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https://github.com/chartjs/Chart.js.git
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362 lines
18 KiB
JavaScript
362 lines
18 KiB
JavaScript
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(function() {
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"use strict";
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var root = this,
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Chart = root.Chart,
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helpers = Chart.helpers;
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var LinearRadialScale = Chart.Element.extend({
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initialize: function() {
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this.size = helpers.min([this.height, this.width]);
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this.drawingArea = (this.options.display) ? (this.size / 2) - (this.options.labels.fontSize / 2 + this.options.labels.backdropPaddingY) : (this.size / 2);
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},
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calculateCenterOffset: function(value) {
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// Take into account half font size + the yPadding of the top value
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var scalingFactor = this.drawingArea / (this.max - this.min);
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return (value - this.min) * scalingFactor;
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},
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update: function() {
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if (!this.options.lineArc) {
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this.setScaleSize();
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} else {
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this.drawingArea = (this.options.display) ? (this.size / 2) - (this.fontSize / 2 + this.backdropPaddingY) : (this.size / 2);
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}
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this.buildYLabels();
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},
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calculateRange: helpers.noop, // overridden in chart
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generateTicks: function() {
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// We need to decide how many ticks we are going to have. Each tick draws a grid line.
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// There are two possibilities. The first is that the user has manually overridden the scale
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// calculations in which case the job is easy. The other case is that we have to do it ourselves
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//
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// We assume at this point that the scale object has been updated with the following values
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// by the chart.
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// min: this is the minimum value of the scale
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// max: this is the maximum value of the scale
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// options: contains the options for the scale. This is referenced from the user settings
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// rather than being cloned. This ensures that updates always propogate to a redraw
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// Reset the ticks array. Later on, we will draw a grid line at these positions
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// The array simply contains the numerical value of the spots where ticks will be
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this.ticks = [];
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if (this.options.override) {
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// The user has specified the manual override. We use <= instead of < so that
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// we get the final line
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for (var i = 0; i <= this.options.override.steps; ++i) {
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var value = this.options.override.start + (i * this.options.override.stepWidth);
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ticks.push(value);
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}
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} else {
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// Figure out what the max number of ticks we can support it is based on the size of
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// the axis area. For now, we say that the minimum tick spacing in pixels must be 50
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// We also limit the maximum number of ticks to 11 which gives a nice 10 squares on
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// the graph
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var maxTicks = Math.min(11, Math.ceil(this.drawingArea / (2 * this.options.labels.fontSize)));
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// Make sure we always have at least 2 ticks
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maxTicks = Math.max(2, maxTicks);
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// To get a "nice" value for the tick spacing, we will use the appropriately named
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// "nice number" algorithm. See http://stackoverflow.com/questions/8506881/nice-label-algorithm-for-charts-with-minimum-ticks
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// for details.
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// If we are forcing it to begin at 0, but 0 will already be rendered on the chart,
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// do nothing since that would make the chart weird. If the user really wants a weird chart
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// axis, they can manually override it
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if (this.options.beginAtZero) {
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var minSign = helpers.sign(this.min);
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var maxSign = helpers.sign(this.max);
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if (minSign < 0 && maxSign < 0) {
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// move the top up to 0
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this.max = 0;
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} else if (minSign > 0 && maxSign > 0) {
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// move the botttom down to 0
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this.min = 0;
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}
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}
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var niceRange = helpers.niceNum(this.max - this.min, false);
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var spacing = helpers.niceNum(niceRange / (maxTicks - 1), true);
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var niceMin = Math.floor(this.min / spacing) * spacing;
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var niceMax = Math.ceil(this.max / spacing) * spacing;
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// Put the values into the ticks array
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for (var j = niceMin; j <= niceMax; j += spacing) {
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this.ticks.push(j);
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}
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}
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if (this.options.position == "left" || this.options.position == "right") {
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// We are in a vertical orientation. The top value is the highest. So reverse the array
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this.ticks.reverse();
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}
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// At this point, we need to update our max and min given the tick values since we have expanded the
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// range of the scale
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this.max = helpers.max(this.ticks);
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this.min = helpers.min(this.ticks);
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},
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buildYLabels: function() {
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this.yLabels = [];
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helpers.each(this.ticks, function(tick, index, ticks) {
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var label;
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if (this.options.labels.userCallback) {
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// If the user provided a callback for label generation, use that as first priority
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label = this.options.labels.userCallback(tick, index, ticks);
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} else if (this.options.labels.template) {
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// else fall back to the template string
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label = helpers.template(this.options.labels.template, {
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value: tick
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});
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}
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this.yLabels.push(label ? label : "");
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}, this);
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},
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getCircumference: function() {
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return ((Math.PI * 2) / this.valuesCount);
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},
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setScaleSize: function() {
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/*
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* Right, this is really confusing and there is a lot of maths going on here
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* The gist of the problem is here: https://gist.github.com/nnnick/696cc9c55f4b0beb8fe9
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*
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* Reaction: https://dl.dropboxusercontent.com/u/34601363/toomuchscience.gif
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*
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* Solution:
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*
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* We assume the radius of the polygon is half the size of the canvas at first
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* at each index we check if the text overlaps.
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*
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* Where it does, we store that angle and that index.
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*
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* After finding the largest index and angle we calculate how much we need to remove
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* from the shape radius to move the point inwards by that x.
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*
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* We average the left and right distances to get the maximum shape radius that can fit in the box
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* along with labels.
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*
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* Once we have that, we can find the centre point for the chart, by taking the x text protrusion
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* on each side, removing that from the size, halving it and adding the left x protrusion width.
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*
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* This will mean we have a shape fitted to the canvas, as large as it can be with the labels
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* and position it in the most space efficient manner
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*
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* https://dl.dropboxusercontent.com/u/34601363/yeahscience.gif
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*/
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// Get maximum radius of the polygon. Either half the height (minus the text width) or half the width.
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// Use this to calculate the offset + change. - Make sure L/R protrusion is at least 0 to stop issues with centre points
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var largestPossibleRadius = helpers.min([(this.height / 2 - this.options.pointLabels.fontSize - 5), this.width / 2]),
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pointPosition,
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i,
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textWidth,
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halfTextWidth,
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furthestRight = this.width,
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furthestRightIndex,
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furthestRightAngle,
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furthestLeft = 0,
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furthestLeftIndex,
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furthestLeftAngle,
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xProtrusionLeft,
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xProtrusionRight,
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radiusReductionRight,
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radiusReductionLeft,
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maxWidthRadius;
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this.ctx.font = helpers.fontString(this.options.pointLabels.fontSize, this.options.pointLabels.fontStyle, this.options.pointLabels.fontFamily);
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for (i = 0; i < this.valuesCount; i++) {
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// 5px to space the text slightly out - similar to what we do in the draw function.
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pointPosition = this.getPointPosition(i, largestPossibleRadius);
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textWidth = this.ctx.measureText(helpers.template(this.options.labels.template, {
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value: this.labels[i]
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})).width + 5;
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if (i === 0 || i === this.valuesCount / 2) {
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// If we're at index zero, or exactly the middle, we're at exactly the top/bottom
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// of the radar chart, so text will be aligned centrally, so we'll half it and compare
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// w/left and right text sizes
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halfTextWidth = textWidth / 2;
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if (pointPosition.x + halfTextWidth > furthestRight) {
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furthestRight = pointPosition.x + halfTextWidth;
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furthestRightIndex = i;
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}
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if (pointPosition.x - halfTextWidth < furthestLeft) {
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furthestLeft = pointPosition.x - halfTextWidth;
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furthestLeftIndex = i;
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}
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} else if (i < this.valuesCount / 2) {
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// Less than half the values means we'll left align the text
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if (pointPosition.x + textWidth > furthestRight) {
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furthestRight = pointPosition.x + textWidth;
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furthestRightIndex = i;
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}
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} else if (i > this.valuesCount / 2) {
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// More than half the values means we'll right align the text
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if (pointPosition.x - textWidth < furthestLeft) {
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furthestLeft = pointPosition.x - textWidth;
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furthestLeftIndex = i;
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}
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}
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}
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xProtrusionLeft = furthestLeft;
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xProtrusionRight = Math.ceil(furthestRight - this.width);
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furthestRightAngle = this.getIndexAngle(furthestRightIndex);
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furthestLeftAngle = this.getIndexAngle(furthestLeftIndex);
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radiusReductionRight = xProtrusionRight / Math.sin(furthestRightAngle + Math.PI / 2);
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radiusReductionLeft = xProtrusionLeft / Math.sin(furthestLeftAngle + Math.PI / 2);
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// Ensure we actually need to reduce the size of the chart
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radiusReductionRight = (helpers.isNumber(radiusReductionRight)) ? radiusReductionRight : 0;
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radiusReductionLeft = (helpers.isNumber(radiusReductionLeft)) ? radiusReductionLeft : 0;
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this.drawingArea = largestPossibleRadius - (radiusReductionLeft + radiusReductionRight) / 2;
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//this.drawingArea = min([maxWidthRadius, (this.height - (2 * (this.pointLabelFontSize + 5)))/2])
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this.setCenterPoint(radiusReductionLeft, radiusReductionRight);
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},
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setCenterPoint: function(leftMovement, rightMovement) {
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var maxRight = this.width - rightMovement - this.drawingArea,
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maxLeft = leftMovement + this.drawingArea;
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this.xCenter = (maxLeft + maxRight) / 2;
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// Always vertically in the centre as the text height doesn't change
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this.yCenter = (this.height / 2);
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},
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getIndexAngle: function(index) {
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var angleMultiplier = (Math.PI * 2) / this.valuesCount;
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// Start from the top instead of right, so remove a quarter of the circle
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return index * angleMultiplier - (Math.PI / 2);
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},
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getPointPosition: function(index, distanceFromCenter) {
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var thisAngle = this.getIndexAngle(index);
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return {
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x: (Math.cos(thisAngle) * distanceFromCenter) + this.xCenter,
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y: (Math.sin(thisAngle) * distanceFromCenter) + this.yCenter
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};
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},
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draw: function() {
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if (this.options.display) {
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var ctx = this.ctx;
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helpers.each(this.yLabels, function(label, index) {
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// Don't draw a centre value
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if (index > 0) {
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var yCenterOffset = index * (this.drawingArea / Math.max(this.ticks.length, 1)),
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yHeight = this.yCenter - yCenterOffset,
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pointPosition;
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// Draw circular lines around the scale
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if (this.options.gridLines.show) {
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ctx.strokeStyle = this.options.gridLines.color;
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ctx.lineWidth = this.options.gridLines.lineWidth;
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if (this.options.lineArc) {
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ctx.beginPath();
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ctx.arc(this.xCenter, this.yCenter, yCenterOffset, 0, Math.PI * 2);
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ctx.closePath();
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ctx.stroke();
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} else {
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ctx.beginPath();
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for (var i = 0; i < this.valuesCount; i++) {
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pointPosition = this.getPointPosition(i, this.calculateCenterOffset(this.ticks[index]));
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if (i === 0) {
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ctx.moveTo(pointPosition.x, pointPosition.y);
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} else {
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ctx.lineTo(pointPosition.x, pointPosition.y);
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}
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}
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ctx.closePath();
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ctx.stroke();
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}
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}
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if (this.options.labels.show) {
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ctx.font = helpers.fontString(this.options.labels.fontSize, this.options.labels.fontStyle, this.options.labels.fontFamily);
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if (this.showLabelBackdrop) {
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var labelWidth = ctx.measureText(label).width;
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ctx.fillStyle = this.options.labels.backdropColor;
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ctx.fillRect(
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this.xCenter - labelWidth / 2 - this.options.labels.backdropPaddingX,
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yHeight - this.fontSize / 2 - this.options.labels.backdropPaddingY,
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labelWidth + this.options.labels.backdropPaddingX * 2,
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this.options.labels.fontSize + this.options.lables.backdropPaddingY * 2
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);
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}
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ctx.textAlign = 'center';
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ctx.textBaseline = "middle";
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ctx.fillStyle = this.options.labels.fontColor;
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ctx.fillText(label, this.xCenter, yHeight);
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}
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}
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}, this);
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if (!this.options.lineArc) {
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ctx.lineWidth = this.options.angleLines.lineWidth;
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ctx.strokeStyle = this.options.angleLines.color;
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for (var i = this.valuesCount - 1; i >= 0; i--) {
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if (this.options.angleLines.show) {
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var outerPosition = this.getPointPosition(i, this.calculateCenterOffset(this.max));
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ctx.beginPath();
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ctx.moveTo(this.xCenter, this.yCenter);
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ctx.lineTo(outerPosition.x, outerPosition.y);
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ctx.stroke();
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ctx.closePath();
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}
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// Extra 3px out for some label spacing
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var pointLabelPosition = this.getPointPosition(i, this.calculateCenterOffset(this.max) + 5);
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ctx.font = helpers.fontString(this.options.pointLabels.fontSize, this.options.pointLabels.fontStyle, this.options.pointLabels.fontFamily);
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ctx.fillStyle = this.options.pointLabels.fontColor;
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var labelsCount = this.labels.length,
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halfLabelsCount = this.labels.length / 2,
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quarterLabelsCount = halfLabelsCount / 2,
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upperHalf = (i < quarterLabelsCount || i > labelsCount - quarterLabelsCount),
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exactQuarter = (i === quarterLabelsCount || i === labelsCount - quarterLabelsCount);
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if (i === 0) {
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ctx.textAlign = 'center';
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} else if (i === halfLabelsCount) {
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ctx.textAlign = 'center';
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} else if (i < halfLabelsCount) {
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ctx.textAlign = 'left';
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} else {
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||
|
|
ctx.textAlign = 'right';
|
||
|
|
}
|
||
|
|
|
||
|
|
// Set the correct text baseline based on outer positioning
|
||
|
|
if (exactQuarter) {
|
||
|
|
ctx.textBaseline = 'middle';
|
||
|
|
} else if (upperHalf) {
|
||
|
|
ctx.textBaseline = 'bottom';
|
||
|
|
} else {
|
||
|
|
ctx.textBaseline = 'top';
|
||
|
|
}
|
||
|
|
|
||
|
|
ctx.fillText(this.labels[i], pointLabelPosition.x, pointLabelPosition.y);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
});
|
||
|
|
Chart.scales.registerScaleType("radialLinear", LinearRadialScale);
|
||
|
|
|
||
|
|
|
||
|
|
}).call(this);
|