accessibility-developer-tools
Version:
This is a library of accessibility-related testing and utility code.
47 lines (44 loc) • 1.79 kB
JavaScript
// Copyright 2013 Google Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
goog.require('axs.AuditRules');
goog.require('axs.constants.Severity');
goog.require('axs.utils');
/**
* Meaningful images should not be used in element backgrounds.
*/
axs.AuditRules.addRule({
name: 'elementsWithMeaningfulBackgroundImage',
severity: axs.constants.Severity.WARNING,
relevantElementMatcher: function(element, flags) {
return !flags.hidden;
},
heading: 'Meaningful images should not be used in element backgrounds',
url: 'https://github.com/GoogleChrome/accessibility-developer-tools/wiki/Audit-Rules#ax_image_01',
test: function(el) {
if (el.textContent && el.textContent.length > 0) {
return false;
}
var style = window.getComputedStyle(el, null);
var bgImage = style.backgroundImage;
if (!bgImage || bgImage === 'undefined' || bgImage === 'none' ||
bgImage.indexOf('url') != 0) {
return false;
}
var width = parseInt(style.width, 10);
var height = parseInt(style.height, 10);
// TODO(bobbrose): could also check for background repeat and position.
return width < 150 && height < 150;
},
code: 'AX_IMAGE_01'
});