CanvasRenderingContext2D.drawFocusIfNeeded()

by 2 contributors:

The CanvasRenderingContext2D.drawFocusIfNeeded() method of the Canvas 2D API draws a focus ring around the current path or given path, If a given element is focused.

Syntax

void ctx.drawFocusIfNeeded(element);
void ctx.drawFocusIfNeeded(path, element);

Parameters

element
The element to check whether it is focused or not.
path
A Path2D path to use.

Examples

Using the drawFocusIfNeeded method

This is just a simple code snippet which uses the drawFocusIfNeeded method.

HTML

<canvas id="canvas">
  <input id="button" type="range" min="1" max="12">
</canvas>

JavaScript

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

button.focus();

ctx.beginPath();
ctx.rect(10, 10, 30, 30);
ctx.drawFocusIfNeeded(button);

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">
<input id="button" type="range" min="1" max="12">
</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">
ctx.beginPath();
ctx.rect(10, 10, 30, 30);
ctx.drawFocusIfNeeded(button);</textarea>
var canvas = document.getElementById("canvas");
var ctx = canvas.getContext("2d");
var textarea = document.getElementById("code");
var button = document.getElementById("button");
var reset = document.getElementById("reset");
var edit = document.getElementById("edit");
var code = textarea.value;
button.focus();

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

Specification Status Comment
WHATWG HTML Living Standard
The definition of 'CanvasRenderingContext2D.drawFocusIfNeeded' in that specification.
Living Standard Initial definition

Browser compatibility

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari
Basic support (Yes) 29 (29)[1]
32 (32)[2]
Not supported (Yes) (Yes)
Path parameter (Yes) Not supported Not supported (Yes) (Yes)
Feature Android Chrome for Android Firefox Mobile (Gecko) IE Mobile Opera Mobile Safari Mobile
Basic support (Yes) (Yes) 29 (29)[1]
32 (32)[2]
Not supported (Yes) (Yes)
Path parameter (Yes) (Yes) Not supported Not supported (Yes) (Yes)

[1] In Gecko 28 (Firefox 28 / Thunderbird 28 / SeaMonkey 2.25 / Firefox OS 1.3), this method was implemented as drawSystemFocusRing, but has been renamed to the standard drawFocusIfNeeded in Gecko 29 (Firefox 29 / Thunderbird 29 / SeaMonkey 2.26).

[2] Prior to Gecko 32 (Firefox 32 / Thunderbird 32 / SeaMonkey 2.29 / Firefox OS 2.0) this method was deactivated by default behind the flag canvas.focusring.enabled.

See also

Document Tags and Contributors

Contributors to this page: Sebastianz, fscholz
Last updated by: Sebastianz,
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