// Copyright 2014 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
/**
* @fileoverview Braille command definitions.
* These types are adapted from Chrome's private braille API.
* They can be found in the Chrome source repo at:
* src/chrome/common/extensions/api/braille_display_private.idl
* We define them here since they don't actually exist as bindings under
* chrome.brailleDisplayPrivate.*.
*/
import {KeyCode} from '/common/key_code.js';
import {TestImportManager} from '/common/testing/test_import_manager.js';
interface Modifiers {
altKey?: boolean;
ctrlKey?: boolean;
shiftKey?: boolean;
}
// TODO(b/326623426): Move DomKeyCode to common/.
enum DomKeyCode {
ARROW_DOWN = 'ArrowDown',
ARROW_LEFT = 'ArrowLeft',
ARROW_RIGHT = 'ArrowRight',
ARROW_UP = 'ArrowUp',
AUDIO_VOLUME_DOWN = 'AudioVolumeDown',
AUDIO_VOLUME_UP = 'AudioVolumeUp',
BACKSPACE = 'Backspace',
DELETE = 'Delete',
END = 'End',
ENTER = 'Enter',
ESCAPE = 'Escape',
HOME = 'Home',
INSERT = 'Insert',
PAGE_DOWN = 'PageDown',
PAGE_UP = 'PageUp',
TAB = 'Tab',
}
/** The set of commands sent from a braille display. */
export import BrailleKeyCommand = chrome.brailleDisplayPrivate.KeyCommand;
/**
* Represents a key event from a braille display.
*
* command The name of the command.
* displayPosition The 0-based position relative to the start of the currently
* displayed text. Used for commands that involve routing
* keys or similar. The position is given in characters,
* not braille cells.
* brailleDots Dots that were pressed for braille input commands. Bit mask
* where bit 0 represents dot 1 etc.
* standardKeyCode DOM level 4 key code.
* standardKeyChar DOM key event character.
* altKey Whether the alt key was pressed.
* ctrlKey Whether the control key was pressed.
* shiftKey Whether the shift key was pressed.
*/
export type BrailleKeyEvent = chrome.brailleDisplayPrivate.KeyEvent;
export namespace BrailleKeyEvent {
/**
* Returns the numeric key code for a DOM level 4 key code string.
* NOTE: Only the key codes produced by the brailleDisplayPrivate API are
* supported.
* @param code DOM level 4 key code.
* @return The numeric key code, or {@code undefined} if unknown.
*/
export function keyCodeToLegacyCode(code: string): number {
return BrailleKeyEvent.legacyKeyCodeMap[code];
}
/**
* Returns a char value appropriate for a synthezised key event for a given
* key code.
* @param keyCode The DOM level 4 key code.
* @return Integer character code.
*/
export function keyCodeToCharValue(keyCode: string): number {
const SPECIAL_CODES: Record<string, number> = {
[DomKeyCode.BACKSPACE]: 0x08,
[DomKeyCode.TAB]: 0x09,
[DomKeyCode.ENTER]: 0x0A,
};
// Note, the Chrome virtual keyboard falls back on the first character of
// the key code if the key is not one of the above. Do the same here.
return SPECIAL_CODES[keyCode] || keyCode.charCodeAt(0);
}
/*
* Note: Some of the below mappings contain raw braille dot
* patterns. These are written out in binary form to make clear
* exactly what dots in the braille cell make up the pattern. The
* braille cell is arranged in a 2 by 4 dot grid with each dot
* assigned a number from 1-8.
* 1 4
* 2 5
* 3 6
* 7 8
*
* In binary form, the dot number minus 1 maps to the bit position
* (from right to left).
* For example, dots 1-6-7 would be
* 0b1100001
*/
/** Maps a braille pattern to a standard key code. */
export const brailleDotsToStandardKeyCode: Record<number, string> = {
0b1: 'A',
0b11: 'B',
0b1001: 'C',
0b11001: 'D',
0b10001: 'E',
0b1011: 'F',
0b11011: 'G',
0b10011: 'H',
0b1010: 'I',
0b11010: 'J',
0b101: 'K',
0b111: 'L',
0b1101: 'M',
0b11101: 'N',
0b10101: 'O',
0b1111: 'P',
0b11111: 'Q',
0b10111: 'R',
0b1110: 'S',
0b11110: 'T',
0b100101: 'U',
0b100111: 'V',
0b111010: 'W',
0b101101: 'X',
0b111101: 'Y',
0b110101: 'Z',
0b110100: '0',
0b10: '1',
0b110: '2',
0b10010: '3',
0b110010: '4',
0b100010: '5',
0b10110: '6',
0b110110: '7',
0b100110: '8',
0b10100: '9',
};
/** Maps a braille chord pattern to a standard key code. */
export const brailleChordsToStandardKeyCode: Record<number, string> = {
0b1000000: DomKeyCode.BACKSPACE,
0b10100: DomKeyCode.TAB,
0b110101: DomKeyCode.ESCAPE,
0b101000: DomKeyCode.ENTER,
};
/** Maps a braille dot chord pattern to standard key modifiers. */
export const brailleDotsToModifiers: Record<number, Modifiers> = {
0b010010: {ctrlKey: true},
0b100100: {altKey: true},
0b1000100: {shiftKey: true},
0b1010010: {ctrlKey: true, shiftKey: true},
0b1100100: {altKey: true, shiftKey: true},
};
/** Map from DOM level 4 key codes to legacy numeric key codes. */
export const legacyKeyCodeMap: Record<string, number> = {
[DomKeyCode.BACKSPACE]: KeyCode.BACK,
[DomKeyCode.TAB]: KeyCode.TAB,
[DomKeyCode.ENTER]: KeyCode.RETURN,
[DomKeyCode.ESCAPE]: KeyCode.ESCAPE,
[DomKeyCode.HOME]: KeyCode.HOME,
[DomKeyCode.ARROW_LEFT]: KeyCode.LEFT,
[DomKeyCode.ARROW_UP]: KeyCode.UP,
[DomKeyCode.ARROW_RIGHT]: KeyCode.RIGHT,
[DomKeyCode.ARROW_DOWN]: KeyCode.DOWN,
[DomKeyCode.PAGE_UP]: KeyCode.PRIOR,
[DomKeyCode.PAGE_DOWN]: KeyCode.NEXT,
[DomKeyCode.END]: KeyCode.END,
[DomKeyCode.INSERT]: KeyCode.INSERT,
[DomKeyCode.DELETE]: KeyCode.DELETE,
[DomKeyCode.AUDIO_VOLUME_DOWN]: KeyCode.VOLUME_DOWN,
[DomKeyCode.AUDIO_VOLUME_UP]: KeyCode.VOLUME_UP,
};
}
// Add 0-9.
for (let i = '0'.charCodeAt(0); i < '9'.charCodeAt(0); ++i) {
BrailleKeyEvent.legacyKeyCodeMap[String.fromCharCode(i)] =
/** @type {Key.Code} */ (i);
}
// Add A-Z.
for (let i = 'A'.charCodeAt(0); i < 'Z'.charCodeAt(0); ++i) {
BrailleKeyEvent.legacyKeyCodeMap[String.fromCharCode(i)] =
/** @type {Key.Code} */ (i);
}
// Add the F1 to F12 keys.
for (let i = 0; i < 12; ++i) {
BrailleKeyEvent.legacyKeyCodeMap['F' + (i + 1)] =
/** @type {Key.Code} */ (112 + i);
}
/**
* The state of a braille display as represented in the
* chrome.brailleDisplayPrivate API.
* TODO: Convert this to an interface once the typescript migration is complete.
*/
export abstract class BrailleDisplayState {
abstract available: boolean;
abstract cellSize: number;
abstract textColumnCount: number;
abstract textRowCount: number;
}
TestImportManager.exportForTesting(
['BrailleKeyCommand', BrailleKeyCommand],
['BrailleKeyEvent', BrailleKeyEvent]);
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