2 * chessboard.js v0.3.0+asn
4 * Copyright 2013 Chris Oakman
5 * Portions copyright 2022 Steinar H. Gunderson
6 * Released under the MIT license
7 * http://chessboardjs.com/license
12 // start anonymous scope
16 //------------------------------------------------------------------------------
17 // Chess Util Functions
18 //------------------------------------------------------------------------------
19 var COLUMNS = 'abcdefgh'.split('');
21 function validMove(move) {
22 // move should be a string
23 if (typeof move !== 'string') return false;
25 // move should be in the form of "e2-e4", "f6-d5"
26 var tmp = move.split('-');
27 if (tmp.length !== 2) return false;
29 return (validSquare(tmp[0]) === true && validSquare(tmp[1]) === true);
32 function validSquare(square) {
33 if (typeof square !== 'string') return false;
34 return (square.search(/^[a-h][1-8]$/) !== -1);
37 function validPieceCode(code) {
38 if (typeof code !== 'string') return false;
39 return (code.search(/^[bw][KQRNBP]$/) !== -1);
42 // TODO: this whole function could probably be replaced with a single regex
43 function validFen(fen) {
44 if (typeof fen !== 'string') return false;
46 // cut off any move, castling, etc info from the end
47 // we're only interested in position information
48 fen = fen.replace(/ .+$/, '');
50 // FEN should be 8 sections separated by slashes
51 var chunks = fen.split('/');
52 if (chunks.length !== 8) return false;
54 // check the piece sections
55 for (var i = 0; i < 8; i++) {
56 if (chunks[i] === '' ||
57 chunks[i].length > 8 ||
58 chunks[i].search(/[^kqrbnpKQRNBP1-8]/) !== -1) {
66 function validPositionObject(pos) {
67 if (typeof pos !== 'object') return false;
70 if (pos.hasOwnProperty(i) !== true) continue;
72 if (validSquare(i) !== true || validPieceCode(pos[i]) !== true) {
80 // convert FEN piece code to bP, wK, etc
81 function fenToPieceCode(piece) {
83 if (piece.toLowerCase() === piece) {
84 return 'b' + piece.toUpperCase();
88 return 'w' + piece.toUpperCase();
91 // convert bP, wK, etc code to FEN structure
92 function pieceCodeToFen(piece) {
93 var tmp = piece.split('');
97 return tmp[1].toUpperCase();
101 return tmp[1].toLowerCase();
104 // convert FEN string to position object
105 // returns false if the FEN string is invalid
106 function fenToObj(fen) {
107 if (validFen(fen) !== true) {
111 // cut off any move, castling, etc info from the end
112 // we're only interested in position information
113 fen = fen.replace(/ .+$/, '');
115 var rows = fen.split('/');
119 for (var i = 0; i < 8; i++) {
120 var row = rows[i].split('');
123 // loop through each character in the FEN section
124 for (var j = 0; j < row.length; j++) {
125 // number / empty squares
126 if (row[j].search(/[1-8]/) !== -1) {
127 var emptySquares = parseInt(row[j], 10);
128 colIndex += emptySquares;
132 var square = COLUMNS[colIndex] + currentRow;
133 position[square] = fenToPieceCode(row[j]);
144 // position object to FEN string
145 // returns false if the obj is not a valid position object
146 function objToFen(obj) {
147 if (validPositionObject(obj) !== true) {
154 for (var i = 0; i < 8; i++) {
155 for (var j = 0; j < 8; j++) {
156 var square = COLUMNS[j] + currentRow;
159 if (obj.hasOwnProperty(square) === true) {
160 fen += pieceCodeToFen(obj[square]);
176 // squeeze the numbers together
177 // haha, I love this solution...
178 fen = fen.replace(/11111111/g, '8');
179 fen = fen.replace(/1111111/g, '7');
180 fen = fen.replace(/111111/g, '6');
181 fen = fen.replace(/11111/g, '5');
182 fen = fen.replace(/1111/g, '4');
183 fen = fen.replace(/111/g, '3');
184 fen = fen.replace(/11/g, '2');
193 window.ChessBoard = function(containerElOrId, cfg) {
198 //------------------------------------------------------------------------------
200 //------------------------------------------------------------------------------
202 var MINIMUM_JQUERY_VERSION = '1.7.0',
203 START_FEN = 'rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR',
204 START_POSITION = fenToObj(START_FEN);
206 // use unique class names to prevent clashing with anything else on the page
207 // and simplify selectors
209 alpha: 'alpha-d2270',
210 board: 'board-b72b1',
211 chessboard: 'chessboard-63f37',
212 clearfix: 'clearfix-7da63',
213 highlight1: 'highlight1-32417',
214 highlight2: 'highlight2-9c5d2',
215 notation: 'notation-322f9',
216 numeric: 'numeric-fc462',
217 piece: 'piece-417db',
219 sparePieces: 'spare-pieces-7492f',
220 sparePiecesBottom: 'spare-pieces-bottom-ae20f',
221 sparePiecesTop: 'spare-pieces-top-4028b',
222 square: 'square-55d63'
225 CSSColor['white'] = 'white-1e1d7';
226 CSSColor['black'] = 'black-3c85d';
228 //------------------------------------------------------------------------------
229 // Module Scope Variables
230 //------------------------------------------------------------------------------
239 // constructor return object
242 //------------------------------------------------------------------------------
244 //------------------------------------------------------------------------------
246 var ANIMATION_HAPPENING = false,
247 BOARD_BORDER_SIZE = 2,
248 CURRENT_ORIENTATION = 'white',
249 CURRENT_POSITION = {},
252 DRAGGED_PIECE_LOCATION,
253 DRAGGED_PIECE_SOURCE,
254 DRAGGING_A_PIECE = false,
255 SPARE_PIECE_ELS_IDS = {},
259 //------------------------------------------------------------------------------
261 //------------------------------------------------------------------------------
263 // http://stackoverflow.com/questions/105034/how-to-create-a-guid-uuid-in-javascript
264 function createId() {
265 return 'xxxx-xxxx-xxxx-xxxx-xxxx-xxxx-xxxx-xxxx'.replace(/x/g, function(c) {
266 var r = Math.random() * 16 | 0;
267 return r.toString(16);
271 function deepCopy(thing) {
272 return JSON.parse(JSON.stringify(thing));
275 function parseSemVer(version) {
276 var tmp = version.split('.');
278 major: parseInt(tmp[0], 10),
279 minor: parseInt(tmp[1], 10),
280 patch: parseInt(tmp[2], 10)
284 // returns true if version is >= minimum
285 function compareSemVer(version, minimum) {
286 version = parseSemVer(version);
287 minimum = parseSemVer(minimum);
289 var versionNum = (version.major * 10000 * 10000) +
290 (version.minor * 10000) + version.patch;
291 var minimumNum = (minimum.major * 10000 * 10000) +
292 (minimum.minor * 10000) + minimum.patch;
294 return (versionNum >= minimumNum);
297 //------------------------------------------------------------------------------
298 // Validation / Errors
299 //------------------------------------------------------------------------------
302 * @param {!number} code
303 * @param {!string} msg
304 * @param {Object=} obj
306 function error(code, msg, obj) {
307 // do nothing if showErrors is not set
308 if (cfg.hasOwnProperty('showErrors') !== true ||
309 cfg.showErrors === false) {
313 var errorText = 'ChessBoard Error ' + code + ': ' + msg;
316 if (cfg.showErrors === 'console' &&
317 typeof console === 'object' &&
318 typeof console.log === 'function') {
319 console.log(errorText);
320 if (arguments.length >= 2) {
327 if (cfg.showErrors === 'alert') {
329 errorText += '\n\n' + JSON.stringify(obj);
331 window.alert(errorText);
336 if (typeof cfg.showErrors === 'function') {
337 cfg.showErrors(code, msg, obj);
341 // check dependencies
342 function checkDeps() {
343 // if containerId is a string, it must be the ID of a DOM node
344 if (typeof containerElOrId === 'string') {
346 if (containerElOrId === '') {
347 window.alert('ChessBoard Error 1001: ' +
348 'The first argument to ChessBoard() cannot be an empty string.' +
353 // make sure the container element exists in the DOM
354 var el = document.getElementById(containerElOrId);
356 window.alert('ChessBoard Error 1002: Element with id "' +
357 containerElOrId + '" does not exist in the DOM.' +
362 // set the containerEl
366 // else it must be a DOM node
368 containerEl = containerElOrId;
374 function validAnimationSpeed(speed) {
375 if (speed === 'fast' || speed === 'slow') {
379 if ((parseInt(speed, 10) + '') !== (speed + '')) {
386 // validate config / set default options
387 function expandConfig() {
388 if (typeof cfg === 'string' || validPositionObject(cfg) === true) {
394 // default for orientation is white
395 if (cfg.orientation !== 'black') {
396 cfg.orientation = 'white';
398 CURRENT_ORIENTATION = cfg.orientation;
400 // default for showNotation is true
401 if (cfg.showNotation !== false) {
402 cfg.showNotation = true;
405 // default for draggable is false
406 if (cfg.draggable !== true) {
407 cfg.draggable = false;
410 // default for dropOffBoard is 'snapback'
411 if (cfg.dropOffBoard !== 'trash') {
412 cfg.dropOffBoard = 'snapback';
415 // default for sparePieces is false
416 if (cfg.sparePieces !== true) {
417 cfg.sparePieces = false;
420 // draggable must be true if sparePieces is enabled
421 if (cfg.sparePieces === true) {
422 cfg.draggable = true;
425 // default piece theme is wikipedia
426 if (cfg.hasOwnProperty('pieceTheme') !== true ||
427 (typeof cfg.pieceTheme !== 'string' &&
428 typeof cfg.pieceTheme !== 'function')) {
429 cfg.pieceTheme = 'img/chesspieces/wikipedia/{piece}.png';
433 if (cfg.hasOwnProperty('appearSpeed') !== true ||
434 validAnimationSpeed(cfg.appearSpeed) !== true) {
435 cfg.appearSpeed = 200;
437 if (cfg.hasOwnProperty('moveSpeed') !== true ||
438 validAnimationSpeed(cfg.moveSpeed) !== true) {
441 if (cfg.hasOwnProperty('snapbackSpeed') !== true ||
442 validAnimationSpeed(cfg.snapbackSpeed) !== true) {
443 cfg.snapbackSpeed = 50;
445 if (cfg.hasOwnProperty('snapSpeed') !== true ||
446 validAnimationSpeed(cfg.snapSpeed) !== true) {
449 if (cfg.hasOwnProperty('trashSpeed') !== true ||
450 validAnimationSpeed(cfg.trashSpeed) !== true) {
451 cfg.trashSpeed = 100;
454 // make sure position is valid
455 if (cfg.hasOwnProperty('position') === true) {
456 if (cfg.position === 'start') {
457 CURRENT_POSITION = deepCopy(START_POSITION);
460 else if (validFen(cfg.position) === true) {
461 CURRENT_POSITION = fenToObj(cfg.position);
464 else if (validPositionObject(cfg.position) === true) {
465 CURRENT_POSITION = deepCopy(cfg.position);
469 error(7263, 'Invalid value passed to config.position.', cfg.position);
476 //------------------------------------------------------------------------------
478 //------------------------------------------------------------------------------
480 // calculates square size based on the width of the container
481 // got a little CSS black magic here, so let me explain:
482 // get the width of the container element (could be anything), reduce by 1 for
483 // fudge factor, and then keep reducing until we find an exact mod 8 for
485 function calculateSquareSize() {
486 var containerWidth = parseInt(getComputedStyle(containerEl).width, 10);
488 // defensive, prevent infinite loop
489 if (! containerWidth || containerWidth <= 0) {
494 var boardWidth = containerWidth - 1;
496 while (boardWidth % 8 !== 0 && boardWidth > 0) {
500 return (boardWidth / 8);
503 // create random IDs for elements
504 function createElIds() {
505 // squares on the board
506 for (var i = 0; i < COLUMNS.length; i++) {
507 for (var j = 1; j <= 8; j++) {
508 var square = COLUMNS[i] + j;
509 SQUARE_ELS_IDS[square] = square + '-' + createId();
514 var pieces = 'KQRBNP'.split('');
515 for (var i = 0; i < pieces.length; i++) {
516 var whitePiece = 'w' + pieces[i];
517 var blackPiece = 'b' + pieces[i];
518 SPARE_PIECE_ELS_IDS[whitePiece] = whitePiece + '-' + createId();
519 SPARE_PIECE_ELS_IDS[blackPiece] = blackPiece + '-' + createId();
523 //------------------------------------------------------------------------------
525 //------------------------------------------------------------------------------
527 function buildBoardContainer() {
528 var html = '<div class="' + CSS.chessboard + '">';
530 if (cfg.sparePieces === true) {
531 html += '<div class="' + CSS.sparePieces + ' ' +
532 CSS.sparePiecesTop + '"></div>';
535 html += '<div class="' + CSS.board + '"></div>';
537 if (cfg.sparePieces === true) {
538 html += '<div class="' + CSS.sparePieces + ' ' +
539 CSS.sparePiecesBottom + '"></div>';
548 var buildSquare = function(color, size, id) {
549 var html = '<div class="' + CSS.square + ' ' + CSSColor[color] + '" ' +
550 'style="width: ' + size + 'px; height: ' + size + 'px" ' +
553 if (cfg.showNotation === true) {
563 function buildBoard(orientation) {
564 if (orientation !== 'black') {
565 orientation = 'white';
570 // algebraic notation / orientation
571 var alpha = deepCopy(COLUMNS);
573 if (orientation === 'black') {
578 var squareColor = 'white';
579 for (var i = 0; i < 8; i++) {
580 html += '<div class="' + CSS.row + '">';
581 for (var j = 0; j < 8; j++) {
582 var square = alpha[j] + row;
584 html += '<div class="' + CSS.square + ' ' + CSSColor[squareColor] + ' ' +
585 'square-' + square + '" ' +
586 'style="width: ' + SQUARE_SIZE + 'px; height: ' + SQUARE_SIZE + 'px" ' +
587 'id="' + SQUARE_ELS_IDS[square] + '" ' +
588 'data-square="' + square + '">';
590 if (cfg.showNotation === true) {
592 if ((orientation === 'white' && row === 1) ||
593 (orientation === 'black' && row === 8)) {
594 html += '<div class="' + CSS.notation + ' ' + CSS.alpha + '">' +
600 html += '<div class="' + CSS.notation + ' ' + CSS.numeric + '">' +
605 html += '</div>'; // end .square
607 squareColor = (squareColor === 'white' ? 'black' : 'white');
609 html += '<div class="' + CSS.clearfix + '"></div></div>';
611 squareColor = (squareColor === 'white' ? 'black' : 'white');
613 if (orientation === 'white') {
624 function buildPieceImgSrc(piece) {
625 if (typeof cfg.pieceTheme === 'function') {
626 return cfg.pieceTheme(piece);
629 if (typeof cfg.pieceTheme === 'string') {
630 return cfg.pieceTheme.replace(/{piece}/g, piece);
633 // NOTE: this should never happen
634 error(8272, 'Unable to build image source for cfg.pieceTheme.');
639 * @param {!string} piece
640 * @param {boolean=} hidden
641 * @param {!string=} id
643 function buildPiece(piece, hidden, id) {
644 var html = '<img src="' + buildPieceImgSrc(piece) + '" ';
645 if (id && typeof id === 'string') {
646 html += 'id="' + id + '" ';
649 'class="' + CSS.piece + '" ' +
650 'data-piece="' + piece + '" ' +
651 'style="width: ' + SQUARE_SIZE + 'px;' +
652 'height: ' + SQUARE_SIZE + 'px;';
653 if (hidden === true) {
654 html += 'display:none;';
658 let elem = document.createElement('template');
659 elem.innerHTML = html;
663 function buildSparePieces(color) {
664 var pieces = ['wK', 'wQ', 'wR', 'wB', 'wN', 'wP'];
665 if (color === 'black') {
666 pieces = ['bK', 'bQ', 'bR', 'bB', 'bN', 'bP'];
670 for (var i = 0; i < pieces.length; i++) {
671 html += buildPiece(pieces[i], false, SPARE_PIECE_ELS_IDS[pieces[i]]);
677 //------------------------------------------------------------------------------
679 //------------------------------------------------------------------------------
681 function offset(el) { // From https://youmightnotneedjquery.com/.
682 let box = el.getBoundingClientRect();
683 let docElem = document.documentElement;
685 top: box.top + window.pageYOffset - docElem.clientTop,
686 left: box.left + window.pageXOffset - docElem.clientLeft
690 function animateSquareToSquare(src, dest, piece, completeFn) {
691 // get information about the source and destination squares
692 var srcSquareEl = document.getElementById(SQUARE_ELS_IDS[src]);
693 var srcSquarePosition = offset(srcSquareEl);
694 var destSquareEl = document.getElementById(SQUARE_ELS_IDS[dest]);
695 var destSquarePosition = offset(destSquareEl);
697 // create the animated piece and absolutely position it
698 // over the source square
699 var animatedPieceId = createId();
700 document.body.append(buildPiece(piece, true, animatedPieceId));
701 var animatedPieceEl = document.getElementById(animatedPieceId);
702 animatedPieceEl.style.display = null;
703 animatedPieceEl.style.position = 'absolute';
704 animatedPieceEl.style.top = srcSquarePosition.top + 'px';
705 animatedPieceEl.style.left = srcSquarePosition.left + 'px';
707 // remove original piece(s) from source square
708 // TODO: multiple pieces should never really happen, but it will if we are moving
709 // while another animation still isn't done
710 srcSquareEl.querySelectorAll('.' + CSS.piece).forEach((piece) => piece.remove());
713 var complete = function() {
714 // add the "real" piece to the destination square
715 destSquareEl.append(buildPiece(piece));
717 // remove the animated piece
718 animatedPieceEl.remove();
720 // run complete function
721 if (typeof completeFn === 'function') {
726 // animate the piece to the destination square
727 animatedPieceEl.addEventListener('transitionend', complete, {once: true});
728 requestAnimationFrame(() => {
729 animatedPieceEl.style.transitionProperty = 'top left';
730 animatedPieceEl.style.transitionDuration = cfg.moveSpeed + 'ms';
731 animatedPieceEl.style.top = destSquarePosition.top + 'px';
732 animatedPieceEl.style.left = destSquarePosition.left + 'px';
736 function animateSparePieceToSquare(piece, dest, completeFn) {
737 var srcOffset = offset(document.getelementById(SPARE_PIECE_ELS_IDS[piece]));
738 var destSquareEl = document.getElementById(SQUARE_ELS_IDS[dest]);
739 var destOffset = offset(destSquareEl);
741 // create the animate piece
742 var pieceId = createId();
743 document.body.append(buildPiece(piece, true, pieceId));
744 var animatedPieceEl = document.getElementById(pieceId);
745 animatedPieceEl.style.display = '';
746 animatedPieceEl.style.position = 'absolute';
747 animatedPieceEl.style.left = srcOffset.left;
748 animatedPieceEl.style.top = srcOffset.top;
751 var complete = function() {
752 // add the "real" piece to the destination square
753 destSquareEl.querySelector('.' + CSS.piece).remove();
754 destSquareEl.append(buildPiece(piece));
756 // remove the animated piece
757 animatedPieceEl.remove();
759 // run complete function
760 if (typeof completeFn === 'function') {
765 // animate the piece to the destination square
766 // FIXME: support this for non-jquery
768 duration: cfg.moveSpeed,
771 //$(animatedPieceEl).animate(destOffset, opts);
774 function fadeIn(piece, onFinish) {
775 piece.style.opacity = 0;
776 piece.style.display = null;
777 piece.addEventListener('transitionend', onFinish, {once: true});
778 requestAnimationFrame(() => {
779 piece.style.transitionProperty = 'opacity';
780 piece.style.transitionDuration = cfg.appearSpeed + 'ms';
781 piece.style.opacity = 1;
785 function fadeOut(piece, onFinish) {
786 piece.style.opacity = 1;
787 piece.style.display = null;
788 piece.addEventListener('transitionend', onFinish, {once: true});
789 requestAnimationFrame(() => {
790 piece.style.transitionProperty = 'opacity';
791 piece.style.transitionDuration = cfg.trashSpeed + 'ms';
792 piece.style.opacity = 0;
796 // execute an array of animations
797 function doAnimations(a, oldPos, newPos) {
798 ANIMATION_HAPPENING = true;
801 function onFinish(e) {
803 e.target.transitionProperty = null;
808 // exit if all the animations aren't finished
809 if (numFinished !== a.length) return;
811 drawPositionInstant();
812 ANIMATION_HAPPENING = false;
814 // run their onMoveEnd function
815 if (cfg.hasOwnProperty('onMoveEnd') === true &&
816 typeof cfg.onMoveEnd === 'function') {
817 cfg.onMoveEnd(deepCopy(oldPos), deepCopy(newPos));
821 for (var i = 0; i < a.length; i++) {
823 if (a[i].type === 'clear') {
824 document.getElementById(SQUARE_ELS_IDS[a[i].square]).querySelectorAll('.' + CSS.piece).forEach(
825 (piece) => fadeOut(piece, onFinish)
829 // add a piece (no spare pieces)
830 if (a[i].type === 'add' && cfg.sparePieces !== true) {
831 let square = document.getElementById(SQUARE_ELS_IDS[a[i].square]);
832 square.append(buildPiece(a[i].piece, true));
833 let piece = square.querySelector('.' + CSS.piece);
834 fadeIn(piece, onFinish);
837 // add a piece from a spare piece
838 if (a[i].type === 'add' && cfg.sparePieces === true) {
839 animateSparePieceToSquare(a[i].piece, a[i].square, onFinish);
843 if (a[i].type === 'move') {
844 animateSquareToSquare(a[i].source, a[i].destination, a[i].piece,
850 // returns the distance between two squares
851 function squareDistance(s1, s2) {
853 var s1x = COLUMNS.indexOf(s1[0]) + 1;
854 var s1y = parseInt(s1[1], 10);
857 var s2x = COLUMNS.indexOf(s2[0]) + 1;
858 var s2y = parseInt(s2[1], 10);
860 var xDelta = Math.abs(s1x - s2x);
861 var yDelta = Math.abs(s1y - s2y);
863 if (xDelta >= yDelta) return xDelta;
867 // returns an array of closest squares from square
868 function createRadius(square) {
871 // calculate distance of all squares
872 for (var i = 0; i < 8; i++) {
873 for (var j = 0; j < 8; j++) {
874 var s = COLUMNS[i] + (j + 1);
876 // skip the square we're starting from
877 if (square === s) continue;
881 distance: squareDistance(square, s)
887 squares.sort(function(a, b) {
888 return a.distance - b.distance;
891 // just return the square code
893 for (var i = 0; i < squares.length; i++) {
894 squares2.push(squares[i].square);
900 // returns the square of the closest instance of piece
901 // returns false if no instance of piece is found in position
902 function findClosestPiece(position, piece, square) {
903 // create array of closest squares from square
904 var closestSquares = createRadius(square);
906 // search through the position in order of distance for the piece
907 for (var i = 0; i < closestSquares.length; i++) {
908 var s = closestSquares[i];
910 if (position.hasOwnProperty(s) === true && position[s] === piece) {
918 // calculate an array of animations that need to happen in order to get
920 function calculateAnimations(pos1, pos2) {
921 // make copies of both
922 pos1 = deepCopy(pos1);
923 pos2 = deepCopy(pos2);
926 var squaresMovedTo = {};
928 // remove pieces that are the same in both positions
929 for (var i in pos2) {
930 if (pos2.hasOwnProperty(i) !== true) continue;
932 if (pos1.hasOwnProperty(i) === true && pos1[i] === pos2[i]) {
938 // find all the "move" animations
939 for (var i in pos2) {
940 if (pos2.hasOwnProperty(i) !== true) continue;
942 var closestPiece = findClosestPiece(pos1, pos2[i], i);
943 if (closestPiece !== false) {
946 source: closestPiece,
951 delete pos1[closestPiece];
953 squaresMovedTo[i] = true;
957 // add pieces to pos2
958 for (var i in pos2) {
959 if (pos2.hasOwnProperty(i) !== true) continue;
970 // clear pieces from pos1
971 for (var i in pos1) {
972 if (pos1.hasOwnProperty(i) !== true) continue;
974 // do not clear a piece if it is on a square that is the result
975 // of a "move", ie: a piece capture
976 if (squaresMovedTo.hasOwnProperty(i) === true) continue;
990 //------------------------------------------------------------------------------
992 //------------------------------------------------------------------------------
994 function drawPositionInstant() {
996 boardEl.querySelectorAll('.' + CSS.piece).forEach((piece) => piece.remove());
999 for (var i in CURRENT_POSITION) {
1000 if (CURRENT_POSITION.hasOwnProperty(i) !== true) continue;
1002 document.getElementById(SQUARE_ELS_IDS[i]).append(buildPiece(CURRENT_POSITION[i]));
1006 function drawBoard() {
1007 boardEl.innerHTML = buildBoard(CURRENT_ORIENTATION);
1008 drawPositionInstant();
1010 if (cfg.sparePieces === true) {
1011 if (CURRENT_ORIENTATION === 'white') {
1012 sparePiecesTopEl.innerHTML = buildSparePieces('black');
1013 sparePiecesBottomEl.innerHTML = buildSparePieces('white');
1016 sparePiecesTopEl.innerHTML = buildSparePieces('white');
1017 sparePiecesBottomEl.innerHTML = buildSparePieces('black');
1022 // given a position and a set of moves, return a new position
1023 // with the moves executed
1024 function calculatePositionFromMoves(position, moves) {
1025 position = deepCopy(position);
1027 for (var i in moves) {
1028 if (moves.hasOwnProperty(i) !== true) continue;
1030 // skip the move if the position doesn't have a piece on the source square
1031 if (position.hasOwnProperty(i) !== true) continue;
1033 var piece = position[i];
1035 position[moves[i]] = piece;
1041 function setCurrentPosition(position) {
1042 var oldPos = deepCopy(CURRENT_POSITION);
1043 var newPos = deepCopy(position);
1044 var oldFen = objToFen(oldPos);
1045 var newFen = objToFen(newPos);
1047 // do nothing if no change in position
1048 if (oldFen === newFen) return;
1050 // run their onChange function
1051 if (cfg.hasOwnProperty('onChange') === true &&
1052 typeof cfg.onChange === 'function') {
1053 cfg.onChange(oldPos, newPos);
1057 CURRENT_POSITION = position;
1060 function isXYOnSquare(x, y) {
1061 for (var i in SQUARE_ELS_OFFSETS) {
1062 if (SQUARE_ELS_OFFSETS.hasOwnProperty(i) !== true) continue;
1064 var s = SQUARE_ELS_OFFSETS[i];
1065 if (x >= s.left && x < s.left + SQUARE_SIZE &&
1066 y >= s.top && y < s.top + SQUARE_SIZE) {
1074 // records the XY coords of every square into memory
1075 function captureSquareOffsets() {
1076 SQUARE_ELS_OFFSETS = {};
1078 for (var i in SQUARE_ELS_IDS) {
1079 if (SQUARE_ELS_IDS.hasOwnProperty(i) !== true) continue;
1081 SQUARE_ELS_OFFSETS[i] = offset(document.getElementById(SQUARE_ELS_IDS[i]));
1085 function removeSquareHighlights() {
1086 boardEl.querySelectorAll('.' + CSS.square).forEach((piece) => {
1087 piece.classList.remove(CSS.highlight1);
1088 piece.classList.remove(CSS.highlight2);
1092 function snapbackDraggedPiece() {
1093 // there is no "snapback" for spare pieces
1094 if (DRAGGED_PIECE_SOURCE === 'spare') {
1095 trashDraggedPiece();
1099 removeSquareHighlights();
1101 // animation complete
1102 function complete() {
1103 drawPositionInstant();
1104 draggedPieceEl.style.display = 'none';
1106 // run their onSnapbackEnd function
1107 if (cfg.hasOwnProperty('onSnapbackEnd') === true &&
1108 typeof cfg.onSnapbackEnd === 'function') {
1109 cfg.onSnapbackEnd(DRAGGED_PIECE, DRAGGED_PIECE_SOURCE,
1110 deepCopy(CURRENT_POSITION), CURRENT_ORIENTATION);
1114 // get source square position
1115 var sourceSquarePosition =
1116 offset(document.getElementById(SQUARE_ELS_IDS[DRAGGED_PIECE_SOURCE]));
1118 // animate the piece to the target square
1119 draggedPieceEl.addEventListener('transitionend', complete, {once: true});
1120 requestAnimationFrame(() => {
1121 draggedPieceEl.style.transitionProperty = 'top left';
1122 draggedPieceEl.style.transitionDuration = cfg.snapbackSpeed + 'ms';
1123 draggedPieceEl.style.top = sourceSquarePosition.top + 'px';
1124 draggedPieceEl.style.left = sourceSquarePosition.left + 'px';
1128 DRAGGING_A_PIECE = false;
1131 function trashDraggedPiece() {
1132 removeSquareHighlights();
1134 // remove the source piece
1135 var newPosition = deepCopy(CURRENT_POSITION);
1136 delete newPosition[DRAGGED_PIECE_SOURCE];
1137 setCurrentPosition(newPosition);
1139 // redraw the position
1140 drawPositionInstant();
1142 // hide the dragged piece
1143 // FIXME: support this for non-jquery
1144 //$(draggedPieceEl).fadeOut(cfg.trashSpeed);
1147 DRAGGING_A_PIECE = false;
1150 function dropDraggedPieceOnSquare(square) {
1151 removeSquareHighlights();
1154 var newPosition = deepCopy(CURRENT_POSITION);
1155 delete newPosition[DRAGGED_PIECE_SOURCE];
1156 newPosition[square] = DRAGGED_PIECE;
1157 setCurrentPosition(newPosition);
1159 // get target square information
1160 var targetSquarePosition = offset(document.getElementById(SQUARE_ELS_IDS[square]));
1162 // animation complete
1163 var complete = function() {
1164 drawPositionInstant();
1165 draggedPieceEl.style.display = 'none';
1167 // execute their onSnapEnd function
1168 if (cfg.hasOwnProperty('onSnapEnd') === true &&
1169 typeof cfg.onSnapEnd === 'function') {
1170 requestAnimationFrame(() => { // HACK: so that we don't add event handlers from the callback...
1171 cfg.onSnapEnd(DRAGGED_PIECE_SOURCE, square, DRAGGED_PIECE);
1176 // snap the piece to the target square
1177 draggedPieceEl.addEventListener('transitionend', complete, {once: true});
1178 requestAnimationFrame(() => {
1179 draggedPieceEl.style.transitionProperty = 'top left';
1180 draggedPieceEl.style.transitionDuration = cfg.snapSpeed + 'ms';
1181 draggedPieceEl.style.top = targetSquarePosition.top + 'px';
1182 draggedPieceEl.style.left = targetSquarePosition.left + 'px';
1186 DRAGGING_A_PIECE = false;
1189 function beginDraggingPiece(source, piece, x, y) {
1190 // run their custom onDragStart function
1191 // their custom onDragStart function can cancel drag start
1192 if (typeof cfg.onDragStart === 'function' &&
1193 cfg.onDragStart(source, piece,
1194 deepCopy(CURRENT_POSITION), CURRENT_ORIENTATION) === false) {
1199 DRAGGING_A_PIECE = true;
1200 DRAGGED_PIECE = piece;
1201 DRAGGED_PIECE_SOURCE = source;
1203 // if the piece came from spare pieces, location is offboard
1204 if (source === 'spare') {
1205 DRAGGED_PIECE_LOCATION = 'offboard';
1208 DRAGGED_PIECE_LOCATION = source;
1211 // capture the x, y coords of all squares in memory
1212 captureSquareOffsets();
1214 // create the dragged piece
1215 draggedPieceEl.setAttribute('src', buildPieceImgSrc(piece));
1216 draggedPieceEl.style.display = null;
1217 draggedPieceEl.style.position = 'absolute';
1218 draggedPieceEl.style.left = (x - (SQUARE_SIZE / 2)) + 'px';
1219 draggedPieceEl.style.top = (y - (SQUARE_SIZE / 2)) + 'px';
1221 if (source !== 'spare') {
1222 // highlight the source square and hide the piece
1223 let square = document.getElementById(SQUARE_ELS_IDS[source]);
1224 square.classList.add(CSS.highlight1);
1225 square.querySelector('.' + CSS.piece).style.display = 'none';
1229 function updateDraggedPiece(x, y) {
1230 // put the dragged piece over the mouse cursor
1231 draggedPieceEl.style.left = (x - (SQUARE_SIZE / 2)) + 'px';
1232 draggedPieceEl.style.top = (y - (SQUARE_SIZE / 2)) + 'px';
1235 var location = isXYOnSquare(x, y);
1237 // do nothing if the location has not changed
1238 if (location === DRAGGED_PIECE_LOCATION) return;
1240 // remove highlight from previous square
1241 if (validSquare(DRAGGED_PIECE_LOCATION) === true) {
1242 document.getElementById(SQUARE_ELS_IDS[DRAGGED_PIECE_LOCATION])
1243 .classList.remove(CSS.highlight2);
1246 // add highlight to new square
1247 if (validSquare(location) === true) {
1248 document.getElementById(SQUARE_ELS_IDS[location]).classList.add(CSS.highlight2);
1252 if (typeof cfg.onDragMove === 'function') {
1253 cfg.onDragMove(location, DRAGGED_PIECE_LOCATION,
1254 DRAGGED_PIECE_SOURCE, DRAGGED_PIECE,
1255 deepCopy(CURRENT_POSITION), CURRENT_ORIENTATION);
1259 DRAGGED_PIECE_LOCATION = location;
1262 function stopDraggedPiece(location) {
1263 // determine what the action should be
1264 var action = 'drop';
1265 if (location === 'offboard' && cfg.dropOffBoard === 'snapback') {
1266 action = 'snapback';
1268 if (location === 'offboard' && cfg.dropOffBoard === 'trash') {
1272 // run their onDrop function, which can potentially change the drop action
1273 if (cfg.hasOwnProperty('onDrop') === true &&
1274 typeof cfg.onDrop === 'function') {
1275 var newPosition = deepCopy(CURRENT_POSITION);
1277 // source piece is a spare piece and position is off the board
1278 //if (DRAGGED_PIECE_SOURCE === 'spare' && location === 'offboard') {...}
1279 // position has not changed; do nothing
1281 // source piece is a spare piece and position is on the board
1282 if (DRAGGED_PIECE_SOURCE === 'spare' && validSquare(location) === true) {
1283 // add the piece to the board
1284 newPosition[location] = DRAGGED_PIECE;
1287 // source piece was on the board and position is off the board
1288 if (validSquare(DRAGGED_PIECE_SOURCE) === true && location === 'offboard') {
1289 // remove the piece from the board
1290 delete newPosition[DRAGGED_PIECE_SOURCE];
1293 // source piece was on the board and position is on the board
1294 if (validSquare(DRAGGED_PIECE_SOURCE) === true &&
1295 validSquare(location) === true) {
1297 delete newPosition[DRAGGED_PIECE_SOURCE];
1298 newPosition[location] = DRAGGED_PIECE;
1301 var oldPosition = deepCopy(CURRENT_POSITION);
1303 var result = cfg.onDrop(DRAGGED_PIECE_SOURCE, location, DRAGGED_PIECE,
1304 newPosition, oldPosition, CURRENT_ORIENTATION);
1305 if (result === 'snapback' || result === 'trash') {
1311 if (action === 'snapback') {
1312 snapbackDraggedPiece();
1314 else if (action === 'trash') {
1315 trashDraggedPiece();
1317 else if (action === 'drop') {
1318 dropDraggedPieceOnSquare(location);
1322 //------------------------------------------------------------------------------
1324 //------------------------------------------------------------------------------
1327 widget.clear = function(useAnimation) {
1328 widget.position({}, useAnimation);
1332 // get or set config properties
1333 // TODO: write this, GitHub Issue #1
1334 widget.config = function(arg1, arg2) {
1335 // get the current config
1336 if (arguments.length === 0) {
1337 return deepCopy(cfg);
1342 // remove the widget from the page
1343 widget.destroy = function() {
1345 containerEl.innerHTML = '';
1346 draggedPieceEl.remove();
1349 // shorthand method to get the current FEN
1350 widget.fen = function() {
1351 return widget.position('fen');
1355 widget.flip = function() {
1356 widget.orientation('flip');
1360 // TODO: write this, GitHub Issue #5
1361 widget.highlight = function() {
1367 widget.move = function() {
1368 // no need to throw an error here; just do nothing
1369 if (arguments.length === 0) return;
1371 var useAnimation = true;
1373 // collect the moves into an object
1375 for (var i = 0; i < arguments.length; i++) {
1376 // any "false" to this function means no animations
1377 if (arguments[i] === false) {
1378 useAnimation = false;
1382 // skip invalid arguments
1383 if (validMove(arguments[i]) !== true) {
1384 error(2826, 'Invalid move passed to the move method.', arguments[i]);
1388 var tmp = arguments[i].split('-');
1389 moves[tmp[0]] = tmp[1];
1392 // calculate position from moves
1393 var newPos = calculatePositionFromMoves(CURRENT_POSITION, moves);
1396 widget.position(newPos, useAnimation);
1398 // return the new position object
1402 widget.orientation = function(arg) {
1403 // no arguments, return the current orientation
1404 if (arguments.length === 0) {
1405 return CURRENT_ORIENTATION;
1408 // set to white or black
1409 if (arg === 'white' || arg === 'black') {
1410 CURRENT_ORIENTATION = arg;
1416 if (arg === 'flip') {
1417 CURRENT_ORIENTATION = (CURRENT_ORIENTATION === 'white') ? 'black' : 'white';
1422 error(5482, 'Invalid value passed to the orientation method.', arg);
1426 * @param {!string|!Object} position
1427 * @param {boolean=} useAnimation
1429 widget.position = function(position, useAnimation) {
1430 // no arguments, return the current position
1431 if (arguments.length === 0) {
1432 return deepCopy(CURRENT_POSITION);
1435 // get position as FEN
1436 if (typeof position === 'string' && position.toLowerCase() === 'fen') {
1437 return objToFen(CURRENT_POSITION);
1440 // default for useAnimations is true
1441 if (useAnimation !== false) {
1442 useAnimation = true;
1446 if (typeof position === 'string' && position.toLowerCase() === 'start') {
1447 position = deepCopy(START_POSITION);
1450 // convert FEN to position object
1451 if (validFen(position) === true) {
1452 position = fenToObj(position);
1455 // validate position object
1456 if (validPositionObject(position) !== true) {
1457 error(6482, 'Invalid value passed to the position method.', position);
1461 if (useAnimation === true) {
1462 // start the animations
1463 doAnimations(calculateAnimations(CURRENT_POSITION, position),
1464 CURRENT_POSITION, position);
1466 // set the new position
1467 setCurrentPosition(position);
1471 setCurrentPosition(position);
1472 drawPositionInstant();
1476 widget.resize = function() {
1477 // calulate the new square size
1478 SQUARE_SIZE = calculateSquareSize();
1481 boardEl.style.width = (SQUARE_SIZE * 8) + 'px';
1483 // set drag piece size
1484 if (draggedPieceEl !== null) {
1485 draggedPieceEl.style.height = SQUARE_SIZE + 'px';
1486 draggedPieceEl.style.width = SQUARE_SIZE + 'px';
1490 if (cfg.sparePieces === true) {
1491 containerEl.querySelector('.' + CSS.sparePieces)
1492 .style.paddingLeft = (SQUARE_SIZE + BOARD_BORDER_SIZE) + 'px';
1499 // set the starting position
1500 widget.start = function(useAnimation) {
1501 widget.position('start', useAnimation);
1504 //------------------------------------------------------------------------------
1506 //------------------------------------------------------------------------------
1508 function isTouchDevice() {
1509 return ('ontouchstart' in document.documentElement);
1512 function mousedownSquare(e) {
1513 let target = e.target.closest('.' + CSS.square);
1518 // do nothing if we're not draggable
1519 if (cfg.draggable !== true) return;
1521 var square = target.getAttribute('data-square');
1523 // no piece on this square
1524 if (validSquare(square) !== true ||
1525 CURRENT_POSITION.hasOwnProperty(square) !== true) {
1529 beginDraggingPiece(square, CURRENT_POSITION[square], e.pageX, e.pageY);
1532 function touchstartSquare(e) {
1533 let target = e.target.closest('.' + CSS.square);
1538 // do nothing if we're not draggable
1539 if (cfg.draggable !== true) return;
1541 var square = target.getAttribute('data-square');
1543 // no piece on this square
1544 if (validSquare(square) !== true ||
1545 CURRENT_POSITION.hasOwnProperty(square) !== true) {
1549 e = e.originalEvent;
1550 beginDraggingPiece(square, CURRENT_POSITION[square],
1551 e.changedTouches[0].pageX, e.changedTouches[0].pageY);
1554 function mousedownSparePiece(e) {
1555 if (!e.target.matches('.' + CSS.sparePieces + ' .' + CSS.piece)) {
1559 // do nothing if sparePieces is not enabled
1560 if (cfg.sparePieces !== true) return;
1562 var piece = e.target.getAttribute('data-piece');
1564 beginDraggingPiece('spare', piece, e.pageX, e.pageY);
1567 function touchstartSparePiece(e) {
1568 if (!e.target.matches('.' + CSS.sparePieces + ' .' + CSS.piece)) {
1572 // do nothing if sparePieces is not enabled
1573 if (cfg.sparePieces !== true) return;
1575 var piece = e.target.getAttribute('data-piece');
1577 e = e.originalEvent;
1578 beginDraggingPiece('spare', piece,
1579 e.changedTouches[0].pageX, e.changedTouches[0].pageY);
1582 function mousemoveWindow(e) {
1583 // do nothing if we are not dragging a piece
1584 if (DRAGGING_A_PIECE !== true) return;
1586 updateDraggedPiece(e.pageX, e.pageY);
1589 function touchmoveWindow(e) {
1590 // do nothing if we are not dragging a piece
1591 if (DRAGGING_A_PIECE !== true) return;
1593 // prevent screen from scrolling
1596 updateDraggedPiece(e.originalEvent.changedTouches[0].pageX,
1597 e.originalEvent.changedTouches[0].pageY);
1600 function mouseupWindow(e) {
1601 // do nothing if we are not dragging a piece
1602 if (DRAGGING_A_PIECE !== true) return;
1605 var location = isXYOnSquare(e.pageX, e.pageY);
1607 stopDraggedPiece(location);
1610 function touchendWindow(e) {
1611 // do nothing if we are not dragging a piece
1612 if (DRAGGING_A_PIECE !== true) return;
1615 var location = isXYOnSquare(e.originalEvent.changedTouches[0].pageX,
1616 e.originalEvent.changedTouches[0].pageY);
1618 stopDraggedPiece(location);
1621 function mouseenterSquare(e) {
1622 let target = e.target.closest('.' + CSS.square);
1627 // do not fire this event if we are dragging a piece
1628 // NOTE: this should never happen, but it's a safeguard
1629 if (DRAGGING_A_PIECE !== false) return;
1631 if (cfg.hasOwnProperty('onMouseoverSquare') !== true ||
1632 typeof cfg.onMouseoverSquare !== 'function') return;
1635 var square = target.getAttribute('data-square');
1637 // NOTE: this should never happen; defensive
1638 if (validSquare(square) !== true) return;
1640 // get the piece on this square
1642 if (CURRENT_POSITION.hasOwnProperty(square) === true) {
1643 piece = CURRENT_POSITION[square];
1646 // execute their function
1647 cfg.onMouseoverSquare(square, piece, deepCopy(CURRENT_POSITION),
1648 CURRENT_ORIENTATION);
1651 function mouseleaveSquare(e) {
1652 let target = e.target.closest('.' + CSS.square);
1657 // do not fire this event if we are dragging a piece
1658 // NOTE: this should never happen, but it's a safeguard
1659 if (DRAGGING_A_PIECE !== false) return;
1661 if (cfg.hasOwnProperty('onMouseoutSquare') !== true ||
1662 typeof cfg.onMouseoutSquare !== 'function') return;
1665 var square = target.getAttribute('data-square');
1667 // NOTE: this should never happen; defensive
1668 if (validSquare(square) !== true) return;
1670 // get the piece on this square
1672 if (CURRENT_POSITION.hasOwnProperty(square) === true) {
1673 piece = CURRENT_POSITION[square];
1676 // execute their function
1677 cfg.onMouseoutSquare(square, piece, deepCopy(CURRENT_POSITION),
1678 CURRENT_ORIENTATION);
1681 //------------------------------------------------------------------------------
1683 //------------------------------------------------------------------------------
1685 function addEvents() {
1686 // prevent browser "image drag"
1687 let stopDefault = (e) => {
1688 if (e.target.matches('.' + CSS.piece)) {
1692 document.body.addEventListener('mousedown', stopDefault);
1693 document.body.addEventListener('mousemove', stopDefault);
1695 // mouse drag pieces
1696 boardEl.addEventListener('mousedown', mousedownSquare);
1697 containerEl.addEventListener('mousedown', mousedownSparePiece);
1699 // mouse enter / leave square
1700 boardEl.addEventListener('mouseenter', mouseenterSquare);
1701 boardEl.addEventListener('mouseleave', mouseleaveSquare);
1703 window.addEventListener('mousemove', mousemoveWindow);
1704 window.addEventListener('mouseup', mouseupWindow);
1706 // touch drag pieces
1707 if (isTouchDevice() === true) {
1708 boardEl.addEventListener('touchstart', touchstartSquare);
1709 containerEl.addEventListener('touchstart', touchstartSparePiece);
1710 window.addEventListener('touchmove', touchmoveWindow);
1711 window.addEventListener('touchend', touchendWindow);
1715 function initDom() {
1716 // build board and save it in memory
1717 containerEl.innerHTML = buildBoardContainer();
1718 boardEl = containerEl.querySelector('.' + CSS.board);
1720 if (cfg.sparePieces === true) {
1721 sparePiecesTopEl = containerEl.querySelector('.' + CSS.sparePiecesTop);
1722 sparePiecesBottomEl = containerEl.querySelector('.' + CSS.sparePiecesBottom);
1725 // create the drag piece
1726 var draggedPieceId = createId();
1727 document.body.append(buildPiece('wP', true, draggedPieceId));
1728 draggedPieceEl = document.getElementById(draggedPieceId);
1730 // get the border size
1731 BOARD_BORDER_SIZE = parseInt(boardEl.style.borderLeftWidth, 10);
1733 // set the size and draw the board
1738 if (checkDeps() !== true ||
1739 expandConfig() !== true) return;
1741 // create unique IDs for all the elements we will create
1751 // return the widget object
1754 }; // end window.ChessBoard
1756 // expose util functions
1757 window.ChessBoard.fenToObj = fenToObj;
1758 window.ChessBoard.objToFen = objToFen;
1760 })(); // end anonymous wrapper