculation::Mul => {
                    prev_number = Some(prev_number.unwrap() * val);
                }
                DynamicCalculation::Div => {
                    prev_number = Some(prev_number.unwrap() / val);
                }
                _ => {}
            }
        } else {
            prev_number = Some(val);
        }
    };

    for calc in calcs {
        match calc {
            DynamicCalculation::Percentage(per) => {
                let val = (value / 100.0 * per).round();

                calc_with_op(val, prev_op);

                prev_op = None;
            }
            DynamicCalculation::Pixels(val) => {
                calc_with_op(*val, prev_op);
                prev_op = None;
            }
            _ => prev_op = Some(*calc),
        }
    }

    prev_number.unwrap()
}