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

use euclid;

// in logical pixels
pub type Size = euclid::Size2D<f32>;
pub type Point = euclid::Point2D<f32>;
pub type Vector = euclid::Vector2D<f32>;
pub type Rect = euclid::Rect<f32>;

pub trait RectExt<T> {
    fn left(&self) -> T;
    fn top(&self) -> T;
    fn right(&self) -> T;
    fn bottom(&self) -> T;
    fn width(&self) -> T;
    fn height(&self) -> T;
    fn from_ranges(x: Range, y: Range) -> Self;
    fn x_range(&self) -> Range;
    fn y_range(&self) -> Range;
}
impl RectExt<f32> for Rect {
    fn left(&self) -> f32 {
        self.origin.x
    }
    fn top(&self) -> f32 {
        self.origin.y
    }
    fn right(&self) -> f32 {
        self.origin.x + self.size.width
    }
    fn bottom(&self) -> f32 {
        self.origin.y + self.size.height
    }
    fn width(&self) -> f32 {
        self.size.width
    }
    fn height(&self) -> f32 {
        self.size.height
    }
    fn from_ranges(x: Range, y: Range) -> Self {
        Rect::new(Point::new(x.start, y.start), Size::new(x.end - x.start, y.end - y.start))
    }
    fn x_range(&self) -> Range {
        Range::new(self.left(), self.right())
    }
    fn y_range(&self) -> Range {
        Range::new(self.top(), self.bottom())
    }
}

/// The orientation of **Align**ment along some **Axis**.
#[derive(Copy, Clone, Debug, PartialEq, Eq)]
pub enum Align {
    /// **Align** our **Start** with the **Start** of some other widget along the **Axis**.
    Start,
    /// **Align** our **Middle** with the **Middle** of some other widget along the **Axis**.
    Middle,
    /// **Align** our **End** with the **End** of some other widget along the **Axis**.
    End,
}

impl Default for Align {
    fn default() -> Self {
        Align::Start
    }
}

#[derive(Copy, Clone, Debug, PartialEq)]
pub struct Range {
    /// The start of some `Range` along an axis.
    pub start: f32,
    /// The end of some `Range` along an axis.
    pub end: f32,
}

impl Range {
    pub fn new(start: f32, end: f32) -> Range {
        Range {
            start: start,
            end: end,
        }
    }
    pub fn from_pos_and_len(pos: f32, len: f32) -> Range {
        let half_len = len / 2.0;
        let start = pos - half_len;
        let end = pos + half_len;
        Range::new(start, end)
    }
    pub fn middle(&self) -> f32 {
        (self.end + self.start) / 2.0
    }
    pub fn is_over(&self, pos: f32) -> bool {
        let Range { start, end } = self.undirected();
        pos >= start && pos <= end
    }
    pub fn has_same_direction(self, other: Self) -> bool {
        let self_direction = self.start <= self.end;
        let other_direction = other.start <= other.end;
        self_direction == other_direction
    }
    pub fn shift(self, amount: f32) -> Range {
        Range {
            start: self.start + amount,
            end: self.end + amount,
        }
    }
    pub fn undirected(self) -> Range {
        if self.start > self.end {
            self.invert()
        } else {
            self
        }
    }
    pub fn invert(self) -> Range {
        Range {
            start: self.end,
            end: self.start,
        }
    }
    pub fn align_start_of(self, other: Self) -> Self {
        let diff = if self.has_same_direction(other) {
            other.start - self.start
        } else {
            other.start - self.end
        };
        self.shift(diff)
    }
    pub fn align_middle_of(self, other: Self) -> Self {
        let diff = other.middle() - self.middle();
        self.shift(diff)
    }
    pub fn align_end_of(self, other: Self) -> Self {
        let diff = if self.has_same_direction(other) {
            other.end - self.end
        } else {
            other.end - self.start
        };
        self.shift(diff)
    }
}