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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 19:33:14 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 19:33:14 +0000 |
commit | 36d22d82aa202bb199967e9512281e9a53db42c9 (patch) | |
tree | 105e8c98ddea1c1e4784a60a5a6410fa416be2de /devtools/client/fronts/accessibility.js | |
parent | Initial commit. (diff) | |
download | firefox-esr-36d22d82aa202bb199967e9512281e9a53db42c9.tar.xz firefox-esr-36d22d82aa202bb199967e9512281e9a53db42c9.zip |
Adding upstream version 115.7.0esr.upstream/115.7.0esr
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'devtools/client/fronts/accessibility.js')
-rw-r--r-- | devtools/client/fronts/accessibility.js | 583 |
1 files changed, 583 insertions, 0 deletions
diff --git a/devtools/client/fronts/accessibility.js b/devtools/client/fronts/accessibility.js new file mode 100644 index 0000000000..3a60856164 --- /dev/null +++ b/devtools/client/fronts/accessibility.js @@ -0,0 +1,583 @@ +/* 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 { + FrontClassWithSpec, + registerFront, +} = require("resource://devtools/shared/protocol.js"); +const { + accessibleSpec, + accessibleWalkerSpec, + accessibilitySpec, + parentAccessibilitySpec, + simulatorSpec, +} = require("resource://devtools/shared/specs/accessibility.js"); +const events = require("resource://devtools/shared/event-emitter.js"); + +class AccessibleFront extends FrontClassWithSpec(accessibleSpec) { + constructor(client, targetFront, parentFront) { + super(client, targetFront, parentFront); + + this.before("audited", this.audited.bind(this)); + this.before("name-change", this.nameChange.bind(this)); + this.before("value-change", this.valueChange.bind(this)); + this.before("description-change", this.descriptionChange.bind(this)); + this.before("shortcut-change", this.shortcutChange.bind(this)); + this.before("reorder", this.reorder.bind(this)); + this.before("text-change", this.textChange.bind(this)); + this.before("index-in-parent-change", this.indexInParentChange.bind(this)); + this.before("states-change", this.statesChange.bind(this)); + this.before("actions-change", this.actionsChange.bind(this)); + this.before("attributes-change", this.attributesChange.bind(this)); + } + + marshallPool() { + return this.getParent(); + } + + get useChildTargetToFetchChildren() { + return this._form.useChildTargetToFetchChildren; + } + + get role() { + return this._form.role; + } + + get name() { + return this._form.name; + } + + get value() { + return this._form.value; + } + + get description() { + return this._form.description; + } + + get keyboardShortcut() { + return this._form.keyboardShortcut; + } + + get childCount() { + return this._form.childCount; + } + + get domNodeType() { + return this._form.domNodeType; + } + + get indexInParent() { + return this._form.indexInParent; + } + + get states() { + return this._form.states; + } + + get actions() { + return this._form.actions; + } + + get attributes() { + return this._form.attributes; + } + + get checks() { + return this._form.checks; + } + + form(form) { + this.actorID = form.actor; + this._form = this._form || {}; + Object.assign(this._form, form); + } + + nameChange(name, parent) { + this._form.name = name; + // Name change event affects the tree rendering, we fire this event on + // accessibility walker as the point of interaction for UI. + const accessibilityWalkerFront = this.getParent(); + if (accessibilityWalkerFront) { + events.emit(accessibilityWalkerFront, "name-change", this, parent); + } + } + + valueChange(value) { + this._form.value = value; + } + + descriptionChange(description) { + this._form.description = description; + } + + shortcutChange(keyboardShortcut) { + this._form.keyboardShortcut = keyboardShortcut; + } + + reorder(childCount) { + this._form.childCount = childCount; + // Reorder event affects the tree rendering, we fire this event on + // accessibility walker as the point of interaction for UI. + const accessibilityWalkerFront = this.getParent(); + if (accessibilityWalkerFront) { + events.emit(accessibilityWalkerFront, "reorder", this); + } + } + + textChange() { + // Text event affects the tree rendering, we fire this event on + // accessibility walker as the point of interaction for UI. + const accessibilityWalkerFront = this.getParent(); + if (accessibilityWalkerFront) { + events.emit(accessibilityWalkerFront, "text-change", this); + } + } + + indexInParentChange(indexInParent) { + this._form.indexInParent = indexInParent; + } + + statesChange(states) { + this._form.states = states; + } + + actionsChange(actions) { + this._form.actions = actions; + } + + attributesChange(attributes) { + this._form.attributes = attributes; + } + + audited(checks) { + this._form.checks = this._form.checks || {}; + Object.assign(this._form.checks, checks); + } + + hydrate() { + return super.hydrate().then(properties => { + Object.assign(this._form, properties); + }); + } + + async children() { + if (!this.useChildTargetToFetchChildren) { + return super.children(); + } + + const { walker: domWalkerFront } = await this.targetFront.getFront( + "inspector" + ); + const node = await domWalkerFront.getNodeFromActor(this.actorID, [ + "rawAccessible", + "DOMNode", + ]); + // We are using DOM inspector/walker API here because we want to keep both + // the accessiblity tree and the DOM tree in sync. This is necessary for + // several features that the accessibility panel provides such as inspecting + // a corresponding DOM node or any other functionality that requires DOM + // node ancestries to be resolved all the way up to the top level document. + const { + nodes: [documentNodeFront], + } = await domWalkerFront.children(node); + const accessibilityFront = await documentNodeFront.targetFront.getFront( + "accessibility" + ); + + return accessibilityFront.accessibleWalkerFront.children(); + } + + /** + * Helper function that helps with building a complete snapshot of + * accessibility tree starting at the level of current accessible front. It + * accumulates subtrees from possible out of process frames that are children + * of the current accessible front. + * @param {JSON} snapshot + * Snapshot of the current accessible front or one of its in process + * children when recursing. + * + * @return {JSON} + * Complete snapshot of current accessible front. + */ + async _accumulateSnapshot(snapshot) { + const { childCount, useChildTargetToFetchChildren } = snapshot; + // No children, we are done. + if (childCount === 0) { + return snapshot; + } + + // If current accessible is not a remote frame, continue accumulating inside + // its children. + if (!useChildTargetToFetchChildren) { + const childSnapshots = []; + for (const childSnapshot of snapshot.children) { + childSnapshots.push(this._accumulateSnapshot(childSnapshot)); + } + await Promise.all(childSnapshots); + return snapshot; + } + + // When we have a remote frame, we need to obtain an accessible front for a + // remote frame document and retrieve its snapshot. + const inspectorFront = await this.targetFront.getFront("inspector"); + const frameNodeFront = + await inspectorFront.getNodeActorFromContentDomReference( + snapshot.contentDOMReference + ); + // Remove contentDOMReference and useChildTargetToFetchChildren properties. + delete snapshot.contentDOMReference; + delete snapshot.useChildTargetToFetchChildren; + if (!frameNodeFront) { + return snapshot; + } + + // Remote frame lives in the same process as the current accessible + // front we can retrieve the accessible front directly. + const frameAccessibleFront = await this.parentFront.getAccessibleFor( + frameNodeFront + ); + if (!frameAccessibleFront) { + return snapshot; + } + + const [docAccessibleFront] = await frameAccessibleFront.children(); + const childSnapshot = await docAccessibleFront.snapshot(); + snapshot.children.push(childSnapshot); + + return snapshot; + } + + /** + * Retrieves a complete JSON snapshot for an accessible subtree of a given + * accessible front (inclduing OOP frames). + */ + async snapshot() { + const snapshot = await super.snapshot(); + await this._accumulateSnapshot(snapshot); + return snapshot; + } +} + +class AccessibleWalkerFront extends FrontClassWithSpec(accessibleWalkerSpec) { + constructor(client, targetFront, parentFront) { + super(client, targetFront, parentFront); + + this.documentReady = this.documentReady.bind(this); + this.on("document-ready", this.documentReady); + } + + destroy() { + this.off("document-ready", this.documentReady); + super.destroy(); + } + + form(json) { + this.actorID = json.actor; + } + + documentReady() { + if (this.targetFront.isTopLevel) { + this.emit("top-level-document-ready"); + } + } + + pick(doFocus) { + if (doFocus) { + return this.pickAndFocus(); + } + + return super.pick(); + } + + /** + * Get the accessible object ancestry starting from the given accessible to + * the top level document. The top level document is in the top level content process. + * @param {Object} accessible + * Accessible front to determine the ancestry for. + * + * @return {Array} ancestry + * List of ancestry objects which consist of an accessible with its + * children. + */ + async getAncestry(accessible) { + const ancestry = await super.getAncestry(accessible); + + const parentTarget = await this.targetFront.getParentTarget(); + if (!parentTarget) { + return ancestry; + } + + // Get an accessible front for the parent frame. We go through the + // inspector's walker to keep both inspector and accessibility trees in + // sync. + const { walker: domWalkerFront } = await this.targetFront.getFront( + "inspector" + ); + const frameNodeFront = (await domWalkerFront.getRootNode()).parentNode(); + const accessibilityFront = await parentTarget.getFront("accessibility"); + const { accessibleWalkerFront } = accessibilityFront; + const frameAccessibleFront = await accessibleWalkerFront.getAccessibleFor( + frameNodeFront + ); + + if (!frameAccessibleFront) { + // Most likely we are inside a hidden frame. + return Promise.reject( + `Can't get the ancestry for an accessible front ${accessible.actorID}. It is in the detached tree.` + ); + } + + // Compose the final ancestry out of ancestry for the given accessible in + // the current process and recursively get the ancestry for the frame + // accessible. + ancestry.push( + { + accessible: frameAccessibleFront, + children: await frameAccessibleFront.children(), + }, + ...(await accessibleWalkerFront.getAncestry(frameAccessibleFront)) + ); + + return ancestry; + } + + /** + * Run an accessibility audit for a document that accessibility walker is + * responsible for (in process). In addition to plainly running an audit (in + * cases when the document is in the OOP frame), this method also updates + * relative ancestries of audited accessible objects all the way up to the top + * level document for the toolbox. + * @param {Object} options + * - {Array} types + * types of the accessibility issues to audit for + * - {Function} onProgress + * callback function for a progress audit-event + * - {Boolean} retrieveAncestries (defaults to true) + * Set to false to _not_ retrieve ancestries of audited accessible objects. + * This is used when a specific document is selected in the iframe picker + * and we want to treat it as the root of the accessibility panel tree. + */ + async audit({ types, onProgress, retrieveAncestries = true }) { + const onAudit = new Promise(resolve => { + const auditEventHandler = ({ type, ancestries, progress }) => { + switch (type) { + case "error": + this.off("audit-event", auditEventHandler); + resolve({ error: true }); + break; + case "completed": + this.off("audit-event", auditEventHandler); + resolve({ ancestries }); + break; + case "progress": + onProgress(progress); + break; + default: + break; + } + }; + + this.on("audit-event", auditEventHandler); + super.startAudit({ types }); + }); + + const audit = await onAudit; + // If audit resulted in an error, if there's nothing to report or if the callsite + // explicitly asked to not retrieve ancestries, we are done. + // (no need to check for ancestry across the remote frame hierarchy). + // See also https://bugzilla.mozilla.org/show_bug.cgi?id=1641551 why the rest of + // the code path is only supported when content toolbox fission is enabled. + if (audit.error || audit.ancestries.length === 0 || !retrieveAncestries) { + return audit; + } + + const parentTarget = await this.targetFront.getParentTarget(); + // If there is no parent target, we do not need to update ancestries as we + // are in the top level document. + if (!parentTarget) { + return audit; + } + + // Retrieve an ancestry (cross process) for a current root document and make + // audit report ancestries relative to it. + const [docAccessibleFront] = await this.children(); + let docAccessibleAncestry; + try { + docAccessibleAncestry = await this.getAncestry(docAccessibleFront); + } catch (e) { + // We are in a detached subtree. We do not consider this an error, instead + // we need to ignore the audit for this frame and return an empty report. + return { ancestries: [] }; + } + for (const ancestry of audit.ancestries) { + // Compose the final ancestries out of the ones in the audit report + // relative to this document and the ancestry of the document itself + // (cross process). + ancestry.push(...docAccessibleAncestry); + } + + return audit; + } + + /** + * A helper wrapper function to show tabbing order overlay for a given target. + * The only additional work done is resolving domnode front from a + * ContentDOMReference received from a remote target. + * + * @param {Object} startElm + * domnode front to be used as the starting point for generating the + * tabbing order. + * @param {Number} startIndex + * Starting index for the tabbing order. + */ + async _showTabbingOrder(startElm, startIndex) { + const { contentDOMReference, index } = await super.showTabbingOrder( + startElm, + startIndex + ); + let elm; + if (contentDOMReference) { + const inspectorFront = await this.targetFront.getFront("inspector"); + elm = await inspectorFront.getNodeActorFromContentDomReference( + contentDOMReference + ); + } + + return { elm, index }; + } + + /** + * Show tabbing order overlay for a given target. + * + * @param {Object} startElm + * domnode front to be used as the starting point for generating the + * tabbing order. + * @param {Number} startIndex + * Starting index for the tabbing order. + * + * @return {JSON} + * Tabbing order information for the last element in the tabbing + * order. It includes a domnode front and a tabbing index. If we are + * at the end of the tabbing order for the top level content document, + * the domnode front will be null. If focus manager discovered a + * remote IFRAME, then the domnode front is for the IFRAME itself. + */ + async showTabbingOrder(startElm, startIndex) { + let { elm: currentElm, index: currentIndex } = await this._showTabbingOrder( + startElm, + startIndex + ); + + // If no remote frames were found, currentElm will be null. + while (currentElm) { + // Safety check to ensure that the currentElm is a remote frame. + if (currentElm.useChildTargetToFetchChildren) { + const { walker: domWalkerFront } = + await currentElm.targetFront.getFront("inspector"); + const { + nodes: [childDocumentNodeFront], + } = await domWalkerFront.children(currentElm); + const { accessibleWalkerFront } = + await childDocumentNodeFront.targetFront.getFront("accessibility"); + // Show tabbing order in the remote target, while updating the tabbing + // index. + ({ index: currentIndex } = await accessibleWalkerFront.showTabbingOrder( + childDocumentNodeFront, + currentIndex + )); + } + + // Finished with the remote frame, continue in tabbing order, from the + // remote frame. + ({ elm: currentElm, index: currentIndex } = await this._showTabbingOrder( + currentElm, + currentIndex + )); + } + + return { elm: currentElm, index: currentIndex }; + } +} + +class AccessibilityFront extends FrontClassWithSpec(accessibilitySpec) { + constructor(client, targetFront, parentFront) { + super(client, targetFront, parentFront); + + this.before("init", this.init.bind(this)); + this.before("shutdown", this.shutdown.bind(this)); + + // Attribute name from which to retrieve the actorID out of the target + // actor's form + this.formAttributeName = "accessibilityActor"; + } + + async initialize() { + this.accessibleWalkerFront = await super.getWalker(); + this.simulatorFront = await super.getSimulator(); + const { enabled } = await super.bootstrap(); + this.enabled = enabled; + + try { + this._traits = await this.getTraits(); + } catch (e) { + // @backward-compat { version 84 } getTraits isn't available on older server. + this._traits = {}; + } + } + + get traits() { + return this._traits; + } + + init() { + this.enabled = true; + } + + shutdown() { + this.enabled = false; + } +} + +class ParentAccessibilityFront extends FrontClassWithSpec( + parentAccessibilitySpec +) { + constructor(client, targetFront, parentFront) { + super(client, targetFront, parentFront); + this.before("can-be-enabled-change", this.canBeEnabled.bind(this)); + this.before("can-be-disabled-change", this.canBeDisabled.bind(this)); + + // Attribute name from which to retrieve the actorID out of the target + // actor's form + this.formAttributeName = "parentAccessibilityActor"; + } + + async initialize() { + ({ canBeEnabled: this.canBeEnabled, canBeDisabled: this.canBeDisabled } = + await super.bootstrap()); + } + + canBeEnabled(canBeEnabled) { + this.canBeEnabled = canBeEnabled; + } + + canBeDisabled(canBeDisabled) { + this.canBeDisabled = canBeDisabled; + } +} + +const SimulatorFront = FrontClassWithSpec(simulatorSpec); + +exports.AccessibleFront = AccessibleFront; +registerFront(AccessibleFront); +exports.AccessibleWalkerFront = AccessibleWalkerFront; +registerFront(AccessibleWalkerFront); +exports.AccessibilityFront = AccessibilityFront; +registerFront(AccessibilityFront); +exports.ParentAccessibilityFront = ParentAccessibilityFront; +registerFront(ParentAccessibilityFront); +exports.SimulatorFront = SimulatorFront; +registerFront(SimulatorFront); |