28 lines
3.6 KiB
JavaScript
28 lines
3.6 KiB
JavaScript
/* Flot plugin for drawing all elements of a plot on the canvas.
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Copyright (c) 2007-2013 IOLA and Ole Laursen.
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Licensed under the MIT license.
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Flot normally produces certain elements, like axis labels and the legend, using
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HTML elements. This permits greater interactivity and customization, and often
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looks better, due to cross-browser canvas text inconsistencies and limitations.
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It can also be desirable to render the plot entirely in canvas, particularly
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if the goal is to save it as an image, or if Flot is being used in a context
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where the HTML DOM does not exist, as is the case within Node.js. This plugin
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switches out Flot's standard drawing operations for canvas-only replacements.
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Currently the plugin supports only axis labels, but it will eventually allow
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every element of the plot to be rendered directly to canvas.
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The plugin supports these options:
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{
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canvas: boolean
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}
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The "canvas" option controls whether full canvas drawing is enabled, making it
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possible to toggle on and off. This is useful when a plot uses HTML text in the
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browser, but needs to redraw with canvas text when exporting as an image.
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*/(function(e){function o(t,o){var u=o.Canvas;n==null&&(r=u.prototype.getTextInfo,i=u.prototype.addText,n=u.prototype.render),u.prototype.render=function(){if(!t.getOptions().canvas)return n.call(this);var e=this.context,r=this._textCache;e.save(),e.textBaseline="middle";for(var i in r)if(s.call(r,i)){var o=r[i];for(var u in o)if(s.call(o,u)){var a=o[u],f=!0;for(var l in a)if(s.call(a,l)){var c=a[l],h=c.positions,p=c.lines;f&&(e.fillStyle=c.font.color,e.font=c.font.definition,f=!1);for(var d=0,v;v=h[d];d++)if(v.active)for(var m=0,g;g=v.lines[m];m++)e.fillText(p[m].text,g[0],g[1]);else h.splice(d--,1);h.length==0&&delete a[l]}}}e.restore()},u.prototype.getTextInfo=function(n,i,s,o,u){if(!t.getOptions().canvas)return r.call(this,n,i,s,o,u);var a,f,l,c;i=""+i,typeof s=="object"?a=s.style+" "+s.variant+" "+s.weight+" "+s.size+"px "+s.family:a=s,f=this._textCache[n],f==null&&(f=this._textCache[n]={}),l=f[a],l==null&&(l=f[a]={}),c=l[i];if(c==null){var h=this.context;if(typeof s!="object"){var p=e("<div> </div>").css("position","absolute").addClass(typeof s=="string"?s:null).appendTo(this.getTextLayer(n));s={lineHeight:p.height(),style:p.css("font-style"),variant:p.css("font-variant"),weight:p.css("font-weight"),family:p.css("font-family"),color:p.css("color")},s.size=p.css("line-height",1).height(),p.remove()}a=s.style+" "+s.variant+" "+s.weight+" "+s.size+"px "+s.family,c=l[i]={width:0,height:0,positions:[],lines:[],font:{definition:a,color:s.color}},h.save(),h.font=a;var d=(i+"").replace(/<br ?\/?>|\r\n|\r/g,"\n").split("\n");for(var v=0;v<d.length;++v){var m=d[v],g=h.measureText(m);c.width=Math.max(g.width,c.width),c.height+=s.lineHeight,c.lines.push({text:m,width:g.width,height:s.lineHeight})}h.restore()}return c},u.prototype.addText=function(e,n,r,s,o,u,a,f,l){if(!t.getOptions().canvas)return i.call(this,e,n,r,s,o,u,a,f,l);var c=this.getTextInfo(e,s,o,u,a),h=c.positions,p=c.lines;r+=c.height/p.length/2,l=="middle"?r=Math.round(r-c.height/2):l=="bottom"?r=Math.round(r-c.height):r=Math.round(r),!(window.opera&&window.opera.version().split(".")[0]<12)||(r-=2);for(var d=0,v;v=h[d];d++)if(v.x==n&&v.y==r){v.active=!0;return}v={active:!0,lines:[],x:n,y:r},h.push(v);for(var d=0,m;m=p[d];d++)f=="center"?v.lines.push([Math.round(n-m.width/2),r]):f=="right"?v.lines.push([Math.round(n-m.width),r]):v.lines.push([Math.round(n),r]),r+=m.height}}var t={canvas:!0},n,r,i,s=Object.prototype.hasOwnProperty;e.plot.plugins.push({init:o,options:t,name:"canvas",version:"1.0"})})(jQuery); |