/*

* Paper.js - The Swiss Army Knife of Vector Graphics Scripting.

* http://paperjs.org/

*

* Copyright (c) 2011 - 2013, Juerg Lehni & Jonathan Puckey

* http://lehni.org/ & http://jonathanpuckey.com/

*

* Distributed under the MIT license. See LICENSE file for details.

*

* All rights reserved.

*/

/**

* @name Key

* @namespace

*/

var Key = new function() {

// TODO: Make sure the keys are called the same as in Scriptographer

// Missing: tab, cancel, clear, page-down, page-up, comma, minus, period,

// slash, etc etc etc.

var keys = {

8: 'backspace',

9: 'tab',

13: 'enter',

16: 'shift',

17: 'control',

18: 'option',

19: 'pause',

20: 'caps-lock',

27: 'escape',

32: 'space',

35: 'end',

36: 'home',

37: 'left',

38: 'up',

39: 'right',

40: 'down',

46: 'delete',

91: 'command',

93: 'command', // WebKit right command button

224: 'command' // Gecko command button

},

// Use Base.merge to convert into a Base object, for #toString()

modifiers = Base.merge({

shift: false,

control: false,

option: false,

command: false,

capsLock: false,

space: false

}),

// Since only keypress gets proper keyCodes that are actually representing

// characters, we need to perform a little trickery here to use these codes

// in onKeyDown/Up: keydown is used to store the downCode and handle

// modifiers and special keys such as arrows, space, etc, keypress fires the

// actual onKeyDown event and maps the keydown keyCode to the keypress

// charCode so keyup can do the right thing too.

charCodeMap = {}, // keyCode -> charCode mappings for pressed keys

keyMap = {}, // Map for currently pressed keys

downCode; // The last keyCode from keydown

function handleKey(down, keyCode, charCode, event) {

var character = String.fromCharCode(charCode),

key = keys[keyCode] || character.toLowerCase(),

type = down ? 'keydown' : 'keyup',

view = View._focused,

scope = view && view.isVisible() && view._scope,

tool = scope && scope._tool;

keyMap[key] = down;

if (tool && tool.responds(type)) {

// Call the onKeyDown or onKeyUp handler if present

tool.fire(type, new KeyEvent(down, key, character, event));

if (view)

view.draw(true);

}

}

DomEvent.add(document, {

keydown: function(event) {

var code = event.which || event.keyCode;

// If the keyCode is in keys, it needs to be handled by keydown and

// not in keypress after (arrows for example wont be triggering

// a keypress, but space would).

var key = keys[code], name;

if (key) {

// Detect modifiers and mark them as pressed

if ((name = Base.camelize(key)) in modifiers)

modifiers[name] = true;

// No char code for special keys, but mark as pressed

charCodeMap[code] = 0;

handleKey(true, code, null, event);

// Do not set downCode as we handled it already. Space would

// be handled twice otherwise, once here, once in keypress.

} else {

downCode = code;

}

},

keypress: function(event) {

if (downCode != null) {

var code = event.which || event.keyCode;

// Link the downCode from keydown with the code form keypress,

// so keyup can retrieve that code again.

charCodeMap[downCode] = code;

handleKey(true, downCode, code, event);

downCode = null;

}

},

keyup: function(event) {

var code = event.which || event.keyCode,

key = keys[code], name;

// Detect modifiers and mark them as released

if (key && (name = Base.camelize(key)) in modifiers)

modifiers[name] = false;

if (charCodeMap[code] != null) {

handleKey(false, code, charCodeMap[code], event);

delete charCodeMap[code];

}

}

});

return /** @lends Key */{

modifiers: modifiers,

/**

* Checks whether the specified key is pressed.

*

* @param {String} key One of: 'backspace', 'enter', 'shift', 'control',

* 'option', 'pause', 'caps-lock', 'escape', 'space', 'end', 'home',

* 'left', 'up', 'right', 'down', 'delete', 'command'

* @return {Boolean} {@true if the key is pressed}

*

* @example

* // Whenever the user clicks, create a circle shaped path. If the

* // 'a' key is pressed, fill it with red, otherwise fill it with blue:

* function onMouseDown(event) {

* var path = new Path.Circle(event.point, 10);

* if (Key.isDown('a')) {

* path.fillColor = 'red';

* } else {

* path.fillColor = 'blue';

* }

* }

*/

isDown: function(key) {

return !!keyMap[key];

}

};

};