signature_pad.min.js

/*!
 * Signature Pad v1.2.3 | https://github.com/szimek/signature_pad
 * (c) 2013 Szymon Nowak | Released under the MIT license
 */
var SignaturePad=function(a){"use strict";var b=function(a,b){var c=b||{};this.velocityFilterWeight=c.velocityFilterWeight||.7,this.minWidth=c.minWidth||.5,this.maxWidth=c.maxWidth||2.5,this.dotSize=c.dotSize||function(){return(this.minWidth+this.maxWidth)/2},this.penColor=c.penColor||"black",this.backgroundColor=c.backgroundColor||"rgba(0,0,0,0)",this._canvas=a,this._ctx=a.getContext("2d"),this.clear(),this._handleMouseEvents(),this._handleTouchEvents()};b.prototype.clear=function(){var a=this._ctx,b=this._canvas;a.fillStyle=this.backgroundColor,a.clearRect(0,0,b.width,b.height),a.fillRect(0,0,b.width,b.height),this._reset()},b.prototype.toDataURL=function(){var a=this._canvas;return a.toDataURL.apply(a,arguments)},b.prototype.fromDataURL=function(a){var b=this,c=new Image;this._reset(),c.src=a,c.onload=function(){b._ctx.drawImage(c,0,0,b._canvas.width,b._canvas.height)},this._isEmpty=!1},b.prototype._handleMouseEvents=function(){var b=this;this._mouseButtonDown=!1,this._canvas.addEventListener("mousedown",function(a){if(1===a.which){b._mouseButtonDown=!0,b._reset();var c=b._createPoint(a);b._addPoint(c)}}),this._canvas.addEventListener("mousemove",function(a){if(b._mouseButtonDown){var c=b._createPoint(a);b._addPoint(c)}}),a.addEventListener("mouseup",function(a){if(1===a.which&&b._mouseButtonDown){b._mouseButtonDown=!1;var c=b.points.length>2,d=b.points[0],e=b._ctx,f="function"==typeof b.dotSize?b.dotSize.call(b):b.dotSize;!c&&d&&(e.beginPath(),b._drawPoint(d.x,d.y,f),e.closePath(),e.fill())}})},b.prototype._handleTouchEvents=function(){var b=this;this._canvas.addEventListener("touchstart",function(a){b._reset();var c=a.changedTouches[0],d=b._createPoint(c);b._addPoint(d)}),this._canvas.addEventListener("touchmove",function(a){a.preventDefault();var c=a.changedTouches[0],d=b._createPoint(c);b._addPoint(d)}),a.addEventListener("touchend",function(a){var c=a.target===b._canvas,d=b.points.length>2,e=b.points[0],f=b._ctx,g="function"==typeof b.dotSize?b.dotSize.call(b):b.dotSize;c&&!d&&e&&(f.beginPath(),b._drawPoint(e.x,e.y,g),f.closePath(),f.fill())})},b.prototype.isEmpty=function(){return this._isEmpty},b.prototype._reset=function(){this.points=[],this._lastVelocity=0,this._lastWidth=(this.minWidth+this.maxWidth)/2,this._isEmpty=!0,this._ctx.fillStyle=this.penColor},b.prototype._createPoint=function(a){var b=this._canvas.getBoundingClientRect();return new c(a.clientX-b.left,a.clientY-b.top)},b.prototype._addPoint=function(a){var b,c,e,f,g=this.points;g.push(a),g.length>2&&(3===g.length&&g.unshift(g[0]),f=this._calculateCurveControlPoints(g[0],g[1],g[2]),b=f.c2,f=this._calculateCurveControlPoints(g[1],g[2],g[3]),c=f.c1,e=new d(g[1],b,c,g[2]),this._addCurve(e),g.shift())},b.prototype._calculateCurveControlPoints=function(a,b,d){var e=a.x-b.x,f=a.y-b.y,g=b.x-d.x,h=b.y-d.y,i={x:(a.x+b.x)/2,y:(a.y+b.y)/2},j={x:(b.x+d.x)/2,y:(b.y+d.y)/2},k=Math.sqrt(e*e+f*f),l=Math.sqrt(g*g+h*h),m=i.x-j.x,n=i.y-j.y,o=l/(k+l),p={x:j.x+m*o,y:j.y+n*o},q=b.x-p.x,r=b.y-p.y;return{c1:new c(i.x+q,i.y+r),c2:new c(j.x+q,j.y+r)}},b.prototype._addCurve=function(a){var b,c,d=a.startPoint,e=a.endPoint;b=e.velocityFrom(d),b=this.velocityFilterWeight*b+(1-this.velocityFilterWeight)*this._lastVelocity,c=this._strokeWidth(b),this._drawCurve(a,this._lastWidth,c),this._lastVelocity=b,this._lastWidth=c},b.prototype._drawPoint=function(a,b,c){var d=this._ctx;d.moveTo(a,b),d.arc(a,b,c,0,2*Math.PI,!1),this._isEmpty=!1},b.prototype._drawCurve=function(a,b,c){var d,e,f,g,h,i,j,k,l,m,n,o=this._ctx,p=c-b;for(d=Math.floor(a.length()),o.beginPath(),f=0;d>f;f++)g=f/d,h=g*g,i=h*g,j=1-g,k=j*j,l=k*j,m=l*a.startPoint.x,m+=3*k*g*a.control1.x,m+=3*j*h*a.control2.x,m+=i*a.endPoint.x,n=l*a.startPoint.y,n+=3*k*g*a.control1.y,n+=3*j*h*a.control2.y,n+=i*a.endPoint.y,e=b+i*p,this._drawPoint(m,n,e);o.closePath(),o.fill()},b.prototype._strokeWidth=function(a){return Math.max(this.maxWidth/(a+1),this.minWidth)};var c=function(a,b,c){this.x=a,this.y=b,this.time=c||(new Date).getTime()};c.prototype.velocityFrom=function(a){return this.distanceTo(a)/(this.time-a.time)},c.prototype.distanceTo=function(a){return Math.sqrt(Math.pow(this.x-a.x,2)+Math.pow(this.y-a.y,2))};var d=function(a,b,c,d){this.startPoint=a,this.control1=b,this.control2=c,this.endPoint=d};return d.prototype.length=function(){var a,b,c,d,e,f,g,h,i=10,j=0;for(a=0;i>=a;a++)b=a/i,c=this._point(b,this.startPoint.x,this.control1.x,this.control2.x,this.endPoint.x),d=this._point(b,this.startPoint.y,this.control1.y,this.control2.y,this.endPoint.y),a>0&&(g=c-e,h=d-f,j+=Math.sqrt(g*g+h*h)),e=c,f=d;return j},d.prototype._point=function(a,b,c,d,e){return b*(1-a)*(1-a)*(1-a)+3*c*(1-a)*(1-a)*a+3*d*(1-a)*a*a+e*a*a*a},b}(document);