--- a/lib/flot/jquery.flot.js +++ b/lib/flot/jquery.flot.js @@ -1,1 +1,2600 @@ - +/*! Javascript plotting library for jQuery, v. 0.7. + * + * Released under the MIT license by IOLA, December 2007. + * + */ + +// first an inline dependency, jquery.colorhelpers.js, we inline it here +// for convenience + +/* Plugin for jQuery for working with colors. + * + * Version 1.1. + * + * Inspiration from jQuery color animation plugin by John Resig. + * + * Released under the MIT license by Ole Laursen, October 2009. + * + * Examples: + * + * $.color.parse("#fff").scale('rgb', 0.25).add('a', -0.5).toString() + * var c = $.color.extract($("#mydiv"), 'background-color'); + * console.log(c.r, c.g, c.b, c.a); + * $.color.make(100, 50, 25, 0.4).toString() // returns "rgba(100,50,25,0.4)" + * + * Note that .scale() and .add() return the same modified object + * instead of making a new one. + * + * V. 1.1: Fix error handling so e.g. parsing an empty string does + * produce a color rather than just crashing. + */ +(function(B){B.color={};B.color.make=function(F,E,C,D){var G={};G.r=F||0;G.g=E||0;G.b=C||0;G.a=D!=null?D:1;G.add=function(J,I){for(var H=0;H<J.length;++H){G[J.charAt(H)]+=I}return G.normalize()};G.scale=function(J,I){for(var H=0;H<J.length;++H){G[J.charAt(H)]*=I}return G.normalize()};G.toString=function(){if(G.a>=1){return"rgb("+[G.r,G.g,G.b].join(",")+")"}else{return"rgba("+[G.r,G.g,G.b,G.a].join(",")+")"}};G.normalize=function(){function H(J,K,I){return K<J?J:(K>I?I:K)}G.r=H(0,parseInt(G.r),255);G.g=H(0,parseInt(G.g),255);G.b=H(0,parseInt(G.b),255);G.a=H(0,G.a,1);return G};G.clone=function(){return B.color.make(G.r,G.b,G.g,G.a)};return G.normalize()};B.color.extract=function(D,C){var E;do{E=D.css(C).toLowerCase();if(E!=""&&E!="transparent"){break}D=D.parent()}while(!B.nodeName(D.get(0),"body"));if(E=="rgba(0, 0, 0, 0)"){E="transparent"}return B.color.parse(E)};B.color.parse=function(F){var E,C=B.color.make;if(E=/rgb\(\s*([0-9]{1,3})\s*,\s*([0-9]{1,3})\s*,\s*([0-9]{1,3})\s*\)/.exec(F)){return C(parseInt(E[1],10),parseInt(E[2],10),parseInt(E[3],10))}if(E=/rgba\(\s*([0-9]{1,3})\s*,\s*([0-9]{1,3})\s*,\s*([0-9]{1,3})\s*,\s*([0-9]+(?:\.[0-9]+)?)\s*\)/.exec(F)){return C(parseInt(E[1],10),parseInt(E[2],10),parseInt(E[3],10),parseFloat(E[4]))}if(E=/rgb\(\s*([0-9]+(?:\.[0-9]+)?)\%\s*,\s*([0-9]+(?:\.[0-9]+)?)\%\s*,\s*([0-9]+(?:\.[0-9]+)?)\%\s*\)/.exec(F)){return C(parseFloat(E[1])*2.55,parseFloat(E[2])*2.55,parseFloat(E[3])*2.55)}if(E=/rgba\(\s*([0-9]+(?:\.[0-9]+)?)\%\s*,\s*([0-9]+(?:\.[0-9]+)?)\%\s*,\s*([0-9]+(?:\.[0-9]+)?)\%\s*,\s*([0-9]+(?:\.[0-9]+)?)\s*\)/.exec(F)){return C(parseFloat(E[1])*2.55,parseFloat(E[2])*2.55,parseFloat(E[3])*2.55,parseFloat(E[4]))}if(E=/#([a-fA-F0-9]{2})([a-fA-F0-9]{2})([a-fA-F0-9]{2})/.exec(F)){return C(parseInt(E[1],16),parseInt(E[2],16),parseInt(E[3],16))}if(E=/#([a-fA-F0-9])([a-fA-F0-9])([a-fA-F0-9])/.exec(F)){return C(parseInt(E[1]+E[1],16),parseInt(E[2]+E[2],16),parseInt(E[3]+E[3],16))}var D=B.trim(F).toLowerCase();if(D=="transparent"){return C(255,255,255,0)}else{E=A[D]||[0,0,0];return C(E[0],E[1],E[2])}};var A={aqua:[0,255,255],azure:[240,255,255],beige:[245,245,220],black:[0,0,0],blue:[0,0,255],brown:[165,42,42],cyan:[0,255,255],darkblue:[0,0,139],darkcyan:[0,139,139],darkgrey:[169,169,169],darkgreen:[0,100,0],darkkhaki:[189,183,107],darkmagenta:[139,0,139],darkolivegreen:[85,107,47],darkorange:[255,140,0],darkorchid:[153,50,204],darkred:[139,0,0],darksalmon:[233,150,122],darkviolet:[148,0,211],fuchsia:[255,0,255],gold:[255,215,0],green:[0,128,0],indigo:[75,0,130],khaki:[240,230,140],lightblue:[173,216,230],lightcyan:[224,255,255],lightgreen:[144,238,144],lightgrey:[211,211,211],lightpink:[255,182,193],lightyellow:[255,255,224],lime:[0,255,0],magenta:[255,0,255],maroon:[128,0,0],navy:[0,0,128],olive:[128,128,0],orange:[255,165,0],pink:[255,192,203],purple:[128,0,128],violet:[128,0,128],red:[255,0,0],silver:[192,192,192],white:[255,255,255],yellow:[255,255,0]}})(jQuery); + +// the actual Flot code +(function($) { + function Plot(placeholder, data_, options_, plugins) { + // data is on the form: + // [ series1, series2 ... ] + // where series is either just the data as [ [x1, y1], [x2, y2], ... ] + // or { data: [ [x1, y1], [x2, y2], ... ], label: "some label", ... } + + var series = [], + options = { + // the color theme used for graphs + colors: ["#edc240", "#afd8f8", "#cb4b4b", "#4da74d", "#9440ed"], + legend: { + show: true, + noColumns: 1, // number of colums in legend table + labelFormatter: null, // fn: string -> string + labelBoxBorderColor: "#ccc", // border color for the little label boxes + container: null, // container (as jQuery object) to put legend in, null means default on top of graph + position: "ne", // position of default legend container within plot + margin: 5, // distance from grid edge to default legend container within plot + backgroundColor: null, // null means auto-detect + backgroundOpacity: 0.85 // set to 0 to avoid background + }, + xaxis: { + show: null, // null = auto-detect, true = always, false = never + position: "bottom", // or "top" + mode: null, // null or "time" + color: null, // base color, labels, ticks + tickColor: null, // possibly different color of ticks, e.g. "rgba(0,0,0,0.15)" + transform: null, // null or f: number -> number to transform axis + inverseTransform: null, // if transform is set, this should be the inverse function + min: null, // min. value to show, null means set automatically + max: null, // max. value to show, null means set automatically + autoscaleMargin: null, // margin in % to add if auto-setting min/max + ticks: null, // either [1, 3] or [[1, "a"], 3] or (fn: axis info -> ticks) or app. number of ticks for auto-ticks + tickFormatter: null, // fn: number -> string + labelWidth: null, // size of tick labels in pixels + labelHeight: null, + reserveSpace: null, // whether to reserve space even if axis isn't shown + tickLength: null, // size in pixels of ticks, or "full" for whole line + alignTicksWithAxis: null, // axis number or null for no sync + + // mode specific options + tickDecimals: null, // no. of decimals, null means auto + tickSize: null, // number or [number, "unit"] + minTickSize: null, // number or [number, "unit"] + monthNames: null, // list of names of months + timeformat: null, // format string to use + twelveHourClock: false // 12 or 24 time in time mode + }, + yaxis: { + autoscaleMargin: 0.02, + position: "left" // or "right" + }, + xaxes: [], + yaxes: [], + series: { + points: { + show: false, + radius: 3, + lineWidth: 2, // in pixels + fill: true, + fillColor: "#ffffff", + symbol: "circle" // or callback + }, + lines: { + // we don't put in show: false so we can see + // whether lines were actively disabled + lineWidth: 2, // in pixels + fill: false, + fillColor: null, + steps: false + }, + bars: { + show: false, + lineWidth: 2, // in pixels + barWidth: 1, // in units of the x axis + fill: true, + fillColor: null, + align: "left", // or "center" + horizontal: false + }, + shadowSize: 3 + }, + grid: { + show: true, + aboveData: false, + color: "#545454", // primary color used for outline and labels + backgroundColor: null, // null for transparent, else color + borderColor: null, // set if different from the grid color + tickColor: null, // color for the ticks, e.g. "rgba(0,0,0,0.15)" + labelMargin: 5, // in pixels + axisMargin: 8, // in pixels + borderWidth: 2, // in pixels + minBorderMargin: null, // in pixels, null means taken from points radius + markings: null, // array of ranges or fn: axes -> array of ranges + markingsColor: "#f4f4f4", + markingsLineWidth: 2, + // interactive stuff + clickable: false, + hoverable: false, + autoHighlight: true, // highlight in case mouse is near + mouseActiveRadius: 10 // how far the mouse can be away to activate an item + }, + hooks: {} + }, + canvas = null, // the canvas for the plot itself + overlay = null, // canvas for interactive stuff on top of plot + eventHolder = null, // jQuery object that events should be bound to + ctx = null, octx = null, + xaxes = [], yaxes = [], + plotOffset = { left: 0, right: 0, top: 0, bottom: 0}, + canvasWidth = 0, canvasHeight = 0, + plotWidth = 0, plotHeight = 0, + hooks = { + processOptions: [], + processRawData: [], + processDatapoints: [], + drawSeries: [], + draw: [], + bindEvents: [], + drawOverlay: [], + shutdown: [] + }, + plot = this; + + // public functions + plot.setData = setData; + plot.setupGrid = setupGrid; + plot.draw = draw; + plot.getPlaceholder = function() { return placeholder; }; + plot.getCanvas = function() { return canvas; }; + plot.getPlotOffset = function() { return plotOffset; }; + plot.width = function () { return plotWidth; }; + plot.height = function () { return plotHeight; }; + plot.offset = function () { + var o = eventHolder.offset(); + o.left += plotOffset.left; + o.top += plotOffset.top; + return o; + }; + plot.getData = function () { return series; }; + plot.getAxes = function () { + var res = {}, i; + $.each(xaxes.concat(yaxes), function (_, axis) { + if (axis) + res[axis.direction + (axis.n != 1 ? axis.n : "") + "axis"] = axis; + }); + return res; + }; + plot.getXAxes = function () { return xaxes; }; + plot.getYAxes = function () { return yaxes; }; + plot.c2p = canvasToAxisCoords; + plot.p2c = axisToCanvasCoords; + plot.getOptions = function () { return options; }; + plot.highlight = highlight; + plot.unhighlight = unhighlight; + plot.triggerRedrawOverlay = triggerRedrawOverlay; + plot.pointOffset = function(point) { + return { + left: parseInt(xaxes[axisNumber(point, "x") - 1].p2c(+point.x) + plotOffset.left), + top: parseInt(yaxes[axisNumber(point, "y") - 1].p2c(+point.y) + plotOffset.top) + }; + }; + plot.shutdown = shutdown; + plot.resize = function () { + getCanvasDimensions(); + resizeCanvas(canvas); + resizeCanvas(overlay); + }; + + // public attributes + plot.hooks = hooks; + + // initialize + initPlugins(plot); + parseOptions(options_); + setupCanvases(); + setData(data_); + setupGrid(); + draw(); + bindEvents(); + + + function executeHooks(hook, args) { + args = [plot].concat(args); + for (var i = 0; i < hook.length; ++i) + hook[i].apply(this, args); + } + + function initPlugins() { + for (var i = 0; i < plugins.length; ++i) { + var p = plugins[i]; + p.init(plot); + if (p.options) + $.extend(true, options, p.options); + } + } + + function parseOptions(opts) { + var i; + + $.extend(true, options, opts); + + if (options.xaxis.color == null) + options.xaxis.color = options.grid.color; + if (options.yaxis.color == null) + options.yaxis.color = options.grid.color; + + if (options.xaxis.tickColor == null) // backwards-compatibility + options.xaxis.tickColor = options.grid.tickColor; + if (options.yaxis.tickColor == null) // backwards-compatibility + options.yaxis.tickColor = options.grid.tickColor; + + if (options.grid.borderColor == null) + options.grid.borderColor = options.grid.color; + if (options.grid.tickColor == null) + options.grid.tickColor = $.color.parse(options.grid.color).scale('a', 0.22).toString(); + + // fill in defaults in axes, copy at least always the + // first as the rest of the code assumes it'll be there + for (i = 0; i < Math.max(1, options.xaxes.length); ++i) + options.xaxes[i] = $.extend(true, {}, options.xaxis, options.xaxes[i]); + for (i = 0; i < Math.max(1, options.yaxes.length); ++i) + options.yaxes[i] = $.extend(true, {}, options.yaxis, options.yaxes[i]); + + // backwards compatibility, to be removed in future + if (options.xaxis.noTicks && options.xaxis.ticks == null) + options.xaxis.ticks = options.xaxis.noTicks; + if (options.yaxis.noTicks && options.yaxis.ticks == null) + options.yaxis.ticks = options.yaxis.noTicks; + if (options.x2axis) { + options.xaxes[1] = $.extend(true, {}, options.xaxis, options.x2axis); + options.xaxes[1].position = "top"; + } + if (options.y2axis) { + options.yaxes[1] = $.extend(true, {}, options.yaxis, options.y2axis); + options.yaxes[1].position = "right"; + } + if (options.grid.coloredAreas) + options.grid.markings = options.grid.coloredAreas; + if (options.grid.coloredAreasColor) + options.grid.markingsColor = options.grid.coloredAreasColor; + if (options.lines) + $.extend(true, options.series.lines, options.lines); + if (options.points) + $.extend(true, options.series.points, options.points); + if (options.bars) + $.extend(true, options.series.bars, options.bars); + if (options.shadowSize != null) + options.series.shadowSize = options.shadowSize; + + // save options on axes for future reference + for (i = 0; i < options.xaxes.length; ++i) + getOrCreateAxis(xaxes, i + 1).options = options.xaxes[i]; + for (i = 0; i < options.yaxes.length; ++i) + getOrCreateAxis(yaxes, i + 1).options = options.yaxes[i]; + + // add hooks from options + for (var n in hooks) + if (options.hooks[n] && options.hooks[n].length) + hooks[n] = hooks[n].concat(options.hooks[n]); + + executeHooks(hooks.processOptions, [options]); + } + + function setData(d) { + series = parseData(d); + fillInSeriesOptions(); + processData(); + } + + function parseData(d) { + var res = []; + for (var i = 0; i < d.length; ++i) { + var s = $.extend(true, {}, options.series); + + if (d[i].data != null) { + s.data = d[i].data; // move the data instead of deep-copy + delete d[i].data; + + $.extend(true, s, d[i]); + + d[i].data = s.data; + } + else + s.data = d[i]; + res.push(s); + } + + return res; + } + + function axisNumber(obj, coord) { + var a = obj[coord + "axis"]; + if (typeof a == "object") // if we got a real axis, extract number + a = a.n; + if (typeof a != "number") + a = 1; // default to first axis + return a; + } + + function allAxes() { + // return flat array without annoying null entries + return $.grep(xaxes.concat(yaxes), function (a) { return a; }); + } + + function canvasToAxisCoords(pos) { + // return an object with x/y corresponding to all used axes + var res = {}, i, axis; + for (i = 0; i < xaxes.length; ++i) { + axis = xaxes[i]; + if (axis && axis.used) + res["x" + axis.n] = axis.c2p(pos.left); + } + + for (i = 0; i < yaxes.length; ++i) { + axis = yaxes[i]; + if (axis && axis.used) + res["y" + axis.n] = axis.c2p(pos.top); + } + + if (res.x1 !== undefined) + res.x = res.x1; + if (res.y1 !== undefined) + res.y = res.y1; + + return res; + } + + function axisToCanvasCoords(pos) { + // get canvas coords from the first pair of x/y found in pos + var res = {}, i, axis, key; + + for (i = 0; i < xaxes.length; ++i) { + axis = xaxes[i]; + if (axis && axis.used) { + key = "x" + axis.n; + if (pos[key] == null && axis.n == 1) + key = "x"; + + if (pos[key] != null) { + res.left = axis.p2c(pos[key]); + break; + } + } + } + + for (i = 0; i < yaxes.length; ++i) { + axis = yaxes[i]; + if (axis && axis.used) { + key = "y" + axis.n; + if (pos[key] == null && axis.n == 1) + key = "y"; + + if (pos[key] != null) { + res.top = axis.p2c(pos[key]); + break; + } + } + } + + return res; + } + + function getOrCreateAxis(axes, number) { + if (!axes[number - 1]) + axes[number - 1] = { + n: number, // save the number for future reference + direction: axes == xaxes ? "x" : "y", + options: $.extend(true, {}, axes == xaxes ? options.xaxis : options.yaxis) + }; + + return axes[number - 1]; + } + + function fillInSeriesOptions() { + var i; + + // collect what we already got of colors + var neededColors = series.length, + usedColors = [], + assignedColors = []; + for (i = 0; i < series.length; ++i) { + var sc = series[i].color; + if (sc != null) { + --neededColors; + if (typeof sc == "number") + assignedColors.push(sc); + else + usedColors.push($.color.parse(series[i].color)); + } + } + + // we might need to generate more colors if higher indices + // are assigned + for (i = 0; i < assignedColors.length; ++i) { + neededColors = Math.max(neededColors, assignedColors[i] + 1); + } + + // produce colors as needed + var colors = [], variation = 0; + i = 0; + while (colors.length < neededColors) { + var c; + if (options.colors.length == i) // check degenerate case + c = $.color.make(100, 100, 100); + else + c = $.color.parse(options.colors[i]); + + // vary color if needed + var sign = variation % 2 == 1 ? -1 : 1; + c.scale('rgb', 1 + sign * Math.ceil(variation / 2) * 0.2) + + // FIXME: if we're getting to close to something else, + // we should probably skip this one + colors.push(c); + + ++i; + if (i >= options.colors.length) { + i = 0; + ++variation; + } + } + + // fill in the options + var colori = 0, s; + for (i = 0; i < series.length; ++i) { + s = series[i]; + + // assign colors + if (s.color == null) { + s.color = colors[colori].toString(); + ++colori; + } + else if (typeof s.color == "number") + s.color = colors[s.color].toString(); + + // turn on lines automatically in case nothing is set + if (s.lines.show == null) { + var v, show = true; + for (v in s) + if (s[v] && s[v].show) { + show = false; + break; + } + if (show) + s.lines.show = true; + } + + // setup axes + s.xaxis = getOrCreateAxis(xaxes, axisNumber(s, "x")); + s.yaxis = getOrCreateAxis(yaxes, axisNumber(s, "y")); + } + } + + function processData() { + var topSentry = Number.POSITIVE_INFINITY, + bottomSentry = Number.NEGATIVE_INFINITY, + fakeInfinity = Number.MAX_VALUE, + i, j, k, m, length, + s, points, ps, x, y, axis, val, f, p; + + function updateAxis(axis, min, max) { + if (min < axis.datamin && min != -fakeInfinity) + axis.datamin = min; + if (max > axis.datamax && max != fakeInfinity) + axis.datamax = max; + } + + $.each(allAxes(), function (_, axis) { + // init axis + axis.datamin = topSentry; + axis.datamax = bottomSentry; + axis.used = false; + }); + + for (i = 0; i < series.length; ++i) { + s = series[i]; + s.datapoints = { points: [] }; + + executeHooks(hooks.processRawData, [ s, s.data, s.datapoints ]); + } + + // first pass: clean and copy data + for (i = 0; i < series.length; ++i) { + s = series[i]; + + var data = s.data, format = s.datapoints.format; + + if (!format) { + format = []; + // find out how to copy + format.push({ x: true, number: true, required: true }); + format.push({ y: true, number: true, required: true }); + + if (s.bars.show || (s.lines.show && s.lines.fill)) { + format.push({ y: true, number: true, required: false, defaultValue: 0 }); + if (s.bars.horizontal) { + delete format[format.length - 1].y; + format[format.length - 1].x = true; + } + } + + s.datapoints.format = format; + } + + if (s.datapoints.pointsize != null) + continue; // already filled in + + s.datapoints.pointsize = format.length; + + ps = s.datapoints.pointsize; + points = s.datapoints.points; + + insertSteps = s.lines.show && s.lines.steps; + s.xaxis.used = s.yaxis.used = true; + + for (j = k = 0; j < data.length; ++j, k += ps) { + p = data[j]; + + var nullify = p == null; + if (!nullify) { + for (m = 0; m < ps; ++m) { + val = p[m]; + f = format[m]; + + if (f) { + if (f.number && val != null) { + val = +val; // convert to number + if (isNaN(val)) + val = null; + else if (val == Infinity) + val = fakeInfinity; + else if (val == -Infinity) + val = -fakeInfinity; + } + + if (val == null) { + if (f.required) + nullify = true; + + if (f.defaultValue != null) + val = f.defaultValue; + } + } + + points[k + m] = val; + } + } + + if (nullify) { + for (m = 0; m < ps; ++m) { + val = points[k + m]; + if (val != null) { + f = format[m]; + // extract min/max info + if (f.x) + updateAxis(s.xaxis, val, val); + if (f.y) + updateAxis(s.yaxis, val, val); + } + points[k + m] = null; + } + } + else { + // a little bit of line specific stuff that + // perhaps shouldn't be here, but lacking + // better means... + if (insertSteps && k > 0 + && points[k - ps] != null + && points[k - ps] != points[k] + && points[k - ps + 1] != points[k + 1]) { + // copy the point to make room for a middle point + for (m = 0; m < ps; ++m) + points[k + ps + m] = points[k + m]; + + // middle point has same y + points[k + 1] = points[k - ps + 1]; + + // we've added a point, better reflect that + k += ps; + } + } + } + } + + // give the hooks a chance to run + for (i = 0; i < series.length; ++i) { + s = series[i]; + + executeHooks(hooks.processDatapoints, [ s, s.datapoints]); + } + + // second pass: find datamax/datamin for auto-scaling + for (i = 0; i < series.length; ++i) { + s = series[i]; + points = s.datapoints.points, + ps = s.datapoints.pointsize; + + var xmin = topSentry, ymin = topSentry, + xmax = bottomSentry, ymax = bottomSentry; + + for (j = 0; j < points.length; j += ps) { + if (points[j] == null) + continue; + + for (m = 0; m < ps; ++m) { + val = points[j + m]; + f = format[m]; + if (!f || val == fakeInfinity || val == -fakeInfinity) + continue; + + if (f.x) { + if (val < xmin) + xmin = val; + if (val > xmax) + xmax = val; + } + if (f.y) { + if (val < ymin) + ymin = val; + if (val > ymax) + ymax = val; + } + } + } + + if (s.bars.show) { + // make sure we got room for the bar on the dancing floor + var delta = s.bars.align == "left" ? 0 : -s.bars.barWidth/2; + if (s.bars.horizontal) { + ymin += delta; + ymax += delta + s.bars.barWidth; + } + else { + xmin += delta; + xmax += delta + s.bars.barWidth; + } + } + + updateAxis(s.xaxis, xmin, xmax); + updateAxis(s.yaxis, ymin, ymax); + } + + $.each(allAxes(), function (_, axis) { + if (axis.datamin == topSentry) + axis.datamin = null; + if (axis.datamax == bottomSentry) + axis.datamax = null; + }); + } + + function makeCanvas(skipPositioning, cls) { + var c = document.createElement('canvas'); + c.className = cls; + c.width = canvasWidth; + c.height = canvasHeight; + + if (!skipPositioning) + $(c).css({ position: 'absolute', left: 0, top: 0 }); + + $(c).appendTo(placeholder); + + if (!c.getContext) // excanvas hack + c = window.G_vmlCanvasManager.initElement(c); + + // used for resetting in case we get replotted + c.getContext("2d").save(); + + return c; + } + + function getCanvasDimensions() { + canvasWidth = placeholder.width(); + canvasHeight = placeholder.height(); + + if (canvasWidth <= 0 || canvasHeight <= 0) + throw "Invalid dimensions for plot, width = " + canvasWidth + ", height = " + canvasHeight; + } + + function resizeCanvas(c) { + // resizing should reset the state (excanvas seems to be + // buggy though) + if (c.width != canvasWidth) + c.width = canvasWidth; + + if (c.height != canvasHeight) + c.height = canvasHeight; + + // so try to get back to the initial state (even if it's + // gone now, this should be safe according to the spec) + var cctx = c.getContext("2d"); + cctx.restore(); + + // and save again + cctx.save(); + } + + function setupCanvases() { + var reused, + existingCanvas = placeholder.children("canvas.base"), + existingOverlay = placeholder.children("canvas.overlay"); + + if (existingCanvas.length == 0 || existingOverlay == 0) { + // init everything + + placeholder.html(""); // make sure placeholder is clear + + placeholder.css({ padding: 0 }); // padding messes up the positioning + + if (placeholder.css("position") == 'static') + placeholder.css("position", "relative"); // for positioning labels and overlay + + getCanvasDimensions(); + + canvas = makeCanvas(true, "base"); + overlay = makeCanvas(false, "overlay"); // overlay canvas for interactive features + + reused = false; + } + else { + // reuse existing elements + + canvas = existingCanvas.get(0); + overlay = existingOverlay.get(0); + + reused = true; + } + + ctx = canvas.getContext("2d"); + octx = overlay.getContext("2d"); + + // we include the canvas in the event holder too, because IE 7 + // sometimes has trouble with the stacking order + eventHolder = $([overlay, canvas]); + + if (reused) { + // run sh