extensions/browser/extension_registry_observer.h

   1 // Copyright 2014 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 EXTENSIONS_BROWSER_EXTENSION_REGISTRY_OBSERVER_H_
   6 #define EXTENSIONS_BROWSER_EXTENSION_REGISTRY_OBSERVER_H_
   7
   8 #include "extensions/browser/uninstall_reason.h"
   9 #include "extensions/common/extension.h"
  10
  11 namespace content {
  12 class BrowserContext;
  13 }
  14
  15 namespace extensions {
  16
  17 class Extension;
  18 class ExtensionRegistry;
  19 struct UnloadedExtensionInfo;
  20
  21 // Observer for ExtensionRegistry. Exists in a separate header file to reduce
  22 // the include file burden for typical clients of ExtensionRegistry.
  23 class ExtensionRegistryObserver {
  24  public:
  25   virtual ~ExtensionRegistryObserver() {}
  26
  27   // Called after an extension is loaded. The extension will exclusively exist
  28   // in the enabled_extensions set of ExtensionRegistry.
  29   virtual void OnExtensionLoaded(
  30       content::BrowserContext* browser_context,
  31       const Extension* extension) {}
  32
  33   // Called after an extension is unloaded. The extension no longer exists in
  34   // the set |ExtensionRegistry::enabled_extensions()|, but it can still be a
  35   // member of one of the other sets, like disabled, blacklisted or terminated.
  36   virtual void OnExtensionUnloaded(content::BrowserContext* browser_context,
  37                                    const Extension* extension,
  38                                    UnloadedExtensionInfo::Reason reason) {}
  39
  40   // Called when |extension| is about to be installed. |is_update| is true if
  41   // the installation is the result of it updating, in which case |old_name| is
  42   // the name of the extension's previous version.
  43   // If true, |from_ephemeral| indicates that the extension was previously
  44   // installed ephemerally and has been promoted to a regular installed
  45   // extension. |is_update| will be true, although the version has not
  46   // necessarily changed.
  47   // The ExtensionRegistry will not be tracking |extension| at the time this
  48   // event is fired, but will be immediately afterwards (note: not necessarily
  49   // enabled; it might be installed in the disabled or even blacklisted sets,
  50   // for example).
  51   // Note that it's much more common to care about extensions being loaded
  52   // (OnExtensionLoaded).
  53   //
  54   // TODO(tmdiep): We should stash the state of the previous extension version
  55   // somewhere and have observers retrieve it. |is_update|, |from_ephemeral|
  56   // and |old_name| can be removed when this is done.
  57   virtual void OnExtensionWillBeInstalled(
  58       content::BrowserContext* browser_context,
  59       const Extension* extension,
  60       bool is_update,
  61       bool from_ephemeral,
  62       const std::string& old_name) {}
  63
  64   // Called when the installation of |extension| is complete. At this point the
  65   // extension is tracked in one of the ExtensionRegistry sets, but is not
  66   // necessarily enabled.
  67   virtual void OnExtensionInstalled(content::BrowserContext* browser_context,
  68                                     const Extension* extension,
  69                                     bool is_update) {}
  70
  71   // Called after an extension is uninstalled. The extension no longer exists in
  72   // any of the ExtensionRegistry sets (enabled, disabled, etc.).
  73   virtual void OnExtensionUninstalled(content::BrowserContext* browser_context,
  74                                       const Extension* extension,
  75                                       UninstallReason reason) {}
  76
  77   // Notifies observers that the observed object is going away.
  78   virtual void OnShutdown(ExtensionRegistry* registry) {}
  79 };
  80
  81 }  // namespace extensions
  82
  83 #endif  // EXTENSIONS_BROWSER_EXTENSION_REGISTRY_OBSERVER_H_