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+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+module.metadata = {
+ "stability": "unstable"
+};
+
+const { observer: keyboardObserver } = require("./observer");
+const { getKeyForCode, normalize, isFunctionKey,
+ MODIFIERS } = require("./utils");
+
+/**
+ * Register a global `hotkey` that executes `listener` when the key combination
+ * in `hotkey` is pressed. If more then one `listener` is registered on the same
+ * key combination only last one will be executed.
+ *
+ * @param {string} hotkey
+ * Key combination in the format of 'modifier key'.
+ *
+ * Examples:
+ *
+ * "accel s"
+ * "meta shift i"
+ * "control alt d"
+ *
+ * Modifier keynames:
+ *
+ * - **shift**: The Shift key.
+ * - **alt**: The Alt key. On the Macintosh, this is the Option key. On
+ * Macintosh this can only be used in conjunction with another modifier,
+ * since `Alt+Letter` combinations are reserved for entering special
+ * characters in text.
+ * - **meta**: The Meta key. On the Macintosh, this is the Command key.
+ * - **control**: The Control key.
+ * - **accel**: The key used for keyboard shortcuts on the user's platform,
+ * which is Control on Windows and Linux, and Command on Mac. Usually, this
+ * would be the value you would use.
+ *
+ * @param {function} listener
+ * Function to execute when the `hotkey` is executed.
+ */
+exports.register = function register(hotkey, listener) {
+ hotkey = normalize(hotkey);
+ hotkeys[hotkey] = listener;
+};
+
+/**
+ * Unregister a global `hotkey`. If passed `listener` is not the one registered
+ * for the given `hotkey`, the call to this function will be ignored.
+ *
+ * @param {string} hotkey
+ * Key combination in the format of 'modifier key'.
+ * @param {function} listener
+ * Function that will be invoked when the `hotkey` is pressed.
+ */
+exports.unregister = function unregister(hotkey, listener) {
+ hotkey = normalize(hotkey);
+ if (hotkeys[hotkey] === listener)
+ delete hotkeys[hotkey];
+};
+
+/**
+ * Map of hotkeys and associated functions.
+ */
+const hotkeys = exports.hotkeys = {};
+
+keyboardObserver.on("keydown", function onKeypress(event, window) {
+ let key, modifiers = [];
+ let isChar = "isChar" in event && event.isChar;
+ let which = "which" in event ? event.which : null;
+ let keyCode = "keyCode" in event ? event.keyCode : null;
+
+ if ("shiftKey" in event && event.shiftKey)
+ modifiers.push("shift");
+ if ("altKey" in event && event.altKey)
+ modifiers.push("alt");
+ if ("ctrlKey" in event && event.ctrlKey)
+ modifiers.push("control");
+ if ("metaKey" in event && event.metaKey)
+ modifiers.push("meta");
+
+ // If it's not a printable character then we fall back to a human readable
+ // equivalent of one of the following constants.
+ // http://dxr.mozilla.org/mozilla-central/source/dom/interfaces/events/nsIDOMKeyEvent.idl
+ key = getKeyForCode(keyCode);
+
+ // If only non-function (f1 - f24) key or only modifiers are pressed we don't
+ // have a valid combination so we return immediately (Also, sometimes
+ // `keyCode` may be one for the modifier which means we do not have a
+ // modifier).
+ if (!key || (!isFunctionKey(key) && !modifiers.length) || key in MODIFIERS)
+ return;
+
+ let combination = normalize({ key: key, modifiers: modifiers });
+ let hotkey = hotkeys[combination];
+
+ if (hotkey) {
+ try {
+ hotkey();
+ } catch (exception) {
+ console.exception(exception);
+ } finally {
+ // Work around bug 582052 by preventing the (nonexistent) default action.
+ event.preventDefault();
+ }
+ }
+});