1use anyhow::anyhow;
2use serde::Deserialize;
3use smallvec::SmallVec;
4use std::fmt::Write;
5
6/// A keystroke and associated metadata generated by the platform
7#[derive(Clone, Debug, Eq, PartialEq, Default, Deserialize, Hash)]
8pub struct Keystroke {
9 /// the state of the modifier keys at the time the keystroke was generated
10 pub modifiers: Modifiers,
11
12 /// key is the character printed on the key that was pressed
13 /// e.g. for option-s, key is "s"
14 pub key: String,
15
16 /// ime_key is the character inserted by the IME engine when that key was pressed.
17 /// e.g. for option-s, ime_key is "ß"
18 pub ime_key: Option<String>,
19}
20
21impl Keystroke {
22 /// When matching a key we cannot know whether the user intended to type
23 /// the ime_key or the key itself. On some non-US keyboards keys we use in our
24 /// bindings are behind option (for example `$` is typed `alt-ç` on a Czech keyboard),
25 /// and on some keyboards the IME handler converts a sequence of keys into a
26 /// specific character (for example `"` is typed as `" space` on a brazilian keyboard).
27 ///
28 /// This method generates a list of potential keystroke candidates that could be matched
29 /// against when resolving a keybinding.
30 pub(crate) fn match_candidates(&self) -> SmallVec<[Keystroke; 2]> {
31 let mut possibilities = SmallVec::new();
32 match self.ime_key.as_ref() {
33 Some(ime_key) => {
34 if ime_key != &self.key {
35 possibilities.push(Keystroke {
36 modifiers: Modifiers {
37 control: self.modifiers.control,
38 alt: false,
39 shift: false,
40 command: false,
41 function: false,
42 },
43 key: ime_key.to_string(),
44 ime_key: None,
45 });
46 }
47 possibilities.push(Keystroke {
48 ime_key: None,
49 ..self.clone()
50 });
51 }
52 None => possibilities.push(self.clone()),
53 }
54 possibilities
55 }
56
57 /// key syntax is:
58 /// [ctrl-][alt-][shift-][cmd-][fn-]key[->ime_key]
59 /// ime_key syntax is only used for generating test events,
60 /// when matching a key with an ime_key set will be matched without it.
61 pub fn parse(source: &str) -> anyhow::Result<Self> {
62 let mut control = false;
63 let mut alt = false;
64 let mut shift = false;
65 let mut command = false;
66 let mut function = false;
67 let mut key = None;
68 let mut ime_key = None;
69
70 let mut components = source.split('-').peekable();
71 while let Some(component) = components.next() {
72 match component {
73 "ctrl" => control = true,
74 "alt" => alt = true,
75 "shift" => shift = true,
76 "cmd" => command = true,
77 "fn" => function = true,
78 _ => {
79 if let Some(next) = components.peek() {
80 if next.is_empty() && source.ends_with('-') {
81 key = Some(String::from("-"));
82 break;
83 } else if next.len() > 1 && next.starts_with('>') {
84 key = Some(String::from(component));
85 ime_key = Some(String::from(&next[1..]));
86 components.next();
87 } else {
88 return Err(anyhow!("Invalid keystroke `{}`", source));
89 }
90 } else {
91 key = Some(String::from(component));
92 }
93 }
94 }
95 }
96
97 let key = key.ok_or_else(|| anyhow!("Invalid keystroke `{}`", source))?;
98
99 Ok(Keystroke {
100 modifiers: Modifiers {
101 control,
102 alt,
103 shift,
104 command,
105 function,
106 },
107 key,
108 ime_key,
109 })
110 }
111}
112
113impl std::fmt::Display for Keystroke {
114 fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
115 if self.modifiers.control {
116 f.write_char('^')?;
117 }
118 if self.modifiers.alt {
119 f.write_char('⌥')?;
120 }
121 if self.modifiers.command {
122 f.write_char('⌘')?;
123 }
124 if self.modifiers.shift {
125 f.write_char('⇧')?;
126 }
127 let key = match self.key.as_str() {
128 "backspace" => '⌫',
129 "up" => '↑',
130 "down" => '↓',
131 "left" => '←',
132 "right" => '→',
133 "tab" => '⇥',
134 "escape" => '⎋',
135 key => {
136 if key.len() == 1 {
137 key.chars().next().unwrap().to_ascii_uppercase()
138 } else {
139 return f.write_str(key);
140 }
141 }
142 };
143 f.write_char(key)
144 }
145}
146
147/// The state of the modifier keys at some point in time
148#[derive(Copy, Clone, Debug, Eq, PartialEq, Default, Deserialize, Hash)]
149pub struct Modifiers {
150 /// The control key
151 pub control: bool,
152
153 /// The alt key
154 /// Sometimes also known as the 'meta' key
155 pub alt: bool,
156
157 /// The shift key
158 pub shift: bool,
159
160 /// The command key, on macos
161 /// the windows key, on windows
162 pub command: bool,
163
164 /// The function key
165 pub function: bool,
166}
167
168impl Modifiers {
169 /// Returns true if any modifier key is pressed
170 pub fn modified(&self) -> bool {
171 self.control || self.alt || self.shift || self.command || self.function
172 }
173
174 /// helper method for Modifiers with no modifiers
175 pub fn none() -> Modifiers {
176 Default::default()
177 }
178
179 /// helper method for Modifiers with just command
180 pub fn command() -> Modifiers {
181 Modifiers {
182 command: true,
183 ..Default::default()
184 }
185 }
186
187 /// helper method for Modifiers with just shift
188 pub fn shift() -> Modifiers {
189 Modifiers {
190 shift: true,
191 ..Default::default()
192 }
193 }
194
195 /// helper method for Modifiers with command + shift
196 pub fn command_shift() -> Modifiers {
197 Modifiers {
198 shift: true,
199 command: true,
200 ..Default::default()
201 }
202 }
203}