Consume Mojo services directly in Blink's WebUSB implementation.

content/renderer/usb/web_usb_client_impl.cc

-// Copyright 2015 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 "content/renderer/usb/web_usb_client_impl.h"
-
-#include <stddef.h>
-
-#include <memory>
-#include <utility>
-
-#include "base/bind.h"
-#include "base/callback.h"
-#include "base/memory/ptr_util.h"
-#include "base/move.h"
-#include "base/strings/utf_string_conversions.h"
-#include "content/child/mojo/type_converters.h"
-#include "content/child/scoped_web_callbacks.h"
-#include "content/public/common/service_registry.h"
-#include "content/renderer/usb/type_converters.h"
-#include "content/renderer/usb/web_usb_device_impl.h"
-#include "mojo/public/cpp/bindings/array.h"
-#include "mojo/public/cpp/bindings/interface_request.h"
-#include "third_party/WebKit/public/platform/WebCallbacks.h"
-#include "third_party/WebKit/public/platform/modules/webusb/WebUSBDeviceFilter.h"
-#include "third_party/WebKit/public/platform/modules/webusb/WebUSBDeviceInfo.h"
-#include "third_party/WebKit/public/platform/modules/webusb/WebUSBDeviceRequestOptions.h"
-#include "third_party/WebKit/public/platform/modules/webusb/WebUSBError.h"
-
-namespace content {
-
-namespace {
-
-const char kNoServiceError[] = "USB service unavailable.";
-
-// Generic default rejection handler for any WebUSB callbacks type. Assumes
-// |CallbacksType| is a blink::WebCallbacks<T, const blink::WebUSBError&>
-// for any type |T|.
-template <typename CallbacksType>
-void RejectCallbacksWithError(const blink::WebUSBError& error,
-                              std::unique_ptr<CallbacksType> callbacks) {
-  callbacks->onError(error);
-}
-
-// Create a new ScopedWebCallbacks for WebUSB client callbacks, defaulting to
-// a "no service" rejection.
-template <typename CallbacksType>
-ScopedWebCallbacks<CallbacksType> MakeScopedUSBCallbacks(
-    CallbacksType* callbacks) {
-  return make_scoped_web_callbacks(
-      callbacks,
-      base::Bind(&RejectCallbacksWithError<CallbacksType>,
-                 blink::WebUSBError(blink::WebUSBError::Error::NotFound,
-                                    base::ASCIIToUTF16(kNoServiceError))));
-}
-
-void OnGetDevicesComplete(
-    ScopedWebCallbacks<blink::WebUSBClientGetDevicesCallbacks> scoped_callbacks,
-    device::usb::DeviceManager* device_manager,
-    mojo::Array<device::usb::DeviceInfoPtr> results) {
-  // TODO(dcheng): This WebVector should hold smart pointers.
-  std::unique_ptr<blink::WebVector<blink::WebUSBDevice*>> devices(
-      new blink::WebVector<blink::WebUSBDevice*>(results.size()));
-  for (size_t i = 0; i < results.size(); ++i) {
-    device::usb::DevicePtr device;
-    device_manager->GetDevice(results[i]->guid, mojo::GetProxy(&device));
-    (*devices)[i] = new WebUSBDeviceImpl(
-        std::move(device),
-        mojo::ConvertTo<blink::WebUSBDeviceInfo>(results[i]));
-  }
-  scoped_callbacks.PassCallbacks()->onSuccess(std::move(devices));
-}
-
-void OnRequestDevicesComplete(
-    ScopedWebCallbacks<blink::WebUSBClientRequestDeviceCallbacks> callbacks,
-    device::usb::DeviceManager* device_manager,
-    device::usb::DeviceInfoPtr result) {
-  auto scoped_callbacks = callbacks.PassCallbacks();
-  if (result) {
-    device::usb::DevicePtr device;
-    device_manager->GetDevice(result->guid, mojo::GetProxy(&device));
-    std::unique_ptr<blink::WebUSBDevice> web_usb_device(new WebUSBDeviceImpl(
-        std::move(device), mojo::ConvertTo<blink::WebUSBDeviceInfo>(result)));
-
-    scoped_callbacks->onSuccess(std::move(web_usb_device));
-  } else {
-    scoped_callbacks->onError(
-        blink::WebUSBError(blink::WebUSBError::Error::NotFound,
-                           base::ASCIIToUTF16("No device selected.")));
-  }
-}
-
-}  // namespace
-
-WebUSBClientImpl::WebUSBClientImpl(content::ServiceRegistry* service_registry)
-    : service_registry_(service_registry) {}
-
-WebUSBClientImpl::~WebUSBClientImpl() {}
-
-void WebUSBClientImpl::getDevices(
-    blink::WebUSBClientGetDevicesCallbacks* callbacks) {
-  auto scoped_callbacks = MakeScopedUSBCallbacks(callbacks);
-  GetDeviceManager()->GetDevices(
-      nullptr,
-      base::Bind(&OnGetDevicesComplete, base::Passed(&scoped_callbacks),
-                 base::Unretained(device_manager_.get())));
-}
-
-void WebUSBClientImpl::requestDevice(
-    const blink::WebUSBDeviceRequestOptions& options,
-    blink::WebUSBClientRequestDeviceCallbacks* callbacks) {
-  if (!chooser_service_) {
-    service_registry_->ConnectToRemoteService(
-        mojo::GetProxy(&chooser_service_));
-  }
-
-  auto scoped_callbacks = MakeScopedUSBCallbacks(callbacks);
-
-  mojo::Array<device::usb::DeviceFilterPtr> device_filters =
-      mojo::Array<device::usb::DeviceFilterPtr>::From(options.filters);
-
-  chooser_service_->GetPermission(
-      std::move(device_filters),
-      base::Bind(&OnRequestDevicesComplete, base::Passed(&scoped_callbacks),
-                 base::Unretained(device_manager_.get())));
-}
-
-void WebUSBClientImpl::addObserver(Observer* observer) {
-  if (observers_.empty()) {
-    // Set up two sequential calls to GetDeviceChanges to avoid latency.
-    device::usb::DeviceManager* device_manager = GetDeviceManager();
-    device_manager->GetDeviceChanges(base::Bind(
-        &WebUSBClientImpl::OnDeviceChangeNotification, base::Unretained(this)));
-    device_manager->GetDeviceChanges(base::Bind(
-        &WebUSBClientImpl::OnDeviceChangeNotification, base::Unretained(this)));
-  }
-
-  observers_.insert(observer);
-}
-
-void WebUSBClientImpl::removeObserver(Observer* observer) {
-  DCHECK(ContainsKey(observers_, observer));
-  observers_.erase(observer);
-}
-
-device::usb::DeviceManager* WebUSBClientImpl::GetDeviceManager() {
-  if (!device_manager_)
-    service_registry_->ConnectToRemoteService(mojo::GetProxy(&device_manager_));
-  return device_manager_.get();
-}
-
-void WebUSBClientImpl::OnDeviceChangeNotification(
-    device::usb::DeviceChangeNotificationPtr notification) {
-  if (observers_.empty())
-    return;
-
-  device_manager_->GetDeviceChanges(base::Bind(
-      &WebUSBClientImpl::OnDeviceChangeNotification, base::Unretained(this)));
-  for (size_t i = 0; i < notification->devices_added.size(); ++i) {
-    const device::usb::DeviceInfoPtr& device_info =
-        notification->devices_added[i];
-    for (auto observer : observers_) {
-      device::usb::DevicePtr device;
-      device_manager_->GetDevice(device_info->guid, mojo::GetProxy(&device));
-      observer->onDeviceConnected(base::WrapUnique(new WebUSBDeviceImpl(
-          std::move(device),
-          mojo::ConvertTo<blink::WebUSBDeviceInfo>(device_info))));
-    }
-  }
-  for (size_t i = 0; i < notification->devices_removed.size(); ++i) {
-    const device::usb::DeviceInfoPtr& device_info =
-        notification->devices_removed[i];
-    for (auto observer : observers_)
-      observer->onDeviceDisconnected(base::WrapUnique(new WebUSBDeviceImpl(
-          nullptr, mojo::ConvertTo<blink::WebUSBDeviceInfo>(device_info))));
-  }
-}
-
-}  // namespace content