rsynko_ui/
key.rs

1/// Names one key independently of the mechanism that reports it.
2#[derive(Clone, Copy, Debug, PartialEq, Eq)]
3pub enum Key {
4    /// Names the key moving a cursor toward the preceding value.
5    Up,
6    /// Names the key moving a cursor toward the following value.
7    Down,
8    /// Names the key moving a text cursor toward the preceding scalar.
9    Left,
10    /// Names the key moving a text cursor toward the following scalar.
11    Right,
12    /// Names the key activating the selected value.
13    Enter,
14    /// Names the key leaving the current page.
15    Escape,
16    /// Names the key deleting before a text cursor.
17    Backspace,
18    /// Names the key deleting at a text cursor.
19    Delete,
20    /// Names the key moving a text cursor to its line beginning.
21    Home,
22    /// Names the key moving a text cursor to its line end.
23    End,
24    /// Names one typed Unicode scalar.
25    Character(char),
26}
27
28impl Key {
29    /// Names the key the way a menu states it.
30    #[must_use]
31    pub fn label(self) -> String {
32        match self {
33            Self::Up => "↑".to_owned(),
34            Self::Down => "↓".to_owned(),
35            Self::Left => "←".to_owned(),
36            Self::Right => "→".to_owned(),
37            Self::Enter => "Enter".to_owned(),
38            Self::Escape => "Esc".to_owned(),
39            Self::Backspace => "Backspace".to_owned(),
40            Self::Delete => "Del".to_owned(),
41            Self::Home => "Home".to_owned(),
42            Self::End => "End".to_owned(),
43            Self::Character(' ') => "Space".to_owned(),
44            Self::Character(character) => character.to_string(),
45        }
46    }
47
48    /// Observes the scalar a typed key contributes to a text draft.
49    #[must_use]
50    pub const fn typed(self) -> Option<char> {
51        match self {
52            Self::Character(character) => Some(character),
53            Self::Up
54            | Self::Down
55            | Self::Left
56            | Self::Right
57            | Self::Enter
58            | Self::Escape
59            | Self::Backspace
60            | Self::Delete
61            | Self::Home
62            | Self::End => None,
63        }
64    }
65}
66
67/// Denotes one key press together with the modifiers that change what it denotes.
68#[derive(Clone, Copy, Debug, PartialEq, Eq)]
69pub struct Keystroke {
70    /// Names the pressed key.
71    pub key: Key,
72    /// States whether the control modifier was held.
73    pub control: bool,
74    /// States whether the alternate modifier was held.
75    pub alternate: bool,
76}
77
78impl Keystroke {
79    /// Denotes one unmodified key press.
80    #[must_use]
81    pub const fn plain(key: Key) -> Self {
82        Self {
83            key,
84            control: false,
85            alternate: false,
86        }
87    }
88
89    /// Denotes one key press with the control modifier held.
90    #[must_use]
91    pub const fn control(key: Key) -> Self {
92        Self {
93            key,
94            control: true,
95            alternate: false,
96        }
97    }
98
99    /// Observes whether any modifier was held.
100    #[must_use]
101    pub const fn modified(self) -> bool {
102        self.control || self.alternate
103    }
104
105    /// Names the keystroke the way a menu states it.
106    #[must_use]
107    pub fn label(self) -> String {
108        // A modified character names itself in upper case, the way keyboards print it.
109        let key = if self.modified() {
110            self.key.label().to_uppercase()
111        } else {
112            self.key.label()
113        };
114        match (self.control, self.alternate) {
115            (false, false) => key,
116            (true, false) => format!("Ctrl+{key}"),
117            (false, true) => format!("Alt+{key}"),
118            (true, true) => format!("Ctrl+Alt+{key}"),
119        }
120    }
121}
122
123/// Names the keystroke that leaves the application from every page.
124pub const EXIT_KEYSTROKE: Keystroke = Keystroke::control(Key::Character('q'));
rsynko_ui/key.rs

rsynko_ui/
key.rs
