client/src/components/Board.vue

   1 <script>
   2 import { getSquareId, getSquareFromId } from "@/utils/squareId";
   3 import { ArrayFun } from "@/utils/array";
   4 import { store } from "@/store";
   5 export default {
   6   name: "my-board",
   7   // Last move cannot be guessed from here, and is required for highlights.
   8   // vr: object to check moves, print board...
   9   // userColor is left undefined for an external observer
  10   props: [
  11     "vr",
  12     "lastMove",
  13     "analyze",
  14     "score",
  15     "incheck",
  16     "orientation",
  17     "userColor",
  18     "vname"
  19   ],
  20   data: function() {
  21     return {
  22       mobileBrowser: ("ontouchstart" in window),
  23       possibleMoves: [], //filled after each valid click/dragstart
  24       choices: [], //promotion pieces, or checkered captures... (as moves)
  25       containerPos: null,
  26       selectedPiece: null, //moving piece (or clicked piece)
  27       start: null, //pixels coordinates + id of starting square (click or drag)
  28       startArrow: null,
  29       movingArrow: null,
  30       arrows: [], //object of {start: x,y / end: x,y}
  31       circles: {}, //object of squares' ID --> true (TODO: use a set?)
  32       click: "",
  33       clickTime: 0,
  34       settings: store.state.settings
  35     };
  36   },
  37   render(h) {
  38     if (!this.vr) {
  39       // Return empty div of class 'game' to avoid error when setting size
  40       return h(
  41         "div",
  42         { "class": { game: true } }
  43       );
  44     }
  45     const [sizeX, sizeY] = [V.size.x, V.size.y];
  46     // Precompute hints squares to facilitate rendering
  47     let hintSquares = ArrayFun.init(sizeX, sizeY, false);
  48     this.possibleMoves.forEach(m => {
  49       hintSquares[m.end.x][m.end.y] = true;
  50     });
  51     // Also precompute in-check squares
  52     let incheckSq = ArrayFun.init(sizeX, sizeY, false);
  53     this.incheck.forEach(sq => {
  54       incheckSq[sq[0]][sq[1]] = true;
  55     });
  56
  57     let lm = this.lastMove;
  58     // Precompute lastMove highlighting squares
  59     const lmHighlights = {};
  60     if (!!lm) {
  61       if (!Array.isArray(lm)) lm = [lm];
  62       lm.forEach(m => {
  63         if (!m.start.noHighlight && V.OnBoard(m.start.x, m.start.y))
  64           lmHighlights[m.start.x + sizeX * m.start.y] = true;
  65         if (!m.end.noHighlight && V.OnBoard(m.end.x, m.end.y))
  66           lmHighlights[m.end.x + sizeX * m.end.y] = true;
  67         if (!!m.start.toplay)
  68           // For Dice variant (at least?)
  69           lmHighlights[m.start.toplay[0] + sizeX * m.start.toplay[1]] = true;
  70       });
  71     }
  72     const showLight = (
  73       this.settings.highlight &&
  74       ["all", "highlight"].includes(V.ShowMoves)
  75     );
  76     const showCheck = (
  77       this.settings.highlight &&
  78       ["all", "highlight", "byrow"].includes(V.ShowMoves)
  79     );
  80     const orientation = !V.CanFlip ? "w" : this.orientation;
  81     // Ensure that squares colors do not change when board is flipped
  82     const lightSquareMod = (sizeX + sizeY) % 2;
  83     const showPiece = (x, y) => {
  84       return (
  85         this.vr.board[x][y] != V.EMPTY &&
  86         (!this.vr.enlightened || this.analyze || this.score != "*" ||
  87           (!!this.userColor && this.vr.enlightened[this.userColor][x][y]))
  88       );
  89     };
  90     const inHighlight = (x, y) => {
  91       return showLight && !!lmHighlights[x + sizeX * y];
  92     };
  93     const inShadow = (x, y) => {
  94       return (
  95         !this.analyze &&
  96         this.score == "*" &&
  97         this.vr.enlightened &&
  98         (!this.userColor || !this.vr.enlightened[this.userColor][x][y])
  99       );
 100     };
 101     // Create board element (+ reserves if needed by variant)
 102     let elementArray = [];
 103     const gameDiv = h(
 104       "div",
 105       {
 106         attrs: { id: "gamePosition" },
 107         "class": {
 108           game: true,
 109           clearer: true
 110         }
 111       },
 112       [...Array(sizeX).keys()].map(i => {
 113         const ci = orientation == "w" ? i : sizeX - i - 1;
 114         return h(
 115           "div",
 116           {
 117             "class": {
 118               row: true
 119             },
 120             style: { opacity: this.choices.length > 0 ? "0.5" : "1" }
 121           },
 122           [...Array(sizeY).keys()].map(j => {
 123             const cj = orientation == "w" ? j : sizeY - j - 1;
 124             const squareId = "sq-" + ci + "-" + cj;
 125             let elems = [];
 126             if (showPiece(ci, cj)) {
 127               let pieceSpecs = {
 128                 "class": {
 129                   piece: true,
 130                   ghost:
 131                     !!this.selectedPiece &&
 132                     this.selectedPiece.parentNode.id == squareId
 133                 },
 134                 attrs: {
 135                   src:
 136                     "/images/pieces/" +
 137                     this.vr.getPpath(
 138                       this.vr.board[ci][cj],
 139                       // Extra args useful for some variants:
 140                       this.userColor,
 141                       this.score,
 142                       this.orientation) +
 143                     V.IMAGE_EXTENSION
 144                 }
 145               };
 146               if (this.arrows.length == 0)
 147                 pieceSpecs["style"] = { position: "absolute" };
 148               elems.push(h("img", pieceSpecs));
 149             }
 150             if (this.settings.hints && hintSquares[ci][cj]) {
 151               elems.push(
 152                 h("img", {
 153                   "class": {
 154                     "mark-square": true
 155                   },
 156                   attrs: {
 157                     src: "/images/mark.svg"
 158                   }
 159                 })
 160               );
 161             }
 162             if (!!this.circles[squareId]) {
 163               elems.push(
 164                 h("img", {
 165                   "class": {
 166                     "circle-square": true
 167                   },
 168                   attrs: {
 169                     src: "/images/circle.svg"
 170                   }
 171                 })
 172               );
 173             }
 174             const oddity = (ci + cj) % 2;
 175             const lightSquare = (
 176               (!V.DarkBottomRight && oddity == lightSquareMod) ||
 177               (V.DarkBottomRight && oddity != lightSquareMod)
 178             );
 179             return h(
 180               "div",
 181               {
 182                 "class": {
 183                   board: true,
 184                   ["board" + sizeY]: true,
 185                   "light-square":
 186                     !V.Notoodark && lightSquare && !V.Monochrome,
 187                   "dark-square":
 188                     !V.Notoodark && (!lightSquare || !!V.Monochrome),
 189                   "middle-square": V.Notoodark,
 190                   [this.settings.bcolor]: true,
 191                   "in-shadow": inShadow(ci, cj),
 192                   "highlight": inHighlight(ci, cj),
 193                   "incheck-light":
 194                     showCheck && lightSquare && incheckSq[ci][cj],
 195                   "incheck-dark":
 196                     showCheck && !lightSquare && incheckSq[ci][cj],
 197                   "hover-highlight": this.vr.hoverHighlight(ci, cj)
 198                 },
 199                 attrs: {
 200                   id: getSquareId({ x: ci, y: cj })
 201                 }
 202               },
 203               elems
 204             );
 205           })
 206         );
 207       })
 208     );
 209     if (!!this.vr.reserve) {
 210       const playingColor = this.userColor || "w"; //default for an observer
 211       const shiftIdx = playingColor == "w" ? 0 : 1;
 212       // Some variants have more than sizeY reserve pieces (Clorange: 10)
 213       const reserveSquareNb = Math.max(sizeY, V.RESERVE_PIECES.length);
 214       let myReservePiecesArray = [];
 215       if (!!this.vr.reserve[playingColor]) {
 216         for (let i = 0; i < V.RESERVE_PIECES.length; i++) {
 217           const qty = this.vr.reserve[playingColor][V.RESERVE_PIECES[i]];
 218           myReservePiecesArray.push(
 219             h(
 220               "div",
 221               {
 222                 "class": { board: true, ["board" + reserveSquareNb]: true },
 223                 attrs: { id: getSquareId({ x: sizeX + shiftIdx, y: i }) },
 224                 style: { opacity: qty > 0 ? 1 : 0.35 }
 225               },
 226               [
 227                 h("img", {
 228                   // NOTE: class "reserve" not used currently
 229                   "class": { piece: true, reserve: true },
 230                   attrs: {
 231                     src:
 232                       "/images/pieces/" +
 233                       this.vr.getReservePpath(i, playingColor, orientation) +
 234                       ".svg"
 235                   }
 236                 }),
 237                 h(
 238                   "sup",
 239                   {
 240                     "class": { "reserve-count": true },
 241                     style: { top: "calc(100% + 5px)" }
 242                   },
 243                   [ qty ]
 244                 )
 245               ]
 246             )
 247           );
 248         }
 249       }
 250       let oppReservePiecesArray = [];
 251       const oppCol = V.GetOppCol(playingColor);
 252       if (!!this.vr.reserve[oppCol]) {
 253         for (let i = 0; i < V.RESERVE_PIECES.length; i++) {
 254           const qty = this.vr.reserve[oppCol][V.RESERVE_PIECES[i]];
 255           oppReservePiecesArray.push(
 256             h(
 257               "div",
 258               {
 259                 "class": { board: true, ["board" + reserveSquareNb]: true },
 260                 attrs: { id: getSquareId({ x: sizeX + (1 - shiftIdx), y: i }) },
 261                 style: { opacity: qty > 0 ? 1 : 0.35 }
 262               },
 263               [
 264                 h("img", {
 265                   "class": { piece: true, reserve: true },
 266                   attrs: {
 267                     src:
 268                       "/images/pieces/" +
 269                       this.vr.getReservePpath(i, oppCol, orientation) +
 270                       ".svg"
 271                   }
 272                 }),
 273                 h(
 274                   "sup",
 275                   {
 276                     "class": { "reserve-count": true },
 277                     style: { top: "calc(100% + 5px)" }
 278                   },
 279                   [ qty ]
 280                 )
 281               ]
 282             )
 283           );
 284         }
 285       }
 286       const myReserveTop = (
 287         (playingColor == 'w' && orientation == 'b') ||
 288         (playingColor == 'b' && orientation == 'w')
 289       );
 290       const hasReserveTop = (
 291         (myReserveTop && !!this.vr.reserve[playingColor]) ||
 292         (!myReserveTop && !!this.vr.reserve[oppCol])
 293       );
 294       // "var" because must be reachable from outside this block
 295       var hasReserveBottom = (
 296         (myReserveTop && !!this.vr.reserve[oppCol]) ||
 297         (!myReserveTop && !!this.vr.reserve[playingColor])
 298       );
 299       // Center reserves, assuming same number of pieces for each side:
 300       const nbReservePieces = myReservePiecesArray.length;
 301       const marginLeft =
 302         ((100 - nbReservePieces * (100 / reserveSquareNb)) / 2) + "%";
 303       if (hasReserveTop) {
 304         var reserveTop =
 305           h(
 306             "div",
 307             {
 308               "class": {
 309                 game: true,
 310                 "reserve-div": true
 311               },
 312               style: {
 313                 "margin-left": marginLeft
 314               }
 315             },
 316             [
 317               h(
 318                 "div",
 319                 {
 320                   "class": {
 321                     row: true,
 322                     "reserve-row": true
 323                   }
 324                 },
 325                 myReserveTop ? myReservePiecesArray : oppReservePiecesArray
 326               )
 327             ]
 328           );
 329       }
 330       if (hasReserveBottom) {
 331         var reserveBottom =
 332           h(
 333             "div",
 334             {
 335               "class": {
 336                 game: true,
 337                 "reserve-div": true
 338               },
 339               style: {
 340                 "margin-left": marginLeft
 341               }
 342             },
 343             [
 344               h(
 345                 "div",
 346                 {
 347                   "class": {
 348                     row: true,
 349                     "reserve-row": true
 350                   }
 351                 },
 352                 myReserveTop ? oppReservePiecesArray : myReservePiecesArray
 353               )
 354             ]
 355           );
 356       }
 357       if (hasReserveTop) elementArray.push(reserveTop);
 358     }
 359     elementArray.push(gameDiv);
 360     if (!!this.vr.reserve && hasReserveBottom)
 361       elementArray.push(reserveBottom);
 362     const boardElt = document.getElementById("gamePosition");
 363     // boardElt might be undefine (at first drawing)
 364     if (this.choices.length > 0 && !!boardElt) {
 365       const squareWidth = boardElt.offsetWidth / sizeY;
 366       const offset = [boardElt.offsetTop, boardElt.offsetLeft];
 367       const maxNbeltsPerRow = Math.min(this.choices.length, sizeY);
 368       let topOffset = offset[0] + (sizeY / 2) * squareWidth - squareWidth / 2;
 369       let choicesHeight = squareWidth;
 370       if (this.choices.length >= sizeY) {
 371         // A second row is required (Eightpieces variant)
 372         topOffset -= squareWidth / 2;
 373         choicesHeight *= 2;
 374       }
 375       const choices = h(
 376         "div",
 377         {
 378           attrs: { id: "choices" },
 379           "class": { row: true },
 380           style: {
 381             top: topOffset + "px",
 382             left:
 383               offset[1] +
 384               (squareWidth * Math.max(sizeY - this.choices.length, 0)) / 2 +
 385               "px",
 386             width: (maxNbeltsPerRow * squareWidth) + "px",
 387             height: choicesHeight + "px"
 388           }
 389         },
 390         [ h(
 391           "div",
 392           {
 393             "class": { "full-width": true }
 394           },
 395           this.choices.map(m => {
 396             // A "choice" is a move
 397             const applyMove = (e) => {
 398               e.stopPropagation();
 399               // Force a delay between move is shown and clicked
 400               // (otherwise a "double-click" bug might occur)
 401               if (Date.now() - this.clickTime < 200) return;
 402               this.choices = [];
 403               this.play(m);
 404             };
 405             const stopPropagation = (e) => { e.stopPropagation(); }
 406             const onClick =
 407               this.mobileBrowser
 408                 // Must cancel mousedown logic:
 409                 ? { touchstart: stopPropagation, touchend: applyMove }
 410                 : { mousedown: stopPropagation, mouseup: applyMove };
 411             return h(
 412               "div",
 413               {
 414                 "class": {
 415                   board: true,
 416                   ["board" + sizeY]: true
 417                 },
 418                 style: {
 419                   width: (100 / maxNbeltsPerRow) + "%",
 420                   "padding-bottom": (100 / maxNbeltsPerRow) + "%"
 421                 }
 422               },
 423               [
 424                 h("img", {
 425                   attrs: {
 426                     src:
 427                       "/images/pieces/" +
 428                       // orientation: extra arg useful for some variants
 429                       this.vr.getPPpath(m, this.orientation) +
 430                       V.IMAGE_EXTENSION
 431                   },
 432                   "class": { "choice-piece": true },
 433                   on: onClick
 434                 })
 435               ]
 436             );
 437           })
 438         ) ]
 439       );
 440       elementArray.unshift(choices);
 441     }
 442     let onEvents = {};
 443     // NOTE: click = mousedown + mouseup
 444     if (this.mobileBrowser) {
 445       onEvents = {
 446         on: {
 447           touchstart: this.mousedown,
 448           touchmove: this.mousemove,
 449           touchend: this.mouseup
 450         }
 451       };
 452     }
 453     else {
 454       onEvents = {
 455         on: {
 456           mousedown: this.mousedown,
 457           mousemove: this.mousemove,
 458           mouseup: this.mouseup,
 459           contextmenu: this.blockContextMenu
 460         }
 461       };
 462     }
 463     return (
 464       h(
 465         "div",
 466         Object.assign({ attrs: { id: "rootBoardElement" } }, onEvents),
 467         elementArray
 468       )
 469     );
 470   },
 471   updated: function() {
 472     this.re_setDrawings();
 473   },
 474   methods: {
 475     blockContextMenu: function(e) {
 476       e.preventDefault();
 477       e.stopPropagation();
 478       return false;
 479     },
 480     cancelResetArrows: function() {
 481       this.startArrow = null;
 482       this.arrows = [];
 483       this.circles = {};
 484       const curCanvas = document.getElementById("arrowCanvas");
 485       if (!!curCanvas) curCanvas.parentNode.removeChild(curCanvas);
 486     },
 487     coordsToXY: function(coords, top, left, squareWidth) {
 488       return {
 489         // [1] for x and [0] for y because conventions in rules are inversed.
 490         x: (
 491           left + window.scrollX +
 492           (
 493             squareWidth *
 494             (this.orientation == 'w' ? coords[1] : (V.size.y - coords[1]))
 495           )
 496         ),
 497         y: (
 498           top + window.scrollY +
 499           (
 500             squareWidth *
 501             (this.orientation == 'w' ? coords[0] : (V.size.x - coords[0]))
 502           )
 503         )
 504       };
 505     },
 506     computeEndArrow: function(start, end, top, left, squareWidth) {
 507       const endCoords = this.coordsToXY(end, top, left, squareWidth);
 508       const delta = [endCoords.x - start.x, endCoords.y - start.y];
 509       const dist = Math.sqrt(delta[0] * delta[0] + delta[1] * delta[1]);
 510       // Simple heuristic for now, just remove 1/3 square.
 511       // TODO: should depend on the orientation.
 512       const fracSqWidth = squareWidth / 3;
 513       return {
 514         x: endCoords.x - delta[0] * fracSqWidth / dist,
 515         y: endCoords.y - delta[1] * fracSqWidth / dist
 516       };
 517     },
 518     drawCurrentArrow: function() {
 519       const boardElt = document.getElementById("gamePosition");
 520       const squareWidth = boardElt.offsetWidth / V.size.y;
 521       const bPos = boardElt.getBoundingClientRect();
 522       const aStart =
 523         this.coordsToXY(
 524           [this.startArrow[0] + 0.5, this.startArrow[1] + 0.5],
 525           bPos.top, bPos.left, squareWidth);
 526       const aEnd =
 527         this.computeEndArrow(
 528           aStart, [this.movingArrow[0] + 0.5, this.movingArrow[1] + 0.5],
 529           bPos.top, bPos.left, squareWidth);
 530       let currentArrow = document.getElementById("currentArrow");
 531       const d =
 532         "M" + aStart.x + "," + aStart.y + " " + "L" + aEnd.x + "," + aEnd.y;
 533       const arrowWidth = squareWidth / 4;
 534       if (!!currentArrow) currentArrow.setAttribute("d", d);
 535       else {
 536         let domArrow =
 537           document.createElementNS("http://www.w3.org/2000/svg", "path");
 538         domArrow.classList.add("svg-arrow");
 539         domArrow.id = "currentArrow";
 540         domArrow.setAttribute("d", d);
 541         domArrow.style = "stroke-width:" + arrowWidth + "px";
 542         document.getElementById("arrowCanvas")
 543           .insertAdjacentElement("beforeend", domArrow);
 544       }
 545     },
 546     addArrow: function(arrow) {
 547       this.arrows.push(arrow);
 548       // Also add to DOM:
 549       const boardElt = document.getElementById("gamePosition");
 550       const squareWidth = boardElt.offsetWidth / V.size.y;
 551       const bPos = boardElt.getBoundingClientRect();
 552       const newArrow =
 553         this.getSvgArrow(arrow, bPos.top, bPos.left, squareWidth);
 554       document.getElementById("arrowCanvas")
 555         .insertAdjacentElement("beforeend", newArrow);
 556     },
 557     getSvgArrow: function(arrow, top, left, squareWidth) {
 558       const aStart =
 559         this.coordsToXY(
 560           [arrow.start[0] + 0.5, arrow.start[1] + 0.5],
 561           top, left, squareWidth);
 562       const aEnd =
 563         this.computeEndArrow(
 564           aStart, [arrow.end[0] + 0.5, arrow.end[1] + 0.5],
 565           top, left, squareWidth);
 566       const arrowWidth = squareWidth / 4;
 567       let path =
 568         document.createElementNS("http://www.w3.org/2000/svg", "path");
 569       path.classList.add("svg-arrow");
 570       path.setAttribute(
 571         "d",
 572         "M" + aStart.x + "," + aStart.y + " " + "L" + aEnd.x + "," + aEnd.y
 573       );
 574       path.style = "stroke-width:" + arrowWidth + "px";
 575       return path;
 576     },
 577     re_setDrawings: function() {
 578       // Remove current canvas, if any
 579       const curCanvas = document.getElementById("arrowCanvas");
 580       if (!!curCanvas) curCanvas.parentNode.removeChild(curCanvas);
 581       // Add some drawing on board (for some variants + arrows and circles)
 582       const boardElt = document.getElementById("gamePosition");
 583       const squareWidth = boardElt.offsetWidth / V.size.y;
 584       const bPos = boardElt.getBoundingClientRect();
 585       let svgArrows = [];
 586       this.arrows.forEach(a => {
 587         svgArrows.push(this.getSvgArrow(a, bPos.top, bPos.left, squareWidth));
 588       });
 589       let vLines = [];
 590       if (!!V.Lines) {
 591         V.Lines.forEach(line => {
 592           const lStart =
 593             this.coordsToXY(line[0], bPos.top, bPos.left, squareWidth);
 594           const lEnd =
 595             this.coordsToXY(line[1], bPos.top, bPos.left, squareWidth);
 596           let path =
 597             document.createElementNS("http://www.w3.org/2000/svg", "path");
 598           if (line[0][0] == line[1][0] || line[0][1] == line[1][1])
 599             path.classList.add("svg-line");
 600           else
 601             // "Diagonals" are drawn with a lighter color (TODO: generalize)
 602             path.classList.add("svg-diag");
 603           path.setAttribute(
 604             "d",
 605             "M" + lStart.x + "," + lStart.y + " " +
 606               "L" + lEnd.x + "," + lEnd.y
 607           );
 608           vLines.push(path);
 609         });
 610       }
 611       let arrowCanvas =
 612         document.createElementNS("http://www.w3.org/2000/svg", "svg");
 613       arrowCanvas.id = "arrowCanvas";
 614       arrowCanvas.setAttribute("stroke", "none");
 615       let defs =
 616         document.createElementNS("http://www.w3.org/2000/svg", "defs");
 617       const arrowWidth = squareWidth / 4;
 618       let marker =
 619         document.createElementNS("http://www.w3.org/2000/svg", "marker");
 620       marker.id = "arrow";
 621       marker.setAttribute("markerWidth", (2 * arrowWidth) + "px");
 622       marker.setAttribute("markerHeight", (3 * arrowWidth) + "px");
 623       marker.setAttribute("markerUnits", "userSpaceOnUse");
 624       marker.setAttribute("refX", "0");
 625       marker.setAttribute("refY", (1.5 * arrowWidth) + "px");
 626       marker.setAttribute("orient", "auto");
 627       let head =
 628         document.createElementNS("http://www.w3.org/2000/svg", "path");
 629       head.classList.add("arrow-head");
 630       head.setAttribute(
 631         "d",
 632         "M0,0 L0," + (3 * arrowWidth) + " L" +
 633           (2 * arrowWidth) + "," + (1.5 * arrowWidth) + " z"
 634       );
 635       marker.appendChild(head);
 636       defs.appendChild(marker);
 637       arrowCanvas.appendChild(defs);
 638       svgArrows.concat(vLines).forEach(av => arrowCanvas.appendChild(av));
 639       document.getElementById("rootBoardElement").appendChild(arrowCanvas);
 640     },
 641     mousedown: function(e) {
 642       e.preventDefault();
 643       if (!this.mobileBrowser && e.which != 3)
 644         // Cancel current drawing and circles, if any
 645         this.cancelResetArrows();
 646       if (this.mobileBrowser || e.which == 1) {
 647         // Mouse left button
 648         if (!this.start) {
 649           this.containerPos =
 650             document.getElementById("boardContainer").getBoundingClientRect();
 651           // NOTE: classList[0] is enough: 'piece' is the first assigned class
 652           const withPiece = (e.target.classList[0] == "piece");
 653           // Show possible moves if current player allowed to play
 654           const startSquare =
 655             getSquareFromId(withPiece ? e.target.parentNode.id : e.target.id);
 656           this.possibleMoves = [];
 657           const color = this.analyze ? this.vr.turn : this.userColor;
 658           if (this.vr.canIplay(color, startSquare)) {
 659             // Emit the click event which could be used by some variants
 660             const targetId =
 661               (withPiece ? e.target.parentNode.id : e.target.id);
 662             this.$emit("click-square", getSquareFromId(targetId));
 663             if (withPiece) {
 664               this.possibleMoves = this.vr.getPossibleMovesFrom(startSquare);
 665               // For potential drag'n drop, remember start coordinates
 666               // (to center the piece on mouse cursor)
 667               let parent = e.target.parentNode; //surrounding square
 668               const rect = parent.getBoundingClientRect();
 669               this.start = {
 670                 x: rect.x + rect.width / 2,
 671                 y: rect.y + rect.width / 2,
 672                 id: parent.id
 673               };
 674               // Add the moving piece to the board, just after current image
 675               this.selectedPiece = e.target.cloneNode();
 676               Object.assign(
 677                 this.selectedPiece.style,
 678                 {
 679                   position: "absolute",
 680                   top: 0,
 681                   display: "inline-block",
 682                   zIndex: 3000
 683                 }
 684               );
 685               parent.insertBefore(this.selectedPiece, e.target.nextSibling);
 686             }
 687           }
 688         }
 689         else this.processMoveAttempt(e);
 690       }
 691       else if (e.which == 3) {
 692         // Mouse right button
 693         this.containerPos =
 694           document.getElementById("gamePosition").getBoundingClientRect();
 695         let elem = e.target;
 696         // Next loop because of potential marks
 697         while (elem.tagName == "IMG") elem = elem.parentNode;
 698         this.startArrow = getSquareFromId(elem.id);
 699       }
 700     },
 701     mousemove: function(e) {
 702       if (!this.selectedPiece && !this.startArrow) return;
 703       // Cancel if off boardContainer
 704       const [offsetX, offsetY] =
 705         this.mobileBrowser
 706           ? [e.changedTouches[0].clientX, e.changedTouches[0].clientY]
 707           : [e.clientX, e.clientY];
 708       if (
 709         offsetX < this.containerPos.left ||
 710         offsetX > this.containerPos.right ||
 711         offsetY < this.containerPos.top ||
 712         offsetY > this.containerPos.bottom
 713       ) {
 714         if (!!this.selectedPiece) {
 715           this.selectedPiece.parentNode.removeChild(this.selectedPiece);
 716           delete this.selectedPiece;
 717           this.selectedPiece = null;
 718           this.start = null;
 719           this.possibleMoves = []; //in case of
 720           this.click = "";
 721           let selected = document.querySelector(".ghost");
 722           if (!!selected) selected.classList.remove("ghost");
 723         }
 724         else {
 725           this.startArrow = null;
 726           this.movingArrow = null;
 727           const currentArrow = document.getElementById("currentArrow");
 728           if (!!currentArrow)
 729             currentArrow.parentNode.removeChild(currentArrow);
 730         }
 731         return;
 732       }
 733       e.preventDefault();
 734       if (!!this.selectedPiece) {
 735         // There is an active element: move it around
 736         Object.assign(
 737           this.selectedPiece.style,
 738           {
 739             left: offsetX - this.start.x + "px",
 740             top: offsetY - this.start.y + "px"
 741           }
 742         );
 743       }
 744       else {
 745         let elem = e.target;
 746         // Next loop because of potential marks
 747         while (elem.tagName == "IMG") elem = elem.parentNode;
 748         // To center the arrow in square:
 749         const movingCoords = getSquareFromId(elem.id);
 750         if (
 751           movingCoords[0] != this.startArrow[0] ||
 752           movingCoords[1] != this.startArrow[1]
 753         ) {
 754           this.movingArrow = movingCoords;
 755           this.drawCurrentArrow();
 756         }
 757       }
 758     },
 759     mouseup: function(e) {
 760       e.preventDefault();
 761       if (this.mobileBrowser || e.which == 1) {
 762         if (!this.selectedPiece) return;
 763         // Drag'n drop. Selected piece is no longer needed:
 764         this.selectedPiece.parentNode.removeChild(this.selectedPiece);
 765         delete this.selectedPiece;
 766         this.selectedPiece = null;
 767         this.processMoveAttempt(e);
 768       } else if (e.which == 3) {
 769         if (!this.startArrow) return;
 770         // Mouse right button
 771         this.movingArrow = null;
 772         this.processArrowAttempt(e);
 773       }
 774     },
 775     // Called by BaseGame after partially undoing multi-moves:
 776     resetCurrentAttempt: function() {
 777       this.possibleMoves = [];
 778       this.start = null;
 779       this.click = "";
 780       this.selectedPiece = null;
 781     },
 782     processMoveAttempt: function(e) {
 783       // Obtain the move from start and end squares
 784       const [offsetX, offsetY] =
 785         this.mobileBrowser
 786           ? [e.changedTouches[0].clientX, e.changedTouches[0].clientY]
 787           : [e.clientX, e.clientY];
 788       let landing = document.elementFromPoint(offsetX, offsetY);
 789       // Next condition: classList.contains(piece) fails because of marks
 790       while (landing.tagName == "IMG") landing = landing.parentNode;
 791       if (this.start.id == landing.id) {
 792         if (this.click == landing.id) {
 793           // Second click on same square: cancel current move
 794           this.possibleMoves = [];
 795           this.start = null;
 796           this.click = "";
 797         } else this.click = landing.id;
 798         return;
 799       }
 800       this.start = null;
 801       // OK: process move attempt, landing is a square node
 802       let endSquare = getSquareFromId(landing.id);
 803       let moves = this.findMatchingMoves(endSquare);
 804       this.possibleMoves = [];
 805       if (moves.length > 1) {
 806         this.clickTime = Date.now();
 807         this.choices = moves;
 808       } else if (moves.length == 1) this.play(moves[0]);
 809       // else: forbidden move attempt
 810     },
 811     processArrowAttempt: function(e) {
 812       // Obtain the arrow from start and end squares
 813       const [offsetX, offsetY] = [e.clientX, e.clientY];
 814       let landing = document.elementFromPoint(offsetX, offsetY);
 815       // Next condition: classList.contains(piece) fails because of marks
 816       while (landing.tagName == "IMG") landing = landing.parentNode;
 817       const landingCoords = getSquareFromId(landing.id);
 818       if (
 819         this.startArrow[0] == landingCoords[0] &&
 820         this.startArrow[1] == landingCoords[1]
 821       ) {
 822         // Draw (or erase) a circle
 823         this.$set(this.circles, landing.id, !this.circles[landing.id]);
 824       }
 825       else {
 826         // OK: add arrow, landing is a new square
 827         const currentArrow = document.getElementById("currentArrow");
 828         currentArrow.parentNode.removeChild(currentArrow);
 829         this.addArrow({
 830           start: this.startArrow,
 831           end: landingCoords
 832         });
 833       }
 834       this.startArrow = null;
 835     },
 836     findMatchingMoves: function(endSquare) {
 837       // Run through moves list and return the matching set (if promotions...)
 838       return (
 839         this.possibleMoves.filter(m => {
 840           return (endSquare[0] == m.end.x && endSquare[1] == m.end.y);
 841         })
 842       );
 843     },
 844     play: function(move) {
 845       this.$emit("play-move", move);
 846     }
 847   }
 848 };
 849 </script>
 850
 851 <style lang="sass">
 852 // SVG dynamically added, so not scoped
 853 #arrowCanvas
 854   pointer-events: none
 855   position: absolute
 856   top: 0
 857   left: 0
 858   width: 100%
 859   height: 100%
 860
 861 .svg-arrow
 862   opacity: 0.65
 863   stroke: #5f0e78
 864   fill: none
 865   marker-end: url(#arrow)
 866
 867 .svg-line
 868   stroke: black
 869
 870 .svg-diag
 871   stroke: grey
 872
 873 .arrow-head
 874   fill: #5f0e78
 875 </style>
 876
 877 <style lang="sass" scoped>
 878 @import "@/styles/_board_squares_img.sass";
 879
 880 //.game.reserve-div
 881   // TODO: would be cleaner to restrict width so that it doesn't overflow
 882   // Commented out because pieces would disappear over the board otherwise:
 883   //overflow: hidden
 884 .reserve-count
 885   width: 100%
 886   text-align: center
 887   display: inline-block
 888   position: absolute
 889 .reserve-row
 890   margin-bottom: 15px
 891
 892 .full-width
 893   width: 100%
 894
 895 .game
 896   user-select: none
 897   width: 100%
 898   margin: 0
 899   .board
 900     cursor: pointer
 901
 902 #choices
 903   user-select: none
 904   margin: 0
 905   position: absolute
 906   z-index: 300
 907   overflow-y: inherit
 908   background-color: rgba(0,0,0,0)
 909   img
 910     cursor: pointer
 911     background-color: #e6ee9c
 912     &:hover
 913       background-color: skyblue
 914     &.choice-piece
 915       width: 100%
 916       height: auto
 917       display: block
 918
 919 img.ghost
 920   // NOTE: no need to set z-index here, since opacity is low
 921   position: absolute
 922   opacity: 0.5
 923   top: 0
 924
 925 .incheck-light
 926   background-color: rgba(204, 51, 0, 0.7) !important
 927 .incheck-dark
 928   background-color: rgba(204, 51, 0, 0.9) !important
 929
 930 // TODO: no predefined highlight colors, but layers. How?
 931
 932 .hover-highlight:hover
 933   // TODO: color dependant on board theme, or inner border...
 934   background-color: #C571E6 !important
 935
 936 .highlight
 937   &.light-square
 938     &.lichess
 939       background-color: #cdd26a
 940     &.chesscom
 941       background-color: #f7f783
 942     &.chesstempo
 943       background-color: #9f9fff
 944     &.orangecc
 945       background-color: #fef273
 946   &.dark-square
 947     &.lichess
 948       background-color: #aaa23a
 949     &.chesscom
 950       background-color: #bacb44
 951     &.chesstempo
 952       background-color: #557fff
 953     &.orangecc
 954       background-color: #e8c525
 955   &.middle-square
 956     &.lichess
 957       background-color: #BCBA52
 958     &.chesscom
 959       background-color: #D9E164
 960     &.chesstempo
 961       background-color: #7A8FFF
 962     &.orangecc
 963       background-color: #F3DC4C
 964 </style>