chrome/browser/spellchecker/spellcheck_host_impl.h

   1 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef CHROME_BROWSER_SPELLCHECKER_SPELLCHECK_HOST_IMPL_H_
   6 #define CHROME_BROWSER_SPELLCHECKER_SPELLCHECK_HOST_IMPL_H_
   7 #pragma once
   8
   9 #include <string>
  10 #include <vector>
  11
  12 #include "base/compiler_specific.h"
  13 #include "base/file_path.h"
  14 #include "base/memory/scoped_ptr.h"
  15 #include "base/memory/weak_ptr.h"
  16 #include "chrome/browser/spellchecker/spellcheck_host.h"
  17 #include "chrome/browser/spellchecker/spellcheck_profile_provider.h"
  18 #include "content/public/common/url_fetcher_delegate.h"
  19 #include "content/public/browser/notification_observer.h"
  20 #include "content/public/browser/notification_registrar.h"
  21
  22 // This class implements the SpellCheckHost interface to provide the
  23 // functionalities listed below:
  24 // * Adding a word to the custom dictionary;
  25 // * Storing the custom dictionary to the file, and read it back
  26 //   from the file during the initialization.
  27 // * Downloading a dictionary and map it for the renderer, and;
  28 // * Calling the platform spellchecker attached to the browser;
  29 //
  30 // To download a dictionary and initialize it without blocking the UI thread,
  31 // this class also implements the URLFetcher::Delegate() interface. This
  32 // initialization status is notified to the UI thread through the
  33 // SpellCheckProfileProvider interface.
  34 //
  35 // We expect a profile creates an instance of this class through a factory
  36 // method, SpellCheckHost::Create() and uses only the SpellCheckHost interface
  37 // provided by this class.
  38 //   spell_check_host_ = SpellCheckHost::Create(...)
  39 //
  40 // Available languages for the checker, which we need to specify via Create(),
  41 // can be listed using SpellCheckHost::GetAvailableLanguages() static method.
  42 class SpellCheckHostImpl : public SpellCheckHost,
  43                            public content::URLFetcherDelegate,
  44                            public content::NotificationObserver {
  45  public:
  46   SpellCheckHostImpl(SpellCheckProfileProvider* profile,
  47                      const std::string& language,
  48                      net::URLRequestContextGetter* request_context_getter,
  49                      SpellCheckHostMetrics* metrics);
  50
  51   virtual ~SpellCheckHostImpl();
  52
  53   void Initialize();
  54
  55   // SpellCheckHost implementation
  56   virtual void UnsetProfile() OVERRIDE;
  57   virtual void InitForRenderer(content::RenderProcessHost* process) OVERRIDE;
  58   virtual void AddWord(const std::string& word) OVERRIDE;
  59   virtual const base::PlatformFile& GetDictionaryFile() const OVERRIDE;
  60   virtual const std::string& GetLanguage() const OVERRIDE;
  61   virtual bool IsUsingPlatformChecker() const OVERRIDE;
  62
  63  private:
  64   typedef SpellCheckProfileProvider::CustomWordList CustomWordList;
  65
  66   // These two classes can destruct us.
  67   friend class content::BrowserThread;
  68   friend class DeleteTask<SpellCheckHostImpl>;
  69
  70   // Figure out the location for the dictionary. This is only non-trivial for
  71   // Windows:
  72   // The default place whether the spellcheck dictionary can reside is
  73   // chrome::DIR_APP_DICTIONARIES. However, for systemwide installations,
  74   // this directory may not have permissions for download. In that case, the
  75   // alternate directory for download is chrome::DIR_USER_DATA.
  76   void InitializeDictionaryLocation();
  77   void InitializeDictionaryLocationComplete();
  78
  79   // The reply point for PostTaskAndReply. Called when AddWord is finished
  80   // adding a word in the background.
  81   void AddWordComplete(const std::string& word);
  82
  83   // Inform |profile_| that initialization has finished.
  84   // |custom_words| holds the custom word list which was
  85   // loaded at the file thread.
  86   void InformProfileOfInitializationWithCustomWords(
  87       CustomWordList* custom_words);
  88
  89   // An alternative version of InformProfileOfInitializationWithCustomWords()
  90   // which implies empty |custom_words|.
  91   void InformProfileOfInitialization();
  92
  93   // If |dictionary_file_| is missing, we attempt to download it.
  94   void DownloadDictionary();
  95
  96   // Loads a custom dictionary from disk.
  97   void LoadCustomDictionary(CustomWordList* custom_words);
  98
  99   // Write a custom dictionary addition to disk.
 100   void WriteWordToCustomDictionary(const std::string& word);
 101
 102   // Returns a metrics counter associated with this object,
 103   // or null when metrics recording is disabled.
 104   virtual SpellCheckHostMetrics* GetMetrics() const OVERRIDE;
 105
 106   // Returns true if the dictionary is ready to use.
 107   virtual bool IsReady() const OVERRIDE;
 108
 109   // content::URLFetcherDelegate implementation.  Called when we finish
 110   // downloading the spellcheck dictionary; saves the dictionary to |data_|.
 111   virtual void OnURLFetchComplete(const content::URLFetcher* source) OVERRIDE;
 112
 113   // NotificationProfile implementation.
 114   virtual void Observe(int type,
 115                        const content::NotificationSource& source,
 116                        const content::NotificationDetails& details) OVERRIDE;
 117
 118   // Saves |data_| to disk. Run on the file thread.
 119   void SaveDictionaryData();
 120   void SaveDictionaryDataComplete();
 121
 122   // Verifies the specified BDict file exists and it is sane. This function
 123   // should be called before opening the file so we can delete it and download a
 124   // new dictionary if it is corrupted.
 125   bool VerifyBDict(const FilePath& path) const;
 126
 127   // May be NULL.
 128   SpellCheckProfileProvider* profile_;
 129
 130   // The desired location of the dictionary file (whether or not t exists yet).
 131   FilePath bdict_file_path_;
 132
 133   // The location of the custom words file.
 134   FilePath custom_dictionary_file_;
 135
 136   // State whether a dictionary has been partially, or fully saved. If the
 137   // former, shortcut Initialize.
 138   bool dictionary_saved_;
 139
 140   // The language of the dictionary file.
 141   std::string language_;
 142
 143   // The file descriptor/handle for the dictionary file.
 144   base::PlatformFile file_;
 145
 146   // We don't want to attempt to download a missing dictionary file more than
 147   // once.
 148   bool tried_to_download_;
 149
 150   // Whether we should use the platform spellchecker instead of Hunspell.
 151   bool use_platform_spellchecker_;
 152
 153   // Data received from the dictionary download.
 154   std::string data_;
 155
 156   // Used for downloading the dictionary file. We don't hold a reference, and
 157   // it is only valid to use it on the UI thread.
 158   net::URLRequestContextGetter* request_context_getter_;
 159
 160   // Used for downloading the dictionary file.
 161   scoped_ptr<content::URLFetcher> fetcher_;
 162
 163   content::NotificationRegistrar registrar_;
 164
 165   // An optional metrics counter given by the constructor.
 166   SpellCheckHostMetrics* metrics_;
 167
 168   base::WeakPtrFactory<SpellCheckHostImpl> weak_ptr_factory_;
 169
 170   scoped_ptr<CustomWordList> custom_words_;
 171
 172   DISALLOW_COPY_AND_ASSIGN(SpellCheckHostImpl);
 173 };
 174
 175 #endif  // CHROME_BROWSER_SPELLCHECKER_SPELLCHECK_HOST_IMPL_H_