Sync starting language and input method preferences

chrome/browser/chromeos/input_method/input_method_syncer.cc

Index: chrome/browser/chromeos/input_method/input_method_syncer.cc
diff --git a/chrome/browser/chromeos/input_method/input_method_syncer.cc b/chrome/browser/chromeos/input_method/input_method_syncer.cc
new file mode 100644
index 0000000000000000000000000000000000000000..1c82be758cc3f12bd09e0fde499099bb557b10de
--- /dev/null
+++ b/chrome/browser/chromeos/input_method/input_method_syncer.cc
@@ -0,0 +1,328 @@
+// Copyright 2014 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/chromeos/input_method/input_method_syncer.h"
+
+#include <algorithm>
+#include <set>
+#include <vector>
+
+#include "base/bind.h"
+#include "base/strings/string_split.h"
+#include "base/strings/string_util.h"
+#include "base/task_runner.h"
+#include "base/task_runner_util.h"
+#include "chrome/browser/browser_process.h"
+#include "chrome/browser/prefs/pref_service_syncable.h"
+#include "chrome/common/pref_names.h"
+#include "components/pref_registry/pref_registry_syncable.h"
+#include "content/public/browser/browser_thread.h"
+#include "ui/base/ime/chromeos/component_extension_ime_manager.h"
+#include "ui/base/ime/chromeos/extension_ime_util.h"
+#include "ui/base/l10n/l10n_util.h"
+
+namespace chromeos {
+namespace input_method {
+namespace {
+
+// Checks input method IDs, converting engine IDs to input method IDs and
+// removing unsupported IDs from |values|.
+void CheckAndResolveInputMethodIDs(
+    const input_method::InputMethodDescriptors& supported_descriptors,
+    std::vector<std::string>* values) {
+  // Extract the supported input method IDs into a set.
+  std::set<std::string> supported_input_method_ids;
+  for (const auto& descriptor : supported_descriptors)
+    supported_input_method_ids.insert(descriptor.id());
+
+  // Convert engine IDs to input method extension IDs.
+  std::transform(values->begin(), values->end(), values->begin(),
+                 extension_ime_util::GetInputMethodIDByEngineID);
+
+  // Remove values that aren't found in the set of supported input method IDs.
+  std::vector<std::string>::iterator it = values->begin();
+  while (it != values->end()) {
+    if (it->size() && supported_input_method_ids.find(*it) !=
+                      supported_input_method_ids.end()) {
+      ++it;
+    } else {
+      it = values->erase(it);
+    }
+  }
+}
+
+// Checks whether each language is supported, replacing locales with variants
+// if they are available. Must be called on a thread that allows IO.
+std::string CheckAndResolveLocales(const std::string& languages) {
+  DCHECK(content::BrowserThread::GetBlockingPool()->RunsTasksOnCurrentThread());
+  if (languages.empty())
+    return languages;
+  std::vector<std::string> values;
+  base::SplitString(languages, ',', &values);
+
+  const std::string app_locale = g_browser_process->GetApplicationLocale();
+
+  std::vector<std::string> accept_language_codes;
+  l10n_util::GetAcceptLanguagesForLocale(app_locale, &accept_language_codes);
+  std::sort(accept_language_codes.begin(), accept_language_codes.end());
+
+  // Remove unsupported language values.
+  std::vector<std::string>::iterator value_iter = values.begin();
+  while (value_iter != values.end()) {
+    if (binary_search(accept_language_codes.begin(),
+                      accept_language_codes.end(),
+                      *value_iter)) {
+      ++value_iter;
+      continue;
+    }
+
+    // If a language code resolves to a supported backup locale, replace it
+    // with the resolved locale.
+    std::string resolved_locale;
+    if (l10n_util::CheckAndResolveLocale(*value_iter, &resolved_locale)) {
+      if (binary_search(accept_language_codes.begin(),
+                        accept_language_codes.end(),
+                        resolved_locale)) {
+        *value_iter = resolved_locale;
+        ++value_iter;
+        continue;
+      }
+    }
+    value_iter = values.erase(value_iter);
+  }
+
+  return JoinString(values, ',');
+}
+
+// Appends tokens from |src| that are not in |dest| to |dest|.
+void MergeLists(std::vector<std::string>* dest,
+                const std::vector<std::string>& src) {
+  // Keep track of already-added tokens.
+  std::set<std::string> unique_tokens(dest->begin(), dest->end());
+
+  for (const std::string& token : src) {
+    // Skip token if it's already in |dest|.
+    if (binary_search(unique_tokens.begin(), unique_tokens.end(), token))
+      continue;
+    dest->push_back(token);
+    unique_tokens.insert(token);
+  }
+}
+
+}  // anonymous namespace
+
+InputMethodSyncer::InputMethodSyncer(
+    PrefServiceSyncable* prefs,
+    scoped_refptr<input_method::InputMethodManager::State> ime_state)
+    : prefs_(prefs),
+      ime_state_(ime_state),
+      merging_(false),
+      weak_factory_(this) {
+}
+
+InputMethodSyncer::~InputMethodSyncer() {
+  prefs_->RemoveObserver(this);
+}
+
+// static
+void InputMethodSyncer::RegisterProfilePrefs(
+    user_prefs::PrefRegistrySyncable* registry) {
+  registry->RegisterStringPref(
+      prefs::kLanguagePreferredLanguagesSyncable,
+      "",
+      user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
+  registry->RegisterStringPref(
+      prefs::kLanguagePreloadEnginesSyncable,
+      "",
+      user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
+  registry->RegisterStringPref(
+      prefs::kLanguageEnabledExtensionImesSyncable,
+      "",
+      user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
+  registry->RegisterBooleanPref(
+      prefs::kLanguageShouldMergeInputMethods,
+      false,
+      user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
+}
+
+void InputMethodSyncer::Initialize() {
+  // This causes OnIsSyncingChanged to be called when the value of
+  // PrefService::IsSyncing() changes.
+  prefs_->AddObserver(this);
+
+  preferred_languages_syncable_.Init(prefs::kLanguagePreferredLanguagesSyncable,
+                                     prefs_);
+  preload_engines_syncable_.Init(prefs::kLanguagePreloadEnginesSyncable,
+                                 prefs_);
+  enabled_extension_imes_syncable_.Init(
+      prefs::kLanguageEnabledExtensionImesSyncable, prefs_);
+
+  BooleanPrefMember::NamedChangeCallback callback =
+      base::Bind(&InputMethodSyncer::OnPreferenceChanged,
+                 base::Unretained(this));
+  preferred_languages_.Init(prefs::kLanguagePreferredLanguages,
+                            prefs_, callback);
+  preload_engines_.Init(prefs::kLanguagePreloadEngines,
+                        prefs_, callback);
+  enabled_extension_imes_.Init(
+      prefs::kLanguageEnabledExtensionImes, prefs_, callback);
+
+  // If we have already synced but haven't merged input methods yet, do so now.
+  if (prefs_->GetBoolean(prefs::kLanguageShouldMergeInputMethods) &&
+      !(preferred_languages_syncable_.GetValue().empty() &&
+        preload_engines_syncable_.GetValue().empty() &&
+        enabled_extension_imes_syncable_.GetValue().empty())) {
+    MergeSyncedPrefs();
+  }
+}
+
+void InputMethodSyncer::MergeSyncedPrefs() {
+  // This should only be done after the first ever sync.
+  DCHECK(prefs_->GetBoolean(prefs::kLanguageShouldMergeInputMethods));
+  prefs_->SetBoolean(prefs::kLanguageShouldMergeInputMethods, false);
+  merging_ = true;
+
+  std::string preferred_languages_syncable =
+      preferred_languages_syncable_.GetValue();
+  std::string preload_engines_syncable =
+      preload_engines_syncable_.GetValue();
+  std::string enabled_extension_imes_syncable =
+      enabled_extension_imes_syncable_.GetValue();
+
+  std::vector<std::string> synced_tokens;
+  std::vector<std::string> new_tokens;
+
+  // First, set the syncable prefs to the union of the local and synced prefs.
+  base::SplitString(
+      preferred_languages_syncable_.GetValue(), ',', &synced_tokens);
+  base::SplitString(preferred_languages_.GetValue(), ',', &new_tokens);
+
+  // Append the synced values to the current values.
+  MergeLists(&new_tokens, synced_tokens);
+  preferred_languages_syncable_.SetValue(JoinString(new_tokens, ','));
+
+  base::SplitString(
+      enabled_extension_imes_syncable_.GetValue(), ',', &synced_tokens);
+  base::SplitString(enabled_extension_imes_.GetValue(), ',', &new_tokens);
+
+  MergeLists(&new_tokens, synced_tokens);
+  enabled_extension_imes_syncable_.SetValue(JoinString(new_tokens, ','));
+
+  // Revert preload engines to legacy component IDs.
+  base::SplitString(preload_engines_.GetValue(), ',', &new_tokens);
+  std::transform(new_tokens.begin(), new_tokens.end(), new_tokens.begin(),
+                 extension_ime_util::GetComponentIDByInputMethodID);
+  base::SplitString(
+      preload_engines_syncable_.GetValue(), ',', &synced_tokens);
+
+  MergeLists(&new_tokens, synced_tokens);
+  preload_engines_syncable_.SetValue(JoinString(new_tokens, ','));
+
+  // Second, set the local prefs, incorporating new values from the sync server.
+  preload_engines_.SetValue(
+      AddSupportedInputMethodValues(preload_engines_.GetValue(),
+                                    preload_engines_syncable,
+                                    prefs::kLanguagePreloadEngines));
+  enabled_extension_imes_.SetValue(
+      AddSupportedInputMethodValues(enabled_extension_imes_.GetValue(),
+                                    enabled_extension_imes_syncable,
+                                    prefs::kLanguageEnabledExtensionImes));
+
+  // Remove unsupported locales before updating the local languages preference.
+  std::string languages(
+      AddSupportedInputMethodValues(preferred_languages_.GetValue(),
+                                    preferred_languages_syncable,
+                                    prefs::kLanguagePreferredLanguages));
+  base::PostTaskAndReplyWithResult(
+      content::BrowserThread::GetBlockingPool(),
+      FROM_HERE,
+      base::Bind(&CheckAndResolveLocales, languages),
+      base::Bind(&InputMethodSyncer::FinishMerge,
+                 weak_factory_.GetWeakPtr()));
+}
+
+std::string InputMethodSyncer::AddSupportedInputMethodValues(
+    const std::string& pref,
+    const std::string& synced_pref,
+    const char* pref_name) {
+  std::vector<std::string> old_tokens;
+  std::vector<std::string> new_tokens;
+  base::SplitString(pref, ',', &old_tokens);
+  base::SplitString(synced_pref, ',', &new_tokens);
+
+  // Check and convert the new tokens.
+  if (pref_name == prefs::kLanguagePreloadEngines ||
+      pref_name == prefs::kLanguageEnabledExtensionImes) {
+    input_method::InputMethodManager* manager =
+        input_method::InputMethodManager::Get();
+    scoped_ptr<input_method::InputMethodDescriptors> supported_descriptors;
+
+    if (pref_name == prefs::kLanguagePreloadEngines) {
+      // Set the known input methods.
+      supported_descriptors = manager->GetSupportedInputMethods();
+      // Add the available component extension IMEs.
+      ComponentExtensionIMEManager* component_extension_manager =
+          manager->GetComponentExtensionIMEManager();
+      input_method::InputMethodDescriptors component_descriptors =
+          component_extension_manager->GetAllIMEAsInputMethodDescriptor();
+      supported_descriptors->insert(supported_descriptors->end(),
+                                    component_descriptors.begin(),
+                                    component_descriptors.end());
+    } else {
+      supported_descriptors.reset(new input_method::InputMethodDescriptors);
+      ime_state_->GetInputMethodExtensions(supported_descriptors.get());
+    }
+    CheckAndResolveInputMethodIDs(*supported_descriptors, &new_tokens);
+  } else if (pref_name != prefs::kLanguagePreferredLanguages) {
+    NOTREACHED() << "Attempting to merge an invalid preference.";
+    // kLanguagePreferredLanguages is checked in CheckAndResolveLocales().
+  }
+
+  // Do the actual merging.
+  MergeLists(&old_tokens, new_tokens);
+  return JoinString(old_tokens, ',');
+}
+
+void InputMethodSyncer::FinishMerge(const std::string& languages) {
+  // Since the merge only removed locales that are unsupported on this system,
+  // we don't need to update the syncable prefs. If the local preference changes
+  // later, the sync server will lose the values we dropped. That's okay since
+  // the values from this device should then become the new defaults anyway.
+  preferred_languages_.SetValue(languages);
+
+  // We've finished merging.
+  merging_ = false;
+}
+
+void InputMethodSyncer::OnPreferenceChanged(const std::string& pref_name) {
+  DCHECK(pref_name == prefs::kLanguagePreferredLanguages ||
+         pref_name == prefs::kLanguagePreloadEngines ||
+         pref_name == prefs::kLanguageEnabledExtensionImes);
+
+  if (merging_ || prefs_->GetBoolean(prefs::kLanguageShouldMergeInputMethods))
+    return;
+
+  // Set the language and input prefs at the same time. Otherwise we may,
+  // e.g., use a stale languages setting but push a new preload engines setting.
+  preferred_languages_syncable_.SetValue(preferred_languages_.GetValue());
+  enabled_extension_imes_syncable_.SetValue(enabled_extension_imes_.GetValue());
+
+  // For preload engines, use legacy xkb IDs so the preference can sync
+  // across Chrome OS and Chromium OS.
+  std::vector<std::string> engines;
+  base::SplitString(preload_engines_.GetValue(), ',', &engines);
+  std::transform(engines.begin(), engines.end(), engines.begin(),
+                 extension_ime_util::GetComponentIDByInputMethodID);
+  preload_engines_syncable_.SetValue(JoinString(engines, ','));
+}
+
+void InputMethodSyncer::OnIsSyncingChanged() {
+  if (prefs_->GetBoolean(prefs::kLanguageShouldMergeInputMethods) &&
+      prefs_->IsSyncing()) {
+    MergeSyncedPrefs();
+  }
+}
+
+}  // namespace input_method
+}  // namespace chromeos