chrome/browser/background/background_application_list_model.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_BACKGROUND_BACKGROUND_APPLICATION_LIST_MODEL_H_
   6 #define CHROME_BROWSER_BACKGROUND_BACKGROUND_APPLICATION_LIST_MODEL_H_
   7
   8 #include <map>
   9 #include <string>
  10
  11 #include "base/basictypes.h"
  12 #include "base/observer_list.h"
  13 #include "content/public/browser/notification_observer.h"
  14 #include "content/public/browser/notification_registrar.h"
  15 #include "extensions/common/extension.h"
  16
  17 class Profile;
  18
  19 namespace gfx {
  20 class ImageSkia;
  21 }
  22
  23 // Model for list of Background Applications associated with a Profile (i.e.
  24 // extensions with kBackgroundPermission set, or hosted apps with a
  25 // BackgroundContents).
  26 class BackgroundApplicationListModel : public content::NotificationObserver {
  27  public:
  28   // Observer is informed of changes to the model.  Users of the
  29   // BackgroundApplicationListModel should anticipate that associated data,
  30   // e. g. the Icon, may exist and yet not be immediately available.  When the
  31   // data becomes available, OnApplicationDataChanged will be invoked for all
  32   // Observers of the model.
  33   class Observer {
  34    public:
  35     // Invoked when data that the model associates with the extension, such as
  36     // the Icon, has changed.
  37     virtual void OnApplicationDataChanged(
  38         const extensions::Extension* extension,
  39         Profile* profile);
  40
  41     // Invoked when the model detects a previously unknown extension and/or when
  42     // it no longer detects a previously known extension.
  43     virtual void OnApplicationListChanged(Profile* profile);
  44
  45    protected:
  46     virtual ~Observer();
  47   };
  48
  49   // Create a new model associated with profile.
  50   explicit BackgroundApplicationListModel(Profile* profile);
  51
  52   virtual ~BackgroundApplicationListModel();
  53
  54   // Associate observer with this model.
  55   void AddObserver(Observer* observer);
  56
  57   // Return the icon associated with |extension| or NULL.  NULL indicates either
  58   // that there is no icon associated with the extension, or that a pending
  59   // task to retrieve the icon has not completed.  See the Observer class above.
  60   //
  61   // NOTE: The model manages the ImageSkia result, that is it "owns" the memory,
  62   //       releasing it if the associated background application is unloaded.
  63   // NOTE: All icons are currently sized as
  64   //       ExtensionIconSet::EXTENSION_ICON_BITTY.
  65   const gfx::ImageSkia* GetIcon(const extensions::Extension* extension);
  66
  67   // Return the position of |extension| within this list model.
  68   int GetPosition(const extensions::Extension* extension) const;
  69
  70   // Return the extension at the specified |position| in this list model.
  71   const extensions::Extension* GetExtension(int position) const;
  72
  73   // Returns true if the passed extension is a background app.
  74   static bool IsBackgroundApp(const extensions::Extension& extension,
  75                               Profile* profile);
  76
  77   // Dissociate observer from this model.
  78   void RemoveObserver(Observer* observer);
  79
  80   extensions::ExtensionList::const_iterator begin() const {
  81     return extensions_.begin();
  82   }
  83
  84   extensions::ExtensionList::const_iterator end() const {
  85     return extensions_.end();
  86   }
  87
  88   size_t size() const {
  89     return extensions_.size();
  90   }
  91
  92  private:
  93   // Contains data associated with a background application that is not
  94   // represented by the Extension class.
  95   class Application;
  96
  97   // Associates extension id strings with Application objects.
  98   typedef std::map<std::string, Application*> ApplicationMap;
  99
 100   // Identifies and caches data related to the extension.
 101   void AssociateApplicationData(const extensions::Extension* extension);
 102
 103   // Clears cached data related to |extension|.
 104   void DissociateApplicationData(const extensions::Extension* extension);
 105
 106   // Returns the Application associated with |extension| or NULL.
 107   const Application* FindApplication(
 108       const extensions::Extension* extension) const;
 109
 110   // Returns the Application associated with |extension| or NULL.
 111   Application* FindApplication(const extensions::Extension* extension);
 112
 113   // content::NotificationObserver implementation.
 114   virtual void Observe(int type,
 115                        const content::NotificationSource& source,
 116                        const content::NotificationDetails& details) OVERRIDE;
 117
 118   // Notifies observers that some of the data associated with this background
 119   // application, e. g. the Icon, has changed.
 120   void SendApplicationDataChangedNotifications(
 121       const extensions::Extension* extension);
 122
 123   // Notifies observers that at least one background application has been added
 124   // or removed.
 125   void SendApplicationListChangedNotifications();
 126
 127   // Invoked by Observe for NOTIFICATION_EXTENSION_LOADED.
 128   void OnExtensionLoaded(const extensions::Extension* extension);
 129
 130   // Invoked by Observe for NOTIFICATION_EXTENSION_UNLOADED.
 131   void OnExtensionUnloaded(const extensions::Extension* extension);
 132
 133   // Invoked by Observe for NOTIFICATION_EXTENSION_PERMISSIONS_UPDATED.
 134   void OnExtensionPermissionsUpdated(
 135       const extensions::Extension* extension,
 136       extensions::UpdatedExtensionPermissionsInfo::Reason reason,
 137       const extensions::PermissionSet* permissions);
 138
 139   // Refresh the list of background applications and generate notifications.
 140   void Update();
 141
 142   // Determines if the given extension has to be considered a "background app"
 143   // due to its use of PushMessaging. Normally every extension that expectes
 144   // push messages is classified as "background app", however there are some
 145   // rare exceptions, so this function implements a whitelist.
 146   static bool RequiresBackgroundModeForPushMessaging(
 147       const extensions::Extension& extension);
 148
 149   ApplicationMap applications_;
 150   extensions::ExtensionList extensions_;
 151   ObserverList<Observer> observers_;
 152   Profile* profile_;
 153   content::NotificationRegistrar registrar_;
 154
 155   DISALLOW_COPY_AND_ASSIGN(BackgroundApplicationListModel);
 156 };
 157
 158 #endif  // CHROME_BROWSER_BACKGROUND_BACKGROUND_APPLICATION_LIST_MODEL_H_