chrome/blink: Add functionality for in-product help for media elements.

chrome/browser/android/media_iph_manager.cc

+// Copyright 2017 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/android/media_iph_manager.h"
+
+#include "base/memory/ptr_util.h"
+#include "base/optional.h"
+#include "content/public/browser/navigation_handle.h"
+#include "content/public/browser/render_frame_host.h"
+#include "content/public/browser/render_widget_host_view.h"
+#include "mojo/public/cpp/bindings/strong_binding.h"
+#include "services/service_manager/public/cpp/bind_source_info.h"
+#include "services/service_manager/public/cpp/interface_provider.h"
+
+namespace {
+
+void SendDismissUIToRenderer(content::RenderFrameHost* render_frame_host) {
+  chrome::mojom::MediaIPHDelegateServicePtr delegate_service;
+  render_frame_host->GetRemoteInterfaces()->GetInterface(&delegate_service);
+  delegate_service->WidgetDismissed();
+}
+
+}  // namespace
+
+class MediaIPHManager::MediaIPHService : public chrome::mojom::MediaIPHService {
+ public:
+  MediaIPHService(content::RenderFrameHost* render_frame_host,
+                  MediaIPHManager* manager)
+      : render_frame_host_(render_frame_host), manager_(manager) {
+    DCHECK(render_frame_host_);
+    DCHECK(manager_);
+  }
+  ~MediaIPHService() override = default;
+
+  // chrome::mojom::MediaPromoUI implementation.
+  void ShowIPHWidget(const gfx::Rect& button_rect, bool new_request) override {
+    manager_->ShowIPHWidget(render_frame_host_, button_rect, new_request);
+  }
+
+  void HideIPHWidget() override { manager_->HideIPHWidget(render_frame_host_); }
+
+ private:
+  content::RenderFrameHost* render_frame_host_;
+  MediaIPHManager* manager_;
+};
+
+MediaIPHManager::MediaIPHManager(content::WebContents* web_contents,
+                                 MediaIPHManagerClient* client)
+    : WebContentsObserver(web_contents), client_(client), weak_factory_(this) {
+  DCHECK(client_);
+}
+
+MediaIPHManager::~MediaIPHManager() {
+  if (active_render_frame_host_) {
+    client_->DismissMediaDownloadIPH();
+  }
+}
+
+void MediaIPHManager::WidgetDismissed() {
+  DCHECK(active_render_frame_host_);
+
+  SendDismissUIToRenderer(active_render_frame_host_);
+  active_render_frame_host_ = nullptr;
+}
+
+void MediaIPHManager::RenderFrameCreated(
+    content::RenderFrameHost* render_frame_host) {
+  // Register the bridge service for the renderer to request showing the UI.
+  render_frame_host->GetInterfaceRegistry()->AddInterface(
+      base::Bind(&MediaIPHManager::CreateIPHService, weak_factory_.GetWeakPtr(),
+                 render_frame_host));
+}
+
+void MediaIPHManager::RenderFrameDeleted(
+    content::RenderFrameHost* render_frame_host) {
+  if (active_render_frame_host_ != render_frame_host)
+    return;
+  client_->DismissMediaDownloadIPH();
+}
+
+void MediaIPHManager::CreateIPHService(
+    content::RenderFrameHost* render_frame_host,
+    const service_manager::BindSourceInfo& source_info,
+    chrome::mojom::MediaIPHServiceRequest request) {
+  mojo::MakeStrongBinding(
+      base::MakeUnique<MediaIPHService>(render_frame_host, this),
+      std::move(request));
+}
+
+void MediaIPHManager::ShowIPHWidget(content::RenderFrameHost* render_frame_host,
+                                    const gfx::Rect& rect_in_main_frame,
+                                    bool new_request) {
+  if (active_render_frame_host_ &&
+      active_render_frame_host_ != render_frame_host) {
+    // If we are currently showing the UI for another frame, inform the
+    // requesting frame that the widget can not be shown.
+    SendDismissUIToRenderer(render_frame_host);
+    return;
+  }
+
+  if (!active_render_frame_host_) {
+    // We might have dismissed the widget while this update was in flight.
+    if (!new_request)
+      return;
+
+    // If we don't want to show the IPH for this button, inform the renderer.
+    if (!client_->ShowMediaDownloadIPH()) {
+      SendDismissUIToRenderer(render_frame_host);
+      return;
+    }
+
+    active_render_frame_host_ = render_frame_host;
+  }
+
+  client_->UpdateMediaDownloadIPHPosition(rect_in_main_frame);
+}
+
+void MediaIPHManager::HideIPHWidget(
+    content::RenderFrameHost* render_frame_host) {
+  // We might have dismissed the widget for this frame already.
+  if (active_render_frame_host_ != render_frame_host)
+    return;
+  client_->DismissMediaDownloadIPH();
+}