Revamp shortcuts handler (not tested yet)

dev/shortcuts.js

@@ -0,0 +1,70 @@
+"use strict";
+
+(win => {
+
+const
+	doc = document,
+	meta = /Mac OS X/.test(navigator.userAgent) ? 'meta' : 'ctrl',
+	actions = {},
+	toArray = v => Array.isArray(v) ? v : [v];
+let
+	_scope = 'all';
+
+doc.addEventListener('keydown', event => {
+	const key = (event.key||event.code||'').toLowerCase();
+	if (actions[key] && win.shortcuts.filter(event)) {
+		let modifiers = [];
+		event.altKey && modifiers.push('alt');
+		event.ctrlKey && modifiers.push('ctrl');
+		event.metaKey && modifiers.push('meta');
+		event.shiftKey && modifiers.push('shift');
+		modifiers = modifiers.join('+');
+		if (actions[key][modifiers]) {
+			// for each potential shortcut
+			actions[key][modifiers].forEach(cmd => {
+				// see if it's in the current scope
+				if (cmd.scope.includes(_scope) || cmd.scope == 'all') {
+					try {
+						// call the handler and stop the event if neccessary
+						if (cmd.method(event) === false) {
+							event.preventDefault();
+							event.stopPropagation();
+						}
+					} catch (e) {
+						console.error(e);
+					}
+				}
+			});
+		}
+	}
+});
+
+win.shortcuts = {
+	add: (keys, modifiers, scope, method) => {
+		if (method === undefined) {
+			method = scope;
+			scope = 'all';
+		}
+		toArray(keys).forEach(key => {
+			key = key.toLowerCase();
+			if (!actions[key]) {
+				actions[key] = {};
+			}
+			modifiers = toArray(modifiers)
+				.map(key => 'meta' == key ? meta : key)
+				.unique().sort().join('+');
+			if (!actions[key][modifiers]) {
+				actions[key][modifiers] = [];
+			}
+			actions[key][modifiers].push({scope:toArray(scope), method:method});
+		});
+	},
+	setScope: scope => _scope = scope || 'all',
+	getScope: () => _scope,
+	getMetaKey: () => meta,
+	// ignore keydown in any element that supports keyboard input
+	filter: event => !(event.target.matches
+		&& (event.target.matches('input,select,textarea') || event.target.closest('[contenteditable]')))
+};
+
+})(this);