VersaWhiteboard/public/js/whiteboard.js

var whiteboard = {
	canvas: null,
	ctx: null,
	drawcolor: "black",
	tool: "pen",
	thickness: 4,
	prevX: null,
	prevY: null,
	drawFlag: false,
	oldGCO: null,
	mouseover: false,
	lineCap: "round", //butt, square
	backgroundGrid: null,
	canvasElement: null,
	cursorContainer: null,
	imgContainer: null,
	svgContainer: null, //For draw prev
	mouseOverlay: null,
	ownCursor: null,
	drawBuffer: [],
	drawId: 0, //Used for undo function
	imgDragActive: false,
	settings: {
		whiteboardId: "0",
		username: "unknown",
		sendFunction: null,
		canvasWidth: 3000,
		canvasHeight: 2000,
		backgroundGridUrl: './img/KtEBa2.png'
	},
	loadWhiteboard: function (whiteboardContainer, newSettings) {
		var svgns = "http://www.w3.org/2000/svg";
		var _this = this;
		for (var i in newSettings) {
			this.settings[i] = newSettings[i];
		}
		this.settings["username"] = this.settings["username"].replace(/[^0-9a-z]/gi, '');
		this.settings["whiteboardId"] = this.settings["whiteboardId"].replace(/[^0-9a-z]/gi, '');

		var startCoords = [];
		var svgLine = null;
		var svgRect = null;
		var svgCirle = null;
		var latestTouchCoods = null;
		//Background
		_this.backgroundGrid = $('<div style="position: absolute; left:0px; top:0; opacity: 0.2; background-image:url(\'' + _this.settings["backgroundGridUrl"] + '\'); height: 100%; width: 100%;"></div>');

		_this.imgContainer = $('<div style="position: absolute; left:0px; top:0; height: 100%; width: 100%;"></div>');
		//Canvas
		_this.canvasElement = $('<canvas id="whiteboardCanvas" style="position: absolute; left:0px; top:0; cursor:crosshair;"></canvas>');

		_this.svgContainer = $('<svg style="position: absolute; top:0px; left:0px;" width="' + _this.settings.canvasWidth + '" height="' + _this.settings.canvasHeight + '"></svg>');

		_this.cursorContainer = $('<div style="position: absolute; left:0px; top:0; height: 100%; width: 100%;"></div>');

		_this.dropIndicator = $('<div style="position:absolute; height: 100%; width: 100%; border: 7px dashed gray; text-align: center; top: 0px; left: 0px; color: gray; font-size: 23em; display: none;"><i class="far fa-plus-square" aria-hidden="true"></i></div>')

		_this.mouseOverlay = $('<div style="cursor:none; position: absolute; left:0px; top:0; height: 100%; width: 100%;"></div>');



		$(whiteboardContainer).append(_this.backgroundGrid).append(_this.imgContainer).append(_this.canvasElement).append(_this.svgContainer).append(_this.dropIndicator).append(_this.cursorContainer).append(this.mouseOverlay);
		this.canvas = $("#whiteboardCanvas")[0];
		this.canvas.height = _this.settings.canvasHeight;
		this.canvas.width = _this.settings.canvasWidth;
		this.ctx = this.canvas.getContext("2d");
		this.oldGCO = this.ctx.globalCompositeOperation;

		$(_this.mouseOverlay).on("mousedown touchstart", function (e) {
			if (_this.imgDragActive) {
				return;
			}
			_this.drawFlag = true;
			_this.prevX = (e.offsetX || e.pageX - $(e.target).offset().left);
			_this.prevY = (e.offsetY || e.pageY - $(e.target).offset().top);
			if (!_this.prevX || !_this.prevY) {
				var touche = e.touches[0];
				_this.prevX = touche.clientX - $(_this.mouseOverlay).offset().left;
				_this.prevY = touche.clientY - $(_this.mouseOverlay).offset().top;
				latestTouchCoods = [_this.prevX, _this.prevY];
			}

			if (_this.tool === "pen") {
				_this.drawPenLine(_this.prevX, _this.prevY, _this.prevX, _this.prevY, _this.drawcolor, _this.thickness);
				_this.sendFunction({ "t": _this.tool, "d": [_this.prevX, _this.prevY, _this.prevX, _this.prevY], "c": _this.drawcolor, "th": _this.thickness });
			} else if (_this.tool === "eraser") {
				_this.drawEraserLine(_this.prevX, _this.prevY, _this.prevX, _this.prevY, _this.thickness);
				_this.sendFunction({ "t": _this.tool, "d": [_this.prevX, _this.prevY, _this.prevX, _this.prevY], "th": _this.thickness });
			} else if (_this.tool === "line") {
				startCoords = [_this.prevX, _this.prevY];
				svgLine = document.createElementNS(svgns, 'line');
				svgLine.setAttribute('stroke', 'gray');
				svgLine.setAttribute('stroke-dasharray', '5, 5');
				svgLine.setAttribute('x1', _this.prevX);
				svgLine.setAttribute('y1', _this.prevY);
				svgLine.setAttribute('x2', _this.prevX + 1);
				svgLine.setAttribute('y2', _this.prevY + 1);
				_this.svgContainer.append(svgLine);
			} else if (_this.tool === "rect" || _this.tool === "recSelect") {
				_this.svgContainer.find("rect").remove();
				svgRect = document.createElementNS(svgns, 'rect');
				svgRect.setAttribute('stroke', 'gray');
				svgRect.setAttribute('stroke-dasharray', '5, 5');
				svgRect.setAttribute('style', 'fill-opacity:0.0;');
				svgRect.setAttribute('x', _this.prevX);
				svgRect.setAttribute('y', _this.prevY);
				svgRect.setAttribute('width', 0);
				svgRect.setAttribute('height', 0);
				_this.svgContainer.append(svgRect);
				startCoords = [_this.prevX, _this.prevY];
			} else if (_this.tool === "circle") {
				svgCirle = document.createElementNS(svgns, 'circle');
				svgCirle.setAttribute('stroke', 'gray');
				svgCirle.setAttribute('stroke-dasharray', '5, 5');
				svgCirle.setAttribute('style', 'fill-opacity:0.0;');
				svgCirle.setAttribute('cx', _this.prevX);
				svgCirle.setAttribute('cy', _this.prevY);
				svgCirle.setAttribute('r', 0);
				_this.svgContainer.append(svgCirle);
				startCoords = [_this.prevX, _this.prevY];
			}
		});

		$(_this.mouseOverlay).on("mousemove touchmove", function (e) {
			e.preventDefault();
			if (_this.imgDragActive) {
				return;
			}
			var currX = (e.offsetX || e.pageX - $(e.target).offset().left);
			var currY = (e.offsetY || e.pageY - $(e.target).offset().top);
			window.requestAnimationFrame(function () {
				if ((!currX || !currY) && e.touches && e.touches[0]) {
					var touche = e.touches[0];
					currX = touche.clientX - $(_this.mouseOverlay).offset().left;
					currY = touche.clientY - $(_this.mouseOverlay).offset().top;
					latestTouchCoods = [currX, currY];
				}

				if (_this.drawFlag) {
					if (_this.tool === "pen") {
						_this.drawPenLine(currX, currY, _this.prevX, _this.prevY, _this.drawcolor, _this.thickness);
						_this.sendFunction({ "t": _this.tool, "d": [currX, currY, _this.prevX, _this.prevY], "c": _this.drawcolor, "th": _this.thickness });
					} else if (_this.tool == "eraser") {
						_this.drawEraserLine(currX, currY, _this.prevX, _this.prevY, _this.thickness);
						_this.sendFunction({ "t": _this.tool, "d": [currX, currY, _this.prevX, _this.prevY], "th": _this.thickness });
					}
					_this.prevX = currX;
					_this.prevY = currY;
				}

				if (_this.tool === "eraser") {
					var left = currX - _this.thickness;
					var top = currY - _this.thickness;
					_this.ownCursor.css({ "top": top + "px", "left": left + "px" });
				} else if (_this.tool === "pen") {
					var left = currX - _this.thickness / 2;
					var top = currY - _this.thickness / 2;
					_this.ownCursor.css({ "top": top + "px", "left": left + "px" });
				} else if (_this.tool === "line") {
					if (svgLine) {
						if (shiftPressed) {
							var angs = getRoundedAngles(currX, currY);
							currX = angs.x;
							currY = angs.y;
						}
						svgLine.setAttribute('x2', currX);
						svgLine.setAttribute('y2', currY);
					}
				} else if (_this.tool === "rect" || (_this.tool === "recSelect" && _this.drawFlag)) {
					if (svgRect) {
						var width = Math.abs(currX - startCoords[0]);
						var height = Math.abs(currY - startCoords[1]);
						if (shiftPressed) {
							height = width;
							var x = currX < startCoords[0] ? startCoords[0] - width : startCoords[0];
							var y = currY < startCoords[1] ? startCoords[1] - width : startCoords[1];
							svgRect.setAttribute('x', x);
							svgRect.setAttribute('y', y);
						} else {
							var x = currX < startCoords[0] ? currX : startCoords[0];
							var y = currY < startCoords[1] ? currY : startCoords[1];
							svgRect.setAttribute('x', x);
							svgRect.setAttribute('y', y);
						}

						svgRect.setAttribute('width', width);
						svgRect.setAttribute('height', height);
					}
				} else if (_this.tool === "circle") {
					var a = currX - startCoords[0];
					var b = currY - startCoords[1];
					var r = Math.sqrt(a * a + b * b);
					if (svgCirle) {
						svgCirle.setAttribute('r', r);
					}
				}
			});
			_this.sendFunction({ "t": "cursor", "event": "move", "d": [currX, currY], "username": _this.settings.username });
		});

		$(_this.mouseOverlay).on("mouseup touchend touchcancel", function (e) {
			if (_this.imgDragActive) {
				return;
			}
			_this.drawFlag = false;
			_this.drawId++;
			_this.ctx.globalCompositeOperation = _this.oldGCO;
			var currX = (e.offsetX || e.pageX - $(e.target).offset().left);
			var currY = (e.offsetY || e.pageY - $(e.target).offset().top);
			if ((!currX || !currY) && e.touches[0]) {
				currX = latestTouchCoods[0];
				currY = latestTouchCoods[1];
				_this.sendFunction({ "t": "cursor", "event": "out", "username": _this.settings.username });
			}

			if (_this.tool === "line") {
				if (shiftPressed) {
					var angs = getRoundedAngles(currX, currY);
					currX = angs.x;
					currY = angs.y;
				}
				_this.drawPenLine(currX, currY, startCoords[0], startCoords[1], _this.drawcolor, _this.thickness);
				_this.sendFunction({ "t": _this.tool, "d": [currX, currY, startCoords[0], startCoords[1]], "c": _this.drawcolor, "th": _this.thickness });
				_this.svgContainer.find("line").remove();
			} else if (_this.tool === "rect") {
				if (shiftPressed) {
					if ((currY - startCoords[1]) * (currX - startCoords[0]) > 0) {
						currY = startCoords[1] + (currX - startCoords[0]);
					} else {
						currY = startCoords[1] - (currX - startCoords[0]);
					}
				}
				_this.drawRec(startCoords[0], startCoords[1], currX, currY, _this.drawcolor, _this.thickness);
				_this.sendFunction({ "t": _this.tool, "d": [startCoords[0], startCoords[1], currX, currY], "c": _this.drawcolor, "th": _this.thickness });
				_this.svgContainer.find("rect").remove();
			} else if (_this.tool === "circle") {
				var a = currX - startCoords[0];
				var b = currY - startCoords[1];
				var r = Math.sqrt(a * a + b * b);
				_this.drawCircle(startCoords[0], startCoords[1], r, _this.drawcolor, _this.thickness);
				_this.sendFunction({ "t": _this.tool, "d": [startCoords[0], startCoords[1], r], "c": _this.drawcolor, "th": _this.thickness });
				_this.svgContainer.find("circle").remove();
			} else if (_this.tool === "recSelect") {
				_this.imgDragActive = true;
				if (shiftPressed) {
					if ((currY - startCoords[1]) * (currX - startCoords[0]) > 0) {
						currY = startCoords[1] + (currX - startCoords[0]);
					} else {
						currY = startCoords[1] - (currX - startCoords[0]);
					}
				}

				var width = Math.abs(startCoords[0] - currX);
				var height = Math.abs(startCoords[1] - currY);
				var left = startCoords[0] < currX ? startCoords[0] : currX;
				var top = startCoords[1] < currY ? startCoords[1] : currY;
				_this.mouseOverlay.css({ "cursor": "default" });
				var imgDiv = $('<div style="position:absolute; left:' + left + 'px; top:' + top + 'px; width:' + width + 'px; border: 2px dotted gray; overflow: hidden; height:' + height + 'px;" cursor:move;">' +
					'<canvas style="cursor:move; position:absolute; top:0px; left:0px;" width="' + width + '" height="' + height + '"/>' +
					'<div style="position:absolute; right:5px; top:3px;">' +
					'<button draw="1" style="margin: 0px 0px; background: #03a9f4; padding: 5px; margin-top: 3px; color: white;" class="addToCanvasBtn btn btn-default">Drop</button> ' +
					'<button style="margin: 0px 0px; background: #03a9f4; padding: 5px; margin-top: 3px; color: white;" class="xCanvasBtn btn btn-default">x</button>' +
					'</div>' +
					'</div>');
				var dragCanvas = $(imgDiv).find("canvas");
				var dragOutOverlay = $('<div class="dragOutOverlay" style="position:absolute; left:' + left + 'px; top:' + top + 'px; width:' + width + 'px; height:' + height + 'px; background:white;"></div>');
				_this.mouseOverlay.append(dragOutOverlay);
				_this.mouseOverlay.append(imgDiv);

				var destCanvasContext = dragCanvas[0].getContext('2d');
				destCanvasContext.drawImage(_this.canvas, left, top, width, height, 0, 0, width, height);
				imgDiv.find(".xCanvasBtn").click(function () {
					_this.imgDragActive = false;
					if (_this.tool === "pen") {
						_this.mouseOverlay.css({ "cursor": "none" });
					} else {
						_this.mouseOverlay.css({ "cursor": "crosshair" });
					}
					imgDiv.remove();
					dragOutOverlay.remove();
				});
				imgDiv.find(".addToCanvasBtn").click(function () {
					_this.imgDragActive = false;
					if (_this.tool === "pen") {
						_this.mouseOverlay.css({ "cursor": "none" });
					} else {
						_this.mouseOverlay.css({ "cursor": "crosshair" });
					}
					var widthT = imgDiv.width();
					var heightT = imgDiv.height();
					var p = imgDiv.position();
					var leftT = Math.round(p.left * 100) / 100;
					var topT = Math.round(p.top * 100) / 100;
					//xf, yf, xt, yt, width, height
					_this.drawId++;
					_this.sendFunction({ "t": _this.tool, "d": [left, top, leftT, topT, width, height] });
					_this.dragCanvasRectContent(left, top, leftT, topT, width, height);
					imgDiv.remove();
					dragOutOverlay.remove();
				});
				imgDiv.draggable();
				_this.svgContainer.find("rect").remove();
			}
		});

		$(_this.mouseOverlay).on("mouseout", function (e) {
			if (_this.imgDragActive) {
				return;
			}
			_this.drawFlag = false;
			_this.mouseover = false;
			_this.ctx.globalCompositeOperation = _this.oldGCO;
			_this.ownCursor.remove();
			_this.svgContainer.find("line").remove();
			_this.svgContainer.find("rect").remove();
			_this.svgContainer.find("circle").remove();
			_this.sendFunction({ "t": "cursor", "event": "out" });
		});

		$(_this.mouseOverlay).on("mouseover", function (e) {
			if (_this.imgDragActive) {
				return;
			}
			if (!_this.mouseover) {
				var color = _this.drawcolor;
				var widthHeight = _this.thickness;
				if (_this.tool === "eraser") {
					color = "#00000000";
					widthHeight = widthHeight * 2;
				}
				if (_this.tool === "eraser" || _this.tool === "pen") {
					_this.ownCursor = $('<div id="ownCursor" style="background:' + color + '; border:1px solid gray; position:absolute; width:' + widthHeight + 'px; height:' + widthHeight + 'px; border-radius:50%;"></div>');
					_this.cursorContainer.append(_this.ownCursor);
				}
			}
			_this.mouseover = true;
		});

		var strgPressed = false;
		var zPressed = false;
		var shiftPressed = false;
		$(document).on("keydown", function (e) {
			if (e.which == 17) {
				strgPressed = true;
			} else if (e.which == 90) {
				if (strgPressed && !zPressed) {
					_this.undoWhiteboardClick();
				}
				zPressed = true;
			} else if (e.which == 16) {
				shiftPressed = true;
			} else if (e.which == 27) { //Esc
				if (!_this.drawFlag)
					_this.svgContainer.empty();
				_this.mouseOverlay.find(".xCanvasBtn").click(); //Remove all current drops
			} else if (e.which == 46) { //Remove / Entf
				$.each(_this.mouseOverlay.find(".dragOutOverlay"), function () {
					var width = $(this).width();
					var height = $(this).height();
					var p = $(this).position();
					var left = Math.round(p.left * 100) / 100;
					var top = Math.round(p.top * 100) / 100;
					_this.drawId++;
					_this.sendFunction({ "t": "eraseRec", "d": [left, top, width, height] });
					_this.eraseRec(left, top, width, height);
				});
				_this.mouseOverlay.find(".xCanvasBtn").click(); //Remove all current drops
			}
			//console.log(e.which);
		});
		$(document).on("keyup", function (e) {
			if (e.which == 17) {
				strgPressed = false;
			} else if (e.which == 90) {
				zPressed = false;
			} else if (e.which == 16) {
				shiftPressed = false;
			}
		});

		function getRoundedAngles(currX, currY) { //For drawing lines at 0,45,90° ....
			var x = currX - startCoords[0];
			var y = currY - startCoords[1];
			var angle = Math.atan2(x, y) * (180 / Math.PI);
			var angle45 = Math.round(angle / 45) * 45;
			if (angle45 % 90 == 0) {
				if (Math.abs(currX - startCoords[0]) > Math.abs(currY - startCoords[1])) {
					currY = startCoords[1]
				} else {
					currX = startCoords[0]
				}
			} else {
				if ((currY - startCoords[1]) * (currX - startCoords[0]) > 0) {
					currX = startCoords[0] + (currY - startCoords[1]);
				} else {
					currX = startCoords[0] - (currY - startCoords[1]);
				}
			}
			return { "x": currX, "y": currY };
		}
	},
	dragCanvasRectContent: function (xf, yf, xt, yt, width, height) {
		var tempCanvas = document.createElement('canvas');
		tempCanvas.width = width;
		tempCanvas.height = height;
		var tempCanvasContext = tempCanvas.getContext('2d');
		tempCanvasContext.drawImage(this.canvas, xf, yf, width, height, 0, 0, width, height);
		this.eraseRec(xf, yf, width, height);
		this.ctx.drawImage(tempCanvas, xt, yt);
	},
	eraseRec: function (fromX, fromY, width, height) {
		var _this = this;
		_this.ctx.beginPath();
		_this.ctx.rect(fromX, fromY, width, height);
		_this.ctx.fillStyle = "rgba(0,0,0,1)";
		_this.ctx.globalCompositeOperation = "destination-out";
		_this.ctx.fill();
		_this.ctx.closePath();
		_this.ctx.globalCompositeOperation = _this.oldGCO;
	},
	drawPenLine: function (fromX, fromY, toX, toY, color, thickness) {
		var _this = this;
		_this.ctx.beginPath();
		_this.ctx.moveTo(fromX, fromY);
		_this.ctx.lineTo(toX, toY);
		_this.ctx.strokeStyle = color;
		_this.ctx.lineWidth = thickness;
		_this.ctx.lineCap = _this.lineCap;
		_this.ctx.stroke();
		_this.ctx.closePath();
	},
	drawEraserLine: function (fromX, fromY, toX, toY, thickness) {
		var _this = this;
		_this.ctx.beginPath();
		_this.ctx.moveTo(fromX, fromY);
		_this.ctx.lineTo(toX, toY);
		_this.ctx.strokeStyle = "rgba(0,0,0,1)";
		_this.ctx.lineWidth = thickness * 2;
		_this.ctx.lineCap = _this.lineCap;
		_this.ctx.globalCompositeOperation = "destination-out";
		_this.ctx.stroke();
		_this.ctx.closePath();
		_this.ctx.globalCompositeOperation = _this.oldGCO;
	},
	drawRec: function (fromX, fromY, toX, toY, color, thickness) {
		var _this = this;
		toX = toX - fromX;
		toY = toY - fromY;
		_this.ctx.beginPath();
		_this.ctx.rect(fromX, fromY, toX, toY);
		_this.ctx.strokeStyle = color;
		_this.ctx.lineWidth = thickness;
		_this.ctx.lineCap = _this.lineCap;
		_this.ctx.stroke();
		_this.ctx.closePath();
	},
	drawCircle: function (fromX, fromY, radius, color, thickness) {
		var _this = this;
		_this.ctx.beginPath();
		_this.ctx.arc(fromX, fromY, radius, 0, 2 * Math.PI, false);
		_this.ctx.lineWidth = thickness;
		_this.ctx.strokeStyle = color;
		_this.ctx.stroke();
	},
	clearWhiteboard: function () {
		var _this = this;
		_this.canvas.height = _this.canvas.height;
		_this.imgContainer.empty();
		_this.sendFunction({ "t": "clear" });
		_this.drawBuffer = [];
		_this.drawId = 0;
	},
	addImgToCanvasByUrl: function (url) {
		var _this = this;
		_this.imgDragActive = true;
		_this.mouseOverlay.css({ "cursor": "default" });
		var imgDiv = $('<div style="border: 2px dashed gray; position:absolute; left:200px; top:200px; min-width:160px; min-height:100px; cursor:move;">' +
			'<img style="width:100%; height:100%;" src="' + url + '">' +
			'<div style="position:absolute; right:5px; top:3px;">' +
			'<button draw="1" style="margin: 0px 0px; background: #03a9f4; padding: 5px; margin-top: 3px; color: white;" class="addToCanvasBtn btn btn-default">Draw to canvas</button> ' +
			'<button draw="0" style="margin: 0px 0px; background: #03a9f4; padding: 5px; margin-top: 3px; color: white;" class="addToCanvasBtn btn btn-default">Add to background</button> ' +
			'<button style="margin: 0px 0px; background: #03a9f4; padding: 5px; margin-top: 3px; color: white;" class="xCanvasBtn btn btn-default">x</button>' +
			'</div>' +
			'<i style="position:absolute; bottom: -4px; right: 2px; font-size: 2em; color: gray; transform: rotate(-45deg);" class="fas fa-sort-down" aria-hidden="true"></i>' +
			'</div>');
		imgDiv.find(".xCanvasBtn").click(function () {
			_this.imgDragActive = false;
			if (_this.tool === "pen") {
				_this.mouseOverlay.css({ "cursor": "none" });
			} else if (_this.tool === "mouse") {
				_this.mouseOverlay.css({ "cursor": "auto" });
			} else {
				_this.mouseOverlay.css({ "cursor": "crosshair" });
			}
			imgDiv.remove();
		});
		imgDiv.find(".addToCanvasBtn").click(function () {
			var draw = $(this).attr("draw");
			_this.imgDragActive = false;
			if (_this.tool === "pen") {
				_this.mouseOverlay.css({ "cursor": "none" });
			} else if (_this.tool === "mouse") {
				_this.mouseOverlay.css({ "cursor": "auto" });
			} else {
				_this.mouseOverlay.css({ "cursor": "crosshair" });
			}
			var width = imgDiv.width();
			var height = imgDiv.height();
			var p = imgDiv.position();
			var left = Math.round(p.left * 100) / 100;
			var top = Math.round(p.top * 100) / 100;
			if (draw == "1") { //draw image to canvas
				_this.drawImgToCanvas(url, width, height, left, top);
			} else { //Add image to background
				_this.drawImgToBackground(url, width, height, left, top);
			}
			_this.sendFunction({ "t": "addImgBG", "draw": draw, "url": url, "d": [width, height, left, top] });
			_this.drawId++;
			imgDiv.remove();
		});
		_this.mouseOverlay.append(imgDiv);
		imgDiv.draggable();
		imgDiv.resizable();
	},
	drawImgToBackground(url, width, height, left, top) {
		this.imgContainer.append('<img crossorigin="anonymous" style="width:' + width + 'px; height:' + height + 'px; position:absolute; top:' + top + 'px; left:' + left + 'px;" src="' + url + '">')
	},
	drawImgToCanvas(url, width, height, left, top, doneCallback) {
		var _this = this;
		var img = document.createElement('img');
		img.onload = function () {
			_this.ctx.drawImage(img, left, top, width, height);
			if (doneCallback) {
				doneCallback();
			}
		}
		img.src = url;
	},
	undoWhiteboard: function (username) { //Not call this directly because you will get out of sync whit others...
		var _this = this;
		if (!username) {
			username = _this.settings.username;
		}
		for (var i = _this.drawBuffer.length - 1; i >= 0; i--) {
			if (_this.drawBuffer[i]["username"] == username) {
				var drawId = _this.drawBuffer[i]["drawId"];
				for (var i = _this.drawBuffer.length - 1; i >= 0; i--) {
					if (_this.drawBuffer[i]["drawId"] == drawId && _this.drawBuffer[i]["username"] == username) {
						_this.drawBuffer.splice(i, 1);
					}
				}
				break;
			}
		}
		_this.canvas.height = _this.canvas.height;
		_this.imgContainer.empty();
		console.log(_this.drawBuffer)
		_this.loadDataInSteps(_this.drawBuffer, false, function (stepData) {
			//Nothing to do
		});
	},
	undoWhiteboardClick: function () {
		this.sendFunction({ "t": "undo" });
		this.undoWhiteboard();
	},
	setTool: function (tool) {
		this.tool = tool;
		if (tool === "pen" || tool === "eraser") {
			this.mouseOverlay.css({ "cursor": "none" });
		} else if (tool === "mouse") {
			this.mouseOverlay.css({ "cursor": "default" });
		} else {
			this.mouseOverlay.css({ "cursor": "crosshair" });
		}
		this.mouseOverlay.find(".xCanvasBtn").click();
	},
	handleEventsAndData: function (content, isNewData, doneCallback) {
		var _this = this;
		var tool = content["t"];
		var data = content["d"];
		var color = content["c"];
		var username = content["username"];
		var thickness = content["th"];
		window.requestAnimationFrame(function () {
			if (tool === "line" || tool === "pen") {
				_this.drawPenLine(data[0], data[1], data[2], data[3], color, thickness);
			} else if (tool === "rect") {
				_this.drawRec(data[0], data[1], data[2], data[3], color, thickness);
			} else if (tool === "circle") {
				_this.drawCircle(data[0], data[1], data[2], color, thickness);
			} else if (tool === "eraser") {
				_this.drawEraserLine(data[0], data[1], data[2], data[3], thickness);
			} else if (tool === "eraseRec") {
				_this.eraseRec(data[0], data[1], data[2], data[3]);
			} else if (tool === "recSelect") {
				_this.dragCanvasRectContent(data[0], data[1], data[2], data[3], data[4], data[5]);
			} else if (tool === "addImgBG") {
				if (content["draw"] == "1") {
					_this.drawImgToCanvas(content["url"], data[0], data[1], data[2], data[3], doneCallback)
				} else {
					_this.drawImgToBackground(content["url"], data[0], data[1], data[2], data[3]);
				}
			} else if (tool === "clear") {
				_this.canvas.height = _this.canvas.height;
				this.imgContainer.empty();
				this.drawBuffer = [];
				this.drawId = 0;
			} else if (tool === "cursor" && _this.settings) {
				if (content["event"] === "move") {
					if (_this.cursorContainer.find("." + content["username"]).length >= 1) {
						_this.cursorContainer.find("." + content["username"]).css({ "left": data[0] + "px", "top": data[1] + "px" });
					} else {
						_this.cursorContainer.append('<div style="font-size:0.8em; padding-left:2px; padding-right:2px; background:gray; color:white; border-radius:3px; position:absolute; left:' + data[0] + '; top:' + data[1] + ';" class="userbadge ' + content["username"] + '">' +
							'<div style="width:4px; height:4px; background:gray; position:absolute; top:-2px; left:-2px; border-radius:50%;"></div>' +
							content["username"] + '</div>');
					}
				} else {
					_this.cursorContainer.find("." + content["username"]).remove();
				}
			} else if (tool === "undo") {
				_this.undoWhiteboard(username);
			}
		});

		if (isNewData && (tool === "line" || tool === "pen" || tool === "rect" || tool === "circle" || tool === "eraser" || tool === "addImgBG" || tool === "recSelect" || tool === "eraseRec")) {
			content["drawId"] = content["drawId"] ? content["drawId"] : _this.drawId;
			content["username"] = content["username"] ? content["username"] : _this.settings.username;
			_this.drawBuffer.push(content);
		}
	},
	userLeftWhiteboard(username) {
		this.cursorContainer.find("." + username).remove();
	},
	refreshUserBadges() {
		this.cursorContainer.find(".userbadge").remove();
	},
	getImageDataBase64() {
		_this = this;
		var width = this.mouseOverlay.width();
		var height = this.mouseOverlay.height();
		var copyCanvas = document.createElement('canvas');
		copyCanvas.width = width;
		copyCanvas.height = height;
		var ctx = copyCanvas.getContext("2d");

		$.each(_this.imgContainer.find("img"), function () {
			var width = $(this).width();
			var height = $(this).height();
			var p = $(this).position();
			var left = Math.round(p.left * 100) / 100;
			var top = Math.round(p.top * 100) / 100;
			ctx.drawImage(this, left, top, width, height);
		});

		var destCtx = copyCanvas.getContext('2d');
		destCtx.drawImage(this.canvas, 0, 0);
		var url = copyCanvas.toDataURL();
		return url;
	},
	getImageDataJson() {
		var sendObj = [];
		for (var i = 0; i < this.drawBuffer.length; i++) {
			sendObj.push(JSON.parse(JSON.stringify(this.drawBuffer[i])));
			delete sendObj[i]["username"];
			delete sendObj[i]["wid"];
			delete sendObj[i]["drawId"];
		}
		return JSON.stringify(sendObj);
	},
	loadData: function (content) {
		var _this = this;
		_this.loadDataInSteps(content, true, function (stepData) {
			if (stepData["username"] == _this.settings.username && _this.drawId < stepData["drawId"]) {
				_this.drawId = stepData["drawId"] + 1;
			}
		});
	},
	loadDataInSteps(content, isNewData, callAfterEveryStep, doneCallback) {
		var _this = this;
		function lData(index) {
			for (var i = index; i < content.length; i++) {
				if (content[i]["t"] === "addImgBG" && content[i]["draw"] == "1") {
					_this.handleEventsAndData(content[i], isNewData, function () {
						callAfterEveryStep(content[i], i);
						lData(i + 1);
					});
					break;
				} else {
					_this.handleEventsAndData(content[i], isNewData);
					callAfterEveryStep(content[i], i);
				}
			}
		}
		lData(0);
	},
	loadJsonData(content) {
		var _this = this;
		_this.loadDataInSteps(content, false, function (stepData, index) {
			_this.sendFunction(stepData);
			if (index >= content.length - 1) { //Done with all data
				_this.drawId++;
			}
		});
	},
	sendFunction: function (content) { //Sends every draw to server
		var _this = this;
		content["wid"] = _this.settings.whiteboardId;
		content["username"] = _this.settings.username;
		content["drawId"] = _this.drawId;

		var tool = content["t"];
		if (_this.settings.sendFunction) {
			_this.settings.sendFunction(content);
		}
		if (tool === "line" || tool === "pen" || tool === "rect" || tool === "circle" || tool === "eraser" || tool === "addImgBG" || tool === "recSelect" || tool === "eraseRec") {
			_this.drawBuffer.push(content);
		}
	},
	isRecRecCollision: function (rx1, ry1, rw1, rh1, rx2, ry2, rw2, rh2) {
		return rx1 < rx2 + rw2 && rx1 + rw1 > rx2 && ry1 < ry2 + rh2 && rh1 + ry1 > ry2;
	},
	isRecPointCollision: function (rx, ry, rw, rh, px, py) {
		return rx <= px && px <= rx + rw && ry <= py && py <= ry + rh;
	}
}