1 files changed, 159 insertions, 0 deletions
diff --git a/remote/cdp/targets/TargetList.sys.mjs b/remote/cdp/targets/TargetList.sys.mjs
new file mode 100644
index 0000000000..a68b36763f
--- /dev/null
+++ b/remote/cdp/targets/TargetList.sys.mjs
@@ -0,0 +1,159 @@
+/* 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/. */
+
+const lazy = {};
+
+ChromeUtils.defineESModuleGetters(lazy, {
+  EventEmitter: "resource://gre/modules/EventEmitter.sys.mjs",
+
+  MainProcessTarget:
+    "chrome://remote/content/cdp/targets/MainProcessTarget.sys.mjs",
+  TabManager: "chrome://remote/content/shared/TabManager.sys.mjs",
+  TabObserver: "chrome://remote/content/cdp/observers/TargetObserver.sys.mjs",
+  TabTarget: "chrome://remote/content/cdp/targets/TabTarget.sys.mjs",
+});
+
+export class TargetList {
+  constructor() {
+    // Target ID -> Target
+    this._targets = new Map();
+
+    lazy.EventEmitter.decorate(this);
+  }
+
+  /**
+   * Start listing and listening for all the debuggable targets
+   */
+  async watchForTargets() {
+    await this.watchForTabs();
+  }
+
+  unwatchForTargets() {
+    this.unwatchForTabs();
+  }
+
+  /**
+   * Watch for all existing and new tabs being opened.
+   * So that we can create the related TabTarget instance for
+   * each of them.
+   */
+  async watchForTabs() {
+    if (this.tabObserver) {
+      throw new Error("Targets is already watching for new tabs");
+    }
+
+    this.tabObserver = new lazy.TabObserver({ registerExisting: true });
+
+    // Handle creation of tab targets for opened tabs.
+    this.tabObserver.on("open", async (eventName, tab) => {
+      const target = new lazy.TabTarget(this, tab.linkedBrowser);
+      this.registerTarget(target);
+    });
+
+    // Handle removal of tab targets when tabs are closed.
+    this.tabObserver.on("close", (eventName, tab) => {
+      const browser = tab.linkedBrowser;
+
+      // Ignore unloaded tabs.
+      if (browser.browserId === 0) {
+        return;
+      }
+
+      const id = lazy.TabManager.getIdForBrowser(browser);
+      const target = Array.from(this._targets.values()).find(
+        target => target.id == id
+      );
+      if (target) {
+        this.destroyTarget(target);
+      }
+    });
+    await this.tabObserver.start();
+  }
+
+  unwatchForTabs() {
+    if (this.tabObserver) {
+      this.tabObserver.stop();
+      this.tabObserver = null;
+    }
+  }
+
+  /**
+   * To be called right after instantiating a new Target instance.
+   * This will hold the new instance in the list and notify about
+   * its creation.
+   */
+  registerTarget(target) {
+    this._targets.set(target.id, target);
+    this.emit("target-created", target);
+  }
+
+  /**
+   * To be called when the debuggable target has been destroy.
+   * So that we can notify it no longer exists and disconnect
+   * all connecting made to debug it.
+   */
+  destroyTarget(target) {
+    target.destructor();
+    this._targets.delete(target.id);
+    this.emit("target-destroyed", target);
+  }
+
+  /**
+   * Destroy all the registered target of all kinds.
+   * This will end up dropping all connections made to debug any of them.
+   */
+  destructor() {
+    for (const target of this) {
+      this.destroyTarget(target);
+    }
+    this._targets.clear();
+    if (this.mainProcessTarget) {
+      this.mainProcessTarget = null;
+    }
+
+    this.unwatchForTargets();
+  }
+
+  get size() {
+    return this._targets.size;
+  }
+
+  /**
+   * Get Target instance by target id
+   *
+   * @param {string} id
+   *     Target id
+   *
+   * @returns {Target}
+   */
+  getById(id) {
+    return this._targets.get(id);
+  }
+
+  /**
+   * Get the Target instance for the main process.
+   * This target is a singleton and only exposes a subset of domains.
+   */
+  getMainProcessTarget() {
+    if (!this.mainProcessTarget) {
+      this.mainProcessTarget = new lazy.MainProcessTarget(this);
+      this.registerTarget(this.mainProcessTarget);
+    }
+    return this.mainProcessTarget;
+  }
+
+  *[Symbol.iterator]() {
+    for (const target of this._targets.values()) {
+      yield target;
+    }
+  }
+
+  toJSON() {
+    return [...this];
+  }
+
+  toString() {
+    return `[object TargetList ${this.size}]`;
+  }
+}