The Tor Browser: addon-sdk/source/lib/sdk/keyboard/hotkeys.js@b8a032363ba2

Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6

     1 /* This Source Code Form is subject to the terms of the Mozilla Public

     2  * License, v. 2.0. If a copy of the MPL was not distributed with this

     3  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

     5 "use strict";

     7 module.metadata = {

     8   "stability": "unstable"

     9 };

    11 const { observer: keyboardObserver } = require("./observer");

    12 const { getKeyForCode, normalize, isFunctionKey,

    13         MODIFIERS } = require("./utils");

    15 /**

    16  * Register a global `hotkey` that executes `listener` when the key combination

    17  * in `hotkey` is pressed. If more then one `listener` is registered on the same

    18  * key combination only last one will be executed.

    19  *

    20  * @param {string} hotkey

    21  *    Key combination in the format of 'modifier key'.

    22  *

    23  * Examples:

    24  *

    25  *     "accel s"

    26  *     "meta shift i"

    27  *     "control alt d"

    28  *

    29  * Modifier keynames:

    30  *

    31  *  - **shift**: The Shift key.

    32  *  - **alt**: The Alt key. On the Macintosh, this is the Option key. On

    33  *    Macintosh this can only be used in conjunction with another modifier,

    34  *    since `Alt+Letter` combinations are reserved for entering special

    35  *    characters in text.

    36  *  - **meta**: The Meta key. On the Macintosh, this is the Command key.

    37  *  - **control**: The Control key.

    38  *  - **accel**: The key used for keyboard shortcuts on the user's platform,

    39  *    which is Control on Windows and Linux, and Command on Mac. Usually, this

    40  *    would be the value you would use.

    41  *

    42  * @param {function} listener

    43  *    Function to execute when the `hotkey` is executed.

    44  */

    45 exports.register = function register(hotkey, listener) {

    46   hotkey = normalize(hotkey);

    47   hotkeys[hotkey] = listener;

    48 };

    50 /**

    51  * Unregister a global `hotkey`. If passed `listener` is not the one registered

    52  * for the given `hotkey`, the call to this function will be ignored.

    53  *

    54  * @param {string} hotkey

    55  *    Key combination in the format of 'modifier key'.

    56  * @param {function} listener

    57  *    Function that will be invoked when the `hotkey` is pressed.

    58  */

    59 exports.unregister = function unregister(hotkey, listener) {

    60   hotkey = normalize(hotkey);

    61   if (hotkeys[hotkey] === listener)

    62     delete hotkeys[hotkey];

    63 };

    65 /**

    66  * Map of hotkeys and associated functions.

    67  */

    68 const hotkeys = exports.hotkeys = {};

    70 keyboardObserver.on("keydown", function onKeypress(event, window) {

    71   let key, modifiers = [];

    72   let isChar = "isChar" in event && event.isChar;

    73   let which = "which" in event ? event.which : null;

    74   let keyCode = "keyCode" in event ? event.keyCode : null;

    76   if ("shiftKey" in event && event.shiftKey)

    77     modifiers.push("shift");

    78   if ("altKey" in event && event.altKey)

    79     modifiers.push("alt");

    80   if ("ctrlKey" in event && event.ctrlKey)

    81     modifiers.push("control");

    82   if ("metaKey" in event && event.metaKey)

    83     modifiers.push("meta");

    85   // If it's not a printable character then we fall back to a human readable

    86   // equivalent of one of the following constants.

    87   // http://mxr.mozilla.org/mozilla-central/source/dom/interfaces/events/nsIDOMKeyEvent.idl

    88   key = getKeyForCode(keyCode);

    90   // If only non-function (f1 - f24) key or only modifiers are pressed we don't

    91   // have a valid combination so we return immediately (Also, sometimes

    92   // `keyCode` may be one for the modifier which means we do not have a

    93   // modifier).

    94   if (!key || (!isFunctionKey(key) && !modifiers.length) || key in MODIFIERS)

    95     return;

    97   let combination = normalize({ key: key, modifiers: modifiers });

    98   let hotkey = hotkeys[combination];

   100   if (hotkey) {

   101     try {

   102       hotkey();

   103     } catch (exception) {

   104       console.exception(exception);

   105     } finally {

   106       // Work around bug 582052 by preventing the (nonexistent) default action.

   107       event.preventDefault();

   108     }

   109   }

   110 });

The Tor Browser / file revision