cursive 0.21.1

A TUI (Text User Interface) library focused on ease-of-use.
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

//! Puppet backend
use crossbeam_channel::{self, Receiver, Sender, TryRecvError};

use self::observed::ObservedCell;
use self::observed::ObservedScreen;
use self::observed::ObservedStyle;
use crate::backend;
use crate::event::Event;
use crate::theme;
use crate::Vec2;
use std::cell::{Cell, RefCell};
use std::sync::Arc;
use unicode_segmentation::UnicodeSegmentation;
use unicode_width::UnicodeWidthStr;

pub mod observed;
pub mod observed_screen_view;
mod static_values;

use static_values::*;

/// Puppet backend for testing.
pub struct Backend {
    inner_sender: Sender<Option<Event>>,
    inner_receiver: Receiver<Option<Event>>,
    prev_frame: RefCell<Option<ObservedScreen>>,
    current_frame: RefCell<ObservedScreen>,
    size: Cell<Vec2>,
    current_style: RefCell<Arc<ObservedStyle>>,
    screen_channel: (Sender<ObservedScreen>, Receiver<ObservedScreen>),
    cursor: Cell<Vec2>,
}

impl Backend {
    /// Creates new Puppet backend of given or default size.
    pub fn init(size_op: Option<Vec2>) -> Box<Backend>
    where
        Self: Sized,
    {
        let (inner_sender, inner_receiver) = crossbeam_channel::unbounded();
        let size = size_op.unwrap_or(*DEFAULT_SIZE);

        let mut backend = Backend {
            inner_sender,
            inner_receiver,
            prev_frame: RefCell::new(None),
            current_frame: RefCell::new(ObservedScreen::new(size)),
            size: Cell::new(size),
            cursor: Cell::new(Vec2::zero()),
            current_style: RefCell::new(Arc::new(DEFAULT_OBSERVED_STYLE.clone())),
            screen_channel: crossbeam_channel::unbounded(),
        };

        {
            use backend::Backend;
            backend.refresh();
        }

        Box::new(backend)
    }

    /// Returns current ObservedStyle
    pub fn current_style(&self) -> Arc<ObservedStyle> {
        self.current_style.borrow().clone()
    }

    /// Output stream of consecutive frames rendered by Puppet backend
    pub fn stream(&self) -> Receiver<ObservedScreen> {
        self.screen_channel.1.clone()
    }

    /// Input stream to inject artificial input to Puppet backend.
    pub fn input(&self) -> Sender<Option<Event>> {
        self.inner_sender.clone()
    }
}

impl backend::Backend for Backend {
    fn poll_event(&mut self) -> Option<Event> {
        match self.inner_receiver.try_recv() {
            Ok(event) => event,
            Err(TryRecvError::Empty) => None,
            Err(e) => panic!("{}", e),
        }
    }

    fn set_title(&mut self, _title: String) {}

    fn refresh(&mut self) {
        let size = self.size.get();
        let current_frame = self.current_frame.replace(ObservedScreen::new(size));
        self.prev_frame.replace(Some(current_frame.clone()));
        self.screen_channel.0.send(current_frame).unwrap();
    }

    fn has_colors(&self) -> bool {
        true
    }

    fn screen_size(&self) -> Vec2 {
        self.size.get()
    }

    fn move_to(&self, pos: Vec2) {
        self.cursor.set(pos);
    }

    fn print(&self, text: &str) {
        let pos = self.cursor.get();
        let style = self.current_style.borrow().clone();
        let mut screen = self.current_frame.borrow_mut();
        let mut offset: usize = 0;

        for (idx, grapheme) in text.graphemes(true).enumerate() {
            let cpos = pos + Vec2::new(idx + offset, 0);
            screen[cpos] = Some(ObservedCell::new(
                cpos,
                style.clone(),
                Some(grapheme.to_string()),
            ));

            for _ in 0..grapheme.width() - 1 {
                offset += 1;
                let spos = pos + Vec2::new(idx + offset, 0);
                screen[spos] = Some(ObservedCell::new(spos, style.clone(), None));
            }
        }
        self.cursor.set(pos + (text.width(), 0));
    }

    fn clear(&self, clear_color: theme::Color) {
        let mut cloned_style = (*self.current_style()).clone();
        let mut screen = self.current_frame.borrow_mut();
        cloned_style.colors.back = clear_color;
        screen.clear(&Arc::new(cloned_style))
    }

    // This sets the Colours and returns the previous colours
    // to allow you to set them back when you're done.
    fn set_color(&self, new_colors: theme::ColorPair) -> theme::ColorPair {
        let mut copied_style = (*self.current_style()).clone();
        let old_colors = copied_style.colors;
        copied_style.colors = new_colors;
        self.current_style.replace(Arc::new(copied_style));

        old_colors
    }

    fn set_effect(&self, effect: theme::Effect) {
        let mut copied_style = (*self.current_style()).clone();
        copied_style.effects.insert(effect);
        self.current_style.replace(Arc::new(copied_style));
    }

    fn unset_effect(&self, effect: theme::Effect) {
        let mut copied_style = (*self.current_style()).clone();
        copied_style.effects.remove(effect);
        self.current_style.replace(Arc::new(copied_style));
    }
}