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
use std::ops::Deref;

use crate::{
    prelude::{
        Area,
        Point2D,
        Size2D,
    },
    scaled::Scaled,
};

#[derive(Default, PartialEq, Clone, Debug)]
pub struct AbsolutePosition {
    pub top: Option<f32>,
    pub right: Option<f32>,
    pub bottom: Option<f32>,
    pub left: Option<f32>,
}

#[derive(Default, PartialEq, Clone, Debug)]
pub enum Position {
    #[default]
    Stacked,

    Absolute(Box<AbsolutePosition>),
}

impl Position {
    pub fn is_empty(&self) -> bool {
        match self {
            Self::Absolute(absolute_position) => {
                let AbsolutePosition {
                    top,
                    right,
                    bottom,
                    left,
                } = absolute_position.deref();
                top.is_some() && right.is_some() && bottom.is_some() && left.is_some()
            }
            Self::Stacked => true,
        }
    }

    pub fn new_absolute() -> Self {
        Self::Absolute(Box::new(AbsolutePosition {
            top: None,
            right: None,
            bottom: None,
            left: None,
        }))
    }

    pub fn is_absolute(&self) -> bool {
        matches!(self, Self::Absolute { .. })
    }

    pub fn set_top(&mut self, value: f32) {
        if !self.is_absolute() {
            *self = Self::new_absolute();
        }
        if let Self::Absolute(absolute_position) = self {
            absolute_position.top = Some(value)
        }
    }

    pub fn set_right(&mut self, value: f32) {
        if !self.is_absolute() {
            *self = Self::new_absolute();
        }
        if let Self::Absolute(absolute_position) = self {
            absolute_position.right = Some(value)
        }
    }

    pub fn set_bottom(&mut self, value: f32) {
        if !self.is_absolute() {
            *self = Self::new_absolute();
        }
        if let Self::Absolute(absolute_position) = self {
            absolute_position.bottom = Some(value)
        }
    }

    pub fn set_left(&mut self, value: f32) {
        if !self.is_absolute() {
            *self = Self::new_absolute();
        }
        if let Self::Absolute(absolute_position) = self {
            absolute_position.left = Some(value)
        }
    }

    pub fn get_origin(
        &self,
        available_parent_area: &Area,
        parent_area: &Area,
        area_size: &Size2D,
    ) -> Point2D {
        match self {
            Position::Stacked => available_parent_area.origin,
            Position::Absolute(absolute_position) => {
                let AbsolutePosition {
                    top,
                    right,
                    bottom,
                    left,
                } = absolute_position.deref();
                let y = {
                    let mut y = parent_area.min_y();
                    if let Some(top) = top {
                        y += top;
                    } else if let Some(bottom) = bottom {
                        y = parent_area.max_y() - bottom - area_size.height;
                    }
                    y
                };
                let x = {
                    let mut x = parent_area.min_x();
                    if let Some(left) = left {
                        x += left;
                    } else if let Some(right) = right {
                        x = parent_area.max_x() - right - area_size.width;
                    }
                    x
                };
                Point2D::new(x, y)
            }
        }
    }
}

impl Scaled for Position {
    fn scale(&mut self, scale_factor: f32) {
        if let Self::Absolute(absolute_postion) = self {
            if let Some(top) = &mut absolute_postion.top {
                *top *= scale_factor;
            }
            if let Some(right) = &mut absolute_postion.right {
                *right *= scale_factor;
            }
            if let Some(bottom) = &mut absolute_postion.bottom {
                *bottom *= scale_factor;
            }
            if let Some(left) = &mut absolute_postion.left {
                *left *= scale_factor;
            }
        }
    }
}