Chromium Code Reviews
chromiumcodereview-hr@appspot.gserviceaccount.com (chromiumcodereview-hr) | Please choose your nickname with Settings | Help | Chromium Project | Gerrit Changes | Sign out
(373)

Issues Search
    My Issues | Starred     Open | Closed | All

Unified Diff: ui/accessibility/extensions/caretbrowsing/accessibility_utils.js

Issue 606653005: Revert "Initial checkin of accessibility extensions." (Closed) Base URL: https://chromium.googlesource.com/chromium/src.git@master
Patch Set: Created 6 years, 3 months ago
Use n/p to move between diff chunks; N/P to move between comments. Draft comments are only viewable by you.
Jump to:
View side-by-side diff with in-line comments
Download patch
« no previous file with comments | « ui/accessibility/extensions/caretbrowsing/_locales/en/messages.json ('k') | ui/accessibility/extensions/caretbrowsing/background.js » ('j') | no next file with comments »
Expand Comments ('e') | Collapse Comments ('c') | Show Comments Hide Comments ('s')
Index: ui/accessibility/extensions/caretbrowsing/accessibility_utils.js
diff --git a/ui/accessibility/extensions/caretbrowsing/accessibility_utils.js b/ui/accessibility/extensions/caretbrowsing/accessibility_utils.js
deleted file mode 100644
index ed0e084b7b915de3933c1186e068166d2dff94f7..0000000000000000000000000000000000000000
--- a/ui/accessibility/extensions/caretbrowsing/accessibility_utils.js
+++ /dev/null
@@ -1,1391 +0,0 @@
-// Copyright 2012 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.
-
-axs = {};
-axs.utils = {};
-
-/**
- * @constant
- * @type {string}
- */
-axs.utils.FOCUSABLE_ELEMENTS_SELECTOR =
- 'input:not([type=hidden]):not([disabled]),' +
- 'select:not([disabled]),' +
- 'textarea:not([disabled]),' +
- 'button:not([disabled]),' +
- 'a[href],' +
- 'iframe,' +
- '[tabindex]';
-
-/**
- * @constructor
- * @param {number} red
- * @param {number} green
- * @param {number} blue
- * @param {number} alpha
- */
-axs.utils.Color = function(red, green, blue, alpha) {
- /** @type {number} */
- this.red = red;
-
- /** @type {number} */
- this.green = green;
-
- /** @type {number} */
- this.blue = blue;
-
- /** @type {number} */
- this.alpha = alpha;
-};
-
-/**
- * Calculate the contrast ratio between the two given colors. Returns the ratio
- * to 1, for example for two two colors with a contrast ratio of 21:1, this
- * function will return 21.
- * @param {axs.utils.Color} fgColor
- * @param {axs.utils.Color} bgColor
- * @return {?number}
- */
-axs.utils.calculateContrastRatio = function(fgColor, bgColor) {
- if (!fgColor || !bgColor)
- return null;
-
- if (fgColor.alpha < 1)
- fgColor = axs.utils.flattenColors(fgColor, bgColor);
-
- var fgLuminance = axs.utils.calculateLuminance(fgColor);
- var bgLuminance = axs.utils.calculateLuminance(bgColor);
- var contrastRatio = (Math.max(fgLuminance, bgLuminance) + 0.05) /
- (Math.min(fgLuminance, bgLuminance) + 0.05);
- return contrastRatio;
-};
-
-axs.utils.luminanceRatio = function(luminance1, luminance2) {
- return (Math.max(luminance1, luminance2) + 0.05) /
- (Math.min(luminance1, luminance2) + 0.05);
-}
-
-/**
- * Returns the nearest ancestor which is an Element.
- * @param {Node} node
- * @return {Element}
- */
-axs.utils.parentElement = function(node) {
- if (!node)
- return null;
- if (node.nodeType == Node.DOCUMENT_FRAGMENT_NODE)
- return node.host;
-
- var parentElement = node.parentElement;
- if (parentElement)
- return parentElement;
-
- var parentNode = node.parentNode;
- if (!parentNode)
- return null;
-
- switch (parentNode.nodeType) {
- case Node.ELEMENT_NODE:
- return /** @type {Element} */ (parentNode);
- case Node.DOCUMENT_FRAGMENT_NODE:
- return parentNode.host;
- default:
- return null;
- }
-};
-
-/**
- * Return the corresponding element for the given node.
- * @param {Node} node
- * @return {Element}
- * @suppress {checkTypes}
- */
-axs.utils.asElement = function(node) {
- /** @type {Element} */ var element;
- switch (node.nodeType) {
- case Node.COMMENT_NODE:
- return null; // Skip comments
- case Node.ELEMENT_NODE:
- element = /** (@type {Element}) */ node;
- if (element.tagName.toLowerCase() == 'script')
- return null; // Skip script elements
- break;
- case Node.TEXT_NODE:
- element = axs.utils.parentElement(node);
- break;
- default:
- console.warn('Unhandled node type: ', node.nodeType);
- return null;
- }
- return element;
-}
-
-/**
- * @param {Element} element
- * @return {boolean}
- */
-axs.utils.elementIsTransparent = function(element) {
- return element.style.opacity == '0';
-};
-
-/**
- * @param {Element} element
- * @return {boolean}
- */
-axs.utils.elementHasZeroArea = function(element) {
- var rect = element.getBoundingClientRect();
- var width = rect.right - rect.left;
- var height = rect.top - rect.bottom;
- if (!width || !height)
- return true;
- return false;
-};
-
-/**
- * @param {Element} element
- * @return {boolean}
- */
-axs.utils.elementIsOutsideScrollArea = function(element) {
- var parent = axs.utils.parentElement(element);
-
- var defaultView = element.ownerDocument.defaultView;
- while (parent != defaultView.document.body) {
- if (axs.utils.isClippedBy(element, parent))
- return true;
-
- if (axs.utils.canScrollTo(element, parent) && !axs.utils.elementIsOutsideScrollArea(parent))
- return false;
-
- parent = axs.utils.parentElement(parent);
- }
-
- return !axs.utils.canScrollTo(element, defaultView.document.body);
-};
-
-/**
- * Checks whether it's possible to scroll to the given element within the given container.
- * Assumes that |container| is an ancestor of |element|.
- * If |container| cannot be scrolled, returns True if the element is within its bounding client
- * rect.
- * @param {Element} element
- * @param {Element} container
- * @return {boolean} True iff it's possible to scroll to |element| within |container|.
- */
-axs.utils.canScrollTo = function(element, container) {
- var rect = element.getBoundingClientRect();
- var containerRect = container.getBoundingClientRect();
- var containerTop = containerRect.top;
- var containerLeft = containerRect.left;
- var containerScrollArea =
- { top: containerTop - container.scrollTop,
- bottom: containerTop - container.scrollTop + container.scrollHeight,
- left: containerLeft - container.scrollLeft,
- right: containerLeft - container.scrollLeft + container.scrollWidth };
-
- if (rect.right < containerScrollArea.left || rect.bottom < containerScrollArea.top ||
- rect.left > containerScrollArea.right || rect.top > containerScrollArea.bottom) {
- return false;
- }
-
- var defaultView = element.ownerDocument.defaultView;
- var style = defaultView.getComputedStyle(container);
-
- if (rect.left > containerRect.right || rect.top > containerRect.bottom) {
- return (style.overflow == 'scroll' || style.overflow == 'auto' ||
- container instanceof defaultView.HTMLBodyElement);
- }
-
- return true;
-};
-
-/**
- * Checks whether the given element is clipped by the given container.
- * Assumes that |container| is an ancestor of |element|.
- * @param {Element} element
- * @param {Element} container
- * @return {boolean} True iff |element| is clipped by |container|.
- */
-axs.utils.isClippedBy = function(element, container) {
- var rect = element.getBoundingClientRect();
- var containerRect = container.getBoundingClientRect();
- var containerTop = containerRect.top;
- var containerLeft = containerRect.left;
- var containerScrollArea =
- { top: containerTop - container.scrollTop,
- bottom: containerTop - container.scrollTop + container.scrollHeight,
- left: containerLeft - container.scrollLeft,
- right: containerLeft - container.scrollLeft + container.scrollWidth };
-
- var defaultView = element.ownerDocument.defaultView;
- var style = defaultView.getComputedStyle(container);
-
- if ((rect.right < containerRect.left || rect.bottom < containerRect.top ||
- rect.left > containerRect.right || rect.top > containerRect.bottom) &&
- style.overflow == 'hidden') {
- return true;
- }
-
- if (rect.right < containerScrollArea.left || rect.bottom < containerScrollArea.top)
- return (style.overflow != 'visible');
-
- return false;
-};
-
-/**
- * @param {Node} ancestor A potential ancestor of |node|.
- * @param {Node} node
- * @return {boolean} true if |ancestor| is an ancestor of |node| (including
- * |ancestor| === |node|).
- */
-axs.utils.isAncestor = function(ancestor, node) {
- if (node == null)
- return false;
- if (node === ancestor)
- return true;
-
- return axs.utils.isAncestor(ancestor, node.parentNode);
-}
-
-/**
- * @param {Element} element
- * @return {Array.<Element>} An array of any non-transparent elements which
- * overlap the given element.
- */
-axs.utils.overlappingElements = function(element) {
- if (axs.utils.elementHasZeroArea(element))
- return null;
-
- var overlappingElements = [];
- var clientRects = element.getClientRects();
- for (var i = 0; i < clientRects.length; i++) {
- var rect = clientRects[i];
- var center_x = (rect.left + rect.right) / 2;
- var center_y = (rect.top + rect.bottom) / 2;
- var elementAtPoint = document.elementFromPoint(center_x, center_y);
-
- if (elementAtPoint == null || elementAtPoint == element ||
- axs.utils.isAncestor(elementAtPoint, element) ||
- axs.utils.isAncestor(element, elementAtPoint)) {
- continue;
- }
-
- var overlappingElementStyle = window.getComputedStyle(elementAtPoint, null);
- if (!overlappingElementStyle)
- continue;
-
- var overlappingElementBg = axs.utils.getBgColor(overlappingElementStyle,
- elementAtPoint);
- if (overlappingElementBg && overlappingElementBg.alpha > 0 &&
- overlappingElements.indexOf(elementAtPoint) < 0) {
- overlappingElements.push(elementAtPoint);
- }
- }
-
- return overlappingElements;
-};
-
-/**
- * @param {Element} element
- * @return boolean
- */
-axs.utils.elementIsHtmlControl = function(element) {
- var defaultView = element.ownerDocument.defaultView;
-
- // HTML control
- if (element instanceof defaultView.HTMLButtonElement)
- return true;
- if (element instanceof defaultView.HTMLInputElement)
- return true;
- if (element instanceof defaultView.HTMLSelectElement)
- return true;
- if (element instanceof defaultView.HTMLTextAreaElement)
- return true;
-
- return false;
-};
-
-/**
- * @param {Element} element
- * @return boolean
- */
-axs.utils.elementIsAriaWidget = function(element) {
- if (element.hasAttribute('role')) {
- var roleValue = element.getAttribute('role');
- // TODO is this correct?
- if (roleValue) {
- var role = axs.constants.ARIA_ROLES[roleValue];
- if (role && 'widget' in role['allParentRolesSet'])
- return true;
- }
- }
- return false;
-}
-
-/**
- * @param {Element} element
- * @return {boolean}
- */
-axs.utils.elementIsVisible = function(element) {
- if (axs.utils.elementIsTransparent(element))
- return false;
- if (axs.utils.elementHasZeroArea(element))
- return false;
- if (axs.utils.elementIsOutsideScrollArea(element))
- return false;
-
- var overlappingElements = axs.utils.overlappingElements(element);
- if (overlappingElements.length)
- return false;
-
- return true;
-};
-
-/**
- * @param {CSSStyleDeclaration} style
- * @return {boolean}
- */
-axs.utils.isLargeFont = function(style) {
- var fontSize = style.fontSize;
- var bold = style.fontWeight == 'bold';
- var matches = fontSize.match(/(\d+)px/);
- if (matches) {
- var fontSizePx = parseInt(matches[1], 10);
- var bodyStyle = window.getComputedStyle(document.body, null);
- var bodyFontSize = bodyStyle.fontSize;
- matches = bodyFontSize.match(/(\d+)px/);
- if (matches) {
- var bodyFontSizePx = parseInt(matches[1], 10);
- var boldLarge = bodyFontSizePx * 1.2;
- var large = bodyFontSizePx * 1.5;
- } else {
- var boldLarge = 19.2;
- var large = 24;
- }
- return (bold && fontSizePx >= boldLarge || fontSizePx >= large);
- }
- matches = fontSize.match(/(\d+)em/);
- if (matches) {
- var fontSizeEm = parseInt(matches[1], 10);
- if (bold && fontSizeEm >= 1.2 || fontSizeEm >= 1.5)
- return true;
- return false;
- }
- matches = fontSize.match(/(\d+)%/);
- if (matches) {
- var fontSizePercent = parseInt(matches[1], 10);
- if (bold && fontSizePercent >= 120 || fontSizePercent >= 150)
- return true;
- return false;
- }
- matches = fontSize.match(/(\d+)pt/);
- if (matches) {
- var fontSizePt = parseInt(matches[1], 10);
- if (bold && fontSizePt >= 14 || fontSizePt >= 18)
- return true;
- return false;
- }
- return false;
-};
-
-/**
- * @param {CSSStyleDeclaration} style
- * @param {Element} element
- * @return {?axs.utils.Color}
- */
-axs.utils.getBgColor = function(style, element) {
- var bgColorString = style.backgroundColor;
- var bgColor = axs.utils.parseColor(bgColorString);
- if (!bgColor)
- return null;
-
- if (style.opacity < 1)
- bgColor.alpha = bgColor.alpha * style.opacity
-
- if (bgColor.alpha < 1) {
- var parentBg = axs.utils.getParentBgColor(element);
- if (parentBg == null)
- return null;
-
- bgColor = axs.utils.flattenColors(bgColor, parentBg);
- }
- return bgColor;
-};
-
-/**
- * Gets the effective background color of the parent of |element|.
- * @param {Element} element
- * @return {?axs.utils.Color}
- */
-axs.utils.getParentBgColor = function(element) {
- /** @type {Element} */ var parent = element;
- var bgStack = [];
- var foundSolidColor = null;
- while (parent = axs.utils.parentElement(parent)) {
- var computedStyle = window.getComputedStyle(parent, null);
- if (!computedStyle)
- continue;
-
- var parentBg = axs.utils.parseColor(computedStyle.backgroundColor);
- if (!parentBg)
- continue;
-
- if (computedStyle.opacity < 1)
- parentBg.alpha = parentBg.alpha * computedStyle.opacity;
-
- if (parentBg.alpha == 0)
- continue;
-
- bgStack.push(parentBg);
-
- if (parentBg.alpha == 1) {
- foundSolidColor = true;
- break;
- }
- }
-
- if (!foundSolidColor)
- bgStack.push(new axs.utils.Color(255, 255, 255, 1));
-
- var bg = bgStack.pop();
- while (bgStack.length) {
- var fg = bgStack.pop();
- bg = axs.utils.flattenColors(fg, bg);
- }
- return bg;
-}
-
-/**
- * @param {CSSStyleDeclaration} style
- * @param {axs.utils.Color} bgColor The background color, which may come from
- * another element (such as a parent element), for flattening into the
- * foreground color.
- * @return {?axs.utils.Color}
- */
-axs.utils.getFgColor = function(style, element, bgColor) {
- var fgColorString = style.color;
- var fgColor = axs.utils.parseColor(fgColorString);
- if (!fgColor)
- return null;
-
- if (fgColor.alpha < 1)
- fgColor = axs.utils.flattenColors(fgColor, bgColor);
-
- if (style.opacity < 1) {
- var parentBg = axs.utils.getParentBgColor(element);
- fgColor.alpha = fgColor.alpha * style.opacity;
- fgColor = axs.utils.flattenColors(fgColor, parentBg);
- }
-
- return fgColor;
-};
-
-/**
- * @param {string} colorString The color string from CSS.
- * @return {?axs.utils.Color}
- */
-axs.utils.parseColor = function(colorString) {
- var rgbRegex = /^rgb\((\d+), (\d+), (\d+)\)$/;
- var match = colorString.match(rgbRegex);
-
- if (match) {
- var r = parseInt(match[1], 10);
- var g = parseInt(match[2], 10);
- var b = parseInt(match[3], 10);
- var a = 1
- return new axs.utils.Color(r, g, b, a);
- }
-
- var rgbaRegex = /^rgba\((\d+), (\d+), (\d+), (\d*(\.\d+)?)\)/;
- match = colorString.match(rgbaRegex);
- if (match) {
- var r = parseInt(match[1], 10);
- var g = parseInt(match[2], 10);
- var b = parseInt(match[3] ,10);
- var a = parseFloat(match[4]);
- return new axs.utils.Color(r, g, b, a);
- }
-
- return null;
-};
-
-/**
- * @param {number} value The value of a color channel, 0 <= value <= 0xFF
- * @return {string}
- */
-axs.utils.colorChannelToString = function(value) {
- value = Math.round(value);
- if (value <= 0xF)
- return '0' + value.toString(16);
- return value.toString(16);
-};
-
-/**
- * @param {axs.utils.Color} color
- * @return {string}
- */
-axs.utils.colorToString = function(color) {
- if (color.alpha == 1) {
- return '#' + axs.utils.colorChannelToString(color.red) +
- axs.utils.colorChannelToString(color.green) + axs.utils.colorChannelToString(color.blue);
- }
- else
- return 'rgba(' + [color.red, color.green, color.blue, color.alpha].join(',') + ')';
-};
-
-axs.utils.luminanceFromContrastRatio = function(luminance, contrast, higher) {
- if (higher) {
- var newLuminance = (luminance + 0.05) * contrast - 0.05;
- return newLuminance;
- } else {
- var newLuminance = (luminance + 0.05) / contrast - 0.05;
- return newLuminance;
- }
-};
-
-axs.utils.translateColor = function(ycc, luminance) {
- var oldLuminance = ycc[0];
- if (oldLuminance > luminance)
- var endpoint = 0
- else
- var endpoint = 1;
-
- var d = luminance - oldLuminance;
- var scale = d / (endpoint - oldLuminance)
-
- /** @type {Array.<number>} */ var translatedColor = [ luminance,
- ycc[1] - ycc[1] * scale,
- ycc[2] - ycc[2] * scale ];
- var rgb = axs.utils.fromYCC(translatedColor);
- return rgb;
-};
-
-/**
- * @param {axs.utils.Color} fgColor
- * @param {axs.utils.Color} bgColor
- * @param {number} contrastRatio
- * @param {CSSStyleDeclaration} style
- * @return {Object}
- */
-axs.utils.suggestColors = function(bgColor, fgColor, contrastRatio, style) {
- if (!axs.utils.isLowContrast(contrastRatio, style, true))
- return null;
- var colors = {};
- var bgLuminance = axs.utils.calculateLuminance(bgColor);
- var fgLuminance = axs.utils.calculateLuminance(fgColor);
-
- var levelAAContrast = axs.utils.isLargeFont(style) ? 3.0 : 4.5;
- var levelAAAContrast = axs.utils.isLargeFont(style) ? 4.5 : 7.0;
- var fgLuminanceIsHigher = fgLuminance > bgLuminance;
- var desiredFgLuminanceAA = axs.utils.luminanceFromContrastRatio(bgLuminance, levelAAContrast + 0.02, fgLuminanceIsHigher);
- var desiredFgLuminanceAAA = axs.utils.luminanceFromContrastRatio(bgLuminance, levelAAAContrast + 0.02, fgLuminanceIsHigher);
- var fgYCC = axs.utils.toYCC(fgColor);
-
- if (axs.utils.isLowContrast(contrastRatio, style, false) &&
- desiredFgLuminanceAA <= 1 && desiredFgLuminanceAA >= 0) {
- var newFgColorAA = axs.utils.translateColor(fgYCC, desiredFgLuminanceAA);
- var newContrastRatioAA = axs.utils.calculateContrastRatio(newFgColorAA, bgColor);
- var newLuminance = axs.utils.calculateLuminance(newFgColorAA);
- var suggestedColorsAA = {}
- suggestedColorsAA['fg'] = axs.utils.colorToString(newFgColorAA);
- suggestedColorsAA['bg'] = axs.utils.colorToString(bgColor);
- suggestedColorsAA['contrast'] = newContrastRatioAA.toFixed(2);
- colors['AA'] = suggestedColorsAA;
- }
- if (axs.utils.isLowContrast(contrastRatio, style, true) &&
- desiredFgLuminanceAAA <= 1 && desiredFgLuminanceAAA >= 0) {
- var newFgColorAAA = axs.utils.translateColor(fgYCC, desiredFgLuminanceAAA);
- var newContrastRatioAAA = axs.utils.calculateContrastRatio(newFgColorAAA, bgColor);
- var suggestedColorsAAA = {};
- suggestedColorsAAA['fg'] = axs.utils.colorToString(newFgColorAAA);
- suggestedColorsAAA['bg'] = axs.utils.colorToString(bgColor);
- suggestedColorsAAA['contrast'] = newContrastRatioAAA.toFixed(2);
- colors['AAA'] = suggestedColorsAAA;
- }
- var desiredBgLuminanceAA = axs.utils.luminanceFromContrastRatio(fgLuminance, levelAAContrast + 0.02, !fgLuminanceIsHigher);
- var desiredBgLuminanceAAA = axs.utils.luminanceFromContrastRatio(fgLuminance, levelAAAContrast + 0.02, !fgLuminanceIsHigher);
- var bgLuminanceBoundary = fgLuminanceIsHigher ? 0 : 1;
- var bgYCC = axs.utils.toYCC(bgColor);
-
- if (!('AA' in colors) && axs.utils.isLowContrast(contrastRatio, style, false) &&
- desiredBgLuminanceAA <= 1 && desiredBgLuminanceAA >= 0) {
- var newBgColorAA = axs.utils.translateColor(bgYCC, desiredBgLuminanceAA);
- var newContrastRatioAA = axs.utils.calculateContrastRatio(fgColor, newBgColorAA);
- var suggestedColorsAA = {};
- suggestedColorsAA['bg'] = axs.utils.colorToString(newBgColorAA);
- suggestedColorsAA['fg'] = axs.utils.colorToString(fgColor);
- suggestedColorsAA['contrast'] = newContrastRatioAA.toFixed(2);
- colors['AA'] = suggestedColorsAA;
- }
- if (!('AAA' in colors) && axs.utils.isLowContrast(contrastRatio, style, true) &&
- desiredBgLuminanceAAA <= 1 && desiredBgLuminanceAAA >= 0) {
- var newBgColorAAA = axs.utils.translateColor(bgYCC, desiredBgLuminanceAAA);
- var newContrastRatioAAA = axs.utils.calculateContrastRatio(fgColor, newBgColorAAA);
- var suggestedColorsAAA = {};
- suggestedColorsAAA['bg'] = axs.utils.colorToString(newBgColorAAA);
- suggestedColorsAAA['fg'] = axs.utils.colorToString(fgColor);
- suggestedColorsAAA['contrast'] = newContrastRatioAAA.toFixed(2);
- colors['AAA'] = suggestedColorsAAA;
- }
- return colors;
-}
-
-/**
- * Combine the two given color according to alpha blending.
- * @param {axs.utils.Color} fgColor
- * @param {axs.utils.Color} bgColor
- * @return {axs.utils.Color}
- */
-axs.utils.flattenColors = function(fgColor, bgColor) {
- var alpha = fgColor.alpha;
- var r = ((1 - alpha) * bgColor.red) + (alpha * fgColor.red);
- var g = ((1 - alpha) * bgColor.green) + (alpha * fgColor.green);
- var b = ((1 - alpha) * bgColor.blue) + (alpha * fgColor.blue);
- var a = fgColor.alpha + (bgColor.alpha * (1 - fgColor.alpha));
-
- return new axs.utils.Color(r, g, b, a);
-};
-
-/**
- * Calculate the luminance of the given color using the WCAG algorithm.
- * @param {axs.utils.Color} color
- * @return {number}
- */
-axs.utils.calculateLuminance = function(color) {
-/* var rSRGB = color.red / 255;
- var gSRGB = color.green / 255;
- var bSRGB = color.blue / 255;
-
- var r = rSRGB <= 0.03928 ? rSRGB / 12.92 : Math.pow(((rSRGB + 0.055)/1.055), 2.4);
- var g = gSRGB <= 0.03928 ? gSRGB / 12.92 : Math.pow(((gSRGB + 0.055)/1.055), 2.4);
- var b = bSRGB <= 0.03928 ? bSRGB / 12.92 : Math.pow(((bSRGB + 0.055)/1.055), 2.4);
-
- return 0.2126 * r + 0.7152 * g + 0.0722 * b; */
- var ycc = axs.utils.toYCC(color);
- return ycc[0];
-};
-
-/**
- * Returns an RGB to YCC conversion matrix for the given kR, kB constants.
- * @param {number} kR
- * @param {number} kB
- * @return {Array.<Array.<number>>}
- */
-axs.utils.RGBToYCCMatrix = function(kR, kB) {
- return [
- [
- kR,
- (1 - kR - kB),
- kB
- ],
- [
- -kR/(2 - 2*kB),
- (kR + kB - 1)/(2 - 2*kB),
- (1 - kB)/(2 - 2*kB)
- ],
- [
- (1 - kR)/(2 - 2*kR),
- (kR + kB - 1)/(2 - 2*kR),
- -kB/(2 - 2*kR)
- ]
- ];
-}
-
-/**
- * Return the inverse of the given 3x3 matrix.
- * @param {Array.<Array.<number>>} matrix
- * @return Array.<Array.<number>> The inverse of the given matrix.
- */
-axs.utils.invert3x3Matrix = function(matrix) {
- var a = matrix[0][0];
- var b = matrix[0][1];
- var c = matrix[0][2];
- var d = matrix[1][0];
- var e = matrix[1][1];
- var f = matrix[1][2];
- var g = matrix[2][0];
- var h = matrix[2][1];
- var k = matrix[2][2];
-
- var A = (e*k - f*h);
- var B = (f*g - d*k);
- var C = (d*h - e*g);
- var D = (c*h - b*k);
- var E = (a*k - c*g);
- var F = (g*b - a*h);
- var G = (b*f - c*e);
- var H = (c*d - a*f);
- var K = (a*e - b*d);
-
- var det = a * (e*k - f*h) - b * (k*d - f*g) + c * (d*h - e*g);
- var z = 1/det;
-
- return axs.utils.scalarMultiplyMatrix([
- [ A, D, G ],
- [ B, E, H ],
- [ C, F, K ]
- ], z);
-};
-
-axs.utils.scalarMultiplyMatrix = function(matrix, scalar) {
- var result = [];
- result[0] = [];
- result[1] = [];
- result[2] = [];
-
- for (var i = 0; i < 3; i++) {
- for (var j = 0; j < 3; j++) {
- result[i][j] = matrix[i][j] * scalar;
- }
- }
-
- return result;
-}
-
-axs.utils.kR = 0.2126;
-axs.utils.kB = 0.0722;
-axs.utils.YCC_MATRIX = axs.utils.RGBToYCCMatrix(axs.utils.kR, axs.utils.kB);
-axs.utils.INVERTED_YCC_MATRIX = axs.utils.invert3x3Matrix(axs.utils.YCC_MATRIX);
-
-/**
- * Multiply the given color vector by the given transformation matrix.
- * @param {Array.<Array.<number>>} matrix A 3x3 conversion matrix
- * @param {Array.<number>} vector A 3-element color vector
- * @return {Array.<number>} A 3-element color vector
- */
-axs.utils.convertColor = function(matrix, vector) {
- var a = matrix[0][0];
- var b = matrix[0][1];
- var c = matrix[0][2];
- var d = matrix[1][0];
- var e = matrix[1][1];
- var f = matrix[1][2];
- var g = matrix[2][0];
- var h = matrix[2][1];
- var k = matrix[2][2];
-
- var x = vector[0];
- var y = vector[1];
- var z = vector[2];
-
- return [
- a*x + b*y + c*z,
- d*x + e*y + f*z,
- g*x + h*y + k*z
- ];
-};
-
-axs.utils.multiplyMatrices = function(matrix1, matrix2) {
- var result = [];
- result[0] = [];
- result[1] = [];
- result[2] = [];
-
- for (var i = 0; i < 3; i++) {
- for (var j = 0; j < 3; j++) {
- result[i][j] = matrix1[i][0] * matrix2[0][j] +
- matrix1[i][1] * matrix2[1][j] +
- matrix1[i][2] * matrix2[2][j];
- }
- }
- return result;
-}
-
-/**
- * Convert a given RGB color to YCC.
- */
-axs.utils.toYCC = function(color) {
- var rSRGB = color.red / 255;
- var gSRGB = color.green / 255;
- var bSRGB = color.blue / 255;
-
- var r = rSRGB <= 0.03928 ? rSRGB / 12.92 : Math.pow(((rSRGB + 0.055)/1.055), 2.4);
- var g = gSRGB <= 0.03928 ? gSRGB / 12.92 : Math.pow(((gSRGB + 0.055)/1.055), 2.4);
- var b = bSRGB <= 0.03928 ? bSRGB / 12.92 : Math.pow(((bSRGB + 0.055)/1.055), 2.4);
-
- return axs.utils.convertColor(axs.utils.YCC_MATRIX, [r, g, b]);
-};
-
-/**
- * Convert a color from a YCC color (as a vector) to an RGB color
- * @param {Array.<number>} yccColor
- * @return {axs.utils.Color}
- */
-axs.utils.fromYCC = function(yccColor) {
- var rgb = axs.utils.convertColor(axs.utils.INVERTED_YCC_MATRIX, yccColor);
-
- var r = rgb[0];
- var g = rgb[1];
- var b = rgb[2];
- var rSRGB = r <= 0.00303949 ? (r * 12.92) : (Math.pow(r, (1/2.4)) * 1.055) - 0.055;
- var gSRGB = g <= 0.00303949 ? (g * 12.92) : (Math.pow(g, (1/2.4)) * 1.055) - 0.055;
- var bSRGB = b <= 0.00303949 ? (b * 12.92) : (Math.pow(b, (1/2.4)) * 1.055) - 0.055;
-
- var red = Math.min(Math.max(Math.round(rSRGB * 255), 0), 255);
- var green = Math.min(Math.max(Math.round(gSRGB * 255), 0), 255);
- var blue = Math.min(Math.max(Math.round(bSRGB * 255), 0), 255);
-
- return new axs.utils.Color(red, green, blue, 1);
-};
-
-axs.utils.scalarMultiplyMatrix = function(matrix, scalar) {
- var result = [];
- result[0] = [];
- result[1] = [];
- result[2] = [];
-
- for (var i = 0; i < 3; i++) {
- for (var j = 0; j < 3; j++) {
- result[i][j] = matrix[i][j] * scalar;
- }
- }
-
- return result;
-}
-
-axs.utils.multiplyMatrices = function(matrix1, matrix2) {
- var result = [];
- result[0] = [];
- result[1] = [];
- result[2] = [];
-
- for (var i = 0; i < 3; i++) {
- for (var j = 0; j < 3; j++) {
- result[i][j] = matrix1[i][0] * matrix2[0][j] +
- matrix1[i][1] * matrix2[1][j] +
- matrix1[i][2] * matrix2[2][j];
- }
- }
- return result;
-}
-
-/**
- * @param {Element} element
- * @return {?number}
- */
-axs.utils.getContrastRatioForElement = function(element) {
- var style = window.getComputedStyle(element, null);
- return axs.utils.getContrastRatioForElementWithComputedStyle(style, element);
-};
-
-/**
- * @param {CSSStyleDeclaration} style
- * @param {Element} element
- * @return {?number}
- */
-axs.utils.getContrastRatioForElementWithComputedStyle = function(style, element) {
- if (axs.utils.isElementHidden(element))
- return null;
-
- var bgColor = axs.utils.getBgColor(style, element);
- if (!bgColor)
- return null;
-
- var fgColor = axs.utils.getFgColor(style, element, bgColor);
- if (!fgColor)
- return null;
-
- return axs.utils.calculateContrastRatio(fgColor, bgColor);
-};
-
-/**
- * @param {Element} element
- * @return {boolean}
- */
-axs.utils.isNativeTextElement = function(element) {
- var tagName = element.tagName.toLowerCase();
- var type = element.type ? element.type.toLowerCase() : '';
- if (tagName == 'textarea')
- return true;
- if (tagName != 'input')
- return false;
-
- switch (type) {
- case 'email':
- case 'number':
- case 'password':
- case 'search':
- case 'text':
- case 'tel':
- case 'url':
- case '':
- return true;
- default:
- return false;
- }
-};
-
-/**
- * @param {number} contrastRatio
- * @param {CSSStyleDeclaration} style
- * @param {boolean=} opt_strict Whether to use AA (false) or AAA (true) level
- * @return {boolean}
- */
-axs.utils.isLowContrast = function(contrastRatio, style, opt_strict) {
- // Round to nearest 0.1
- var roundedContrastRatio = (Math.round(contrastRatio * 10) / 10);
- if (!opt_strict) {
- return roundedContrastRatio < 3.0 ||
- (!axs.utils.isLargeFont(style) && roundedContrastRatio < 4.5);
- } else {
- return roundedContrastRatio < 4.5 ||
- (!axs.utils.isLargeFont(style) && roundedContrastRatio < 7.0);
- }
-};
-
-/**
- * @param {Element} element
- * @return {boolean}
- */
-axs.utils.hasLabel = function(element) {
- var tagName = element.tagName.toLowerCase();
- var type = element.type ? element.type.toLowerCase() : '';
-
- if (element.hasAttribute('aria-label'))
- return true;
- if (element.hasAttribute('title'))
- return true;
- if (tagName == 'img' && element.hasAttribute('alt'))
- return true;
- if (tagName == 'input' && type == 'image' && element.hasAttribute('alt'))
- return true;
- if (tagName == 'input' && (type == 'submit' || type == 'reset'))
- return true;
-
- // There's a separate audit that makes sure this points to an actual element or elements.
- if (element.hasAttribute('aria-labelledby'))
- return true;
-
- if (axs.utils.isNativeTextElement(element) && element.hasAttribute('placeholder'))
- return true;
-
- if (element.hasAttribute('id')) {
- var labelsFor = document.querySelectorAll('label[for="' + element.id + '"]');
- if (labelsFor.length > 0)
- return true;
- }
-
- var parent = axs.utils.parentElement(element);
- while (parent) {
- if (parent.tagName.toLowerCase() == 'label') {
- var parentLabel = /** HTMLLabelElement */ parent;
- if (parentLabel.control == element)
- return true;
- }
- parent = axs.utils.parentElement(parent);
- }
- return false;
-};
-
-/**
- * @param {Element} element An element to check.
- * @return {boolean} True if the element is hidden from accessibility.
- */
-axs.utils.isElementHidden = function(element) {
- if (!(element instanceof element.ownerDocument.defaultView.HTMLElement))
- return false;
-
- if (element.hasAttribute('chromevoxignoreariahidden'))
- var chromevoxignoreariahidden = true;
-
- var style = window.getComputedStyle(element, null);
- if (style.display == 'none' || style.visibility == 'hidden')
- return true;
-
- if (element.hasAttribute('aria-hidden') &&
- element.getAttribute('aria-hidden').toLowerCase() == 'true') {
- return !chromevoxignoreariahidden;
- }
-
- return false;
-};
-
-/**
- * @param {Element} element An element to check.
- * @return {boolean} True if the element or one of its ancestors is
- * hidden from accessibility.
- */
-axs.utils.isElementOrAncestorHidden = function(element) {
- if (axs.utils.isElementHidden(element))
- return true;
-
- if (axs.utils.parentElement(element))
- return axs.utils.isElementOrAncestorHidden(axs.utils.parentElement(element));
- else
- return false;
-};
-
-/**
- * @param {Element} element An element to check
- * @return {boolean} True if the given element is an inline element, false
- * otherwise.
- */
-axs.utils.isInlineElement = function(element) {
- var tagName = element.tagName.toUpperCase();
- return axs.constants.InlineElements[tagName];
-}
-
-/**
- * @param {Element} element
- * @return {Object|boolean}
- */
-axs.utils.getRoles = function(element) {
- if (!element.hasAttribute('role'))
- return false;
- var roleValue = element.getAttribute('role');
- var roleNames = roleValue.split(' ');
- var roles = []
- var valid = true;
- for (var i = 0; i < roleNames.length; i++) {
- var role = roleNames[i];
- if (axs.constants.ARIA_ROLES[role])
- roles.push({'name': role, 'details': axs.constants.ARIA_ROLES[role], 'valid': true});
- else {
- roles.push({'name': role, 'valid': false});
- valid = false;
- }
- }
-
- return { 'roles': roles, 'valid': valid };
-};
-
-/**
- * @param {!string} propertyName
- * @param {!string} value
- * @param {!Element} element
- * @return {!Object}
- */
-axs.utils.getAriaPropertyValue = function(propertyName, value, element) {
- var propertyKey = propertyName.replace(/^aria-/, '');
- var property = axs.constants.ARIA_PROPERTIES[propertyKey];
- var result = { 'name': propertyName, 'rawValue': value };
- if (!property) {
- result.valid = false;
- result.reason = '"' + propertyName + '" is not a valid ARIA property';
- return result;
- }
-
- var propertyType = property.valueType;
- if (!propertyType) {
- result.valid = false;
- result.reason = '"' + propertyName + '" is not a valid ARIA property';
- return result;
- }
-
- switch (propertyType) {
- case "idref":
- var isValid = axs.utils.isValidIDRefValue(value, element);
- result.valid = isValid.valid;
- result.reason = isValid.reason;
- result.idref = isValid.idref;
- case "idref_list":
- var idrefValues = value.split(/\s+/);
- result.valid = true;
- for (var i = 0; i < idrefValues.length; i++) {
- var refIsValid = axs.utils.isValidIDRefValue(idrefValues[i], element);
- if (!refIsValid.valid)
- result.valid = false;
- if (result.values)
- result.values.push(refIsValid);
- else
- result.values = [refIsValid];
- }
- return result;
- case "integer":
- case "decimal":
- var validNumber = axs.utils.isValidNumber(value);
- if (!validNumber.valid) {
- result.valid = false;
- result.reason = validNumber.reason;
- return result;
- }
- if (Math.floor(validNumber.value) != validNumber.value) {
- result.valid = false;
- result.reason = '' + value + ' is not a whole integer';
- } else {
- result.valid = true;
- result.value = validNumber.value;
- }
- return result;
- case "number":
- var validNumber = axs.utils.isValidNumber(value);
- if (validNumber.valid) {
- result.valid = true;
- result.value = validNumber.value;
- }
- case "string":
- result.valid = true;
- result.value = value;
- return result;
- case "token":
- var validTokenValue = axs.utils.isValidTokenValue(propertyName, value.toLowerCase());
- if (validTokenValue.valid) {
- result.valid = true;
- result.value = validTokenValue.value;
- return result;
- } else {
- result.valid = false;
- result.value = value;
- result.reason = validTokenValue.reason;
- return result;
- }
- case "token_list":
- var tokenValues = value.split(/\s+/);
- result.valid = true;
- for (var i = 0; i < tokenValues.length; i++) {
- var validTokenValue = axs.utils.isValidTokenValue(propertyName, tokenValues[i].toLowerCase());
- if (!validTokenValue.valid) {
- result.valid = false;
- if (result.reason) {
- result.reason = [ result.reason ];
- result.reason.push(validTokenValue.reason);
- } else {
- result.reason = validTokenValue.reason;
- result.possibleValues = validTokenValue.possibleValues;
- }
- }
- // TODO (more structured result)
- if (result.values)
- result.values.push(validTokenValue.value);
- else
- result.values = [validTokenValue.value];
- }
- return result;
- case "tristate":
- var validTristate = axs.utils.isPossibleValue(value.toLowerCase(), axs.constants.MIXED_VALUES, propertyName);
- if (validTristate.valid) {
- result.valid = true;
- result.value = validTristate.value;
- } else {
- result.valid = false;
- result.value = value;
- result.reason = validTristate.reason;
- }
- return result;
- case "boolean":
- var validBoolean = axs.utils.isValidBoolean(value);
- if (validBoolean.valid) {
- result.valid = true;
- result.value = validBoolean.value;
- } else {
- result.valid = false;
- result.value = value;
- result.reason = validBoolean.reason;
- }
- return result;
- }
- result.valid = false
- result.reason = 'Not a valid ARIA property';
- return result;
-};
-
-/**
- * @param {string} propertyName The name of the property.
- * @param {string} value The value to check.
- * @return {!Object}
- */
-axs.utils.isValidTokenValue = function(propertyName, value) {
- var propertyKey = propertyName.replace(/^aria-/, '');
- var propertyDetails = axs.constants.ARIA_PROPERTIES[propertyKey];
- var possibleValues = propertyDetails.valuesSet;
- return axs.utils.isPossibleValue(value, possibleValues, propertyName);
-};
-
-/**
- * @param {string} value
- * @param {Object.<string, boolean>} possibleValues
- * @return {!Object}
- */
-axs.utils.isPossibleValue = function(value, possibleValues, propertyName) {
- if (!possibleValues[value])
- return { 'valid': false,
- 'value': value,
- 'reason': '"' + value + '" is not a valid value for ' + propertyName,
- 'possibleValues': Object.keys(possibleValues) };
- return { 'valid': true, 'value': value };
-};
-
-/**
- * @param {string} value
- * @return {!Object}
- */
-axs.utils.isValidBoolean = function(value) {
- try {
- var parsedValue = JSON.parse(value);
- } catch (e) {
- parsedValue = '';
- }
- if (typeof(parsedValue) != 'boolean')
- return { 'valid': false,
- 'value': value,
- 'reason': '"' + value + '" is not a true/false value' };
- return { 'valid': true, 'value': parsedValue };
-};
-
-/**
- * @param {string} value
- * @param {!Element} element
- * @return {!Object}
- */
-axs.utils.isValidIDRefValue = function(value, element) {
- if (value.length == 0)
- return { 'valid': true, 'idref': value };
- if (!element.ownerDocument.getElementById(value))
- return { 'valid': false,
- 'idref': value,
- 'reason': 'No element with ID "' + value + '"' };
- return { 'valid': true, 'idref': value };
-};
-
-/**
- * @param {string} value
- * @return {!Object}
- */
-axs.utils.isValidNumber = function(value) {
- try {
- var parsedValue = JSON.parse(value);
- } catch (ex) {
- return { 'valid': false,
- 'value': value,
- 'reason': '"' + value + '" is not a number' };
- }
- if (typeof(parsedValue) != 'number') {
- return { 'valid': false,
- 'value': value,
- 'reason': '"' + value + '" is not a number' };
- }
- return { 'valid': true, 'value': parsedValue };
-};
-
-/**
- * @param {Element} element
- * @return {boolean}
- */
-axs.utils.isElementImplicitlyFocusable = function(element) {
- var defaultView = element.ownerDocument.defaultView;
-
- if (element instanceof defaultView.HTMLAnchorElement ||
- element instanceof defaultView.HTMLAreaElement)
- return element.hasAttribute('href');
- if (element instanceof defaultView.HTMLInputElement ||
- element instanceof defaultView.HTMLSelectElement ||
- element instanceof defaultView.HTMLTextAreaElement ||
- element instanceof defaultView.HTMLButtonElement ||
- element instanceof defaultView.HTMLIFrameElement)
- return !element.disabled;
- return false;
-};
-
-/**
- * Returns an array containing the values of the given JSON-compatible object.
- * (Simply ignores any function values.)
- * @param {Object} obj
- * @return {Array}
- */
-axs.utils.values = function(obj) {
- var values = [];
- for (var key in obj) {
- if (obj.hasOwnProperty(key) && typeof obj[key] != 'function')
- values.push(obj[key]);
- }
- return values;
-};
-
-/**
- * Returns an object containing the same keys and values as the given
- * JSON-compatible object. (Simply ignores any function values.)
- * @param {Object} obj
- * @return {Object}
- */
-axs.utils.namedValues = function(obj) {
- var values = {};
- for (var key in obj) {
- if (obj.hasOwnProperty(key) && typeof obj[key] != 'function')
- values[key] = obj[key];
- }
- return values
-};
-
-/** Gets a CSS selector text for a DOM object.
- * @param {Node} obj The DOM object.
- * @return {string} CSS selector text for the DOM object.
- */
-axs.utils.getQuerySelectorText = function(obj) {
- if (obj == null || obj.tagName == 'HTML') {
- return 'html';
- } else if (obj.tagName == 'BODY') {
- return 'body';
- }
-
- if (obj.hasAttribute) {
- if (obj.id) {
- return '#' + obj.id;
- }
-
- if (obj.className) {
- var selector = '';
- for (var i = 0; i < obj.classList.length; i++)
- selector += '.' + obj.classList[i];
-
- var total = 0;
- if (obj.parentNode) {
- for (i = 0; i < obj.parentNode.children.length; i++) {
- var similar = obj.parentNode.children[i];
- if (axs.browserUtils.matchSelector(similar, selector))
- total++;
- if (similar === obj)
- break;
- }
- } else {
- total = 1;
- }
-
- if (total == 1) {
- return axs.utils.getQuerySelectorText(obj.parentNode) +
- ' > ' + selector;
- }
- }
-
- if (obj.parentNode) {
- var similarTags = obj.parentNode.children;
- var total = 1;
- var i = 0;
- while (similarTags[i] !== obj) {
- if (similarTags[i].tagName == obj.tagName) {
- total++;
- }
- i++;
- }
-
- var next = '';
- if (obj.parentNode.tagName != 'BODY') {
- next = axs.utils.getQuerySelectorText(obj.parentNode) +
- ' > ';
- }
-
- if (total == 1) {
- return next +
- obj.tagName;
- } else {
- return next +
- obj.tagName +
- ':nth-of-type(' + total + ')';
- }
- }
-
- } else if (obj.selectorText) {
- return obj.selectorText;
- }
-
- return '';
-};
« no previous file with comments | « ui/accessibility/extensions/caretbrowsing/_locales/en/messages.json ('k') | ui/accessibility/extensions/caretbrowsing/background.js » ('j') | no next file with comments »

Powered by Google App Engine
This is Rietveld 408576698