1 files changed, 130 insertions, 0 deletions
diff --git a/devtools/server/actors/accessibility/accessibility.js b/devtools/server/actors/accessibility/accessibility.js
new file mode 100644
index 0000000000..6bdf0e9f32
--- /dev/null
+++ b/devtools/server/actors/accessibility/accessibility.js
@@ -0,0 +1,130 @@
+/* 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 { Actor } = require("resource://devtools/shared/protocol.js");
+const {
+  accessibilitySpec,
+} = require("resource://devtools/shared/specs/accessibility.js");
+
+loader.lazyRequireGetter(
+  this,
+  "AccessibleWalkerActor",
+  "resource://devtools/server/actors/accessibility/walker.js",
+  true
+);
+loader.lazyRequireGetter(
+  this,
+  "SimulatorActor",
+  "resource://devtools/server/actors/accessibility/simulator.js",
+  true
+);
+
+/**
+ * The AccessibilityActor is a top level container actor that initializes
+ * accessible walker and is the top-most point of interaction for accessibility
+ * tools UI for a top level content process.
+ */
+class AccessibilityActor extends Actor {
+  constructor(conn, targetActor) {
+    super(conn, accessibilitySpec);
+    // This event is fired when accessibility service is initialized or shut
+    // down. "init" and "shutdown" events are only relayed when the enabled
+    // state matches the event (e.g. the event came from the same process as
+    // the actor).
+    Services.obs.addObserver(this, "a11y-init-or-shutdown");
+    this.targetActor = targetActor;
+  }
+
+  getTraits() {
+    // The traits are used to know if accessibility actors support particular
+    // API on the server side.
+    return {
+      // @backward-compat { version 84 } Fixed on the server by Bug 1654956.
+      tabbingOrder: true,
+    };
+  }
+
+  bootstrap() {
+    return {
+      enabled: this.enabled,
+    };
+  }
+
+  get enabled() {
+    return Services.appinfo.accessibilityEnabled;
+  }
+
+  /**
+   * Observe Accessibility service init and shutdown events. It relays these
+   * events to AccessibilityFront if the event is fired for the a11y service
+   * that lives in the same process.
+   *
+   * @param  {null} subject
+   *         Not used.
+   * @param  {String} topic
+   *         Name of the a11y service event: "a11y-init-or-shutdown".
+   * @param  {String} data
+   *         "0" corresponds to shutdown and "1" to init.
+   */
+  observe(subject, topic, data) {
+    const enabled = data === "1";
+    if (enabled && this.enabled) {
+      this.emit("init");
+    } else if (!enabled && !this.enabled) {
+      if (this.walker) {
+        this.walker.reset();
+      }
+
+      this.emit("shutdown");
+    }
+  }
+
+  /**
+   * Get or create AccessibilityWalker actor, similar to WalkerActor.
+   *
+   * @return {Object}
+   *         AccessibleWalkerActor for the current tab.
+   */
+  getWalker() {
+    if (!this.walker) {
+      this.walker = new AccessibleWalkerActor(this.conn, this.targetActor);
+      this.manage(this.walker);
+    }
+    return this.walker;
+  }
+
+  /**
+   * Get or create Simulator actor, managed by AccessibilityActor,
+   * only if webrender is enabled. Simulator applies color filters on an entire
+   * viewport. This needs to be done using webrender and not an SVG
+   * <feColorMatrix> since it is accelerated and scrolling with filter applied
+   * needs to be smooth (Bug1431466).
+   *
+   * @return {Object|null}
+   *         SimulatorActor for the current tab.
+   */
+  getSimulator() {
+    if (!this.simulator) {
+      this.simulator = new SimulatorActor(this.conn, this.targetActor);
+      this.manage(this.simulator);
+    }
+
+    return this.simulator;
+  }
+
+  /**
+   * Destroy accessibility actor. This method also shutsdown accessibility
+   * service if possible.
+   */
+  async destroy() {
+    super.destroy();
+    Services.obs.removeObserver(this, "a11y-init-or-shutdown");
+    this.walker = null;
+    this.targetActor = null;
+  }
+}
+
+exports.AccessibilityActor = AccessibilityActor;