Enables the user to select multiple languages for spellchecking (UI)

chrome/browser/spellchecker/spellcheck_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/spellchecker/spellcheck_service.h"
 
+#include <algorithm>
+
+#include "base/command_line.h"
 #include "base/prefs/pref_member.h"
 #include "base/prefs/pref_service.h"
 #include "base/strings/string_split.h"
 #include "base/synchronization/waitable_event.h"
 #include "chrome/browser/spellchecker/spellcheck_factory.h"
 #include "chrome/browser/spellchecker/spellcheck_host_metrics.h"
 #include "chrome/browser/spellchecker/spellcheck_hunspell_dictionary.h"
 #include "chrome/browser/spellchecker/spellcheck_platform_mac.h"
 #include "chrome/browser/spellchecker/spelling_service_client.h"
+#include "chrome/common/chrome_switches.h"
 #include "chrome/common/pref_names.h"
 #include "chrome/common/spellcheck_messages.h"
 #include "components/user_prefs/user_prefs.h"
 #include "content/public/browser/browser_context.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/notification_service.h"
 #include "content/public/browser/notification_types.h"
 #include "content/public/browser/render_process_host.h"
 #include "ipc/ipc_platform_file.h"
 
@@ skipping 42 matching lines @@
                  content::NOTIFICATION_RENDERER_PROCESS_CREATED,
                  content::NotificationService::AllSources());
 }
 
 SpellcheckService::~SpellcheckService() {
   // Remove pref observers
   pref_change_registrar_.RemoveAll();
 }
 
 // static
-int SpellcheckService::GetSpellCheckLanguages(
-    content::BrowserContext* context,
-    std::vector<std::string>* languages) {
+std::set<int> SpellcheckService::GetSpellCheckLanguages(
+      content::BrowserContext* context,
+      std::vector<std::string>* languages) {
   PrefService* prefs = user_prefs::UserPrefs::Get(context);
+  std::vector<std::string> dictionary_languages;
+
+  const base::CommandLine* command_line =
+      base::CommandLine::ForCurrentProcess();
+
+  StringPrefMember dictionary_languages_pref;
+  if (command_line->HasSwitch(switches::kEnableMultilingualSpellChecker)) {
+    dictionary_languages_pref.Init(prefs::kSpellCheckDictionaries, prefs);
+    base::SplitString(dictionary_languages_pref.GetValue(),
+                      chrome::spellcheck_common::kDictionaryLanguagesSeparator,
+                      &dictionary_languages);
+  } else {
+    dictionary_languages_pref.Init(prefs::kSpellCheckDictionary, prefs);
+    dictionary_languages.push_back(dictionary_languages_pref.GetValue());
+  }
+
+  auto partition_point = std::partition(
+      dictionary_languages.begin(), dictionary_languages.end(),
+      [](const std::string& language) { return language.length() > 0; });
+  dictionary_languages.erase(partition_point, dictionary_languages.end());

[please use gerrit instead, 2015/02/26 21:30:19]

Instead of repeating this code, perhaps we can put it in spellcheck_common?

std::vector<std::string> GetDictionaryLanguagesPref();

Also, please place a "DCHECK_LT(0, language.length());" inside of the lambda
function. This will help you catch any code that mistakenly writes empty entries
into your preference string. (DCHECKs trigger only in debug builds.)

[Dan Beam, 2015/02/26 22:04:32]

size_t < 0?! mind == blown. i think rouslan@ meant GT (greater than, >), but the
easiest would be:

  DCHECK(!language.empty());

[Dan Beam, 2015/02/26 22:30:23]

oh, I guess the operand order is right in rouslan@'s command, but I think
!empty() is easier to grok

[Klemen Forstnerič, 2015/02/27 15:43:44]

I think so too, DCHECK(!language.empty()) is more readable. Done.

[Klemen Forstnerič, 2015/02/27 15:43:44]

Good idea. Done.

+
+  std::vector<std::string> accept_languages;
   StringPrefMember accept_languages_pref;
-  StringPrefMember dictionary_language_pref;
   accept_languages_pref.Init(prefs::kAcceptLanguages, prefs);
-  dictionary_language_pref.Init(prefs::kSpellCheckDictionary, prefs);
-  std::string dictionary_language = dictionary_language_pref.GetValue();
-
-  // Now scan through the list of accept languages, and find possible mappings
-  // from this list to the existing list of spell check languages.
-  std::vector<std::string> accept_languages;
 
 #if defined(OS_MACOSX)
   if (spellcheck_mac::SpellCheckerAvailable())
     spellcheck_mac::GetAvailableLanguages(&accept_languages);
   else
     base::SplitString(accept_languages_pref.GetValue(), ',', &accept_languages);
 #else
   base::SplitString(accept_languages_pref.GetValue(), ',', &accept_languages);
 #endif  // !OS_MACOSX
 
-  GetSpellCheckLanguagesFromAcceptLanguages(
-      accept_languages, dictionary_language, languages);
+  *languages = dictionary_languages;
+  GetSpellCheckLanguagesFromAcceptLanguages(accept_languages, languages);
 
-  for (size_t i = 0; i < languages->size(); ++i) {
-    if ((*languages)[i] == dictionary_language)
-      return i;
-  }
-  return -1;
+  // |languages| vector begins with the entries from |dictionary_languages|,
+  // therefore these indices are correct.
+  std::set<int> selected_language_indices;
+  for (size_t i = 0; i < dictionary_languages.size(); ++i)
+    selected_language_indices.insert(i);
+
+  return selected_language_indices;
 }
 
 // static
 void SpellcheckService::GetSpellCheckLanguagesFromAcceptLanguages(
     const std::vector<std::string>& accept_languages,
-    const std::string& dictionary_language,
     std::vector<std::string>* languages) {
-  // The current dictionary language should be there.
-  languages->push_back(dictionary_language);
 
   for (std::vector<std::string>::const_iterator i = accept_languages.begin();
        i != accept_languages.end(); ++i) {
     std::string language =
         chrome::spellcheck_common::GetCorrespondingSpellCheckLanguage(*i);
     if (!language.empty() &&
         std::find(languages->begin(), languages->end(), language) ==
         languages->end()) {
       languages->push_back(language);
     }
@@ skipping 151 matching lines @@
   hunspell_dictionary_->AddObserver(this);
   hunspell_dictionary_->Load();
 }
 
 void SpellcheckService::OnUseSpellingServiceChanged() {
   bool enabled = pref_change_registrar_.prefs()->GetBoolean(
       prefs::kSpellCheckUseSpellingService);
   if (metrics_)
     metrics_->RecordSpellingServiceStats(enabled);
 }