event.rs

  1use crate::{
  2    geometry::vector::vec2f,
  3    keymap::Keystroke,
  4    platform::{Event, NavigationDirection},
  5    KeyDownEvent, KeyUpEvent, ModifiersChangedEvent, MouseButton, MouseButtonEvent,
  6    MouseMovedEvent, ScrollWheelEvent,
  7};
  8use cocoa::{
  9    appkit::{NSEvent, NSEventModifierFlags, NSEventType},
 10    base::{id, YES},
 11    foundation::NSString as _,
 12};
 13use core_graphics::{
 14    event::{CGEvent, CGEventFlags, CGKeyCode},
 15    event_source::{CGEventSource, CGEventSourceStateID},
 16};
 17use objc::{class, msg_send, sel, sel_impl};
 18use std::{borrow::Cow, ffi::CStr, os::raw::c_char};
 19
 20const BACKSPACE_KEY: u16 = 0x7f;
 21const SPACE_KEY: u16 = b' ' as u16;
 22const ENTER_KEY: u16 = 0x0d;
 23const NUMPAD_ENTER_KEY: u16 = 0x03;
 24const ESCAPE_KEY: u16 = 0x1b;
 25const TAB_KEY: u16 = 0x09;
 26const SHIFT_TAB_KEY: u16 = 0x19;
 27
 28pub fn key_to_native(key: &str) -> Cow<str> {
 29    use cocoa::appkit::*;
 30    let code = match key {
 31        "space" => SPACE_KEY,
 32        "backspace" => BACKSPACE_KEY,
 33        "up" => NSUpArrowFunctionKey,
 34        "down" => NSDownArrowFunctionKey,
 35        "left" => NSLeftArrowFunctionKey,
 36        "right" => NSRightArrowFunctionKey,
 37        "pageup" => NSPageUpFunctionKey,
 38        "pagedown" => NSPageDownFunctionKey,
 39        "delete" => NSDeleteFunctionKey,
 40        "f1" => NSF1FunctionKey,
 41        "f2" => NSF2FunctionKey,
 42        "f3" => NSF3FunctionKey,
 43        "f4" => NSF4FunctionKey,
 44        "f5" => NSF5FunctionKey,
 45        "f6" => NSF6FunctionKey,
 46        "f7" => NSF7FunctionKey,
 47        "f8" => NSF8FunctionKey,
 48        "f9" => NSF9FunctionKey,
 49        "f10" => NSF10FunctionKey,
 50        "f11" => NSF11FunctionKey,
 51        "f12" => NSF12FunctionKey,
 52        _ => return Cow::Borrowed(key),
 53    };
 54    Cow::Owned(String::from_utf16(&[code]).unwrap())
 55}
 56
 57impl Event {
 58    pub unsafe fn from_native(native_event: id, window_height: Option<f32>) -> Option<Self> {
 59        let event_type = native_event.eventType();
 60
 61        // Filter out event types that aren't in the NSEventType enum.
 62        // See https://github.com/servo/cocoa-rs/issues/155#issuecomment-323482792 for details.
 63        match event_type as u64 {
 64            0 | 21 | 32 | 33 | 35 | 36 | 37 => {
 65                return None;
 66            }
 67            _ => {}
 68        }
 69
 70        match event_type {
 71            NSEventType::NSFlagsChanged => {
 72                let modifiers = native_event.modifierFlags();
 73                let ctrl = modifiers.contains(NSEventModifierFlags::NSControlKeyMask);
 74                let alt = modifiers.contains(NSEventModifierFlags::NSAlternateKeyMask);
 75                let shift = modifiers.contains(NSEventModifierFlags::NSShiftKeyMask);
 76                let cmd = modifiers.contains(NSEventModifierFlags::NSCommandKeyMask);
 77
 78                Some(Self::ModifiersChanged(ModifiersChangedEvent {
 79                    ctrl,
 80                    alt,
 81                    shift,
 82                    cmd,
 83                }))
 84            }
 85            NSEventType::NSKeyDown => Some(Self::KeyDown(KeyDownEvent {
 86                keystroke: parse_keystroke(native_event),
 87                is_held: native_event.isARepeat() == YES,
 88            })),
 89            NSEventType::NSKeyUp => Some(Self::KeyUp(KeyUpEvent {
 90                keystroke: parse_keystroke(native_event),
 91            })),
 92            NSEventType::NSLeftMouseDown
 93            | NSEventType::NSRightMouseDown
 94            | NSEventType::NSOtherMouseDown => {
 95                let button = match native_event.buttonNumber() {
 96                    0 => MouseButton::Left,
 97                    1 => MouseButton::Right,
 98                    2 => MouseButton::Middle,
 99                    3 => MouseButton::Navigate(NavigationDirection::Back),
100                    4 => MouseButton::Navigate(NavigationDirection::Forward),
101                    // Other mouse buttons aren't tracked currently
102                    _ => return None,
103                };
104                let modifiers = native_event.modifierFlags();
105
106                window_height.map(|window_height| {
107                    Self::MouseDown(MouseButtonEvent {
108                        button,
109                        position: vec2f(
110                            native_event.locationInWindow().x as f32,
111                            window_height - native_event.locationInWindow().y as f32,
112                        ),
113                        ctrl: modifiers.contains(NSEventModifierFlags::NSControlKeyMask),
114                        alt: modifiers.contains(NSEventModifierFlags::NSAlternateKeyMask),
115                        shift: modifiers.contains(NSEventModifierFlags::NSShiftKeyMask),
116                        cmd: modifiers.contains(NSEventModifierFlags::NSCommandKeyMask),
117                        click_count: native_event.clickCount() as usize,
118                    })
119                })
120            }
121            NSEventType::NSLeftMouseUp
122            | NSEventType::NSRightMouseUp
123            | NSEventType::NSOtherMouseUp => {
124                let button = match native_event.buttonNumber() {
125                    0 => MouseButton::Left,
126                    1 => MouseButton::Right,
127                    2 => MouseButton::Middle,
128                    3 => MouseButton::Navigate(NavigationDirection::Back),
129                    4 => MouseButton::Navigate(NavigationDirection::Forward),
130                    // Other mouse buttons aren't tracked currently
131                    _ => return None,
132                };
133
134                window_height.map(|window_height| {
135                    let modifiers = native_event.modifierFlags();
136                    Self::MouseUp(MouseButtonEvent {
137                        button,
138                        position: vec2f(
139                            native_event.locationInWindow().x as f32,
140                            window_height - native_event.locationInWindow().y as f32,
141                        ),
142                        ctrl: modifiers.contains(NSEventModifierFlags::NSControlKeyMask),
143                        alt: modifiers.contains(NSEventModifierFlags::NSAlternateKeyMask),
144                        shift: modifiers.contains(NSEventModifierFlags::NSShiftKeyMask),
145                        cmd: modifiers.contains(NSEventModifierFlags::NSCommandKeyMask),
146                        click_count: native_event.clickCount() as usize,
147                    })
148                })
149            }
150            NSEventType::NSScrollWheel => window_height.map(|window_height| {
151                let modifiers = native_event.modifierFlags();
152
153                Self::ScrollWheel(ScrollWheelEvent {
154                    position: vec2f(
155                        native_event.locationInWindow().x as f32,
156                        window_height - native_event.locationInWindow().y as f32,
157                    ),
158                    delta: vec2f(
159                        native_event.scrollingDeltaX() as f32,
160                        native_event.scrollingDeltaY() as f32,
161                    ),
162                    precise: native_event.hasPreciseScrollingDeltas() == YES,
163                    ctrl: modifiers.contains(NSEventModifierFlags::NSControlKeyMask),
164                    alt: modifiers.contains(NSEventModifierFlags::NSAlternateKeyMask),
165                    shift: modifiers.contains(NSEventModifierFlags::NSShiftKeyMask),
166                    cmd: modifiers.contains(NSEventModifierFlags::NSCommandKeyMask),
167                })
168            }),
169            NSEventType::NSLeftMouseDragged
170            | NSEventType::NSRightMouseDragged
171            | NSEventType::NSOtherMouseDragged => {
172                let pressed_button = match native_event.buttonNumber() {
173                    0 => MouseButton::Left,
174                    1 => MouseButton::Right,
175                    2 => MouseButton::Middle,
176                    3 => MouseButton::Navigate(NavigationDirection::Back),
177                    4 => MouseButton::Navigate(NavigationDirection::Forward),
178                    // Other mouse buttons aren't tracked currently
179                    _ => return None,
180                };
181
182                window_height.map(|window_height| {
183                    let modifiers = native_event.modifierFlags();
184                    Self::MouseMoved(MouseMovedEvent {
185                        pressed_button: Some(pressed_button),
186                        position: vec2f(
187                            native_event.locationInWindow().x as f32,
188                            window_height - native_event.locationInWindow().y as f32,
189                        ),
190                        ctrl: modifiers.contains(NSEventModifierFlags::NSControlKeyMask),
191                        alt: modifiers.contains(NSEventModifierFlags::NSAlternateKeyMask),
192                        shift: modifiers.contains(NSEventModifierFlags::NSShiftKeyMask),
193                        cmd: modifiers.contains(NSEventModifierFlags::NSCommandKeyMask),
194                    })
195                })
196            }
197            NSEventType::NSMouseMoved => window_height.map(|window_height| {
198                let modifiers = native_event.modifierFlags();
199                Self::MouseMoved(MouseMovedEvent {
200                    position: vec2f(
201                        native_event.locationInWindow().x as f32,
202                        window_height - native_event.locationInWindow().y as f32,
203                    ),
204                    pressed_button: None,
205                    ctrl: modifiers.contains(NSEventModifierFlags::NSControlKeyMask),
206                    alt: modifiers.contains(NSEventModifierFlags::NSAlternateKeyMask),
207                    shift: modifiers.contains(NSEventModifierFlags::NSShiftKeyMask),
208                    cmd: modifiers.contains(NSEventModifierFlags::NSCommandKeyMask),
209                })
210            }),
211            _ => None,
212        }
213    }
214}
215
216unsafe fn parse_keystroke(native_event: id) -> Keystroke {
217    use cocoa::appkit::*;
218
219    let mut chars_ignoring_modifiers =
220        CStr::from_ptr(native_event.charactersIgnoringModifiers().UTF8String() as *mut c_char)
221            .to_str()
222            .unwrap();
223    let first_char = chars_ignoring_modifiers.chars().next().map(|ch| ch as u16);
224    let modifiers = native_event.modifierFlags();
225
226    let ctrl = modifiers.contains(NSEventModifierFlags::NSControlKeyMask);
227    let alt = modifiers.contains(NSEventModifierFlags::NSAlternateKeyMask);
228    let mut shift = modifiers.contains(NSEventModifierFlags::NSShiftKeyMask);
229    let cmd = modifiers.contains(NSEventModifierFlags::NSCommandKeyMask);
230    let function = modifiers.contains(NSEventModifierFlags::NSFunctionKeyMask)
231        && first_char.map_or(true, |ch| {
232            !(NSUpArrowFunctionKey..=NSModeSwitchFunctionKey).contains(&ch)
233        });
234
235    #[allow(non_upper_case_globals)]
236    let key = match first_char {
237        Some(SPACE_KEY) => "space",
238        Some(BACKSPACE_KEY) => "backspace",
239        Some(ENTER_KEY) | Some(NUMPAD_ENTER_KEY) => "enter",
240        Some(ESCAPE_KEY) => "escape",
241        Some(TAB_KEY) => "tab",
242        Some(SHIFT_TAB_KEY) => "tab",
243        Some(NSUpArrowFunctionKey) => "up",
244        Some(NSDownArrowFunctionKey) => "down",
245        Some(NSLeftArrowFunctionKey) => "left",
246        Some(NSRightArrowFunctionKey) => "right",
247        Some(NSPageUpFunctionKey) => "pageup",
248        Some(NSPageDownFunctionKey) => "pagedown",
249        Some(NSDeleteFunctionKey) => "delete",
250        Some(NSF1FunctionKey) => "f1",
251        Some(NSF2FunctionKey) => "f2",
252        Some(NSF3FunctionKey) => "f3",
253        Some(NSF4FunctionKey) => "f4",
254        Some(NSF5FunctionKey) => "f5",
255        Some(NSF6FunctionKey) => "f6",
256        Some(NSF7FunctionKey) => "f7",
257        Some(NSF8FunctionKey) => "f8",
258        Some(NSF9FunctionKey) => "f9",
259        Some(NSF10FunctionKey) => "f10",
260        Some(NSF11FunctionKey) => "f11",
261        Some(NSF12FunctionKey) => "f12",
262        _ => {
263            let mut chars_ignoring_modifiers_and_shift =
264                chars_for_modified_key(native_event.keyCode(), false, false);
265
266            // Honor ⌘ when Dvorak-QWERTY is used.
267            let chars_with_cmd = chars_for_modified_key(native_event.keyCode(), true, false);
268            if cmd && chars_ignoring_modifiers_and_shift != chars_with_cmd {
269                chars_ignoring_modifiers =
270                    chars_for_modified_key(native_event.keyCode(), true, shift);
271                chars_ignoring_modifiers_and_shift = chars_with_cmd;
272            }
273
274            if shift {
275                if chars_ignoring_modifiers_and_shift
276                    == chars_ignoring_modifiers.to_ascii_lowercase()
277                {
278                    chars_ignoring_modifiers_and_shift
279                } else if chars_ignoring_modifiers_and_shift != chars_ignoring_modifiers {
280                    shift = false;
281                    chars_ignoring_modifiers
282                } else {
283                    chars_ignoring_modifiers
284                }
285            } else {
286                chars_ignoring_modifiers
287            }
288        }
289    };
290
291    Keystroke {
292        ctrl,
293        alt,
294        shift,
295        cmd,
296        function,
297        key: key.into(),
298    }
299}
300
301fn chars_for_modified_key<'a>(code: CGKeyCode, cmd: bool, shift: bool) -> &'a str {
302    // Ideally, we would use `[NSEvent charactersByApplyingModifiers]` but that
303    // always returns an empty string with certain keyboards, e.g. Japanese. Synthesizing
304    // an event with the given flags instead lets us access `characters`, which always
305    // returns a valid string.
306    let event = CGEvent::new_keyboard_event(
307        CGEventSource::new(CGEventSourceStateID::Private).unwrap(),
308        code,
309        true,
310    )
311    .unwrap();
312    let mut flags = CGEventFlags::empty();
313    if cmd {
314        flags |= CGEventFlags::CGEventFlagCommand;
315    }
316    if shift {
317        flags |= CGEventFlags::CGEventFlagShift;
318    }
319    event.set_flags(flags);
320
321    let event: id = unsafe { msg_send![class!(NSEvent), eventWithCGEvent: event] };
322    unsafe {
323        CStr::from_ptr(event.characters().UTF8String())
324            .to_str()
325            .unwrap()
326    }
327}