+/*!
+ * chessboard.js v0.3.0
+ *
+ * Copyright 2013 Chris Oakman
+ * Released under the MIT license
+ * http://chessboardjs.com/license
+ *
+ * Date: 10 Aug 2013
+ */
+
+// start anonymous scope
+;(function() {
+'use strict';
+
+//------------------------------------------------------------------------------
+// Chess Util Functions
+//------------------------------------------------------------------------------
+var COLUMNS = 'abcdefgh'.split('');
+
+function validMove(move) {
+ // move should be a string
+ if (typeof move !== 'string') return false;
+
+ // move should be in the form of "e2-e4", "f6-d5"
+ var tmp = move.split('-');
+ if (tmp.length !== 2) return false;
+
+ return (validSquare(tmp[0]) === true && validSquare(tmp[1]) === true);
+}
+
+function validSquare(square) {
+ if (typeof square !== 'string') return false;
+ return (square.search(/^[a-h][1-8]$/) !== -1);
+}
+
+function validPieceCode(code) {
+ if (typeof code !== 'string') return false;
+ return (code.search(/^[bw][KQRNBP]$/) !== -1);
+}
+
+// TODO: this whole function could probably be replaced with a single regex
+function validFen(fen) {
+ if (typeof fen !== 'string') return false;
+
+ // cut off any move, castling, etc info from the end
+ // we're only interested in position information
+ fen = fen.replace(/ .+$/, '');
+
+ // FEN should be 8 sections separated by slashes
+ var chunks = fen.split('/');
+ if (chunks.length !== 8) return false;
+
+ // check the piece sections
+ for (var i = 0; i < 8; i++) {
+ if (chunks[i] === '' ||
+ chunks[i].length > 8 ||
+ chunks[i].search(/[^kqrbnpKQRNBP1-8]/) !== -1) {
+ return false;
+ }
+ }
+
+ return true;
+}
+
+function validPositionObject(pos) {
+ if (typeof pos !== 'object') return false;
+
+ for (var i in pos) {
+ if (pos.hasOwnProperty(i) !== true) continue;
+
+ if (validSquare(i) !== true || validPieceCode(pos[i]) !== true) {
+ return false;
+ }
+ }
+
+ return true;
+}
+
+// convert FEN piece code to bP, wK, etc
+function fenToPieceCode(piece) {
+ // black piece
+ if (piece.toLowerCase() === piece) {
+ return 'b' + piece.toUpperCase();
+ }
+
+ // white piece
+ return 'w' + piece.toUpperCase();
+}
+
+// convert bP, wK, etc code to FEN structure
+function pieceCodeToFen(piece) {
+ var tmp = piece.split('');
+
+ // white piece
+ if (tmp[0] === 'w') {
+ return tmp[1].toUpperCase();
+ }
+
+ // black piece
+ return tmp[1].toLowerCase();
+}
+
+// convert FEN string to position object
+// returns false if the FEN string is invalid
+function fenToObj(fen) {
+ if (validFen(fen) !== true) {
+ return false;
+ }
+
+ // cut off any move, castling, etc info from the end
+ // we're only interested in position information
+ fen = fen.replace(/ .+$/, '');
+
+ var rows = fen.split('/');
+ var position = {};
+
+ var currentRow = 8;
+ for (var i = 0; i < 8; i++) {
+ var row = rows[i].split('');
+ var colIndex = 0;
+
+ // loop through each character in the FEN section
+ for (var j = 0; j < row.length; j++) {
+ // number / empty squares
+ if (row[j].search(/[1-8]/) !== -1) {
+ var emptySquares = parseInt(row[j], 10);
+ colIndex += emptySquares;
+ }
+ // piece
+ else {
+ var square = COLUMNS[colIndex] + currentRow;
+ position[square] = fenToPieceCode(row[j]);
+ colIndex++;
+ }
+ }
+
+ currentRow--;
+ }
+
+ return position;
+}
+
+// position object to FEN string
+// returns false if the obj is not a valid position object
+function objToFen(obj) {
+ if (validPositionObject(obj) !== true) {
+ return false;
+ }
+
+ var fen = '';
+
+ var currentRow = 8;
+ for (var i = 0; i < 8; i++) {
+ for (var j = 0; j < 8; j++) {
+ var square = COLUMNS[j] + currentRow;
+
+ // piece exists
+ if (obj.hasOwnProperty(square) === true) {
+ fen += pieceCodeToFen(obj[square]);
+ }
+
+ // empty space
+ else {
+ fen += '1';
+ }
+ }
+
+ if (i !== 7) {
+ fen += '/';
+ }
+
+ currentRow--;
+ }
+
+ // squeeze the numbers together
+ // haha, I love this solution...
+ fen = fen.replace(/11111111/g, '8');
+ fen = fen.replace(/1111111/g, '7');
+ fen = fen.replace(/111111/g, '6');
+ fen = fen.replace(/11111/g, '5');
+ fen = fen.replace(/1111/g, '4');
+ fen = fen.replace(/111/g, '3');
+ fen = fen.replace(/11/g, '2');
+
+ return fen;
+}
+
+window['ChessBoard'] = window['ChessBoard'] || function(containerElOrId, cfg) {
+'use strict';
+
+cfg = cfg || {};
+
+//------------------------------------------------------------------------------
+// Constants
+//------------------------------------------------------------------------------
+
+var MINIMUM_JQUERY_VERSION = '1.7.0',
+ START_FEN = 'rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR',
+ START_POSITION = fenToObj(START_FEN);
+
+// use unique class names to prevent clashing with anything else on the page
+// and simplify selectors
+var CSS = {
+ alpha: 'alpha-d2270',
+ black: 'black-3c85d',
+ board: 'board-b72b1',
+ chessboard: 'chessboard-63f37',
+ clearfix: 'clearfix-7da63',
+ highlight1: 'highlight1-32417',
+ highlight2: 'highlight2-9c5d2',
+ notation: 'notation-322f9',
+ numeric: 'numeric-fc462',
+ piece: 'piece-417db',
+ row: 'row-5277c',
+ sparePieces: 'spare-pieces-7492f',
+ sparePiecesBottom: 'spare-pieces-bottom-ae20f',
+ sparePiecesTop: 'spare-pieces-top-4028b',
+ square: 'square-55d63',
+ white: 'white-1e1d7'
+};
+
+//------------------------------------------------------------------------------
+// Module Scope Variables
+//------------------------------------------------------------------------------
+
+// DOM elements
+var containerEl,
+ boardEl,
+ draggedPieceEl,
+ sparePiecesTopEl,
+ sparePiecesBottomEl;
+
+// constructor return object
+var widget = {};
+
+//------------------------------------------------------------------------------
+// Stateful
+//------------------------------------------------------------------------------
+
+var ANIMATION_HAPPENING = false,
+ BOARD_BORDER_SIZE = 2,
+ CURRENT_ORIENTATION = 'white',
+ CURRENT_POSITION = {},
+ SQUARE_SIZE,
+ DRAGGED_PIECE,
+ DRAGGED_PIECE_LOCATION,
+ DRAGGED_PIECE_SOURCE,
+ DRAGGING_A_PIECE = false,
+ SPARE_PIECE_ELS_IDS = {},
+ SQUARE_ELS_IDS = {},
+ SQUARE_ELS_OFFSETS;
+
+//------------------------------------------------------------------------------
+// JS Util Functions
+//------------------------------------------------------------------------------
+
+// http://stackoverflow.com/questions/105034/how-to-create-a-guid-uuid-in-javascript
+function createId() {
+ return 'xxxx-xxxx-xxxx-xxxx-xxxx-xxxx-xxxx-xxxx'.replace(/x/g, function(c) {
+ var r = Math.random() * 16 | 0;
+ return r.toString(16);
+ });
+}
+
+function deepCopy(thing) {
+ return JSON.parse(JSON.stringify(thing));
+}
+
+function parseSemVer(version) {
+ var tmp = version.split('.');
+ return {
+ major: parseInt(tmp[0], 10),
+ minor: parseInt(tmp[1], 10),
+ patch: parseInt(tmp[2], 10)
+ };
+}
+
+// returns true if version is >= minimum
+function compareSemVer(version, minimum) {
+ version = parseSemVer(version);
+ minimum = parseSemVer(minimum);
+
+ var versionNum = (version.major * 10000 * 10000) +
+ (version.minor * 10000) + version.patch;
+ var minimumNum = (minimum.major * 10000 * 10000) +
+ (minimum.minor * 10000) + minimum.patch;
+
+ return (versionNum >= minimumNum);
+}
+
+//------------------------------------------------------------------------------
+// Validation / Errors
+//------------------------------------------------------------------------------
+
+function error(code, msg, obj) {
+ // do nothing if showErrors is not set
+ if (cfg.hasOwnProperty('showErrors') !== true ||
+ cfg.showErrors === false) {
+ return;
+ }
+
+ var errorText = 'ChessBoard Error ' + code + ': ' + msg;
+
+ // print to console
+ if (cfg.showErrors === 'console' &&
+ typeof console === 'object' &&
+ typeof console.log === 'function') {
+ console.log(errorText);
+ if (arguments.length >= 2) {
+ console.log(obj);
+ }
+ return;
+ }
+
+ // alert errors
+ if (cfg.showErrors === 'alert') {
+ if (obj) {
+ errorText += '\n\n' + JSON.stringify(obj);
+ }
+ window.alert(errorText);
+ return;
+ }
+
+ // custom function
+ if (typeof cfg.showErrors === 'function') {
+ cfg.showErrors(code, msg, obj);
+ }
+}
+
+// check dependencies
+function checkDeps() {
+ // if containerId is a string, it must be the ID of a DOM node
+ if (typeof containerElOrId === 'string') {
+ // cannot be empty
+ if (containerElOrId === '') {
+ window.alert('ChessBoard Error 1001: ' +
+ 'The first argument to ChessBoard() cannot be an empty string.' +
+ '\n\nExiting...');
+ return false;
+ }
+
+ // make sure the container element exists in the DOM
+ var el = document.getElementById(containerElOrId);
+ if (! el) {
+ window.alert('ChessBoard Error 1002: Element with id "' +
+ containerElOrId + '" does not exist in the DOM.' +
+ '\n\nExiting...');
+ return false;
+ }
+
+ // set the containerEl
+ containerEl = $(el);
+ }
+
+ // else it must be something that becomes a jQuery collection
+ // with size 1
+ // ie: a single DOM node or jQuery object
+ else {
+ containerEl = $(containerElOrId);
+
+ if (containerEl.length !== 1) {
+ window.alert('ChessBoard Error 1003: The first argument to ' +
+ 'ChessBoard() must be an ID or a single DOM node.' +
+ '\n\nExiting...');
+ return false;
+ }
+ }
+
+ // JSON must exist
+ if (! window.JSON ||
+ typeof JSON.stringify !== 'function' ||
+ typeof JSON.parse !== 'function') {
+ window.alert('ChessBoard Error 1004: JSON does not exist. ' +
+ 'Please include a JSON polyfill.\n\nExiting...');
+ return false;
+ }
+
+ // check for a compatible version of jQuery
+ if (! (typeof window.$ && $.fn && $.fn.jquery &&
+ compareSemVer($.fn.jquery, MINIMUM_JQUERY_VERSION) === true)) {
+ window.alert('ChessBoard Error 1005: Unable to find a valid version ' +
+ 'of jQuery. Please include jQuery ' + MINIMUM_JQUERY_VERSION + ' or ' +
+ 'higher on the page.\n\nExiting...');
+ return false;
+ }
+
+ return true;
+}
+
+function validAnimationSpeed(speed) {
+ if (speed === 'fast' || speed === 'slow') {
+ return true;
+ }
+
+ if ((parseInt(speed, 10) + '') !== (speed + '')) {
+ return false;
+ }
+
+ return (speed >= 0);
+}
+
+// validate config / set default options
+function expandConfig() {
+ if (typeof cfg === 'string' || validPositionObject(cfg) === true) {
+ cfg = {
+ position: cfg
+ };
+ }
+
+ // default for orientation is white
+ if (cfg.orientation !== 'black') {
+ cfg.orientation = 'white';
+ }
+ CURRENT_ORIENTATION = cfg.orientation;
+
+ // default for showNotation is true
+ if (cfg.showNotation !== false) {
+ cfg.showNotation = true;
+ }
+
+ // default for draggable is false
+ if (cfg.draggable !== true) {
+ cfg.draggable = false;
+ }
+
+ // default for dropOffBoard is 'snapback'
+ if (cfg.dropOffBoard !== 'trash') {
+ cfg.dropOffBoard = 'snapback';
+ }
+
+ // default for sparePieces is false
+ if (cfg.sparePieces !== true) {
+ cfg.sparePieces = false;
+ }
+
+ // draggable must be true if sparePieces is enabled
+ if (cfg.sparePieces === true) {
+ cfg.draggable = true;
+ }
+
+ // default piece theme is wikipedia
+ if (cfg.hasOwnProperty('pieceTheme') !== true ||
+ (typeof cfg.pieceTheme !== 'string' &&
+ typeof cfg.pieceTheme !== 'function')) {
+ cfg.pieceTheme = 'img/chesspieces/wikipedia/{piece}.png';
+ }
+
+ // animation speeds
+ if (cfg.hasOwnProperty('appearSpeed') !== true ||
+ validAnimationSpeed(cfg.appearSpeed) !== true) {
+ cfg.appearSpeed = 200;
+ }
+ if (cfg.hasOwnProperty('moveSpeed') !== true ||
+ validAnimationSpeed(cfg.moveSpeed) !== true) {
+ cfg.moveSpeed = 200;
+ }
+ if (cfg.hasOwnProperty('snapbackSpeed') !== true ||
+ validAnimationSpeed(cfg.snapbackSpeed) !== true) {
+ cfg.snapbackSpeed = 50;
+ }
+ if (cfg.hasOwnProperty('snapSpeed') !== true ||
+ validAnimationSpeed(cfg.snapSpeed) !== true) {
+ cfg.snapSpeed = 25;
+ }
+ if (cfg.hasOwnProperty('trashSpeed') !== true ||
+ validAnimationSpeed(cfg.trashSpeed) !== true) {
+ cfg.trashSpeed = 100;
+ }
+
+ // make sure position is valid
+ if (cfg.hasOwnProperty('position') === true) {
+ if (cfg.position === 'start') {
+ CURRENT_POSITION = deepCopy(START_POSITION);
+ }
+
+ else if (validFen(cfg.position) === true) {
+ CURRENT_POSITION = fenToObj(cfg.position);
+ }
+
+ else if (validPositionObject(cfg.position) === true) {
+ CURRENT_POSITION = deepCopy(cfg.position);
+ }
+
+ else {
+ error(7263, 'Invalid value passed to config.position.', cfg.position);
+ }
+ }
+
+ return true;
+}
+
+//------------------------------------------------------------------------------
+// DOM Misc
+//------------------------------------------------------------------------------
+
+// calculates square size based on the width of the container
+// got a little CSS black magic here, so let me explain:
+// get the width of the container element (could be anything), reduce by 1 for
+// fudge factor, and then keep reducing until we find an exact mod 8 for
+// our square size
+function calculateSquareSize() {
+ var containerWidth = parseInt(containerEl.css('width'), 10);
+
+ // defensive, prevent infinite loop
+ if (! containerWidth || containerWidth <= 0) {
+ return 0;
+ }
+
+ // pad one pixel
+ var boardWidth = containerWidth - 1;
+
+ while (boardWidth % 8 !== 0 && boardWidth > 0) {
+ boardWidth--;
+ }
+
+ return (boardWidth / 8);
+}
+
+// create random IDs for elements
+function createElIds() {
+ // squares on the board
+ for (var i = 0; i < COLUMNS.length; i++) {
+ for (var j = 1; j <= 8; j++) {
+ var square = COLUMNS[i] + j;
+ SQUARE_ELS_IDS[square] = square + '-' + createId();
+ }
+ }
+
+ // spare pieces
+ var pieces = 'KQRBNP'.split('');
+ for (var i = 0; i < pieces.length; i++) {
+ var whitePiece = 'w' + pieces[i];
+ var blackPiece = 'b' + pieces[i];
+ SPARE_PIECE_ELS_IDS[whitePiece] = whitePiece + '-' + createId();
+ SPARE_PIECE_ELS_IDS[blackPiece] = blackPiece + '-' + createId();
+ }
+}
+
+//------------------------------------------------------------------------------
+// Markup Building
+//------------------------------------------------------------------------------
+
+function buildBoardContainer() {
+ var html = '<div class="' + CSS.chessboard + '">';
+
+ if (cfg.sparePieces === true) {
+ html += '<div class="' + CSS.sparePieces + ' ' +
+ CSS.sparePiecesTop + '"></div>';
+ }
+
+ html += '<div class="' + CSS.board + '"></div>';
+
+ if (cfg.sparePieces === true) {
+ html += '<div class="' + CSS.sparePieces + ' ' +
+ CSS.sparePiecesBottom + '"></div>';
+ }
+
+ html += '</div>';
+
+ return html;
+}
+
+/*
+var buildSquare = function(color, size, id) {
+ var html = '<div class="' + CSS.square + ' ' + CSS[color] + '" ' +
+ 'style="width: ' + size + 'px; height: ' + size + 'px" ' +
+ 'id="' + id + '">';
+
+ if (cfg.showNotation === true) {
+
+ }
+
+ html += '</div>';
+
+ return html;
+};
+*/
+
+function buildBoard(orientation) {
+ if (orientation !== 'black') {
+ orientation = 'white';
+ }
+
+ var html = '';
+
+ // algebraic notation / orientation
+ var alpha = deepCopy(COLUMNS);
+ var row = 8;
+ if (orientation === 'black') {
+ alpha.reverse();
+ row = 1;
+ }
+
+ var squareColor = 'white';
+ for (var i = 0; i < 8; i++) {
+ html += '<div class="' + CSS.row + '">';
+ for (var j = 0; j < 8; j++) {
+ var square = alpha[j] + row;
+
+ html += '<div class="' + CSS.square + ' ' + CSS[squareColor] + ' ' +
+ 'square-' + square + '" ' +
+ 'style="width: ' + SQUARE_SIZE + 'px; height: ' + SQUARE_SIZE + 'px" ' +
+ 'id="' + SQUARE_ELS_IDS[square] + '" ' +
+ 'data-square="' + square + '">';
+
+ if (cfg.showNotation === true) {
+ // alpha notation
+ if ((orientation === 'white' && row === 1) ||
+ (orientation === 'black' && row === 8)) {
+ html += '<div class="' + CSS.notation + ' ' + CSS.alpha + '">' +
+ alpha[j] + '</div>';
+ }
+
+ // numeric notation
+ if (j === 0) {
+ html += '<div class="' + CSS.notation + ' ' + CSS.numeric + '">' +
+ row + '</div>';
+ }
+ }
+
+ html += '</div>'; // end .square
+
+ squareColor = (squareColor === 'white' ? 'black' : 'white');
+ }
+ html += '<div class="' + CSS.clearfix + '"></div></div>';
+
+ squareColor = (squareColor === 'white' ? 'black' : 'white');
+
+ if (orientation === 'white') {
+ row--;
+ }
+ else {
+ row++;
+ }
+ }
+
+ return html;
+}
+
+function buildPieceImgSrc(piece) {
+ if (typeof cfg.pieceTheme === 'function') {
+ return cfg.pieceTheme(piece);
+ }
+
+ if (typeof cfg.pieceTheme === 'string') {
+ return cfg.pieceTheme.replace(/{piece}/g, piece);
+ }
+
+ // NOTE: this should never happen
+ error(8272, 'Unable to build image source for cfg.pieceTheme.');
+ return '';
+}
+
+function buildPiece(piece, hidden, id) {
+ var html = '<img src="' + buildPieceImgSrc(piece) + '" ';
+ if (id && typeof id === 'string') {
+ html += 'id="' + id + '" ';
+ }
+ html += 'alt="" ' +
+ 'class="' + CSS.piece + '" ' +
+ 'data-piece="' + piece + '" ' +
+ 'style="width: ' + SQUARE_SIZE + 'px;' +
+ 'height: ' + SQUARE_SIZE + 'px;';
+ if (hidden === true) {
+ html += 'display:none;';
+ }
+ html += '" />';
+
+ return html;
+}
+
+function buildSparePieces(color) {
+ var pieces = ['wK', 'wQ', 'wR', 'wB', 'wN', 'wP'];
+ if (color === 'black') {
+ pieces = ['bK', 'bQ', 'bR', 'bB', 'bN', 'bP'];
+ }
+
+ var html = '';
+ for (var i = 0; i < pieces.length; i++) {
+ html += buildPiece(pieces[i], false, SPARE_PIECE_ELS_IDS[pieces[i]]);
+ }
+
+ return html;
+}
+
+//------------------------------------------------------------------------------
+// Animations
+//------------------------------------------------------------------------------
+
+function animateSquareToSquare(src, dest, piece, completeFn) {
+ // get information about the source and destination squares
+ var srcSquareEl = $('#' + SQUARE_ELS_IDS[src]);
+ var srcSquarePosition = srcSquareEl.offset();
+ var destSquareEl = $('#' + SQUARE_ELS_IDS[dest]);
+ var destSquarePosition = destSquareEl.offset();
+
+ // create the animated piece and absolutely position it
+ // over the source square
+ var animatedPieceId = createId();
+ $('body').append(buildPiece(piece, true, animatedPieceId));
+ var animatedPieceEl = $('#' + animatedPieceId);
+ animatedPieceEl.css({
+ display: '',
+ position: 'absolute',
+ top: srcSquarePosition.top,
+ left: srcSquarePosition.left
+ });
+
+ // remove original piece from source square
+ srcSquareEl.find('.' + CSS.piece).remove();
+
+ // on complete
+ var complete = function() {
+ // add the "real" piece to the destination square
+ destSquareEl.append(buildPiece(piece));
+
+ // remove the animated piece
+ animatedPieceEl.remove();
+
+ // run complete function
+ if (typeof completeFn === 'function') {
+ completeFn();
+ }
+ };
+
+ // animate the piece to the destination square
+ var opts = {
+ duration: cfg.moveSpeed,
+ complete: complete
+ };
+ animatedPieceEl.animate(destSquarePosition, opts);
+}
+
+function animateSparePieceToSquare(piece, dest, completeFn) {
+ var srcOffset = $('#' + SPARE_PIECE_ELS_IDS[piece]).offset();
+ var destSquareEl = $('#' + SQUARE_ELS_IDS[dest]);
+ var destOffset = destSquareEl.offset();
+
+ // create the animate piece
+ var pieceId = createId();
+ $('body').append(buildPiece(piece, true, pieceId));
+ var animatedPieceEl = $('#' + pieceId);
+ animatedPieceEl.css({
+ display: '',
+ position: 'absolute',
+ left: srcOffset.left,
+ top: srcOffset.top
+ });
+
+ // on complete
+ var complete = function() {
+ // add the "real" piece to the destination square
+ destSquareEl.find('.' + CSS.piece).remove();
+ destSquareEl.append(buildPiece(piece));
+
+ // remove the animated piece
+ animatedPieceEl.remove();
+
+ // run complete function
+ if (typeof completeFn === 'function') {
+ completeFn();
+ }
+ };
+
+ // animate the piece to the destination square
+ var opts = {
+ duration: cfg.moveSpeed,
+ complete: complete
+ };
+ animatedPieceEl.animate(destOffset, opts);
+}
+
+// execute an array of animations
+function doAnimations(a, oldPos, newPos) {
+ ANIMATION_HAPPENING = true;
+
+ var numFinished = 0;
+ function onFinish() {
+ numFinished++;
+
+ // exit if all the animations aren't finished
+ if (numFinished !== a.length) return;
+
+ drawPositionInstant();
+ ANIMATION_HAPPENING = false;
+
+ // run their onMoveEnd function
+ if (cfg.hasOwnProperty('onMoveEnd') === true &&
+ typeof cfg.onMoveEnd === 'function') {
+ cfg.onMoveEnd(deepCopy(oldPos), deepCopy(newPos));
+ }
+ }
+
+ for (var i = 0; i < a.length; i++) {
+ // clear a piece
+ if (a[i].type === 'clear') {
+ $('#' + SQUARE_ELS_IDS[a[i].square] + ' .' + CSS.piece)
+ .fadeOut(cfg.trashSpeed, onFinish);
+ }
+
+ // add a piece (no spare pieces)
+ if (a[i].type === 'add' && cfg.sparePieces !== true) {
+ $('#' + SQUARE_ELS_IDS[a[i].square])
+ .append(buildPiece(a[i].piece, true))
+ .find('.' + CSS.piece)
+ .fadeIn(cfg.appearSpeed, onFinish);
+ }
+
+ // add a piece from a spare piece
+ if (a[i].type === 'add' && cfg.sparePieces === true) {
+ animateSparePieceToSquare(a[i].piece, a[i].square, onFinish);
+ }
+
+ // move a piece
+ if (a[i].type === 'move') {
+ animateSquareToSquare(a[i].source, a[i].destination, a[i].piece,
+ onFinish);
+ }
+ }
+}
+
+// returns the distance between two squares
+function squareDistance(s1, s2) {
+ s1 = s1.split('');
+ var s1x = COLUMNS.indexOf(s1[0]) + 1;
+ var s1y = parseInt(s1[1], 10);
+
+ s2 = s2.split('');
+ var s2x = COLUMNS.indexOf(s2[0]) + 1;
+ var s2y = parseInt(s2[1], 10);
+
+ var xDelta = Math.abs(s1x - s2x);
+ var yDelta = Math.abs(s1y - s2y);
+
+ if (xDelta >= yDelta) return xDelta;
+ return yDelta;
+}
+
+// returns an array of closest squares from square
+function createRadius(square) {
+ var squares = [];
+
+ // calculate distance of all squares
+ for (var i = 0; i < 8; i++) {
+ for (var j = 0; j < 8; j++) {
+ var s = COLUMNS[i] + (j + 1);
+
+ // skip the square we're starting from
+ if (square === s) continue;
+
+ squares.push({
+ square: s,
+ distance: squareDistance(square, s)
+ });
+ }
+ }
+
+ // sort by distance
+ squares.sort(function(a, b) {
+ return a.distance - b.distance;
+ });
+
+ // just return the square code
+ var squares2 = [];
+ for (var i = 0; i < squares.length; i++) {
+ squares2.push(squares[i].square);
+ }
+
+ return squares2;
+}
+
+// returns the square of the closest instance of piece
+// returns false if no instance of piece is found in position
+function findClosestPiece(position, piece, square) {
+ // create array of closest squares from square
+ var closestSquares = createRadius(square);
+
+ // search through the position in order of distance for the piece
+ for (var i = 0; i < closestSquares.length; i++) {
+ var s = closestSquares[i];
+
+ if (position.hasOwnProperty(s) === true && position[s] === piece) {
+ return s;
+ }
+ }
+
+ return false;
+}
+
+// calculate an array of animations that need to happen in order to get
+// from pos1 to pos2
+function calculateAnimations(pos1, pos2) {
+ // make copies of both
+ pos1 = deepCopy(pos1);
+ pos2 = deepCopy(pos2);
+
+ var animations = [];
+ var squaresMovedTo = {};
+
+ // remove pieces that are the same in both positions
+ for (var i in pos2) {
+ if (pos2.hasOwnProperty(i) !== true) continue;
+
+ if (pos1.hasOwnProperty(i) === true && pos1[i] === pos2[i]) {
+ delete pos1[i];
+ delete pos2[i];
+ }
+ }
+
+ // find all the "move" animations
+ for (var i in pos2) {
+ if (pos2.hasOwnProperty(i) !== true) continue;
+
+ var closestPiece = findClosestPiece(pos1, pos2[i], i);
+ if (closestPiece !== false) {
+ animations.push({
+ type: 'move',
+ source: closestPiece,
+ destination: i,
+ piece: pos2[i]
+ });
+
+ delete pos1[closestPiece];
+ delete pos2[i];
+ squaresMovedTo[i] = true;
+ }
+ }
+
+ // add pieces to pos2
+ for (var i in pos2) {
+ if (pos2.hasOwnProperty(i) !== true) continue;
+
+ animations.push({
+ type: 'add',
+ square: i,
+ piece: pos2[i]
+ })
+
+ delete pos2[i];
+ }
+
+ // clear pieces from pos1
+ for (var i in pos1) {
+ if (pos1.hasOwnProperty(i) !== true) continue;
+
+ // do not clear a piece if it is on a square that is the result
+ // of a "move", ie: a piece capture
+ if (squaresMovedTo.hasOwnProperty(i) === true) continue;
+
+ animations.push({
+ type: 'clear',
+ square: i,
+ piece: pos1[i]
+ });
+
+ delete pos1[i];
+ }
+
+ return animations;
+}
+
+//------------------------------------------------------------------------------
+// Control Flow
+//------------------------------------------------------------------------------
+
+function drawPositionInstant() {
+ // clear the board
+ boardEl.find('.' + CSS.piece).remove();
+
+ // add the pieces
+ for (var i in CURRENT_POSITION) {
+ if (CURRENT_POSITION.hasOwnProperty(i) !== true) continue;
+
+ $('#' + SQUARE_ELS_IDS[i]).append(buildPiece(CURRENT_POSITION[i]));
+ }
+}
+
+function drawBoard() {
+ boardEl.html(buildBoard(CURRENT_ORIENTATION));
+ drawPositionInstant();
+
+ if (cfg.sparePieces === true) {
+ if (CURRENT_ORIENTATION === 'white') {
+ sparePiecesTopEl.html(buildSparePieces('black'));
+ sparePiecesBottomEl.html(buildSparePieces('white'));
+ }
+ else {
+ sparePiecesTopEl.html(buildSparePieces('white'));
+ sparePiecesBottomEl.html(buildSparePieces('black'));
+ }
+ }
+}
+
+// given a position and a set of moves, return a new position
+// with the moves executed
+function calculatePositionFromMoves(position, moves) {
+ position = deepCopy(position);
+
+ for (var i in moves) {
+ if (moves.hasOwnProperty(i) !== true) continue;
+
+ // skip the move if the position doesn't have a piece on the source square
+ if (position.hasOwnProperty(i) !== true) continue;
+
+ var piece = position[i];
+ delete position[i];
+ position[moves[i]] = piece;
+ }
+
+ return position;
+}
+
+function setCurrentPosition(position) {
+ var oldPos = deepCopy(CURRENT_POSITION);
+ var newPos = deepCopy(position);
+ var oldFen = objToFen(oldPos);
+ var newFen = objToFen(newPos);
+
+ // do nothing if no change in position
+ if (oldFen === newFen) return;
+
+ // run their onChange function
+ if (cfg.hasOwnProperty('onChange') === true &&
+ typeof cfg.onChange === 'function') {
+ cfg.onChange(oldPos, newPos);
+ }
+
+ // update state
+ CURRENT_POSITION = position;
+}
+
+function isXYOnSquare(x, y) {
+ for (var i in SQUARE_ELS_OFFSETS) {
+ if (SQUARE_ELS_OFFSETS.hasOwnProperty(i) !== true) continue;
+
+ var s = SQUARE_ELS_OFFSETS[i];
+ if (x >= s.left && x < s.left + SQUARE_SIZE &&
+ y >= s.top && y < s.top + SQUARE_SIZE) {
+ return i;
+ }
+ }
+
+ return 'offboard';
+}
+
+// records the XY coords of every square into memory
+function captureSquareOffsets() {
+ SQUARE_ELS_OFFSETS = {};
+
+ for (var i in SQUARE_ELS_IDS) {
+ if (SQUARE_ELS_IDS.hasOwnProperty(i) !== true) continue;
+
+ SQUARE_ELS_OFFSETS[i] = $('#' + SQUARE_ELS_IDS[i]).offset();
+ }
+}
+
+function removeSquareHighlights() {
+ boardEl.find('.' + CSS.square)
+ .removeClass(CSS.highlight1 + ' ' + CSS.highlight2);
+}
+
+function snapbackDraggedPiece() {
+ // there is no "snapback" for spare pieces
+ if (DRAGGED_PIECE_SOURCE === 'spare') {
+ trashDraggedPiece();
+ return;
+ }
+
+ removeSquareHighlights();
+
+ // animation complete
+ function complete() {
+ drawPositionInstant();
+ draggedPieceEl.css('display', 'none');
+
+ // run their onSnapbackEnd function
+ if (cfg.hasOwnProperty('onSnapbackEnd') === true &&
+ typeof cfg.onSnapbackEnd === 'function') {
+ cfg.onSnapbackEnd(DRAGGED_PIECE, DRAGGED_PIECE_SOURCE,
+ deepCopy(CURRENT_POSITION), CURRENT_ORIENTATION);
+ }
+ }
+
+ // get source square position
+ var sourceSquarePosition =
+ $('#' + SQUARE_ELS_IDS[DRAGGED_PIECE_SOURCE]).offset();
+
+ // animate the piece to the target square
+ var opts = {
+ duration: cfg.snapbackSpeed,
+ complete: complete
+ };
+ draggedPieceEl.animate(sourceSquarePosition, opts);
+
+ // set state
+ DRAGGING_A_PIECE = false;
+}
+
+function trashDraggedPiece() {
+ removeSquareHighlights();
+
+ // remove the source piece
+ var newPosition = deepCopy(CURRENT_POSITION);
+ delete newPosition[DRAGGED_PIECE_SOURCE];
+ setCurrentPosition(newPosition);
+
+ // redraw the position
+ drawPositionInstant();
+
+ // hide the dragged piece
+ draggedPieceEl.fadeOut(cfg.trashSpeed);
+
+ // set state
+ DRAGGING_A_PIECE = false;
+}
+
+function dropDraggedPieceOnSquare(square) {
+ removeSquareHighlights();
+
+ // update position
+ var newPosition = deepCopy(CURRENT_POSITION);
+ delete newPosition[DRAGGED_PIECE_SOURCE];
+ newPosition[square] = DRAGGED_PIECE;
+ setCurrentPosition(newPosition);
+
+ // get target square information
+ var targetSquarePosition = $('#' + SQUARE_ELS_IDS[square]).offset();
+
+ // animation complete
+ var complete = function() {
+ drawPositionInstant();
+ draggedPieceEl.css('display', 'none');
+
+ // execute their onSnapEnd function
+ if (cfg.hasOwnProperty('onSnapEnd') === true &&
+ typeof cfg.onSnapEnd === 'function') {
+ cfg.onSnapEnd(DRAGGED_PIECE_SOURCE, square, DRAGGED_PIECE);
+ }
+ };
+
+ // snap the piece to the target square
+ var opts = {
+ duration: cfg.snapSpeed,
+ complete: complete
+ };
+ draggedPieceEl.animate(targetSquarePosition, opts);
+
+ // set state
+ DRAGGING_A_PIECE = false;
+}
+
+function beginDraggingPiece(source, piece, x, y) {
+ // run their custom onDragStart function
+ // their custom onDragStart function can cancel drag start
+ if (typeof cfg.onDragStart === 'function' &&
+ cfg.onDragStart(source, piece,
+ deepCopy(CURRENT_POSITION), CURRENT_ORIENTATION) === false) {
+ return;
+ }
+
+ // set state
+ DRAGGING_A_PIECE = true;
+ DRAGGED_PIECE = piece;
+ DRAGGED_PIECE_SOURCE = source;
+
+ // if the piece came from spare pieces, location is offboard
+ if (source === 'spare') {
+ DRAGGED_PIECE_LOCATION = 'offboard';
+ }
+ else {
+ DRAGGED_PIECE_LOCATION = source;
+ }
+
+ // capture the x, y coords of all squares in memory
+ captureSquareOffsets();
+
+ // create the dragged piece
+ draggedPieceEl.attr('src', buildPieceImgSrc(piece))
+ .css({
+ display: '',
+ position: 'absolute',
+ left: x - (SQUARE_SIZE / 2),
+ top: y - (SQUARE_SIZE / 2)
+ });
+
+ if (source !== 'spare') {
+ // highlight the source square and hide the piece
+ $('#' + SQUARE_ELS_IDS[source]).addClass(CSS.highlight1)
+ .find('.' + CSS.piece).css('display', 'none');
+ }
+}
+
+function updateDraggedPiece(x, y) {
+ // put the dragged piece over the mouse cursor
+ draggedPieceEl.css({
+ left: x - (SQUARE_SIZE / 2),
+ top: y - (SQUARE_SIZE / 2)
+ });
+
+ // get location
+ var location = isXYOnSquare(x, y);
+
+ // do nothing if the location has not changed
+ if (location === DRAGGED_PIECE_LOCATION) return;
+
+ // remove highlight from previous square
+ if (validSquare(DRAGGED_PIECE_LOCATION) === true) {
+ $('#' + SQUARE_ELS_IDS[DRAGGED_PIECE_LOCATION])
+ .removeClass(CSS.highlight2);
+ }
+
+ // add highlight to new square
+ if (validSquare(location) === true) {
+ $('#' + SQUARE_ELS_IDS[location]).addClass(CSS.highlight2);
+ }
+
+ // run onDragMove
+ if (typeof cfg.onDragMove === 'function') {
+ cfg.onDragMove(location, DRAGGED_PIECE_LOCATION,
+ DRAGGED_PIECE_SOURCE, DRAGGED_PIECE,
+ deepCopy(CURRENT_POSITION), CURRENT_ORIENTATION);
+ }
+
+ // update state
+ DRAGGED_PIECE_LOCATION = location;
+}
+
+function stopDraggedPiece(location) {
+ // determine what the action should be
+ var action = 'drop';
+ if (location === 'offboard' && cfg.dropOffBoard === 'snapback') {
+ action = 'snapback';
+ }
+ if (location === 'offboard' && cfg.dropOffBoard === 'trash') {
+ action = 'trash';
+ }
+
+ // run their onDrop function, which can potentially change the drop action
+ if (cfg.hasOwnProperty('onDrop') === true &&
+ typeof cfg.onDrop === 'function') {
+ var newPosition = deepCopy(CURRENT_POSITION);
+
+ // source piece is a spare piece and position is off the board
+ //if (DRAGGED_PIECE_SOURCE === 'spare' && location === 'offboard') {...}
+ // position has not changed; do nothing
+
+ // source piece is a spare piece and position is on the board
+ if (DRAGGED_PIECE_SOURCE === 'spare' && validSquare(location) === true) {
+ // add the piece to the board
+ newPosition[location] = DRAGGED_PIECE;
+ }
+
+ // source piece was on the board and position is off the board
+ if (validSquare(DRAGGED_PIECE_SOURCE) === true && location === 'offboard') {
+ // remove the piece from the board
+ delete newPosition[DRAGGED_PIECE_SOURCE];
+ }
+
+ // source piece was on the board and position is on the board
+ if (validSquare(DRAGGED_PIECE_SOURCE) === true &&
+ validSquare(location) === true) {
+ // move the piece
+ delete newPosition[DRAGGED_PIECE_SOURCE];
+ newPosition[location] = DRAGGED_PIECE;
+ }
+
+ var oldPosition = deepCopy(CURRENT_POSITION);
+
+ var result = cfg.onDrop(DRAGGED_PIECE_SOURCE, location, DRAGGED_PIECE,
+ newPosition, oldPosition, CURRENT_ORIENTATION);
+ if (result === 'snapback' || result === 'trash') {
+ action = result;
+ }
+ }
+
+ // do it!
+ if (action === 'snapback') {
+ snapbackDraggedPiece();
+ }
+ else if (action === 'trash') {
+ trashDraggedPiece();
+ }
+ else if (action === 'drop') {
+ dropDraggedPieceOnSquare(location);
+ }
+}
+
+//------------------------------------------------------------------------------
+// Public Methods
+//------------------------------------------------------------------------------
+
+// clear the board
+widget.clear = function(useAnimation) {
+ widget.position({}, useAnimation);
+};
+
+/*
+// get or set config properties
+// TODO: write this, GitHub Issue #1
+widget.config = function(arg1, arg2) {
+ // get the current config
+ if (arguments.length === 0) {
+ return deepCopy(cfg);
+ }
+};
+*/
+
+// remove the widget from the page
+widget.destroy = function() {
+ // remove markup
+ containerEl.html('');
+ draggedPieceEl.remove();
+
+ // remove event handlers
+ containerEl.unbind();
+};
+
+// shorthand method to get the current FEN
+widget.fen = function() {
+ return widget.position('fen');
+};
+
+// flip orientation
+widget.flip = function() {
+ widget.orientation('flip');
+};
+
+/*
+// TODO: write this, GitHub Issue #5
+widget.highlight = function() {
+
+};
+*/
+
+// move pieces
+widget.move = function() {
+ // no need to throw an error here; just do nothing
+ if (arguments.length === 0) return;
+
+ var useAnimation = true;
+
+ // collect the moves into an object
+ var moves = {};
+ for (var i = 0; i < arguments.length; i++) {
+ // any "false" to this function means no animations
+ if (arguments[i] === false) {
+ useAnimation = false;
+ continue;
+ }
+
+ // skip invalid arguments
+ if (validMove(arguments[i]) !== true) {
+ error(2826, 'Invalid move passed to the move method.', arguments[i]);
+ continue;
+ }
+
+ var tmp = arguments[i].split('-');
+ moves[tmp[0]] = tmp[1];
+ }
+
+ // calculate position from moves
+ var newPos = calculatePositionFromMoves(CURRENT_POSITION, moves);
+
+ // update the board
+ widget.position(newPos, useAnimation);
+
+ // return the new position object
+ return newPos;
+};
+
+widget.orientation = function(arg) {
+ // no arguments, return the current orientation
+ if (arguments.length === 0) {
+ return CURRENT_ORIENTATION;
+ }
+
+ // set to white or black
+ if (arg === 'white' || arg === 'black') {
+ CURRENT_ORIENTATION = arg;
+ drawBoard();
+ return;
+ }
+
+ // flip orientation
+ if (arg === 'flip') {
+ CURRENT_ORIENTATION = (CURRENT_ORIENTATION === 'white') ? 'black' : 'white';
+ drawBoard();
+ return;
+ }
+
+ error(5482, 'Invalid value passed to the orientation method.', arg);
+};
+
+widget.position = function(position, useAnimation) {
+ // no arguments, return the current position
+ if (arguments.length === 0) {
+ return deepCopy(CURRENT_POSITION);
+ }
+
+ // get position as FEN
+ if (typeof position === 'string' && position.toLowerCase() === 'fen') {
+ return objToFen(CURRENT_POSITION);
+ }
+
+ // default for useAnimations is true
+ if (useAnimation !== false) {
+ useAnimation = true;
+ }
+
+ // start position
+ if (typeof position === 'string' && position.toLowerCase() === 'start') {
+ position = deepCopy(START_POSITION);
+ }
+
+ // convert FEN to position object
+ if (validFen(position) === true) {
+ position = fenToObj(position);
+ }
+
+ // validate position object
+ if (validPositionObject(position) !== true) {
+ error(6482, 'Invalid value passed to the position method.', position);
+ return;
+ }
+
+ if (useAnimation === true) {
+ // start the animations
+ doAnimations(calculateAnimations(CURRENT_POSITION, position),
+ CURRENT_POSITION, position);
+
+ // set the new position
+ setCurrentPosition(position);
+ }
+ // instant update
+ else {
+ setCurrentPosition(position);
+ drawPositionInstant();
+ }
+};
+
+widget.resize = function() {
+ // calulate the new square size
+ SQUARE_SIZE = calculateSquareSize();
+
+ // set board width
+ boardEl.css('width', (SQUARE_SIZE * 8) + 'px');
+
+ // set drag piece size
+ draggedPieceEl.css({
+ height: SQUARE_SIZE,
+ width: SQUARE_SIZE
+ });
+
+ // spare pieces
+ if (cfg.sparePieces === true) {
+ containerEl.find('.' + CSS.sparePieces)
+ .css('paddingLeft', (SQUARE_SIZE + BOARD_BORDER_SIZE) + 'px');
+ }
+
+ // redraw the board
+ drawBoard();
+};
+
+// set the starting position
+widget.start = function(useAnimation) {
+ widget.position('start', useAnimation);
+};
+
+//------------------------------------------------------------------------------
+// Browser Events
+//------------------------------------------------------------------------------
+
+function isTouchDevice() {
+ return ('ontouchstart' in document.documentElement);
+}
+
+// reference: http://www.quirksmode.org/js/detect.html
+function isMSIE() {
+ return (navigator && navigator.userAgent &&
+ navigator.userAgent.search(/MSIE/) !== -1);
+}
+
+function stopDefault(e) {
+ e.preventDefault();
+}
+
+function mousedownSquare(e) {
+ // do nothing if we're not draggable
+ if (cfg.draggable !== true) return;
+
+ var square = $(this).attr('data-square');
+
+ // no piece on this square
+ if (validSquare(square) !== true ||
+ CURRENT_POSITION.hasOwnProperty(square) !== true) {
+ return;
+ }
+
+ beginDraggingPiece(square, CURRENT_POSITION[square], e.pageX, e.pageY);
+}
+
+function touchstartSquare(e) {
+ // do nothing if we're not draggable
+ if (cfg.draggable !== true) return;
+
+ var square = $(this).attr('data-square');
+
+ // no piece on this square
+ if (validSquare(square) !== true ||
+ CURRENT_POSITION.hasOwnProperty(square) !== true) {
+ return;
+ }
+
+ e = e.originalEvent;
+ beginDraggingPiece(square, CURRENT_POSITION[square],
+ e.changedTouches[0].pageX, e.changedTouches[0].pageY);
+}
+
+function mousedownSparePiece(e) {
+ // do nothing if sparePieces is not enabled
+ if (cfg.sparePieces !== true) return;
+
+ var piece = $(this).attr('data-piece');
+
+ beginDraggingPiece('spare', piece, e.pageX, e.pageY);
+}
+
+function touchstartSparePiece(e) {
+ // do nothing if sparePieces is not enabled
+ if (cfg.sparePieces !== true) return;
+
+ var piece = $(this).attr('data-piece');
+
+ e = e.originalEvent;
+ beginDraggingPiece('spare', piece,
+ e.changedTouches[0].pageX, e.changedTouches[0].pageY);
+}
+
+function mousemoveWindow(e) {
+ // do nothing if we are not dragging a piece
+ if (DRAGGING_A_PIECE !== true) return;
+
+ updateDraggedPiece(e.pageX, e.pageY);
+}
+
+function touchmoveWindow(e) {
+ // do nothing if we are not dragging a piece
+ if (DRAGGING_A_PIECE !== true) return;
+
+ // prevent screen from scrolling
+ e.preventDefault();
+
+ updateDraggedPiece(e.originalEvent.changedTouches[0].pageX,
+ e.originalEvent.changedTouches[0].pageY);
+}
+
+function mouseupWindow(e) {
+ // do nothing if we are not dragging a piece
+ if (DRAGGING_A_PIECE !== true) return;
+
+ // get the location
+ var location = isXYOnSquare(e.pageX, e.pageY);
+
+ stopDraggedPiece(location);
+}
+
+function touchendWindow(e) {
+ // do nothing if we are not dragging a piece
+ if (DRAGGING_A_PIECE !== true) return;
+
+ // get the location
+ var location = isXYOnSquare(e.originalEvent.changedTouches[0].pageX,
+ e.originalEvent.changedTouches[0].pageY);
+
+ stopDraggedPiece(location);
+}
+
+function mouseenterSquare(e) {
+ // do not fire this event if we are dragging a piece
+ // NOTE: this should never happen, but it's a safeguard
+ if (DRAGGING_A_PIECE !== false) return;
+
+ if (cfg.hasOwnProperty('onMouseoverSquare') !== true ||
+ typeof cfg.onMouseoverSquare !== 'function') return;
+
+ // get the square
+ var square = $(e.currentTarget).attr('data-square');
+
+ // NOTE: this should never happen; defensive
+ if (validSquare(square) !== true) return;
+
+ // get the piece on this square
+ var piece = false;
+ if (CURRENT_POSITION.hasOwnProperty(square) === true) {
+ piece = CURRENT_POSITION[square];
+ }
+
+ // execute their function
+ cfg.onMouseoverSquare(square, piece, deepCopy(CURRENT_POSITION),
+ CURRENT_ORIENTATION);
+}
+
+function mouseleaveSquare(e) {
+ // do not fire this event if we are dragging a piece
+ // NOTE: this should never happen, but it's a safeguard
+ if (DRAGGING_A_PIECE !== false) return;
+
+ if (cfg.hasOwnProperty('onMouseoutSquare') !== true ||
+ typeof cfg.onMouseoutSquare !== 'function') return;
+
+ // get the square
+ var square = $(e.currentTarget).attr('data-square');
+
+ // NOTE: this should never happen; defensive
+ if (validSquare(square) !== true) return;
+
+ // get the piece on this square
+ var piece = false;
+ if (CURRENT_POSITION.hasOwnProperty(square) === true) {
+ piece = CURRENT_POSITION[square];
+ }
+
+ // execute their function
+ cfg.onMouseoutSquare(square, piece, deepCopy(CURRENT_POSITION),
+ CURRENT_ORIENTATION);
+}
+
+//------------------------------------------------------------------------------
+// Initialization
+//------------------------------------------------------------------------------
+
+function addEvents() {
+ // prevent browser "image drag"
+ $('body').on('mousedown mousemove', '.' + CSS.piece, stopDefault);
+
+ // mouse drag pieces
+ boardEl.on('mousedown', '.' + CSS.square, mousedownSquare);
+ containerEl.on('mousedown', '.' + CSS.sparePieces + ' .' + CSS.piece,
+ mousedownSparePiece);
+
+ // mouse enter / leave square
+ boardEl.on('mouseenter', '.' + CSS.square, mouseenterSquare);
+ boardEl.on('mouseleave', '.' + CSS.square, mouseleaveSquare);
+
+ // IE doesn't like the events on the window object, but other browsers
+ // perform better that way
+ if (isMSIE() === true) {
+ // IE-specific prevent browser "image drag"
+ document.ondragstart = function() { return false; };
+
+ $('body').on('mousemove', mousemoveWindow);
+ $('body').on('mouseup', mouseupWindow);
+ }
+ else {
+ $(window).on('mousemove', mousemoveWindow);
+ $(window).on('mouseup', mouseupWindow);
+ }
+
+ // touch drag pieces
+ if (isTouchDevice() === true) {
+ boardEl.on('touchstart', '.' + CSS.square, touchstartSquare);
+ containerEl.on('touchstart', '.' + CSS.sparePieces + ' .' + CSS.piece,
+ touchstartSparePiece);
+ $(window).on('touchmove', touchmoveWindow);
+ $(window).on('touchend', touchendWindow);
+ }
+}
+
+function initDom() {
+ // build board and save it in memory
+ containerEl.html(buildBoardContainer());
+ boardEl = containerEl.find('.' + CSS.board);
+
+ if (cfg.sparePieces === true) {
+ sparePiecesTopEl = containerEl.find('.' + CSS.sparePiecesTop);
+ sparePiecesBottomEl = containerEl.find('.' + CSS.sparePiecesBottom);
+ }
+
+ // create the drag piece
+ var draggedPieceId = createId();
+ $('body').append(buildPiece('wP', true, draggedPieceId));
+ draggedPieceEl = $('#' + draggedPieceId);
+
+ // get the border size
+ BOARD_BORDER_SIZE = parseInt(boardEl.css('borderLeftWidth'), 10);
+
+ // set the size and draw the board
+ widget.resize();
+}
+
+function init() {
+ if (checkDeps() !== true ||
+ expandConfig() !== true) return;
+
+ // create unique IDs for all the elements we will create
+ createElIds();
+
+ initDom();
+ addEvents();
+}
+
+// go time
+init();
+
+// return the widget object
+return widget;
+
+}; // end window.ChessBoard
+
+// expose util functions
+window.ChessBoard.fenToObj = fenToObj;
+window.ChessBoard.objToFen = objToFen;
+
+})(); // end anonymous wrapper