blob: 3a041ffe1e06dd4e77ac163aebc8bac947466fce [file] [log] [blame]
// 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 "extensions/browser/uninstall_reason.h"
#include "extensions/common/extension.h"
namespace content {
class BrowserContext;
namespace extensions {
class ExtensionRegistry;
// Observer for ExtensionRegistry. Exists in a separate header file to reduce
// the include file burden for typical clients of ExtensionRegistry.
// There are separate event categories for loading (the OnExtensionLoaded,
// OnExtensionReady and OnExtensionUnloaded events) and installing (the
// OnExtensionWillBeInstalled, OnExtensionInstalled and OnExtensionUninstalled)
// extensions.
// For example, comparing OnExtensionLoaded and OnExtensionInstalled,
// OnExtensionLoaded is called whenever an extension is added to the "enabled"
// set of the extension registry. This includes:
// - Extensions being loaded at Chrome startup.
// - Extensions being reloaded:
// * as part of an update.
// * from a crash.
// * from a disabled state (if the user toggled disabled -> enabled).
// * as part of internal bookkeeping (we reload extensions on file access
// being granted, for instance).
// * if the extension requested it (chrome.runtime.reload()).
// * probably others.
// - New extensions being loaded for the first time (as part of installation).
// OnExtensionInstalled is called when a *new* extension is added, *or* when an
// extension is updated to a *new* version. It is not called for existing
// extensions being loaded at startup, etc. In a common run of Chrome, you
// probably won't get many "OnInstalled" events.
// As a general rule, most sites should observe OnExtensionLoaded, because they
// want to see "what are the enabled extensions".
class ExtensionRegistryObserver {
virtual ~ExtensionRegistryObserver() {}
// Called after an extension is loaded. The extension will exclusively exist
// in the enabled_extensions set of ExtensionRegistry.
virtual void OnExtensionLoaded(
content::BrowserContext* browser_context,
const Extension* extension) {}
// Called after an extension is loaded and all necessary browser state is
// initialized to support the start of the extension's child process.
virtual void OnExtensionReady(content::BrowserContext* browser_context,
const Extension* extension) {}
// Called after an extension is unloaded. The extension no longer exists in
// the set |ExtensionRegistry::enabled_extensions()|, but it can still be a
// member of one of the other sets, like disabled, blacklisted or terminated.
virtual void OnExtensionUnloaded(content::BrowserContext* browser_context,
const Extension* extension,
UnloadedExtensionReason reason) {}
// Called when |extension| is about to be installed. |is_update| is true if
// the installation is the result of it updating, in which case |old_name| is
// the name of the extension's previous version.
// The ExtensionRegistry will not be tracking |extension| at the time this
// event is fired, but will be immediately afterwards (note: not necessarily
// enabled; it might be installed in the disabled or even blacklisted sets,
// for example).
// Note that it's much more common to care about extensions being loaded
// (OnExtensionLoaded).
// TODO(tmdiep): We should stash the state of the previous extension version
// somewhere and have observers retrieve it. |is_update|, and |old_name| can
// be removed when this is done.
virtual void OnExtensionWillBeInstalled(
content::BrowserContext* browser_context,
const Extension* extension,
bool is_update,
const std::string& old_name) {}
// Called when the installation of |extension| is complete. At this point the
// extension is tracked in one of the ExtensionRegistry sets, but is not
// necessarily enabled.
virtual void OnExtensionInstalled(content::BrowserContext* browser_context,
const Extension* extension,
bool is_update) {}
// Called after an extension is uninstalled. The extension no longer exists in
// any of the ExtensionRegistry sets (enabled, disabled, etc.).
virtual void OnExtensionUninstalled(content::BrowserContext* browser_context,
const Extension* extension,
UninstallReason reason) {}
// Notifies observers that the observed object is going away.
virtual void OnShutdown(ExtensionRegistry* registry) {}
} // namespace extensions