mirror of
https://github.com/chartjs/Chart.js.git
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118 lines
2.7 KiB
HTML
118 lines
2.7 KiB
HTML
<!doctype html>
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<html>
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<head>
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<title>Radial Gradient</title>
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<script src="../../dist/Chart.js"></script>
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<script src="../utils.js"></script>
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<style>
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canvas {
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-moz-user-select: none;
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-webkit-user-select: none;
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-ms-user-select: none;
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}
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</style>
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</head>
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<body>
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<div style="width: 75%;">
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<canvas id="canvas"></canvas>
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</div>
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<br>
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<br>
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<button id="randomizeData">Randomize Data</button>
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<script>
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var chartColors = window.chartColors;
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var gradient = null;
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var width = null;
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var height = null;
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var config = {
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type: 'polarArea',
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data: {
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datasets: [{
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data: [
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randomScalingFactor(),
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randomScalingFactor(),
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randomScalingFactor(),
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randomScalingFactor(),
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randomScalingFactor(),
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],
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backgroundColor: function(context) {
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var chartArea = context.chart.chartArea;
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if (!chartArea) {
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// This case happens on initial chart load
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return null;
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}
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var chartWidth = chartArea.right - chartArea.left;
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var chartHeight = chartArea.bottom - chartArea.top;
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if (gradient === null || width !== chartWidth || height !== chartHeight) {
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// Create the gradient because this is either the first render
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// or the size of the chart has changed
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width = chartWidth;
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height = chartHeight;
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var centerX = (chartArea.left + chartArea.right) / 2;
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var centerY = (chartArea.top + chartArea.bottom) / 2;
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var r = Math.min(
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(chartArea.right - chartArea.left) / 2,
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(chartArea.bottom - chartArea.top) / 2
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);
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var ctx = context.chart.ctx;
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gradient = ctx.createRadialGradient(centerX, centerY, 0, centerX, centerY, r);
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gradient.addColorStop(0, chartColors.red);
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gradient.addColorStop(0.5, chartColors.green);
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gradient.addColorStop(1, chartColors.purple);
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}
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return gradient;
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},
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label: 'My dataset' // for legend
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}],
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labels: [
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'Red',
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'Orange',
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'Yellow',
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'Green',
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'Blue'
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]
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},
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options: {
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responsive: true,
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legend: {
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position: 'right',
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},
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title: {
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display: true,
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text: 'Chart.js Polar Area Chart'
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},
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scale: {
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ticks: {
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beginAtZero: true
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},
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reverse: false
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},
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animation: {
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animateRotate: false,
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animateScale: true
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}
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}
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};
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window.onload = function() {
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var ctx = document.getElementById('canvas');
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window.myPolarArea = new Chart(ctx, config);
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};
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document.getElementById('randomizeData').addEventListener('click', function() {
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config.data.datasets.forEach(function(piece, i) {
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piece.data.forEach(function(value, j) {
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config.data.datasets[i].data[j] = randomScalingFactor();
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});
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});
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window.myPolarArea.update();
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});
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</script>
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</body>
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</html>
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