| // Copyright 2019 The Fuchsia Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| use anyhow::{format_err, Result}; |
| use fidl_fuchsia_input; |
| use fidl_fuchsia_ui_input3; |
| |
| /// A codepoint returned by [hid_usage_to_code_point] for HID usages that do |
| /// not have an associated code point, e.g. Alt. |
| pub(crate) const EMPTY_CODEPOINT: u32 = 0; |
| |
| /// Standard [qwerty] keymap. |
| /// |
| /// The value of this array at index `u`, where `u` is the usage, can be: |
| /// |
| /// * `None` if the key maps to no `char` (Esc key) |
| /// * `Some((c, None))` if the key maps to `c`, but does not map to any `char` when shift is pressed |
| /// * `Some((c, Some(cs)))` if the key maps to `c` when shift is not pressed and to `cs` when it is |
| /// pressed |
| /// |
| /// [qwerty]: https://en.wikipedia.org/wiki/Keyboard_layout#QWERTY-based_Latin-script_keyboard_layouts |
| pub const QWERTY_MAP: &[Option<(char, Option<char>)>] = &[ |
| // 0x00 |
| None, |
| None, |
| None, |
| None, |
| // HID_USAGE_KEY_A |
| Some(('a', Some('A'))), |
| Some(('b', Some('B'))), |
| Some(('c', Some('C'))), |
| Some(('d', Some('D'))), |
| // 0x08 |
| Some(('e', Some('E'))), |
| Some(('f', Some('F'))), |
| Some(('g', Some('G'))), |
| Some(('h', Some('H'))), |
| // 0x0c |
| Some(('i', Some('I'))), |
| Some(('j', Some('J'))), |
| Some(('k', Some('K'))), |
| Some(('l', Some('L'))), |
| // 0x10 |
| Some(('m', Some('M'))), |
| Some(('n', Some('N'))), |
| Some(('o', Some('O'))), |
| Some(('p', Some('P'))), |
| // 0x14 |
| Some(('q', Some('Q'))), |
| Some(('r', Some('R'))), |
| Some(('s', Some('S'))), |
| Some(('t', Some('T'))), |
| // 0x18 |
| Some(('u', Some('U'))), |
| Some(('v', Some('V'))), |
| Some(('w', Some('W'))), |
| Some(('x', Some('X'))), |
| // 0x1c |
| Some(('y', Some('Y'))), |
| Some(('z', Some('Z'))), |
| Some(('1', Some('!'))), |
| Some(('2', Some('@'))), |
| // 0x20 |
| Some(('3', Some('#'))), |
| Some(('4', Some('$'))), |
| Some(('5', Some('%'))), |
| Some(('6', Some('^'))), |
| // 0x24 |
| Some(('7', Some('&'))), |
| Some(('8', Some('*'))), |
| Some(('9', Some('('))), |
| Some(('0', Some(')'))), |
| // 0x28 |
| None, |
| None, |
| None, |
| None, |
| // 0x2c |
| Some((' ', Some(' '))), |
| Some(('-', Some('_'))), |
| Some(('=', Some('+'))), |
| Some(('[', Some('{'))), |
| // 0x30 |
| Some((']', Some('}'))), |
| Some(('\\', Some('|'))), |
| None, |
| Some((';', Some(':'))), |
| // 0x34 |
| Some(('\'', Some('"'))), |
| Some(('`', Some('~'))), |
| Some((',', Some('<'))), |
| Some(('.', Some('>'))), |
| // 0x38 |
| Some(('/', Some('?'))), |
| None, |
| None, |
| None, |
| // 0x3c |
| None, |
| None, |
| None, |
| None, |
| // 0x40 |
| None, |
| None, |
| None, |
| None, |
| // 0x44 |
| None, |
| None, |
| None, |
| None, |
| // 0x48 |
| None, |
| None, |
| None, |
| None, |
| // 0x4c |
| None, |
| None, |
| None, |
| None, |
| // 0x50 |
| None, |
| None, |
| None, |
| None, |
| // 0x54 |
| Some(('/', None)), |
| Some(('*', None)), |
| Some(('-', None)), |
| Some(('+', None)), |
| // 0x58 |
| None, |
| Some(('1', None)), |
| Some(('2', None)), |
| Some(('3', None)), |
| // 0x5c |
| Some(('4', None)), |
| Some(('5', None)), |
| Some(('6', None)), |
| Some(('7', None)), |
| // 0x60 |
| Some(('8', None)), |
| Some(('9', None)), |
| Some(('0', None)), |
| Some(('.', None)), |
| ]; |
| |
| /// Tracks the current state of "significant" modifier keys. |
| /// |
| /// Currently, a modifier key is "significant" if it affects the mapping of a |
| /// Fuchsia key to a key meaning. |
| #[derive(Default, Debug, Clone, Copy, PartialEq, Eq, Hash)] |
| pub struct ModifierState { |
| /// Whether the Caps Lock level modifier is active. Caps Lock level modifier |
| /// may be active even if the key itself is not actuated. |
| pub caps_lock: bool, |
| /// Whether the left shift modifier key is active. Shift keys are normally |
| /// active only while they are actuated (held pressed). |
| pub left_shift: bool, |
| /// Same as `left_shift`, but for the right shift key. |
| pub right_shift: bool, |
| } |
| |
| impl ModifierState { |
| /// Update the modifier tracker state with this event. |
| /// An error is returned in the case the input is completely unexpectedly broken. |
| pub fn update( |
| &mut self, |
| event: fidl_fuchsia_ui_input3::KeyEventType, |
| key: fidl_fuchsia_input::Key, |
| ) { |
| match event { |
| fidl_fuchsia_ui_input3::KeyEventType::Pressed => match key { |
| fidl_fuchsia_input::Key::LeftShift => self.left_shift = true, |
| fidl_fuchsia_input::Key::RightShift => self.right_shift = true, |
| fidl_fuchsia_input::Key::CapsLock => self.caps_lock = !self.caps_lock, |
| _ => {} |
| }, |
| fidl_fuchsia_ui_input3::KeyEventType::Released => match key { |
| fidl_fuchsia_input::Key::LeftShift => self.left_shift = false, |
| fidl_fuchsia_input::Key::RightShift => self.right_shift = false, |
| _ => {} |
| }, |
| _ => { |
| panic!( |
| "ModifierState::update: unexpected event: {:?} - this is a programmer error", |
| event |
| ); |
| } |
| } |
| } |
| |
| // Returns true if the "shift" level modifier is active. |
| pub fn is_shift_active(&self) -> bool { |
| self.caps_lock | self.left_shift | self.right_shift |
| } |
| } |
| |
| /// Converts a HID usage for a key to a Unicode code point where such a code point exists, based on |
| /// a US QWERTY keyboard layout. Returns EMPTY_CODEPOINT if a code point does not exist (e.g. Alt), |
| /// and an error in case the mapping somehow fails. |
| pub fn hid_usage_to_code_point(hid_usage: u32, modifier_state: &ModifierState) -> Result<u32> { |
| if (hid_usage as usize) < QWERTY_MAP.len() { |
| if let Some(map_entry) = QWERTY_MAP[hid_usage as usize] { |
| if modifier_state.is_shift_active() { |
| map_entry |
| .1 |
| .and_then(|shifted_char| Some(shifted_char as u32)) |
| .ok_or(format_err!("Invalid USB HID code: {:?}", hid_usage)) |
| } else { |
| Ok(map_entry.0 as u32) |
| } |
| } else { |
| Ok(EMPTY_CODEPOINT) // No code point provided by a keymap, e.g. Enter. |
| } |
| } else { |
| Ok(EMPTY_CODEPOINT) // No code point available, e.g. Shift, Alt, etc. |
| } |
| } |
| |
| #[cfg(test)] |
| mod tests { |
| use super::*; |
| |
| const HID_USAGE_KEY_A: u32 = 0x04; |
| |
| #[test] |
| fn spotcheck_keymap() -> Result<()> { |
| assert_eq!( |
| 'a' as u32, |
| hid_usage_to_code_point(HID_USAGE_KEY_A, &ModifierState { ..Default::default() })? |
| ); |
| assert_eq!( |
| 'A' as u32, |
| hid_usage_to_code_point( |
| HID_USAGE_KEY_A, |
| &ModifierState { caps_lock: true, ..Default::default() } |
| )? |
| ); |
| assert_eq!( |
| 'A' as u32, |
| hid_usage_to_code_point( |
| HID_USAGE_KEY_A, |
| &ModifierState { right_shift: true, ..Default::default() } |
| )? |
| ); |
| assert_eq!( |
| 'A' as u32, |
| hid_usage_to_code_point( |
| HID_USAGE_KEY_A, |
| &ModifierState { left_shift: true, ..Default::default() } |
| )? |
| ); |
| Ok(()) |
| } |
| |
| #[test] |
| fn test_modifier_tracker() { |
| let mut modifier_state: ModifierState = Default::default(); |
| assert!(!modifier_state.is_shift_active()); |
| |
| modifier_state.update( |
| fidl_fuchsia_ui_input3::KeyEventType::Pressed, |
| fidl_fuchsia_input::Key::LeftShift, |
| ); |
| assert!(modifier_state.is_shift_active()); |
| modifier_state.update( |
| fidl_fuchsia_ui_input3::KeyEventType::Released, |
| fidl_fuchsia_input::Key::LeftShift, |
| ); |
| assert!(!modifier_state.is_shift_active()); |
| |
| modifier_state.update( |
| fidl_fuchsia_ui_input3::KeyEventType::Pressed, |
| fidl_fuchsia_input::Key::RightShift, |
| ); |
| assert!(modifier_state.is_shift_active()); |
| modifier_state.update( |
| fidl_fuchsia_ui_input3::KeyEventType::Released, |
| fidl_fuchsia_input::Key::RightShift, |
| ); |
| assert!(!modifier_state.is_shift_active()); |
| |
| modifier_state.update( |
| fidl_fuchsia_ui_input3::KeyEventType::Pressed, |
| fidl_fuchsia_input::Key::CapsLock, |
| ); |
| assert!(modifier_state.is_shift_active()); |
| modifier_state.update( |
| fidl_fuchsia_ui_input3::KeyEventType::Released, |
| fidl_fuchsia_input::Key::CapsLock, |
| ); |
| assert!(modifier_state.is_shift_active()); |
| modifier_state.update( |
| fidl_fuchsia_ui_input3::KeyEventType::Pressed, |
| fidl_fuchsia_input::Key::CapsLock, |
| ); |
| assert!(!modifier_state.is_shift_active()); |
| modifier_state.update( |
| fidl_fuchsia_ui_input3::KeyEventType::Released, |
| fidl_fuchsia_input::Key::CapsLock, |
| ); |
| assert!(!modifier_state.is_shift_active()); |
| } |
| |
| // CapsLock ________/""""""""""\___________________ |
| // LeftShift ____________/"""""""""""\______________ |
| #[test] |
| fn test_interleaved_caps_lock_and_shift() { |
| let mut modifier_state: ModifierState = Default::default(); |
| assert!(!modifier_state.is_shift_active()); |
| |
| modifier_state.update( |
| fidl_fuchsia_ui_input3::KeyEventType::Pressed, |
| fidl_fuchsia_input::Key::CapsLock, |
| ); |
| assert!(modifier_state.is_shift_active()); |
| |
| modifier_state.update( |
| fidl_fuchsia_ui_input3::KeyEventType::Pressed, |
| fidl_fuchsia_input::Key::LeftShift, |
| ); |
| assert!(modifier_state.is_shift_active()); |
| |
| modifier_state.update( |
| fidl_fuchsia_ui_input3::KeyEventType::Released, |
| fidl_fuchsia_input::Key::CapsLock, |
| ); |
| assert!(modifier_state.is_shift_active()); |
| |
| modifier_state.update( |
| fidl_fuchsia_ui_input3::KeyEventType::Released, |
| fidl_fuchsia_input::Key::LeftShift, |
| ); |
| // Caps Lock is still active... |
| assert!(modifier_state.is_shift_active()); |
| |
| // Press and release Caps Lock again. |
| modifier_state.update( |
| fidl_fuchsia_ui_input3::KeyEventType::Pressed, |
| fidl_fuchsia_input::Key::CapsLock, |
| ); |
| assert!(!modifier_state.is_shift_active()); |
| |
| modifier_state.update( |
| fidl_fuchsia_ui_input3::KeyEventType::Released, |
| fidl_fuchsia_input::Key::CapsLock, |
| ); |
| assert!(!modifier_state.is_shift_active()); |
| } |
| } |
