[Cast2Class] Add page handler for enterprise casting WebUI.

Stub implementation for the WebUI and page handler, to ensure we have
the mojom, WebUI, and page handler communicating correctly.
Additionally, add ChromeOS EDU team as OWNERS of the enterprise casting
resources folder.

Bug: b/193421383
Change-Id: I346203207f657b0ab1755cf46677749d6a916684
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3064083
Reviewed-by: calamity <calamity@chromium.org>
Reviewed-by: Brian Malcolm <bmalcolm@chromium.org>
Reviewed-by: Sam McNally <sammc@chromium.org>
Commit-Queue: Benjamin Zielinski <bzielinski@google.com>
Cr-Commit-Position: refs/heads/master@{#909038}

chrome/browser/resources/chromeos/enterprise_casting/BUILD.gn

@@ -2,31 +2,53 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
-import("//third_party/closure_compiler/compile_js.gni")
 import("//tools/grit/grit_rule.gni")
+import("//tools/polymer/html_to_js.gni")
+import("//tools/typescript/ts_library.gni")
 import("//ui/webui/resources/tools/generate_grd.gni")
 
 assert(is_chromeos, "enterprise_casting is Chrome OS only.")
 
-mojo_grdp_file = "$target_gen_dir/mojo_resources.grdp"
 resources_grd_file = "$target_gen_dir/resources.grd"
 
-generate_grd("build_mojo_grdp") {
-  input_files = [ "enterprise_casting.mojom-webui.js" ]
-  input_files_base_dir = rebase_path(
-          "${root_gen_dir}/mojom-webui/chrome/browser/ui/webui/chromeos/enterprise_casting",
-          "$root_build_dir")
+html_to_js("web_components") {
+  js_files = [ "enterprise_casting.ts" ]
+}
+
+copy("copy_browser_proxy") {
+  sources = [ "browser_proxy.ts" ]
+  outputs = [ "$target_gen_dir/{{source_file_part}}" ]
+}
+
+copy("copy_mojo") {
   deps = [ "//chrome/browser/ui/webui/chromeos/enterprise_casting:mojo_bindings_webui_js" ]
+  mojom_folder = "$root_gen_dir/mojom-webui/chrome/browser/ui/webui/chromeos/enterprise_casting/"
+  sources = [ "$mojom_folder/enterprise_casting.mojom-webui.js" ]
+  outputs = [ "$target_gen_dir/{{source_file_part}}" ]
+}
 
-  grd_prefix = "enterprise_casting"
-  out_grd = mojo_grdp_file
+ts_library("build_ts") {
+  deps = [ "//third_party/polymer/v3_0:library" ]
+  extra_deps = [
+    ":copy_browser_proxy",
+    ":copy_mojo",
+    ":web_components",
+  ]
+  root_dir = "$target_gen_dir"
+  out_dir = "$target_gen_dir/tsc"
+  tsconfig_base = "tsconfig_base.json"
+  in_files = [
+    "browser_proxy.ts",
+    "enterprise_casting.mojom-webui.js",
+    "enterprise_casting.ts",
+  ]
 }
 
 generate_grd("build_grd") {
   input_files = [ "index.html" ]
   input_files_base_dir = rebase_path(".", "//")
-  deps = [ ":build_mojo_grdp" ]
-  grdp_files = [ mojo_grdp_file ]
+  manifest_files = [ "$target_gen_dir/tsconfig.manifest" ]
+  deps = [ ":build_ts" ]
 
   grd_prefix = "enterprise_casting"
   out_grd = resources_grd_file

chrome/browser/resources/chromeos/enterprise_casting/OWNERS

@@ -0,0 +1,4 @@
+gbj@google.com
+bmalcolm@chromium.org
+bzielinski@google.com
+jacqueli@google.com

chrome/browser/resources/chromeos/enterprise_casting/browser_proxy.ts

@@ -0,0 +1,31 @@
+// Copyright 2021 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import {PageCallbackRouter, PageHandlerFactory, PageHandlerRemote} from './enterprise_casting.mojom-webui.js';
+
+export class BrowserProxy {
+  callbackRouter: PageCallbackRouter;
+  handler: PageHandlerRemote;
+
+  constructor() {
+    this.callbackRouter = new PageCallbackRouter();
+
+    this.handler = new PageHandlerRemote();
+
+    const factory = PageHandlerFactory.getRemote();
+    factory.createPageHandler(
+        this.callbackRouter.$.bindNewPipeAndPassRemote(),
+        this.handler.$.bindNewPipeAndPassReceiver());
+  }
+
+  static getInstance(): BrowserProxy {
+    return instance || (instance = new BrowserProxy());
+  }
+
+  static setInstance(obj: BrowserProxy) {
+    instance = obj;
+  }
+}
+
+let instance: BrowserProxy|null = null;

chrome/browser/resources/chromeos/enterprise_casting/enterprise_casting.html

@@ -0,0 +1,3 @@
+<h1>Cast Receiver</h1>
+<div id="castingPin">Casting PIN: [[pin]]</div>
+<button id="newPin" on-click="requestPin">Generate New PIN</button>

chrome/browser/resources/chromeos/enterprise_casting/enterprise_casting.ts

@@ -0,0 +1,58 @@
+// Copyright 2021 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import {html, PolymerElement} from 'chrome://resources/polymer/v3_0/polymer/polymer_bundled.min.js';
+
+import {BrowserProxy} from './browser_proxy.js';
+import {PageCallbackRouter} from './enterprise_casting.mojom-webui.js';
+
+class EnterpriseCastingElement extends PolymerElement {
+  static get is() {
+    return 'enterprise-casting';
+  }
+
+  static get template() {
+    return html`{__html_template__}`;
+  }
+
+  static get properties() {
+    return {
+      pin: String,
+    };
+  }
+
+  private pin: string;
+  private listenerIds: Array<number>;
+  private router: PageCallbackRouter;
+
+  constructor() {
+    super();
+    this.pin = '';
+    this.listenerIds = [];
+    this.router = BrowserProxy.getInstance().callbackRouter;
+  }
+
+  connectedCallback() {
+    super.connectedCallback();
+    this.listenerIds.push(
+        this.router.setPin.addListener(this.setPin.bind(this)));
+  }
+
+  disconnectedCallback() {
+    super.disconnectedCallback();
+    this.listenerIds.forEach(id => this.router.removeListener(id));
+  }
+
+  requestPin() {
+    BrowserProxy.getInstance().handler.updatePin();
+  }
+
+  private setPin(pin: string) {
+    if (this.pin != pin) {
+      this.pin = pin;
+    }
+  }
+}
+
+customElements.define(EnterpriseCastingElement.is, EnterpriseCastingElement);

chrome/browser/resources/chromeos/enterprise_casting/index.html

@@ -5,10 +5,11 @@
   <meta charset="utf-8">
   <title>Cast Receiver</title>
   <link rel="stylesheet" href="chrome://resources/css/text_defaults.css">
+  <script type="module" src="enterprise_casting.js"></script>
 </head>
 
 <body>
-  enterprise_casting Skeleton
+  <enterprise-casting></enterprise-casting>
 </body>
 
 </html>

chrome/browser/resources/chromeos/enterprise_casting/tsconfig_base.json

@@ -0,0 +1,6 @@
+{
+  "extends": "../../../../../tools/typescript/tsconfig_base.json",
+  "compilerOptions": {
+    "allowJs": true
+  }
+}

chrome/browser/ui/BUILD.gn

@@ -2351,6 +2351,8 @@ static_library("ui") {
       "webui/chromeos/emoji/emoji_page_handler.h",
       "webui/chromeos/emoji/emoji_ui.cc",
       "webui/chromeos/emoji/emoji_ui.h",
+      "webui/chromeos/enterprise_casting/enterprise_casting_handler.cc",
+      "webui/chromeos/enterprise_casting/enterprise_casting_handler.h",
       "webui/chromeos/enterprise_casting/enterprise_casting_ui.cc",
       "webui/chromeos/enterprise_casting/enterprise_casting_ui.h",
       "webui/chromeos/image_source.cc",

chrome/browser/ui/webui/chromeos/enterprise_casting/enterprise_casting.mojom

@@ -4,8 +4,22 @@
 
 module enterprise_casting.mojom;
 
-// Interface for creating enterprise_casting handlers. Implemented by the WebUI
-// controller and used by chrome://enterprise-casting.
+// Used by the WebUI page to bootstrap bidirectional communication.
 interface PageHandlerFactory {
-  // TODO(b/193421383): Add a CreatePageHandler method.
+  // The WebUI page's |BrowserProxy| singleton calls this method when the page
+  // is first initialized.
+  CreatePageHandler(pending_remote<Page> page,
+                    pending_receiver<PageHandler> handler);
+};
+
+// Browser-side handler for requests from WebUI page.
+interface PageHandler {
+  // Triggers a call to |SetPin|.
+  UpdatePin();
+};
+
+// WebUI-side handler for requests from the browser.
+interface Page {
+  // Sets the page with a new casting pin.
+  SetPin(string pin);
 };

chrome/browser/ui/webui/chromeos/enterprise_casting/enterprise_casting_handler.cc

@@ -0,0 +1,23 @@
+// Copyright 2021 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "chrome/browser/ui/webui/chromeos/enterprise_casting/enterprise_casting_handler.h"
+
+#include "base/rand_util.h"
+#include "base/strings/string_number_conversions.h"
+
+namespace chromeos {
+
+EnterpriseCastingHandler::EnterpriseCastingHandler(
+    mojo::PendingReceiver<enterprise_casting::mojom::PageHandler> page_handler,
+    mojo::PendingRemote<enterprise_casting::mojom::Page> page)
+    : page_(std::move(page)), receiver_(this, std::move(page_handler)) {}
+
+EnterpriseCastingHandler::~EnterpriseCastingHandler() = default;
+
+void EnterpriseCastingHandler::UpdatePin() {
+  page_->SetPin(base::NumberToString(base::RandInt(0, 9999)));
+}
+
+}  // namespace chromeos

chrome/browser/ui/webui/chromeos/enterprise_casting/enterprise_casting_handler.h

@@ -0,0 +1,34 @@
+// Copyright 2021 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CHROME_BROWSER_UI_WEBUI_CHROMEOS_ENTERPRISE_CASTING_ENTERPRISE_CASTING_HANDLER_H_
+#define CHROME_BROWSER_UI_WEBUI_CHROMEOS_ENTERPRISE_CASTING_ENTERPRISE_CASTING_HANDLER_H_
+
+#include "base/scoped_observation.h"
+#include "chrome/browser/ui/app_list/search/search_controller.h"
+#include "chrome/browser/ui/webui/chromeos/enterprise_casting/enterprise_casting.mojom.h"
+#include "mojo/public/cpp/bindings/pending_remote.h"
+#include "mojo/public/cpp/bindings/remote.h"
+
+namespace chromeos {
+
+class EnterpriseCastingHandler : public enterprise_casting::mojom::PageHandler {
+ public:
+  EnterpriseCastingHandler(
+      mojo::PendingReceiver<enterprise_casting::mojom::PageHandler>
+          page_handler,
+      mojo::PendingRemote<enterprise_casting::mojom::Page> page);
+  ~EnterpriseCastingHandler() override;
+
+  // enterprise_casting::mojom::PageHandler :
+  void UpdatePin() override;
+
+ private:
+  mojo::Remote<enterprise_casting::mojom::Page> page_;
+  mojo::Receiver<enterprise_casting::mojom::PageHandler> receiver_;
+};
+
+}  // namespace chromeos
+
+#endif  // CHROME_BROWSER_UI_WEBUI_CHROMEOS_ENTERPRISE_CASTING_ENTERPRISE_CASTING_HANDLER_H_

chrome/browser/ui/webui/chromeos/enterprise_casting/enterprise_casting_ui.cc

@@ -37,6 +37,15 @@ void EnterpriseCastingUI::BindInterface(
   factory_receiver_.Bind(std::move(receiver));
 }
 
+void EnterpriseCastingUI::CreatePageHandler(
+    mojo::PendingRemote<enterprise_casting::mojom::Page> page,
+    mojo::PendingReceiver<enterprise_casting::mojom::PageHandler> receiver) {
+  DCHECK(page);
+
+  page_handler_ = std::make_unique<EnterpriseCastingHandler>(
+      std::move(receiver), std::move(page));
+}
+
 WEB_UI_CONTROLLER_TYPE_IMPL(EnterpriseCastingUI)
 
 }  // namespace chromeos

chrome/browser/ui/webui/chromeos/enterprise_casting/enterprise_casting_ui.h

@@ -6,6 +6,7 @@
 #define CHROME_BROWSER_UI_WEBUI_CHROMEOS_ENTERPRISE_CASTING_ENTERPRISE_CASTING_UI_H_
 
 #include "chrome/browser/ui/webui/chromeos/enterprise_casting/enterprise_casting.mojom.h"
+#include "chrome/browser/ui/webui/chromeos/enterprise_casting/enterprise_casting_handler.h"
 #include "mojo/public/cpp/bindings/pending_receiver.h"
 #include "mojo/public/cpp/bindings/pending_remote.h"
 #include "mojo/public/cpp/bindings/receiver.h"
@@ -29,6 +30,13 @@ class EnterpriseCastingUI
           receiver);
 
  private:
+  // launcher_internals::mojom::PageHandlerFactory:
+  void CreatePageHandler(
+      mojo::PendingRemote<enterprise_casting::mojom::Page> page,
+      mojo::PendingReceiver<enterprise_casting::mojom::PageHandler>
+          page_handler) override;
+
+  std::unique_ptr<EnterpriseCastingHandler> page_handler_;
   mojo::Receiver<enterprise_casting::mojom::PageHandlerFactory>
       factory_receiver_{this};