anki/ts/lib/shortcuts.ts

155 lines
4.5 KiB
TypeScript

// Copyright: Ankitects Pty Ltd and contributors
// License: GNU AGPL, version 3 or later; http://www.gnu.org/licenses/agpl.html
import * as tr from "./i18n";
export type Modifier = "Control" | "Alt" | "Shift" | "Meta";
const modifiers: Modifier[] = ["Control", "Alt", "Shift", "Meta"];
function isApplePlatform(): boolean {
return (
window.navigator.platform.startsWith("Mac") ||
window.navigator.platform.startsWith("iP")
);
}
// how modifiers are mapped
const platformModifiers = isApplePlatform()
? ["Meta", "Alt", "Shift", "Control"]
: ["Control", "Alt", "Shift", "OS"];
function splitKeyCombinationString(keyCombinationString: string): string[][] {
return keyCombinationString.split(", ").map((segment) => segment.split("+"));
}
function modifiersToPlatformString(modifiers: string[]): string {
const displayModifiers = isApplePlatform()
? ["^", "⌥", "⇧", "⌘"]
: [`${tr.keyboardCtrl()}+`, "Alt+", `${tr.keyboardShift()}+`, "Win+"];
let result = "";
for (const modifier of modifiers) {
result += displayModifiers[platformModifiers.indexOf(modifier)];
}
return result;
}
const alphabeticPrefix = "Key";
const numericPrefix = "Digit";
const keyToCharacterMap = {
Backslash: "\\",
Backquote: "`",
BracketLeft: "[",
BrackerRight: "]",
Quote: "'",
Semicolon: ";",
Minus: "-",
Equal: "=",
Comma: ",",
Period: ".",
Slash: "/",
};
function keyToPlatformString(key: string): string {
return key.startsWith(alphabeticPrefix)
? key.slice(alphabeticPrefix.length)
: key.startsWith(numericPrefix)
? key.slice(numericPrefix.length)
: Object.prototype.hasOwnProperty.call(keyToCharacterMap, key)
? keyToCharacterMap[key]
: key;
}
function toPlatformString(modifiersAndKey: string[]): string {
return `${modifiersToPlatformString(
modifiersAndKey.slice(0, -1)
)}${keyToPlatformString(modifiersAndKey[modifiersAndKey.length - 1])}`;
}
export function getPlatformString(keyCombinationString: string): string {
return splitKeyCombinationString(keyCombinationString)
.map(toPlatformString)
.join(", ");
}
function checkKey(event: KeyboardEvent, key: string): boolean {
return event.code === key;
}
function checkModifiers(
event: KeyboardEvent,
optionalModifiers: Modifier[],
activeModifiers: string[]
): boolean {
return modifiers.reduce(
(matches: boolean, modifier: string, currentIndex: number): boolean =>
matches &&
(optionalModifiers.includes(modifier as Modifier) ||
event.getModifierState(platformModifiers[currentIndex]) ===
activeModifiers.includes(modifier)),
true
);
}
function check(
event: KeyboardEvent,
optionalModifiers: Modifier[],
modifiersAndKey: string[]
): boolean {
return (
checkKey(event, modifiersAndKey[modifiersAndKey.length - 1]) &&
checkModifiers(event, optionalModifiers, modifiersAndKey.slice(0, -1))
);
}
const shortcutTimeoutMs = 400;
function innerShortcut(
lastEvent: KeyboardEvent,
callback: (event: KeyboardEvent) => void,
optionalModifiers: Modifier[],
...keyCombination: string[][]
): void {
let interval: number;
if (keyCombination.length === 0) {
callback(lastEvent);
} else {
const [nextKey, ...restKeys] = keyCombination;
const handler = (event: KeyboardEvent): void => {
if (check(event, optionalModifiers, nextKey)) {
innerShortcut(event, callback, optionalModifiers, ...restKeys);
clearTimeout(interval);
}
};
interval = setTimeout(
(): void => document.removeEventListener("keydown", handler),
shortcutTimeoutMs
);
document.addEventListener("keydown", handler, { once: true });
}
}
export function registerShortcut(
callback: (event: KeyboardEvent) => void,
keyCombinationString: string,
optionalModifiers: Modifier[] = []
): () => void {
const keyCombination = splitKeyCombinationString(keyCombinationString);
const [firstKey, ...restKeys] = keyCombination;
const handler = (event: KeyboardEvent): void => {
if (check(event, optionalModifiers, firstKey)) {
innerShortcut(event, callback, optionalModifiers, ...restKeys);
}
};
document.addEventListener("keydown", handler);
return (): void => document.removeEventListener("keydown", handler);
}