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

use crate::align::*;
use crate::event::{Event, EventResult};
use crate::rect::Rect;
use crate::theme::ColorStyle;
use crate::view::{View, ViewWrapper};
use crate::Printer;
use crate::Vec2;
use crate::With;
use unicode_width::UnicodeWidthStr;

/// Draws a border around a wrapped view.
#[derive(Debug)]
pub struct Panel<V> {
    // Inner view
    view: V,

    // Possibly empty title.
    title: String,

    // Where to put the title position
    title_position: HAlign,

    // `true` when we needs to relayout
    invalidated: bool,
}

new_default!(Panel<V: Default>);

/// Minimum distance between title and borders.
const TITLE_SPACING: usize = 3;

impl<V> Panel<V> {
    /// Creates a new panel around the given view.
    pub fn new(view: V) -> Self {
        Panel {
            view,
            title: String::new(),
            title_position: HAlign::Center,
            invalidated: true,
        }
    }

    /// Sets the title of the dialog.
    ///
    /// If not empty, it will be visible at the top.
    #[must_use]
    pub fn title<S: Into<String>>(self, label: S) -> Self {
        self.with(|s| s.set_title(label))
    }

    /// Sets the title of the dialog.
    pub fn set_title<S: Into<String>>(&mut self, label: S) {
        self.title = label.into();
        self.invalidate();
    }

    /// Sets the horizontal position of the title in the dialog.
    /// The default position is `HAlign::Center`
    #[must_use]
    pub fn title_position(self, align: HAlign) -> Self {
        self.with(|s| s.set_title_position(align))
    }

    /// Sets the horizontal position of the title in the dialog.
    /// The default position is `HAlign::Center`
    pub fn set_title_position(&mut self, align: HAlign) {
        self.title_position = align;
    }

    fn draw_title(&self, printer: &Printer) {
        if !self.title.is_empty() {
            let available = match printer.size.x.checked_sub(2 * TITLE_SPACING)
            {
                Some(available) => available,
                None => return, /* Panel is too small to even write the decoration. */
            };
            let len = std::cmp::min(self.title.width(), available);
            let x =
                TITLE_SPACING + self.title_position.get_offset(len, available);

            printer
                .offset((x, 0))
                .cropped((len, 1))
                .with_color(ColorStyle::title_primary(), |p| {
                    p.print((0, 0), &self.title)
                });
            printer.with_high_border(false, |printer| {
                printer.print((x - 2, 0), "┤ ");
                printer.print((x + len, 0), " ├");
            });
        }
    }

    fn invalidate(&mut self) {
        self.invalidated = true;
    }

    inner_getters!(self.view: V);
}

impl<V: View> ViewWrapper for Panel<V> {
    wrap_impl!(self.view: V);

    fn wrap_on_event(&mut self, event: Event) -> EventResult {
        self.view.on_event(event.relativized((1, 1)))
    }

    fn wrap_required_size(&mut self, req: Vec2) -> Vec2 {
        // TODO: make borders conditional?
        let req = req.saturating_sub((2, 2));

        let size = self.view.required_size(req) + (2, 2);
        if self.title.is_empty() {
            size
        } else {
            let title_width = self.title.width() + 2 * TITLE_SPACING;
            size.or_max((title_width, 0))
        }
    }

    fn wrap_draw(&self, printer: &Printer) {
        printer.print_box((0, 0), printer.size, true);
        self.draw_title(printer);

        let printer = printer.offset((1, 1)).shrinked((1, 1));
        self.view.draw(&printer);
    }

    fn wrap_layout(&mut self, size: Vec2) {
        self.view.layout(size.saturating_sub((2, 2)));
    }

    fn wrap_important_area(&self, size: Vec2) -> Rect {
        let inner_size = size.saturating_sub((2, 2));
        self.view.important_area(inner_size) + (1, 1)
    }

    fn wrap_needs_relayout(&self) -> bool {
        self.invalidated || self.view.needs_relayout()
    }
}