Integrate the Spelling service to Chrome.

chrome/browser/tab_contents/spelling_menu_observer.cc

+// Copyright (c) 2011 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/tab_contents/spelling_menu_observer.h"
+
+#include <string>
+
+#include "base/json/json_reader.h"
+#include "base/json/string_escape.h"
+#include "base/stringprintf.h"
+#include "base/utf_string_conversions.h"
+#include "base/values.h"
+#include "chrome/app/chrome_command_ids.h"
+#include "chrome/browser/prefs/pref_service.h"
+#include "chrome/browser/profiles/profile.h"
+#include "chrome/browser/tab_contents/render_view_context_menu.h"
+#include "chrome/common/pref_names.h"
+#include "content/browser/renderer_host/render_view_host.h"
+#include "googleurl/src/gurl.h"
+#include "grit/generated_resources.h"
+#include "ui/base/l10n/l10n_util.h"
+#include "unicode/uloc.h"
+#include "webkit/glue/context_menu.h"
+
+#if defined(GOOGLE_CHROME_BUILD)
+#include "chrome/browser/spellchecker/internal/spellcheck_internal.h"
+#endif
+
+SpellingMenuObserver::SpellingMenuObserver(
+    RenderViewContextMenuDelegate* delegate)
+    : delegate_(delegate),
+      loading_frame_(0),
+      succeeded_(false) {
+}
+
+SpellingMenuObserver::~SpellingMenuObserver() {
+}
+
+void SpellingMenuObserver::InitMenu(const ContextMenuParams& params) {
+  // We add this context-menu item only on Google Chrome until we release the
+  // Google Spelling API.
+#if defined(GOOGLE_CHROME_BUILD)

[Ben Goodger (Google), 2011/08/23 16:12:52]

I do wonder if this code shouldn't be ifdefed like this but rather controlled by
a preference that is set to true in a GOOGLE_CHROME_BUILD.

That way it's easier for developers to test and debug this code in typical
Chromium builds just by flipping the bit, rather than having to do a complete
new build with the official build flag set.

[Hironori Bono, 2011/08/25 11:18:58]

Done. I have removed all ifdefs except the above code which includes an internal
header and the default value of the new profile. (The above header file includes
the URL to our test server and its access key.)

+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+
+  // Exit if we are not in an ediable element because we add a menu item only

[Avi (use Gerrit), 2011/08/23 18:38:19]

s/ediable/editable/

[Hironori Bono, 2011/08/25 11:18:58]

Done.

+  // for editable elements.
+  if (!params.is_editable)
+    return;
+
+  Profile* profile = delegate_->GetProfile();
+  if (!profile || !profile->GetRequestContext())
+    return;
+
+  // Retrieve the misspelled word to be sent to the Spelling service.
+  string16 text = params.misspelled_word;
+  if (text.empty())
+    return;
+
+  // Initialize variables used in OnURLFetchComplete(). We copy the input text
+  // to the result text so we can replace its misspelled regions with
+  // suggestions.
+  loading_frame_ = 0;
+  succeeded_ = false;
+  result_ = text;
+
+  // Add a placeholder item. This item will be updated when we receive a
+  // response from the Spelling service. (We do not have to disable this item
+  // now since Chrome will call IsCommandIdEnabled() and disable it.)
+  loading_message_ =
+      l10n_util::GetStringUTF16(IDS_CONTENT_CONTEXT_SPELLING_CHECKING);
+  delegate_->AddMenuItem(IDC_CONTENT_CONTEXT_SPELLING_SUGGESTION,
+                         loading_message_);
+
+  // Invoke a JSON-RPC call to the Spelling service in the background so we can
+  // update the placeholder item when we receive its response. It also starts
+  // the animation timer so we can show animation until we receive it.
+  const PrefService* pref = profile->GetPrefs();
+  std::string language =
+      pref ? pref->GetString(prefs::kSpellCheckDictionary) : "en-US";
+  Invoke(text, language, profile->GetRequestContext());
+#endif
+}
+
+bool SpellingMenuObserver::IsCommandIdSupported(int command_id) {
+  return command_id == IDC_CONTENT_CONTEXT_SPELLING_SUGGESTION;
+}
+
+bool SpellingMenuObserver::IsCommandIdEnabled(int command_id) {
+  return command_id == IDC_CONTENT_CONTEXT_SPELLING_SUGGESTION && succeeded_;
+}
+
+void SpellingMenuObserver::ExecuteCommand(int command_id) {
+  if (IsCommandIdEnabled(command_id))
+    delegate_->GetRenderViewHost()->Replace(result_);
+}
+
+bool SpellingMenuObserver::Invoke(const string16& text,
+                                  const std::string& locale,
+                                  net::URLRequestContextGetter* context) {
+#if defined(GOOGLE_CHROME_BUILD)
+  // Create the parameters needed by Spelling API. Spelling API needs three
+  // parameters: ISO language code, ISO3 country code, and text to be checked by
+  // the service. On the other hand, Chrome uses an ISO locale ID and ith may
+  // not include a country ID, e.g. "fr", "de", etc. To create the input
+  // parameters, we convert the UI locale to a full locale ID, and  convert the
+  // full locale ID to an ISO language code and and ISO3 country code. Also, we
+  // convert the given text to a JSON string, i.e. quote all its non-ASCII
+  // characters.
+  UErrorCode error = U_ZERO_ERROR;
+  char id[ULOC_LANG_CAPACITY + ULOC_SCRIPT_CAPACITY + ULOC_COUNTRY_CAPACITY];
+  uloc_addLikelySubtags(locale.c_str(), id, arraysize(id), &error);
+
+  error = U_ZERO_ERROR;
+  char language[ULOC_LANG_CAPACITY];
+  uloc_getLanguage(id, language, arraysize(language), &error);
+
+  const char* country = uloc_getISO3Country(id);
+
+  std::string encoded_text;
+  base::JsonDoubleQuote(text, false, &encoded_text);
+
+  // Format the JSON request to be sent to the Speling service.

[Avi (use Gerrit), 2011/08/23 18:38:19]

s/Speling/Spelling/

[Hironori Bono, 2011/08/25 11:18:58]

Done.

+  static const char kSpellingRequest[] =
+      "{"
+      "\"method\":\"spelling.check\","
+      "\"apiVersion\":\"v1\","
+      "\"params\":{"
+      "\"text\":\"%s\","
+      "\"language\":\"%s\","
+      "\"origin_country\":\"%s\","
+      "\"key\":\"" SPELLING_SERVICE_KEY "\""
+      "}"
+      "}";
+  std::string request = base::StringPrintf(kSpellingRequest,
+                                           encoded_text.c_str(),
+                                           language, country);
+
+  static const char kSpellingServiceURL[] = SPELLING_SERVICE_URL;
+  GURL url = GURL(kSpellingServiceURL);
+  fetcher_.reset(new URLFetcher(url, URLFetcher::POST, this));
+  fetcher_->set_request_context(context);
+  fetcher_->set_upload_data("application/json", request);
+  fetcher_->Start();
+
+  animation_timer_.Start(base::TimeDelta::FromSeconds(1),
+      this, &SpellingMenuObserver::OnAnimationTimerExpired);
+
+  return true;
+#else
+  return false;
+#endif
+}
+
+void SpellingMenuObserver::OnURLFetchComplete(
+    const URLFetcher* source,
+    const GURL& url,
+    const net::URLRequestStatus& status,
+    int response,
+    const net::ResponseCookies& cookies,
+    const std::string& data) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+
+  fetcher_.reset();
+  animation_timer_.Stop();
+
+  // Parse the response JSON and replace misspelled words in the |result_| text
+  // with their suggestions.
+  succeeded_ = ParseResponse(response, data);
+  if (!succeeded_)
+    result_ = l10n_util::GetStringUTF16(IDS_CONTENT_CONTEXT_SPELLING_CORRECT);
+
+  // Update the menu item with the result text. We enable this item only when
+  // the request text has misspelled words. (We disable this item not only when
+  // we receive a server error but also when the input text consists only of
+  // well-spelled words. For either case, we do not need to replace the input
+  // text.)
+  delegate_->UpdateMenuItem(IDC_CONTENT_CONTEXT_SPELLING_SUGGESTION, succeeded_,
+                            result_);
+}
+
+bool SpellingMenuObserver::ParseResponse(int response,
+                                         const std::string& data) {
+  // When this JSON-RPC call finishes successfully, the Spelling service returns
+  // an JSON object listed below.
+  // * result - an envelope object representing the result from the APIARY
+  //   server, which is the JSON-API front-end for the Spelling service. This
+  //   object consists of the following variable:
+  //   - spellingCheckResponse (SpellingCheckResponse).
+  // * SpellingCheckResponse - an object representing the result from the
+  //   Spelling service. This object consists of the following variable:
+  //   - misspellings (optional array of Misspelling)
+  // * Misspelling - an object representing a misspelling region and its
+  //   suggestions. This object consists of the following variables:
+  //   - charStart (number) - the beginning of the misspelled region;
+  //   - charLength (number) - the length of the misspelled region;
+  //   - suggestions (array of string) - the suggestions for the misspelling
+  //     text, and;
+  //   - canAutoCorrect (optional boolean) - whether we can use the first
+  //     suggestion for auto-correction.
+  // For example, the Spelling service returns the following JSON when we send a
+  // spelling request for "duck goes quisk" as of 16 August, 2011.
+  // {
+  //   "result": {
+  //   "spellingCheckResponse": {
+  //     "misspellings": [{
+  //         "charStart": 10,
+  //         "charLength": 5,
+  //         "suggestions": [{ "suggestion": "quack" }],
+  //         "canAutoCorrect": false
+  //     }]
+  //   }
+  // }
+
+  // When a server error happened in the APIARY server (including when we cannot
+  // get any responses from the server), it returns an HTTP error.
+  if ((response / 100) != 2)
+    return false;
+
+  scoped_ptr<DictionaryValue> value(
+      static_cast<DictionaryValue*>(base::JSONReader::Read(data, true)));
+  if (!value.get() || !value->IsType(base::Value::TYPE_DICTIONARY))
+    return false;
+
+  // Retrieve the array of Misspelling objects. When the APIARY servier failed
+  // calling the Spelling service, it returns a JSON representing the service
+  // error. (In this case, its HTTP status is 200.) We just return false for
+  // this case.
+  ListValue* misspellings = NULL;
+  const char kMisspellings[] = "result.spellingCheckResponse.misspellings";
+  if (!value->GetList(kMisspellings, &misspellings))
+    return false;
+
+  // For each misspelled region, we replace it with its first suggestion.
+  for (size_t i = 0; i < misspellings->GetSize(); ++i) {
+    // Retrieve the i-th misspelling region, which represents misspelling text
+    // in the request text and its alternative.
+    DictionaryValue* misspelling = NULL;
+    if (!misspellings->GetDictionary(i, &misspelling))
+      return false;
+
+    int start = 0;
+    int length = 0;
+    ListValue* suggestions = NULL;
+    if (!misspelling->GetInteger("charStart", &start) ||
+        !misspelling->GetInteger("charLength", &length) ||
+        !misspelling->GetList("suggestions", &suggestions)) {
+      return false;
+    }
+
+    // Retrieve the alternative text and replace the misspelling region with the
+    // alternative.
+    DictionaryValue* suggestion = NULL;
+    string16 text;
+    if (!suggestions->GetDictionary(0, &suggestion) ||
+        !suggestion->GetString("suggestion", &text)) {
+      return false;
+    }
+    result_.replace(start, length, text);
+  }
+
+  return true;
+}
+
+void SpellingMenuObserver::OnAnimationTimerExpired() {
+  if (!fetcher_.get())
+    return;
+
+  // Append '.' characters to the end of "Checking".
+  loading_frame_ = (loading_frame_ + 1) & 3;
+  string16 loading_message = loading_message_;
+  for (int i = 0; i < loading_frame_; ++i)
+    loading_message.push_back('.');
+
+  // Update the menu item with the text. We disable this item to prevent users
+  // from selecting it.
+  delegate_->UpdateMenuItem(IDC_CONTENT_CONTEXT_SPELLING_SUGGESTION,
+                            false, loading_message);
+}