Implement a simple Extension App Omnibox provider.

chrome/browser/autocomplete/extension_app_provider.h

+// Copyright (c) 2011 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.
+//
+//
+// This file contains the Extension App autocomplete provider. The provider
+// is responsible for keeping track of which Extension Apps are installed and
+// their URLs.  An instance of it gets created and managed by the autocomplete
+// controller.
+//
+// For more information on the autocomplete system in general, including how
+// the autocomplete controller and autocomplete providers work, see
+// chrome/browser/autocomplete.h.
+
+#ifndef CHROME_BROWSER_AUTOCOMPLETE_EXTENSION_APP_PROVIDER_H_
+#define CHROME_BROWSER_AUTOCOMPLETE_EXTENSION_APP_PROVIDER_H_
+#pragma once
+
+#include <string>
+#include <utility>
+#include <vector>
+
+#include "base/compiler_specific.h"
+#include "chrome/browser/autocomplete/autocomplete.h"
+#include "content/common/notification_observer.h"
+#include "content/common/notification_registrar.h"
+
+class TemplateURLModel;
+
+class ExtensionAppProvider : public AutocompleteProvider,
+                             public NotificationObserver {
+ public:
+  ExtensionAppProvider(ACProviderListener* listener, Profile* profile);
+
+  // AutocompleteProvider implementation:
+  virtual void Start(const AutocompleteInput& input,
+                     bool minimal_changes) OVERRIDE;
+
+ private:
+  // An ExtensionApp is a pair of Extension Name and the Launch URL.
+  typedef std::pair<std::string, std::string> ExtensionApp;
+  typedef std::vector<ExtensionApp> ExtensionApps;
+
+  virtual ~ExtensionAppProvider();
+
+  // Fetch the current app list and cache it locally.
+  void RefreshAppList();
+
+  // Register for install/uninstall notification so we can update our cache.
+  void RegisterForNotifications();
+
+  // Calculate the relevance of the match.
+  int CalculateRelevance(AutocompleteInput::Type type,
+                         int input_length,
+                         int target_length);
+
+  // NotificationObserver implementation:
+  virtual void Observe(NotificationType type,
+                       const NotificationSource& source,
+                       const NotificationDetails& details) OVERRIDE;
+
+  NotificationRegistrar registrar_;
+
+  // Our cache of ExtensionApp objects (name + url) representing the extension
+  // apps we know about.
+  ExtensionApps extension_apps_;
+
+  DISALLOW_COPY_AND_ASSIGN(ExtensionAppProvider);
+};
+
+#endif  // CHROME_BROWSER_AUTOCOMPLETE_EXTENSION_APP_PROVIDER_H_