discourse/vendor/assets/javascripts/mousetrap.js
2013-10-01 11:16:27 -04:00

865 lines
25 KiB
JavaScript

/**
* Copyright 2012 Craig Campbell
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* Mousetrap is a simple keyboard shortcut library for Javascript with
* no external dependencies
*
* @version 1.2.2
* @url craig.is/killing/mice
*/
(function() {
/**
* mapping of special keycodes to their corresponding keys
*
* everything in this dictionary cannot use keypress events
* so it has to be here to map to the correct keycodes for
* keyup/keydown events
*
* @type {Object}
*/
var _MAP = {
8: 'backspace',
9: 'tab',
13: 'enter',
16: 'shift',
17: 'ctrl',
18: 'alt',
20: 'capslock',
27: 'esc',
32: 'space',
33: 'pageup',
34: 'pagedown',
35: 'end',
36: 'home',
37: 'left',
38: 'up',
39: 'right',
40: 'down',
45: 'ins',
46: 'del',
91: 'meta',
93: 'meta',
224: 'meta'
},
/**
* mapping for special characters so they can support
*
* this dictionary is only used incase you want to bind a
* keyup or keydown event to one of these keys
*
* @type {Object}
*/
_KEYCODE_MAP = {
106: '*',
107: '+',
109: '-',
110: '.',
111 : '/',
186: ';',
187: '=',
188: ',',
189: '-',
190: '.',
191: '/',
192: '`',
219: '[',
220: '\\',
221: ']',
222: '\''
},
/**
* this is a mapping of keys that require shift on a US keypad
* back to the non shift equivelents
*
* this is so you can use keyup events with these keys
*
* note that this will only work reliably on US keyboards
*
* @type {Object}
*/
_SHIFT_MAP = {
'~': '`',
'!': '1',
'@': '2',
'#': '3',
'$': '4',
'%': '5',
'^': '6',
'&': '7',
'*': '8',
'(': '9',
')': '0',
'_': '-',
'+': '=',
':': ';',
'\"': '\'',
'<': ',',
'>': '.',
'?': '/',
'|': '\\'
},
/**
* this is a list of special strings you can use to map
* to modifier keys when you specify your keyboard shortcuts
*
* @type {Object}
*/
_SPECIAL_ALIASES = {
'option': 'alt',
'command': 'meta',
'return': 'enter',
'escape': 'esc'
},
/**
* variable to store the flipped version of _MAP from above
* needed to check if we should use keypress or not when no action
* is specified
*
* @type {Object|undefined}
*/
_REVERSE_MAP,
/**
* a list of all the callbacks setup via Mousetrap.bind()
*
* @type {Object}
*/
_callbacks = {},
/**
* direct map of string combinations to callbacks used for trigger()
*
* @type {Object}
*/
_direct_map = {},
/**
* keeps track of what level each sequence is at since multiple
* sequences can start out with the same sequence
*
* @type {Object}
*/
_sequence_levels = {},
/**
* variable to store the setTimeout call
*
* @type {null|number}
*/
_reset_timer,
/**
* temporary state where we will ignore the next keyup
*
* @type {boolean|string}
*/
_ignore_next_keyup = false,
/**
* are we currently inside of a sequence?
* type of action ("keyup" or "keydown" or "keypress") or false
*
* @type {boolean|string}
*/
_sequence_type = false;
/**
* loop through the f keys, f1 to f19 and add them to the map
* programatically
*/
for (var i = 1; i < 20; ++i) {
_MAP[111 + i] = 'f' + i;
}
/**
* loop through to map numbers on the numeric keypad
*/
for (i = 0; i <= 9; ++i) {
_MAP[i + 96] = i;
}
/**
* cross browser add event method
*
* @param {Element|HTMLDocument} object
* @param {string} type
* @param {Function} callback
* @returns void
*/
function _addEvent(object, type, callback) {
if (object.addEventListener) {
object.addEventListener(type, callback, false);
return;
}
object.attachEvent('on' + type, callback);
}
/**
* takes the event and returns the key character
*
* @param {Event} e
* @return {string}
*/
function _characterFromEvent(e) {
// for keypress events we should return the character as is
if (e.type == 'keypress') {
return String.fromCharCode(e.which);
}
// for non keypress events the special maps are needed
if (_MAP[e.which]) {
return _MAP[e.which];
}
if (_KEYCODE_MAP[e.which]) {
return _KEYCODE_MAP[e.which];
}
// if it is not in the special map
return String.fromCharCode(e.which).toLowerCase();
}
/**
* checks if two arrays are equal
*
* @param {Array} modifiers1
* @param {Array} modifiers2
* @returns {boolean}
*/
function _modifiersMatch(modifiers1, modifiers2) {
return modifiers1.sort().join(',') === modifiers2.sort().join(',');
}
/**
* resets all sequence counters except for the ones passed in
*
* @param {Object} do_not_reset
* @returns void
*/
function _resetSequences(do_not_reset, max_level) {
do_not_reset = do_not_reset || {};
var active_sequences = false,
key;
for (key in _sequence_levels) {
if (do_not_reset[key] && _sequence_levels[key] > max_level) {
active_sequences = true;
continue;
}
_sequence_levels[key] = 0;
}
if (!active_sequences) {
_sequence_type = false;
}
}
/**
* finds all callbacks that match based on the keycode, modifiers,
* and action
*
* @param {string} character
* @param {Array} modifiers
* @param {Event|Object} e
* @param {boolean=} remove - should we remove any matches
* @param {string=} combination
* @returns {Array}
*/
function _getMatches(character, modifiers, e, remove, combination) {
var i,
callback,
matches = [],
action = e.type;
// if there are no events related to this keycode
if (!_callbacks[character]) {
return [];
}
// if a modifier key is coming up on its own we should allow it
if (action == 'keyup' && _isModifier(character)) {
modifiers = [character];
}
// loop through all callbacks for the key that was pressed
// and see if any of them match
for (i = 0; i < _callbacks[character].length; ++i) {
callback = _callbacks[character][i];
// if this is a sequence but it is not at the right level
// then move onto the next match
if (callback.seq && _sequence_levels[callback.seq] != callback.level) {
continue;
}
// if the action we are looking for doesn't match the action we got
// then we should keep going
if (action != callback.action) {
continue;
}
// if this is a keypress event and the meta key and control key
// are not pressed that means that we need to only look at the
// character, otherwise check the modifiers as well
//
// chrome will not fire a keypress if meta or control is down
// safari will fire a keypress if meta or meta+shift is down
// firefox will fire a keypress if meta or control is down
if ((action == 'keypress' && !e.metaKey && !e.ctrlKey) || _modifiersMatch(modifiers, callback.modifiers)) {
// remove is used so if you change your mind and call bind a
// second time with a new function the first one is overwritten
if (remove && callback.combo == combination) {
_callbacks[character].splice(i, 1);
}
matches.push(callback);
}
}
return matches;
}
/**
* takes a key event and figures out what the modifiers are
*
* @param {Event} e
* @returns {Array}
*/
function _eventModifiers(e) {
var modifiers = [];
if (e.shiftKey) {
modifiers.push('shift');
}
if (e.altKey) {
modifiers.push('alt');
}
if (e.ctrlKey) {
modifiers.push('ctrl');
}
if (e.metaKey) {
modifiers.push('meta');
}
return modifiers;
}
/**
* actually calls the callback function
*
* if your callback function returns false this will use the jquery
* convention - prevent default and stop propogation on the event
*
* @param {Function} callback
* @param {Event} e
* @returns void
*/
function _fireCallback(callback, e, combo) {
// if this event should not happen stop here
if (Mousetrap.stopCallback(e, e.target || e.srcElement, combo)) {
return;
}
if (callback(e, combo) === false) {
if (e.preventDefault) {
e.preventDefault();
}
if (e.stopPropagation) {
e.stopPropagation();
}
e.returnValue = false;
e.cancelBubble = true;
}
}
/**
* handles a character key event
*
* @param {string} character
* @param {Event} e
* @returns void
*/
function _handleCharacter(character, e) {
var callbacks = _getMatches(character, _eventModifiers(e), e),
i,
do_not_reset = {},
max_level = 0,
processed_sequence_callback = false;
// loop through matching callbacks for this key event
for (i = 0; i < callbacks.length; ++i) {
// fire for all sequence callbacks
// this is because if for example you have multiple sequences
// bound such as "g i" and "g t" they both need to fire the
// callback for matching g cause otherwise you can only ever
// match the first one
if (callbacks[i].seq) {
processed_sequence_callback = true;
// as we loop through keep track of the max
// any sequence at a lower level will be discarded
max_level = Math.max(max_level, callbacks[i].level);
// keep a list of which sequences were matches for later
do_not_reset[callbacks[i].seq] = 1;
_fireCallback(callbacks[i].callback, e, callbacks[i].combo);
continue;
}
// if there were no sequence matches but we are still here
// that means this is a regular match so we should fire that
if (!processed_sequence_callback && !_sequence_type) {
_fireCallback(callbacks[i].callback, e, callbacks[i].combo);
}
}
// if you are inside of a sequence and the key you are pressing
// is not a modifier key then we should reset all sequences
// that were not matched by this key event
if (e.type == _sequence_type && !_isModifier(character)) {
_resetSequences(do_not_reset, max_level);
}
}
/**
* handles a keydown event
*
* @param {Event} e
* @returns void
*/
function _handleKey(e) {
// normalize e.which for key events
// @see http://stackoverflow.com/questions/4285627/javascript-keycode-vs-charcode-utter-confusion
if (typeof e.which !== 'number') {
e.which = e.keyCode;
}
var character = _characterFromEvent(e);
// no character found then stop
if (!character) {
return;
}
if (e.type == 'keyup' && _ignore_next_keyup == character) {
_ignore_next_keyup = false;
return;
}
_handleCharacter(character, e);
}
/**
* determines if the keycode specified is a modifier key or not
*
* @param {string} key
* @returns {boolean}
*/
function _isModifier(key) {
return key == 'shift' || key == 'ctrl' || key == 'alt' || key == 'meta';
}
/**
* called to set a 1 second timeout on the specified sequence
*
* this is so after each key press in the sequence you have 1 second
* to press the next key before you have to start over
*
* @returns void
*/
function _resetSequenceTimer() {
clearTimeout(_reset_timer);
_reset_timer = setTimeout(_resetSequences, 1000);
}
/**
* reverses the map lookup so that we can look for specific keys
* to see what can and can't use keypress
*
* @return {Object}
*/
function _getReverseMap() {
if (!_REVERSE_MAP) {
_REVERSE_MAP = {};
for (var key in _MAP) {
// pull out the numeric keypad from here cause keypress should
// be able to detect the keys from the character
if (key > 95 && key < 112) {
continue;
}
if (_MAP.hasOwnProperty(key)) {
_REVERSE_MAP[_MAP[key]] = key;
}
}
}
return _REVERSE_MAP;
}
/**
* picks the best action based on the key combination
*
* @param {string} key - character for key
* @param {Array} modifiers
* @param {string=} action passed in
*/
function _pickBestAction(key, modifiers, action) {
// if no action was picked in we should try to pick the one
// that we think would work best for this key
if (!action) {
action = _getReverseMap()[key] ? 'keydown' : 'keypress';
}
// modifier keys don't work as expected with keypress,
// switch to keydown
if (action == 'keypress' && modifiers.length) {
action = 'keydown';
}
return action;
}
/**
* binds a key sequence to an event
*
* @param {string} combo - combo specified in bind call
* @param {Array} keys
* @param {Function} callback
* @param {string=} action
* @returns void
*/
function _bindSequence(combo, keys, callback, action) {
// start off by adding a sequence level record for this combination
// and setting the level to 0
_sequence_levels[combo] = 0;
// if there is no action pick the best one for the first key
// in the sequence
if (!action) {
action = _pickBestAction(keys[0], []);
}
/**
* callback to increase the sequence level for this sequence and reset
* all other sequences that were active
*
* @param {Event} e
* @returns void
*/
var _increaseSequence = function(e) {
_sequence_type = action;
++_sequence_levels[combo];
_resetSequenceTimer();
},
/**
* wraps the specified callback inside of another function in order
* to reset all sequence counters as soon as this sequence is done
*
* @param {Event} e
* @returns void
*/
_callbackAndReset = function(e) {
_fireCallback(callback, e, combo);
// we should ignore the next key up if the action is key down
// or keypress. this is so if you finish a sequence and
// release the key the final key will not trigger a keyup
if (action !== 'keyup') {
_ignore_next_keyup = _characterFromEvent(e);
}
// weird race condition if a sequence ends with the key
// another sequence begins with
setTimeout(_resetSequences, 10);
},
i;
// loop through keys one at a time and bind the appropriate callback
// function. for any key leading up to the final one it should
// increase the sequence. after the final, it should reset all sequences
for (i = 0; i < keys.length; ++i) {
_bindSingle(keys[i], i < keys.length - 1 ? _increaseSequence : _callbackAndReset, action, combo, i);
}
}
/**
* binds a single keyboard combination
*
* @param {string} combination
* @param {Function} callback
* @param {string=} action
* @param {string=} sequence_name - name of sequence if part of sequence
* @param {number=} level - what part of the sequence the command is
* @returns void
*/
function _bindSingle(combination, callback, action, sequence_name, level) {
// make sure multiple spaces in a row become a single space
combination = combination.replace(/\s+/g, ' ');
var sequence = combination.split(' '),
i,
key,
keys,
modifiers = [];
// if this pattern is a sequence of keys then run through this method
// to reprocess each pattern one key at a time
if (sequence.length > 1) {
_bindSequence(combination, sequence, callback, action);
return;
}
// take the keys from this pattern and figure out what the actual
// pattern is all about
keys = combination === '+' ? ['+'] : combination.split('+');
for (i = 0; i < keys.length; ++i) {
key = keys[i];
// normalize key names
if (_SPECIAL_ALIASES[key]) {
key = _SPECIAL_ALIASES[key];
}
// if this is not a keypress event then we should
// be smart about using shift keys
// this will only work for US keyboards however
if (action && action != 'keypress' && _SHIFT_MAP[key]) {
key = _SHIFT_MAP[key];
modifiers.push('shift');
}
// if this key is a modifier then add it to the list of modifiers
if (_isModifier(key)) {
modifiers.push(key);
}
}
// depending on what the key combination is
// we will try to pick the best event for it
action = _pickBestAction(key, modifiers, action);
// make sure to initialize array if this is the first time
// a callback is added for this key
if (!_callbacks[key]) {
_callbacks[key] = [];
}
// remove an existing match if there is one
_getMatches(key, modifiers, {type: action}, !sequence_name, combination);
// add this call back to the array
// if it is a sequence put it at the beginning
// if not put it at the end
//
// this is important because the way these are processed expects
// the sequence ones to come first
_callbacks[key][sequence_name ? 'unshift' : 'push']({
callback: callback,
modifiers: modifiers,
action: action,
seq: sequence_name,
level: level,
combo: combination
});
}
/**
* binds multiple combinations to the same callback
*
* @param {Array} combinations
* @param {Function} callback
* @param {string|undefined} action
* @returns void
*/
function _bindMultiple(combinations, callback, action) {
for (var i = 0; i < combinations.length; ++i) {
_bindSingle(combinations[i], callback, action);
}
}
// start!
_addEvent(document, 'keypress', _handleKey);
_addEvent(document, 'keydown', _handleKey);
_addEvent(document, 'keyup', _handleKey);
var Mousetrap = {
/**
* binds an event to mousetrap
*
* can be a single key, a combination of keys separated with +,
* an array of keys, or a sequence of keys separated by spaces
*
* be sure to list the modifier keys first to make sure that the
* correct key ends up getting bound (the last key in the pattern)
*
* @param {string|Array} keys
* @param {Function} callback
* @param {string=} action - 'keypress', 'keydown', or 'keyup'
* @returns void
*/
bind: function(keys, callback, action) {
_bindMultiple(keys instanceof Array ? keys : [keys], callback, action);
_direct_map[keys + ':' + action] = callback;
return this;
},
/**
* unbinds an event to mousetrap
*
* the unbinding sets the callback function of the specified key combo
* to an empty function and deletes the corresponding key in the
* _direct_map dict.
*
* the keycombo+action has to be exactly the same as
* it was defined in the bind method
*
* TODO: actually remove this from the _callbacks dictionary instead
* of binding an empty function
*
* @param {string|Array} keys
* @param {string} action
* @returns void
*/
unbind: function(keys, action) {
if (_direct_map[keys + ':' + action]) {
delete _direct_map[keys + ':' + action];
this.bind(keys, function() {}, action);
}
return this;
},
/**
* triggers an event that has already been bound
*
* @param {string} keys
* @param {string=} action
* @returns void
*/
trigger: function(keys, action) {
_direct_map[keys + ':' + action]();
return this;
},
/**
* resets the library back to its initial state. this is useful
* if you want to clear out the current keyboard shortcuts and bind
* new ones - for example if you switch to another page
*
* @returns void
*/
reset: function() {
_callbacks = {};
_direct_map = {};
return this;
},
/**
* should we stop this event before firing off callbacks
*
* @param {Event} e
* @param {Element} element
* @return {boolean}
*/
stopCallback: function(e, element, combo) {
// if the element has the class "mousetrap" then no need to stop
if ((' ' + element.className + ' ').indexOf(' mousetrap ') > -1) {
return false;
}
// stop for input, select, and textarea
return element.tagName == 'INPUT' || element.tagName == 'SELECT' || element.tagName == 'TEXTAREA' || (element.contentEditable && element.contentEditable == 'true');
}
};
// expose mousetrap to the global object
window.Mousetrap = Mousetrap;
// expose mousetrap as an AMD module
if (typeof define === 'function' && define.amd) {
define(Mousetrap);
}
}) ();
/**
* adds a bindGlobal method to Mousetrap that allows you to
* bind specific keyboard shortcuts that will still work
* inside a text input field
*
* usage:
* Mousetrap.bindGlobal('ctrl+s', _saveChanges);
*/
Mousetrap = (function(Mousetrap) {
var _global_callbacks = {},
_original_stop_callback = Mousetrap.stopCallback;
Mousetrap.stopCallback = function(e, element, combo) {
if (_global_callbacks[combo]) {
return false;
}
return _original_stop_callback(e, element, combo);
};
Mousetrap.bindGlobal = function(keys, callback, action) {
Mousetrap.bind(keys, callback, action);
if (keys instanceof Array) {
for (var i = 0; i < keys.length; i++) {
_global_callbacks[keys[i]] = true;
}
return;
}
_global_callbacks[keys] = true;
};
Mousetrap.unbindGlobal = function(keys) {
if (keys instanceof Array) {
for (var i = 0; i < keys.length; i++) {
_global_callbacks[keys[i]] = false;
}
return;
}
};
return Mousetrap;
}) (Mousetrap);