miniflux/internal/ui/static/js/keyboard_handler.js
jvoisin d9d17f0d69 Use a Set instead of an array in a KeyboardHandler's member
The variable `triggers` is only used to check if in contains a particular
value. Given that the number of keyboard shortcuts is starting to be
significant, let's future-proof the performances and use a `Set` instead of an
`Array` instead.
2024-03-10 19:41:13 -07:00

75 lines
2 KiB
JavaScript

class KeyboardHandler {
constructor() {
this.queue = [];
this.shortcuts = {};
this.triggers = new Set();
}
on(combination, callback) {
this.shortcuts[combination] = callback;
this.triggers.add(combination.split(" ")[0]);
}
listen() {
document.onkeydown = (event) => {
let key = this.getKey(event);
if (this.isEventIgnored(event, key) || this.isModifierKeyDown(event)) {
return;
}
if (key != "Enter") {
event.preventDefault();
}
this.queue.push(key);
for (let combination in this.shortcuts) {
let keys = combination.split(" ");
if (keys.every((value, index) => value === this.queue[index])) {
this.queue = [];
this.shortcuts[combination](event);
return;
}
if (keys.length === 1 && key === keys[0]) {
this.queue = [];
this.shortcuts[combination](event);
return;
}
}
if (this.queue.length >= 2) {
this.queue = [];
}
};
}
isEventIgnored(event, key) {
return event.target.tagName === "INPUT" ||
event.target.tagName === "TEXTAREA" ||
(this.queue.length < 1 && !this.triggers.has(key));
}
isModifierKeyDown(event) {
return event.getModifierState("Control") || event.getModifierState("Alt") || event.getModifierState("Meta");
}
getKey(event) {
const mapping = {
'Esc': 'Escape',
'Up': 'ArrowUp',
'Down': 'ArrowDown',
'Left': 'ArrowLeft',
'Right': 'ArrowRight'
};
for (let key in mapping) {
if (mapping.hasOwnProperty(key) && key === event.key) {
return mapping[key];
}
}
return event.key;
}
}