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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-28 14:29:10 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-28 14:29:10 +0000
commit2aa4a82499d4becd2284cdb482213d541b8804dd (patch)
treeb80bf8bf13c3766139fbacc530efd0dd9d54394c /devtools/client/fronts/accessibility.js
parentInitial commit. (diff)
downloadfirefox-2aa4a82499d4becd2284cdb482213d541b8804dd.tar.xz
firefox-2aa4a82499d4becd2284cdb482213d541b8804dd.zip
Adding upstream version 86.0.1.upstream/86.0.1upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
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+/* 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("devtools/shared/protocol.js");
+const {
+ accessibleSpec,
+ accessibleWalkerSpec,
+ accessibilitySpec,
+ parentAccessibilitySpec,
+ simulatorSpec,
+} = require("devtools/shared/specs/accessibility");
+const events = require("devtools/shared/event-emitter");
+const Services = require("Services");
+const BROWSER_TOOLBOX_FISSION_ENABLED = Services.prefs.getBoolPref(
+ "devtools.browsertoolbox.fission",
+ false
+);
+
+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 remoteFrame() {
+ return BROWSER_TOOLBOX_FISSION_ENABLED && this._form.remoteFrame;
+ }
+
+ 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.remoteFrame) {
+ 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, remoteFrame } = 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 (!remoteFrame) {
+ 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 remoteFrame properties.
+ delete snapshot.contentDOMReference;
+ delete snapshot.remoteFrame;
+ 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. BROWSER_TOOLBOX_FISSION_ENABLED is false, the top
+ * level document is bound by current target's document. Otherwise, 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);
+ if (!BROWSER_TOOLBOX_FISSION_ENABLED) {
+ // Do not try to get the ancestry across the remote frame hierarchy.
+ return ancestry;
+ }
+
+ 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
+ */
+ async audit({ types, onProgress }) {
+ 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 or there's nothing to report, 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) {
+ 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.remoteFrame) {
+ 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);