Add Chrome To Mobile Service and Views Page Action.

chrome/browser/chrome_to_mobile_service.cc

+// Copyright (c) 2012 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/chrome_to_mobile_service.h"
+
+#include "base/bind.h"
+#include "base/json/json_writer.h"
+#include "base/stringprintf.h"
+#include "base/utf_string_conversions.h"
+#include "base/values.h"
+#include "chrome/app/chrome_command_ids.h"
+#include "chrome/common/cloud_print/cloud_print_helpers.h"

[Scott Byer, 2012/03/12 23:26:23]

Put in alphabetical order.

[msw, 2012/03/13 02:39:14]

Done.

+#include "chrome/browser/printing/cloud_print/cloud_print_url.h"
+#include "chrome/browser/profiles/profile.h"
+#include "chrome/browser/signin/token_service.h"
+#include "chrome/browser/signin/token_service_factory.h"
+#include "chrome/browser/ui/browser.h"
+#include "chrome/browser/ui/browser_list.h"
+#include "chrome/common/guid.h"
+#include "chrome/common/net/gaia/gaia_urls.h"
+#include "chrome/common/net/gaia/oauth2_access_token_fetcher.h"
+#include "content/public/browser/browser_thread.h"
+#include "content/public/browser/web_contents.h"
+#include "content/public/common/url_fetcher.h"
+#include "net/base/escape.h"
+#include "net/base/load_flags.h"
+#include "net/url_request/url_request_context_getter.h"
+
+namespace {
+
+// The maximum number of retries for the URLFetcher requests.
+size_t kMaxRetries = 10;
+
+// Seconds between automatically retrying authentication (on failure).
+int kAuthRetryDelay = 30;
+
+// Seconds between automatically updating the mobile device list.
+int kAutoSearchRetryDelay = 300;
+
+// The cloud print Oath2 scope and 'printer' type of compatible mobile devices.
+const char kOAuth2Scope[] = "https://www.googleapis.com/auth/cloudprint";
+const char kTypeAndroidChromeSnapshot[] = "ANDROID_CHROME_SNAPSHOT";
+
+// The types of Chrome To Mobile requests sent to the cloud print service.
+const char kRequestTypeURL[] = "url";
+const char kRequestTypeDelayedSnapshot[] = "url_with_delayed_snapshot";
+const char kRequestTypeSnapshot[] = "snapshot";
+
+// The snapshot path constants; used with a guid for each MHTML snapshot file.
+const FilePath::CharType kSnapshotPath[] =
+    FILE_PATH_LITERAL("chrome_to_mobile_snapshot_.mht");
+
+// Get the "__c2dm__job_data" tag JSON data for the cloud print job submission.
+std::string GetJobString(const ChromeToMobileService::RequestData& data) {
+  scoped_ptr<DictionaryValue> job(new DictionaryValue());
+  job->SetString("url", data.url.spec());
+  if (data.type == ChromeToMobileService::URL) {
+    job->SetString("type", kRequestTypeURL);
+  } else {
+    job->SetString("snapID", data.snapshot_id);
+    job->SetString("type", (data.type == ChromeToMobileService::SNAPSHOT) ?
+        kRequestTypeSnapshot : kRequestTypeDelayedSnapshot);
+  }
+  std::string job_string;
+  base::JSONWriter::Write(job.get(), false, &job_string);
+  return job_string;
+}
+
+// Get the URL for cloud print job submission; appends query params if needed.
+GURL GetSubmitURL(GURL service_url,
+                  const ChromeToMobileService::RequestData& data) {
+  GURL submit_url = cloud_print::GetUrlForSubmit(service_url);
+  if (data.type == ChromeToMobileService::SNAPSHOT)
+    return submit_url;
+
+  // Append form data to the URL's query for |URL| and |DELAYED_SNAPSHOT| jobs.
+  static const bool kUsePlus = true;
+  std::string tag_string = net::EscapeQueryParamValue(
+      "__c2dm__job_data=" + GetJobString(data), kUsePlus);
+  GURL::Replacements replacements;
+  // Provide dummy content to workaround |errorCode| 412 'Document missing'.
+  std::string query = StringPrintf("printerid=%s&tag=%s&title=%s"
+      "&contentType=text/plain&content=dummy",
+      net::EscapeQueryParamValue(UTF16ToUTF8(data.mobile_id), kUsePlus).c_str(),
+      net::EscapeQueryParamValue(tag_string, kUsePlus).c_str(),
+      net::EscapeQueryParamValue(UTF16ToUTF8(data.title), kUsePlus).c_str());
+  replacements.SetQueryStr(query);
+  return submit_url.ReplaceComponents(replacements);
+}
+
+// Delete the specified file; called as a BlockingPoolTask.
+void DeleteFilePath(const FilePath& file_path) {
+  bool success = file_util::Delete(file_path, false);
+  DCHECK(success);
+}
+
+// Construct POST data and submit the MHTML snapshot file; deletes the snapshot.
+void SubmitSnapshot(content::URLFetcher* request,
+                    const ChromeToMobileService::RequestData& data) {
+  std::string file;
+  if (file_util::ReadFileToString(data.snapshot_path, &file) && !file.empty()) {
+    std::string post_data, mime_boundary;
+    cloud_print::CreateMimeBoundaryForUpload(&mime_boundary);
+    cloud_print::AddMultipartValueForUpload("printerid",
+        UTF16ToUTF8(data.mobile_id), mime_boundary, std::string(), &post_data);
+    cloud_print::AddMultipartValueForUpload("tag", "__c2dm__job_data=" +
+        GetJobString(data), mime_boundary, std::string(), &post_data);
+    cloud_print::AddMultipartValueForUpload("title", UTF16ToUTF8(data.title),
+        mime_boundary, std::string(), &post_data);
+    cloud_print::AddMultipartValueForUpload("contentType", "multipart/related",
+        mime_boundary, std::string(), &post_data);
+
+    // Append the snapshot MHTML content and terminate the request body.
+    post_data.append("--" + mime_boundary + "\r\n"
+        "Content-Disposition: form-data; "
+        "name=\"content\"; filename=\"blob\"\r\n"
+        "Content-Type: text/mhtml\r\n"
+        "\r\n" + file + "\r\n" "--" + mime_boundary + "--\r\n");
+    std::string content_type = "multipart/form-data; boundary=" + mime_boundary;
+    request->SetUploadData(content_type, post_data);
+    request->Start();
+  }
+
+  content::BrowserThread::PostBlockingPoolTask(FROM_HERE,
+      base::Bind(&DeleteFilePath, data.snapshot_path));
+}
+
+}  // namespace
+
+ChromeToMobileService::RequestData::RequestData() {}
+
+ChromeToMobileService::RequestData::~RequestData() {}
+
+ChromeToMobileService::ChromeToMobileService(Profile* profile)
+    : profile_(profile),
+      cloud_print_url_(new CloudPrintURL(profile)),
+      oauth2_retry_count_(0) {
+  content::BrowserThread::PostBlockingPoolTask(FROM_HERE,
+      base::Bind(&ChromeToMobileService::CreateUniqueTempDir,
+                 base::Unretained(this)));
+  RequestMobileListUpdate();
+}
+
+ChromeToMobileService::~ChromeToMobileService() {}
+
+void ChromeToMobileService::OnURLFetchComplete(
+    const content::URLFetcher* source) {
+  if (source == search_request_.get())
+    HandleSearchResponse();
+  else
+    HandleSubmitResponse(source);
+}
+
+void ChromeToMobileService::OnGetTokenSuccess(
+    const std::string& access_token) {
+  oauth2_request_.reset();
+  request_timer_.Stop();
+  oauth2_token_ = access_token;
+  RequestSearch();
+}
+
+void ChromeToMobileService::OnGetTokenFailure(
+    const GoogleServiceAuthError& error) {
+  oauth2_request_.reset();
+  if (request_timer_.IsRunning() || (oauth2_retry_count_++ > kMaxRetries))
+    return;
+  request_timer_.Start(FROM_HERE, base::TimeDelta::FromSeconds(kAuthRetryDelay),
+                       this, &ChromeToMobileService::RequestAuth);
+}
+
+void ChromeToMobileService::RequestMobileListUpdate() {
+  if (oauth2_token_.empty())
+    RequestAuth();
+  else
+    RequestSearch();
+}
+
+void ChromeToMobileService::GenerateSnapshot(base::WeakPtr<Observer> observer) {
+  FilePath path(temp_dir_.path().Append(kSnapshotPath));
+    BrowserList::GetLastActiveWithProfile(profile_)->GetSelectedWebContents()->
+      GenerateMHTML(path.InsertBeforeExtensionASCII(guid::GenerateGUID()),
+                    base::Bind(&Observer::SnapshotGenerated, observer));
+}
+
+void ChromeToMobileService::SendToMobile(const string16& mobile_id,
+                                         const FilePath& snapshot,
+                                         base::WeakPtr<Observer> observer) {
+  DCHECK(!oauth2_token_.empty());
+  RequestData data;
+  data.mobile_id = mobile_id;
+  content::WebContents* web_contents =
+      BrowserList::GetLastActiveWithProfile(profile_)->GetSelectedWebContents();
+  data.url = web_contents->GetURL();
+  data.title = web_contents->GetTitle();
+  data.snapshot_path = snapshot;
+  bool send_snapshot = !snapshot.empty();
+  data.snapshot_id = send_snapshot ? guid::GenerateGUID() : std::string();
+  data.type = send_snapshot ? DELAYED_SNAPSHOT : URL;
+
+  content::URLFetcher* submit_url = CreateRequest(data);

[nyquist, 2012/03/13 00:52:23]

Nit: This naming seems odd to me. submit_request?

[msw, 2012/03/13 02:39:14]

Talked offline: submit_url corresponds with submit_snapshot.

+  request_observer_map_[submit_url] = observer;
+  submit_url->Start();
+
+  if (send_snapshot) {
+    data.type = SNAPSHOT;
+    content::URLFetcher* submit_snapshot = CreateRequest(data);
+    request_observer_map_[submit_snapshot] = observer;
+    content::BrowserThread::PostBlockingPoolTask(FROM_HERE,
+      base::Bind(&SubmitSnapshot, submit_snapshot, data));
+  }
+}
+
+void ChromeToMobileService::CreateUniqueTempDir() {
+  bool success = temp_dir_.CreateUniqueTempDir();
+  DCHECK(success);
+}
+
+content::URLFetcher* ChromeToMobileService::CreateRequest(
+  const RequestData& data) {
+  bool get = data.type != SNAPSHOT;
+  GURL service_url(cloud_print_url_->GetCloudPrintServiceURL());
+  content::URLFetcher* request = content::URLFetcher::Create(
+      data.type == SEARCH ? cloud_print::GetUrlForSearch(service_url) :
+                            GetSubmitURL(service_url, data),
+      get ? content::URLFetcher::GET : content::URLFetcher::POST, this);
+  request->SetRequestContext(profile_->GetRequestContext());
+  request->SetMaxRetries(kMaxRetries);
+  request->SetExtraRequestHeaders("Authorization: OAuth " +
+      oauth2_token_ + "\r\n" + cloud_print::kChromeCloudPrintProxyHeader);
+  request->SetLoadFlags(net::LOAD_DO_NOT_SEND_COOKIES |
+                        net::LOAD_DO_NOT_SAVE_COOKIES);
+  return request;
+}
+
+void ChromeToMobileService::RequestAuth() {
+  DCHECK(oauth2_token_.empty());
+  if (oauth2_request_.get())
+    return;
+
+  GURL auth_url = cloud_print::GetUrlForGetAuthCode(

[nyquist, 2012/03/13 00:52:23]

Dead store. This doesn't seem to be used anywhere.

[msw, 2012/03/13 02:39:14]

Awesome catch! This let me revert some CloudPrint changes:
GetUrlForGetAuthCode, kDefaultCloudPrintOAuthClientId, & GenerateProxyId.

+      cloud_print_url_->GetCloudPrintServiceURL(),
+      cloud_print::kDefaultCloudPrintOAuthClientId,
+      cloud_print::GenerateProxyId());
+  oauth2_request_.reset(
+      new OAuth2AccessTokenFetcher(this, profile_->GetRequestContext()));
+  std::string token = TokenServiceFactory::GetForProfile(profile_)->
+                          GetOAuth2LoginRefreshToken();
+  std::vector<std::string> scopes(1, kOAuth2Scope);
+  oauth2_request_->Start(GaiaUrls::GetInstance()->oauth2_chrome_client_id(),
+      GaiaUrls::GetInstance()->oauth2_chrome_client_secret(), token, scopes);
+}
+
+void ChromeToMobileService::RequestSearch() {
+  DCHECK(!oauth2_token_.empty());
+  if (search_request_.get())
+    return;
+
+  RequestData data;
+  data.type = SEARCH;
+  search_request_.reset(CreateRequest(data));
+  search_request_->Start();
+}
+
+void ChromeToMobileService::HandleSearchResponse() {
+  std::string data;
+  search_request_->GetResponseAsString(&data);
+  search_request_.reset();
+
+  DictionaryValue* json_data = NULL;
+  ListValue* list = NULL;
+  cloud_print::ParseResponseJSON(data, NULL, &json_data);
+  if (json_data && json_data->GetList(cloud_print::kPrinterListValue, &list)) {
+    mobiles_.clear();

[nyquist, 2012/03/13 00:52:23]

Updating this list directly means that clients might get an empty list (or
partly filled), since there seems to be no thread safety between
HandleSearchResponse and retreiving the list of mobiles_.
Could we somewhere make it clear that this service can only be called from the
browser thread (if that is the case)? Or is that implicit given something else?

[msw, 2012/03/13 02:39:14]

I'll gladly take additional thread safety advice, but this should be ok.

I added a precautionary UI thread DCHECK above, ensuring the list is built on
the UI thread (should be the case as the URLFetcher requests are created and
sent by UI inits and updates, and URLFetcher calls back handlers on the same
thread, see doc). |mobiles()| is accessed via LocationBarView::Init|Update and
ChromeToMobileBubbleView::Init; these are also on the UI thread.

I also changed the in-place list building to use a local temp vector and
assignment, to avoid (but not resolve) potential simultaneous thread access in
future iterations of the code.

+    for (size_t index = 0; index < list->GetSize(); index++) {
+      DictionaryValue* mobile_data = NULL;
+      if (list->GetDictionary(index, &mobile_data)) {
+        std::string mobile_type;
+        mobile_data->GetString("type", &mobile_type);
+        if (mobile_type.compare(kTypeAndroidChromeSnapshot) == 0)
+          mobiles_.push_back(mobile_data);
+      }
+    }
+  }
+
+  BrowserList::GetLastActiveWithProfile(profile_)->command_updater()->
+      UpdateCommandEnabled(IDC_CHROME_TO_MOBILE_PAGE, !mobiles_.empty());
+
+  if (!request_timer_.IsRunning())
+    request_timer_.Start(FROM_HERE,
+                         base::TimeDelta::FromSeconds(kAutoSearchRetryDelay),
+                         this, &ChromeToMobileService::RequestSearch);
+}
+
+void ChromeToMobileService::HandleSubmitResponse(
+    const content::URLFetcher* source) {
+  // Get the observer for this response; bail if there is none or it is NULL.
+  RequestObserverMap::iterator i = request_observer_map_.find(source);
+  if (i == request_observer_map_.end())
+    return;
+  base::WeakPtr<Observer> observer = i->second;
+  request_observer_map_.erase(i);
+  if (!observer.get())
+    return;
+
+  // Get the success value from the CloudPrint server response data.
+  std::string data;
+  source->GetResponseAsString(&data);
+  DictionaryValue* json_data = NULL;
+  cloud_print::ParseResponseJSON(data, NULL, &json_data);
+  bool success = false;
+  if (json_data)
+    json_data->GetBoolean("success", &success);
+
+  // Check if the observer is waiting on a second response (url and snapshot).
+  RequestObserverMap::iterator other = request_observer_map_.begin();
+  for (; other != request_observer_map_.end(); ++other) {
+    if (other->second == observer) {
+      // Do not call OnSendComplete for observers waiting on a second response.
+      if (success)
+        return;
+
+      // Ensure a second response is not sent after reporting failure below.
+      request_observer_map_.erase(other);
+      break;
+    }
+  }
+
+  observer->OnSendComplete(success);
+}