coded_chars/
display.rs

1//! This module provides control function that change the display.
2
3use std::fmt::{Display, Formatter};
4use crate::control::ControlSequence;
5
6/// # PP - Preceding page
7///
8/// PP causes the n-th preceding page in the presentation component to be displayed, where n equals the
9/// value of `n`. The effect of this control function on the active presentation position is not defined by this
10/// Standard.
11pub fn previous_page(n: usize) -> ControlSequence {
12    ControlSequence::new(&[&n.to_string()], "V")
13}
14
15/// # NP - Next page
16///
17/// NP causes the n-th following page in the presentation component to be displayed, where n equals the
18/// value of `n`. The effect of this control function on the active presentation position is not defined by this Standard.
19pub fn next_page(n: usize) -> ControlSequence {
20    ControlSequence::new(&[&n.to_string()], "U")
21}
22
23
24/// Use this function to call the control functions `SD`, `SL`, `ST` and `SR`.
25pub fn scroll(n: usize, scroll_direction: ScrollDirection) -> ControlSequence {
26    ControlSequence::new(&[&n.to_string()], &scroll_direction.to_string())
27}
28
29#[derive(Copy, Clone, Debug)]
30pub enum ScrollDirection {
31    /// # SD - Scroll down
32    ///
33    /// SD causes the data in the presentation component to be moved by n line positions if the line orientation
34    /// is horizontal, or by `n` character positions if the line orientation is vertical, such that the data appear to
35    /// move down.
36    ///
37    /// The active presentation position is not affected by this control function.
38    Down,
39
40    /// # SL - Scroll left
41    ///
42    /// SL causes the data in the presentation component to be moved by n character positions if the line
43    /// orientation is horizontal, or by `n` line positions if the line orientation is vertical, such that the data appear
44    /// to move to the left.
45    ///
46    /// The active presentation position is not affected by this control function.
47    Left,
48
49    /// # SR - Scroll right
50    ///
51    /// SR causes the data in the presentation component to be moved by n character positions if the line
52    /// orientation is horizontal, or by `n` line positions if the line orientation is vertical, such that the data appear
53    /// to move to the right.
54    ///
55    /// The active presentation position is not affected by this control function.
56    Right,
57
58    /// # SU - Scroll up
59    ///
60    /// SU causes the data in the presentation component to be moved by n line positions if the line orientation
61    /// is horizontal, or by `n` character positions if the line orientation is vertical, such that the data appear to
62    /// move up.
63    ///
64    /// The active presentation position is not affected by this control function.
65    Up,
66}
67
68impl Display for ScrollDirection {
69    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
70        write!(f, "{}", match self {
71            ScrollDirection::Down => "T",
72            ScrollDirection::Left => " @",
73            ScrollDirection::Right => " A",
74            ScrollDirection::Up => "S",
75        })
76    }
77}
78
79
80#[cfg(test)]
81mod tests {
82    use crate::introducers::CSI;
83    use super::*;
84
85    #[test]
86    fn test_previous_page() {
87        let sequence = previous_page(4);
88        assert_eq!(sequence.to_string(), format!("{}4V", CSI));
89    }
90
91    #[test]
92    fn test_next_page() {
93        let sequence = next_page(3);
94        assert_eq!(sequence.to_string(), format!("{}3U", CSI));
95    }
96
97    #[test]
98    fn test_scroll_down() {
99        let sequence = scroll(5, ScrollDirection::Down);
100        assert_eq!(sequence.to_string(), format!("{}5T", CSI));
101    }
102
103    #[test]
104    fn test_scroll_left() {
105        let sequence = scroll(2, ScrollDirection::Left);
106        assert_eq!(sequence.to_string(), format!("{}2 @", CSI));
107    }
108
109    #[test]
110    fn test_scroll_right() {
111        let sequence = scroll(7, ScrollDirection::Right);
112        assert_eq!(sequence.to_string(), format!("{}7 A", CSI));
113    }
114
115    #[test]
116    fn test_scroll_up() {
117        let sequence = scroll(1, ScrollDirection::Up);
118        assert_eq!(sequence.to_string(), format!("{}1S", CSI));
119    }
120
121    #[test]
122    fn test_scroll_direction_display() {
123        assert_eq!(ScrollDirection::Down.to_string(), "T");
124        assert_eq!(ScrollDirection::Left.to_string(), " @");
125        assert_eq!(ScrollDirection::Right.to_string(), " A");
126        assert_eq!(ScrollDirection::Up.to_string(), "S");
127    }
128}
coded_chars/display.rs

coded_chars/
display.rs
