From 95ba11a427814fa128879c04f558d6ea6e86a167 Mon Sep 17 00:00:00 2001
From: Evert Timberg <evert.timberg+github@gmail.com>
Date: Fri, 1 Nov 2019 07:20:37 -0400
Subject: [PATCH] Add radial and linear gradient sample files (#6666)

* Add radial gradient sample file
* Add linear gradient sample file
---
 samples/advanced/line-gradient.html   | 119 ++++++++++++++++++++++++++
 samples/advanced/radial-gradient.html | 117 +++++++++++++++++++++++++
 samples/samples.js                    |   6 ++
 3 files changed, 242 insertions(+)
 create mode 100644 samples/advanced/line-gradient.html
 create mode 100644 samples/advanced/radial-gradient.html
diff --git a/samples/advanced/line-gradient.html b/samples/advanced/line-gradient.html
new file mode 100644
index 00000000000..b60a17a2716
--- /dev/null
+++ b/samples/advanced/line-gradient.html
@@ -0,0 +1,119 @@
+<!doctype html>
+<html>
+<head>
+<title>Linear Gradient</title>
+	<script src="../../dist/Chart.js"></script>
+	<script src="../utils.js"></script>
+	<style>
+		canvas {
+			-moz-user-select: none;
+			-webkit-user-select: none;
+			-ms-user-select: none;
+		}
+	</style>
+</head>
+
+<body>
+	<div style="width: 75%;">
+		<canvas id="canvas"></canvas>
+	</div>
+	<br>
+	<br>
+	<button id="randomizeData">Randomize Data</button>
+	<script>
+		var chartColors = window.chartColors;
+		var gradient = null;
+		var width = null;
+		var height = null;
+		var config = {
+			type: 'line',
+			data: {
+				labels: ['January', 'February', 'March', 'April', 'May', 'June', 'July'],
+				datasets: [{
+					label: 'My First dataset',
+					borderColor: function(context) {
+						var chartArea = context.chart.chartArea;
+
+						if (!chartArea) {
+							// This case happens on initial chart load
+							return null;
+						}
+
+						var chartWidth = chartArea.right - chartArea.left;
+						var chartHeight = chartArea.bottom - chartArea.top;
+						if (gradient === null || width !== chartWidth || height !== chartHeight) {
+							// Create the gradient because this is either the first render
+							// or the size of the chart has changed
+							width = chartWidth;
+							height = chartHeight;
+							var ctx = context.chart.ctx;
+							gradient = ctx.createLinearGradient(0, chartArea.bottom, 0, chartArea.top);
+							gradient.addColorStop(0, chartColors.blue);
+							gradient.addColorStop(0.5, chartColors.yellow);
+							gradient.addColorStop(1, chartColors.red);
+						}
+
+						return gradient;
+					},
+					data: [
+						randomScalingFactor(),
+						randomScalingFactor(),
+						randomScalingFactor(),
+						randomScalingFactor(),
+						randomScalingFactor(),
+						randomScalingFactor(),
+						randomScalingFactor()
+					],
+					fill: false,
+				}]
+			},
+			options: {
+				responsive: true,
+				title: {
+					display: true,
+					text: 'Chart.js Line Chart'
+				},
+				tooltips: {
+					mode: 'index',
+					intersect: false,
+				},
+				hover: {
+					mode: 'nearest',
+					intersect: true
+				},
+				scales: {
+					xAxes: [{
+						display: true,
+						scaleLabel: {
+							display: true,
+							labelString: 'Month'
+						}
+					}],
+					yAxes: [{
+						display: true,
+						scaleLabel: {
+							display: true,
+							labelString: 'Value'
+						}
+					}]
+				}
+			}
+		};
+
+		window.onload = function() {
+			var ctx = document.getElementById('canvas');
+			window.myPolarArea = new Chart(ctx, config);
+		};
+
+		document.getElementById('randomizeData').addEventListener('click', function() {
+			config.data.datasets.forEach(function(piece, i) {
+				piece.data.forEach(function(value, j) {
+					config.data.datasets[i].data[j] = randomScalingFactor();
+				});
+			});
+			window.myPolarArea.update();
+		});
+	</script>
+</body>
+
+</html>
diff --git a/samples/advanced/radial-gradient.html b/samples/advanced/radial-gradient.html
new file mode 100644
index 00000000000..9c924bcacaa
--- /dev/null
+++ b/samples/advanced/radial-gradient.html
@@ -0,0 +1,117 @@
+<!doctype html>
+<html>
+<head>
+<title>Radial Gradient</title>
+	<script src="../../dist/Chart.js"></script>
+	<script src="../utils.js"></script>
+	<style>
+		canvas {
+			-moz-user-select: none;
+			-webkit-user-select: none;
+			-ms-user-select: none;
+		}
+	</style>
+</head>
+
+<body>
+	<div style="width: 75%;">
+		<canvas id="canvas"></canvas>
+	</div>
+	<br>
+	<br>
+	<button id="randomizeData">Randomize Data</button>
+	<script>
+		var chartColors = window.chartColors;
+		var gradient = null;
+		var width = null;
+		var height = null;
+		var config = {
+			type: 'polarArea',
+			data: {
+				datasets: [{
+					data: [
+						randomScalingFactor(),
+						randomScalingFactor(),
+						randomScalingFactor(),
+						randomScalingFactor(),
+						randomScalingFactor(),
+					],
+					backgroundColor: function(context) {
+						var chartArea = context.chart.chartArea;
+
+						if (!chartArea) {
+							// This case happens on initial chart load
+							return null;
+						}
+
+						var chartWidth = chartArea.right - chartArea.left;
+						var chartHeight = chartArea.bottom - chartArea.top;
+						if (gradient === null || width !== chartWidth || height !== chartHeight) {
+							// Create the gradient because this is either the first render
+							// or the size of the chart has changed
+							width = chartWidth;
+							height = chartHeight;
+							var centerX = (chartArea.left + chartArea.right) / 2;
+							var centerY = (chartArea.top + chartArea.bottom) / 2;
+							var r = Math.min(
+								(chartArea.right - chartArea.left) / 2,
+								(chartArea.bottom - chartArea.top) / 2
+							);
+							var ctx = context.chart.ctx;
+							gradient = ctx.createRadialGradient(centerX, centerY, 0, centerX, centerY, r);
+							gradient.addColorStop(0, chartColors.red);
+							gradient.addColorStop(0.5, chartColors.green);
+							gradient.addColorStop(1, chartColors.purple);
+						}
+
+						return gradient;
+					},
+					label: 'My dataset' // for legend
+				}],
+				labels: [
+					'Red',
+					'Orange',
+					'Yellow',
+					'Green',
+					'Blue'
+				]
+			},
+			options: {
+				responsive: true,
+				legend: {
+					position: 'right',
+				},
+				title: {
+					display: true,
+					text: 'Chart.js Polar Area Chart'
+				},
+				scale: {
+					ticks: {
+						beginAtZero: true
+					},
+					reverse: false
+				},
+				animation: {
+					animateRotate: false,
+					animateScale: true
+				}
+			}
+		};
+
+		window.onload = function() {
+			var ctx = document.getElementById('canvas');
+			window.myPolarArea = new Chart(ctx, config);
+		};
+
+		document.getElementById('randomizeData').addEventListener('click', function() {
+			config.data.datasets.forEach(function(piece, i) {
+				piece.data.forEach(function(value, j) {
+					config.data.datasets[i].data[j] = randomScalingFactor();
+				});
+			});
+			window.myPolarArea.update();
+		});
+	</script>
+</body>
+
+</html>
diff --git a/samples/samples.js b/samples/samples.js
index 2548f48e38a..c8b26e7be9e 100644
--- a/samples/samples.js
+++ b/samples/samples.js
@@ -208,6 +208,12 @@
 		}, {
 			title: 'Content Security Policy',
 			path: 'advanced/content-security-policy.html'
+		}, {
+			title: 'Polar Area Radial Gradient',
+			path: 'advanced/radial-gradient.html'
+		}, {
+			title: 'Line Gradient',
+			path: 'advanced/line-gradient.html'
 		}]
 	}];
 
