CanvasGradient.addColorStop

The CanvasGradient.addColorStop() method adds a new stop, defined by an offset and a color, to the gradient. If the offset is not between 0 and 1, an INDEX_SIZE_ERR is raised, if the color can't be parsed as a CSS <color>, a SYNTAX_ERR is raised.

Syntax

void gradient.addColorStop(offset, color);

Parameters

offset

A number between 0 and 1. An INDEX_SIZE_ERR is raised, if the number is not in that range.

color

A CSS <color>. A SYNTAX_ERR is raised, if the value can not be parsed as a CSS <color> value.

Examples

Using the addColorStop method

This is just a simple code snippet which uses the addColorStop method with a CanvasGradient object.

HTML

<canvas id="canvas"></canvas>

JavaScript

var canvas = document.getElementById('canvas');
var ctx = canvas.getContext('2d');

var gradient = ctx.createLinearGradient(0, 0, 200, 0);
gradient.addColorStop(0, 'green');
gradient.addColorStop(1, 'white');
ctx.fillStyle = gradient;
ctx.fillRect(10, 10, 200, 100);

Edit the code below and see your changes update live in the canvas:

Playable code

<canvas id="canvas" width="400" height="200" class="playable-canvas"></canvas>
<div class="playable-buttons">
  <input id="edit" type="button" value="Edit" />
  <input id="reset" type="button" value="Reset" />
</div>
<textarea id="code" class="playable-code">
var gradient = ctx.createLinearGradient(0,0,200,0);
gradient.addColorStop(0,"green");
gradient.addColorStop(1,"white");
ctx.fillStyle = gradient;
ctx.fillRect(10,10,200,100);</textarea>

var canvas = document.getElementById("canvas");
var ctx = canvas.getContext("2d");
var textarea = document.getElementById("code");
var reset = document.getElementById("reset");
var edit = document.getElementById("edit");
var code = textarea.value;

function drawCanvas() {
  ctx.clearRect(0, 0, canvas.width, canvas.height);
  eval(textarea.value);
}

reset.addEventListener("click", function() {
  textarea.value = code;
  drawCanvas();
});

edit.addEventListener("click", function() {
  textarea.focus();
})

textarea.addEventListener("input", drawCanvas);
window.addEventListener("load", drawCanvas);

Specifications

Browser compatibility

See also

• The interface defining it, CanvasGradient
• CanvasRenderingContext2D.createLinearGradient()
• CanvasRenderingContext2D.createRadialGradient()