chrome/browser/tab_contents/spelling_menu_observer.h

   1 // Copyright (c) 2012 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_TAB_CONTENTS_SPELLING_MENU_OBSERVER_H_
   6 #define CHROME_BROWSER_TAB_CONTENTS_SPELLING_MENU_OBSERVER_H_
   7
   8 #include <vector>
   9
  10 #include "base/compiler_specific.h"
  11 #include "base/memory/scoped_ptr.h"
  12 #include "base/prefs/pref_member.h"
  13 #include "base/strings/string16.h"
  14 #include "base/timer/timer.h"
  15 #include "chrome/browser/spellchecker/spelling_service_client.h"
  16 #include "chrome/browser/tab_contents/render_view_context_menu_observer.h"
  17
  18 class RenderViewContextMenuProxy;
  19 struct SpellCheckResult;
  20
  21 // An observer that listens to events from the RenderViewContextMenu class and
  22 // shows suggestions from the Spelling ("do you mean") service to a context menu
  23 // while we show it. This class implements two interfaces:
  24 // * RenderViewContextMenuObserver
  25 //   This interface is used for adding a menu item and update it while showing.
  26 // * net::URLFetcherDelegate
  27 //   This interface is used for sending a JSON_RPC request to the Spelling
  28 //   service and retrieving its response.
  29 // These interfaces allow this class to make a JSON-RPC call to the Spelling
  30 // service in the background and update the context menu while showing. The
  31 // following snippet describes how to add this class to the observer list of the
  32 // RenderViewContextMenu class.
  33 //
  34 //   void RenderViewContextMenu::InitMenu() {
  35 //     spelling_menu_observer_.reset(new SpellingMenuObserver(this));
  36 //     if (spelling_menu_observer_.get())
  37 //       observers_.AddObserver(spelling_menu_observer.get());
  38 //   }
  39 //
  40 class SpellingMenuObserver : public RenderViewContextMenuObserver {
  41  public:
  42   explicit SpellingMenuObserver(RenderViewContextMenuProxy* proxy);
  43   virtual ~SpellingMenuObserver();
  44
  45   // RenderViewContextMenuObserver implementation.
  46   virtual void InitMenu(const content::ContextMenuParams& params) OVERRIDE;
  47   virtual bool IsCommandIdSupported(int command_id) OVERRIDE;
  48   virtual bool IsCommandIdChecked(int command_id) OVERRIDE;
  49   virtual bool IsCommandIdEnabled(int command_id) OVERRIDE;
  50   virtual void ExecuteCommand(int command_id) OVERRIDE;
  51   virtual void OnMenuCancel() OVERRIDE;
  52
  53   // A callback function called when the Spelling service finishes checking a
  54   // misspelled word.
  55   void OnTextCheckComplete(
  56       SpellingServiceClient::ServiceType type,
  57       bool success,
  58       const base::string16& text,
  59       const std::vector<SpellCheckResult>& results);
  60
  61  private:
  62   // The callback function for base::RepeatingTimer<SpellingMenuClient>. This
  63   // function updates the "loading..." animation in the context-menu item.
  64   void OnAnimationTimerExpired();
  65
  66   // The interface to add a context-menu item and update it. This class uses
  67   // this interface to avoid accesing context-menu items directly.
  68   RenderViewContextMenuProxy* proxy_;
  69
  70   // Suggested words from the local spellchecker. If the spelling service
  71   // returns a word in this list, we hide the context-menu item to prevent
  72   // showing the same word twice.
  73   std::vector<base::string16> suggestions_;
  74
  75   // The string used for animation until we receive a response from the Spelling
  76   // service. The current animation just adds periods at the end of this string:
  77   //   'Loading' -> 'Loading.' -> 'Loading..' -> 'Loading...' (-> 'Loading')
  78   base::string16 loading_message_;
  79   size_t loading_frame_;
  80
  81   // A flag represending whether a JSON-RPC call to the Spelling service
  82   // finished successfully and its response had a suggestion not included in the
  83   // ones provided by the local spellchecker. When this flag is true, we enable
  84   // the context-menu item so users can choose it.
  85   bool succeeded_;
  86
  87   // The misspelled word. When we choose the "Add to dictionary" item, we add
  88   // this word to the custom-word dictionary.
  89   base::string16 misspelled_word_;
  90
  91   // The hash identifier for the misspelled word. Used for collecting user
  92   // feedback to spellcheck suggestions.
  93   uint32 misspelling_hash_;
  94
  95   // The string representing the result of this call. This string is a
  96   // suggestion when this call finished successfully. Otherwise it is error
  97   // text. Until we receive a response from the Spelling service, this string
  98   // stores the input string. (Since the Spelling service sends only misspelled
  99   // words, we replace these misspelled words in the input text with the
 100   // suggested words to create suggestion text.
 101   base::string16 result_;
 102
 103   // The URLFetcher object used for sending a JSON-RPC request.
 104   scoped_ptr<SpellingServiceClient> client_;
 105
 106   // A timer used for loading animation.
 107   base::RepeatingTimer<SpellingMenuObserver> animation_timer_;
 108
 109   // Flag indicating whether online spelling correction service is enabled. When
 110   // this variable is true and we right-click a misspelled word, we send a
 111   // JSON-RPC request to the service and retrieve suggestions.
 112   BooleanPrefMember integrate_spelling_service_;
 113
 114   // Flag indicating whether automatic spelling correction is enabled.
 115   BooleanPrefMember autocorrect_spelling_;
 116
 117   DISALLOW_COPY_AND_ASSIGN(SpellingMenuObserver);
 118 };
 119
 120 #endif  // CHROME_BROWSER_TAB_CONTENTS_SPELLING_MENU_OBSERVER_H_