diff options
Diffstat (limited to 'devtools/server/actors/highlighters/tabbing-order.js')
| -rw-r--r-- | devtools/server/actors/highlighters/tabbing-order.js | 237 |
1 files changed, 237 insertions, 0 deletions
diff --git a/devtools/server/actors/highlighters/tabbing-order.js b/devtools/server/actors/highlighters/tabbing-order.js new file mode 100644 index 0000000000..82d9528cd0 --- /dev/null +++ b/devtools/server/actors/highlighters/tabbing-order.js @@ -0,0 +1,237 @@ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +"use strict"; + +const lazy = {}; +ChromeUtils.defineESModuleGetters(lazy, { + ContentDOMReference: "resource://gre/modules/ContentDOMReference.sys.mjs", +}); +loader.lazyRequireGetter( + this, + ["isFrameWithChildTarget", "isWindowIncluded"], + "resource://devtools/shared/layout/utils.js", + true +); +loader.lazyRequireGetter( + this, + "NodeTabbingOrderHighlighter", + "resource://devtools/server/actors/highlighters/node-tabbing-order.js", + true +); + +const DEFAULT_FOCUS_FLAGS = Services.focus.FLAG_NOSCROLL; + +/** + * The TabbingOrderHighlighter uses focus manager to traverse all focusable + * nodes on the page and then uses the NodeTabbingOrderHighlighter to highlight + * these nodes. + */ +class TabbingOrderHighlighter { + constructor(highlighterEnv) { + this.highlighterEnv = highlighterEnv; + this._highlighters = new Map(); + + this.onMutation = this.onMutation.bind(this); + this.onPageHide = this.onPageHide.bind(this); + this.onWillNavigate = this.onWillNavigate.bind(this); + + this.highlighterEnv.on("will-navigate", this.onWillNavigate); + + const { pageListenerTarget } = highlighterEnv; + pageListenerTarget.addEventListener("pagehide", this.onPageHide); + } + + /** + * Static getter that indicates that TabbingOrderHighlighter supports + * highlighting in XUL windows. + */ + static get XULSupported() { + return true; + } + + get win() { + return this.highlighterEnv.window; + } + + get focusedElement() { + return Services.focus.getFocusedElementForWindow(this.win, true, {}); + } + + set focusedElement(element) { + Services.focus.setFocus(element, DEFAULT_FOCUS_FLAGS); + } + + moveFocus(startElement) { + return Services.focus.moveFocus( + this.win, + startElement.nodeType === Node.DOCUMENT_NODE + ? startElement.documentElement + : startElement, + Services.focus.MOVEFOCUS_FORWARD, + DEFAULT_FOCUS_FLAGS + ); + } + + /** + * Show NodeTabbingOrderHighlighter on each node that belongs to the keyboard + * tabbing order. + * + * @param {DOMNode} startElm + * Starting element to calculate tabbing order from. + * + * @param {JSON} options + * - options.index + * Start index for the tabbing order. Starting index will be 0 at + * the start of the tabbing order highlighting; in remote frames + * starting index will, typically, be greater than 0 (unless there + * was nothing to focus in the top level content document prior to + * the remote frame). + */ + async show(startElm, { index }) { + const focusableElements = []; + const originalFocusedElement = this.focusedElement; + let currentFocusedElement = this.moveFocus(startElm); + while ( + currentFocusedElement && + isWindowIncluded(this.win, currentFocusedElement.ownerGlobal) + ) { + focusableElements.push(currentFocusedElement); + currentFocusedElement = this.moveFocus(currentFocusedElement); + } + + // Allow to flush pending notifications to ensure the PresShell and frames + // are updated. + await new Promise(resolve => Services.tm.dispatchToMainThread(resolve)); + let endElm = this.focusedElement; + if ( + currentFocusedElement && + !isWindowIncluded(this.win, currentFocusedElement.ownerGlobal) + ) { + endElm = null; + } + + if ( + !endElm && + !!focusableElements.length && + isFrameWithChildTarget( + this.highlighterEnv.targetActor, + focusableElements[focusableElements.length - 1] + ) + ) { + endElm = focusableElements[focusableElements.length - 1]; + } + + if (originalFocusedElement && originalFocusedElement !== endElm) { + this.focusedElement = originalFocusedElement; + } + + const highlighters = []; + for (let i = 0; i < focusableElements.length; i++) { + highlighters.push( + this._accumulateHighlighter(focusableElements[i], index++) + ); + } + await Promise.all(highlighters); + + this._trackMutations(); + + return { + contentDOMReference: endElm && lazy.ContentDOMReference.get(endElm), + index, + }; + } + + async _accumulateHighlighter(node, index) { + const highlighter = new NodeTabbingOrderHighlighter(this.highlighterEnv); + await highlighter.isReady; + + highlighter.show(node, { index: index + 1 }); + this._highlighters.set(node, highlighter); + } + + hide() { + this._untrackMutations(); + for (const highlighter of this._highlighters.values()) { + highlighter.destroy(); + } + + this._highlighters.clear(); + } + + /** + * Track mutations in the top level document subtree so that the appropriate + * NodeTabbingOrderHighlighter infobar's could be updated to reflect the + * attribute mutations on relevant nodes. + */ + _trackMutations() { + const { win } = this; + this.currentMutationObserver = new win.MutationObserver(this.onMutation); + this.currentMutationObserver.observe(win.document.documentElement, { + subtree: true, + attributes: true, + }); + } + + _untrackMutations() { + if (!this.currentMutationObserver) { + return; + } + + this.currentMutationObserver.disconnect(); + this.currentMutationObserver = null; + } + + onMutation(mutationList) { + for (const { target } of mutationList) { + const highlighter = this._highlighters.get(target); + if (highlighter) { + highlighter.update(); + } + } + } + + /** + * Update NodeTabbingOrderHighlighter focus styling for a node that, + * potentially, belongs to the tabbing order. + * @param {Object} options + * Options specifying the node and its focused state. + */ + updateFocus({ node, focused }) { + const highlighter = this._highlighters.get(node); + if (!highlighter) { + return; + } + + highlighter.updateFocus(focused); + } + + destroy() { + this.highlighterEnv.off("will-navigate", this.onWillNavigate); + + const { pageListenerTarget } = this.highlighterEnv; + if (pageListenerTarget) { + pageListenerTarget.removeEventListener("pagehide", this.onPageHide); + } + + this.hide(); + this.highlighterEnv = null; + } + + onPageHide({ target }) { + // If a pagehide event is triggered for current window's highlighter, hide + // the highlighter. + if (target.defaultView === this.win) { + this.hide(); + } + } + + onWillNavigate({ isTopLevel }) { + if (isTopLevel) { + this.hide(); + } + } +} + +exports.TabbingOrderHighlighter = TabbingOrderHighlighter; |