chrome/browser/ui/omnibox/alternate_nav_url_fetcher.h

   1 // Copyright 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_UI_OMNIBOX_ALTERNATE_NAV_URL_FETCHER_H_
   6 #define CHROME_BROWSER_UI_OMNIBOX_ALTERNATE_NAV_URL_FETCHER_H_
   7
   8 #include <string>
   9
  10 #include "base/memory/scoped_ptr.h"
  11 #include "content/public/browser/notification_observer.h"
  12 #include "content/public/browser/notification_registrar.h"
  13 #include "net/url_request/url_fetcher_delegate.h"
  14 #include "url/gurl.h"
  15
  16 namespace content {
  17 class NavigationController;
  18 }
  19
  20 namespace net {
  21 class URLFetcher;
  22 class URLRequestStatus;
  23 }
  24
  25 // Attempts to get the HEAD of a host name and displays an info bar if the
  26 // request was successful. This is used for single-word queries where we can't
  27 // tell if the entry was a search or an intranet hostname. The autocomplete bar
  28 // assumes it's a query and issues an AlternateNavURLFetcher to display a "did
  29 // you mean" infobar suggesting a navigation.
  30 //
  31 // The memory management of this object is a bit tricky. The location bar view
  32 // will create us and be responsible for us until we attach as an observer
  33 // after a pending load starts (it will delete us if this doesn't happen).
  34 // Once this pending load starts, we're responsible for deleting ourselves.
  35 // We'll do this in the following cases:
  36 //   * The tab is navigated again once we start listening (so the fetch is no
  37 //     longer useful)
  38 //   * The tab is closed before we show an infobar
  39 //   * The intranet fetch fails
  40 //   * None of the above apply, so we successfully show an infobar
  41 class AlternateNavURLFetcher : public content::NotificationObserver,
  42                                public net::URLFetcherDelegate {
  43  public:
  44   enum State {
  45     NOT_STARTED,
  46     IN_PROGRESS,
  47     SUCCEEDED,
  48     FAILED,
  49   };
  50
  51   explicit AlternateNavURLFetcher(const GURL& alternate_nav_url);
  52   virtual ~AlternateNavURLFetcher();
  53
  54   State state() const { return state_; }
  55
  56  private:
  57   // content::NotificationObserver
  58   virtual void Observe(int type,
  59                        const content::NotificationSource& source,
  60                        const content::NotificationDetails& details) OVERRIDE;
  61
  62   // net::URLFetcherDelegate
  63   virtual void OnURLFetchComplete(const net::URLFetcher* source) OVERRIDE;
  64
  65   // Sets |controller_| to the supplied pointer and begins fetching
  66   // |alternate_nav_url_|.
  67   void StartFetch(content::NavigationController* controller);
  68
  69   // Sets |state_| to either SUCCEEDED or FAILED depending on the result of the
  70   // fetch.
  71   void SetStatusFromURLFetch(const GURL& url,
  72                              const net::URLRequestStatus& status,
  73                              int response_code);
  74
  75   // Displays the infobar if all conditions are met (the page has loaded and
  76   // the fetch of the alternate URL succeeded).  Unless we're still waiting on
  77   // one of the above conditions to finish, this will also delete us, as whether
  78   // or not we show an infobar, there is no reason to live further.
  79   void ShowInfobarIfPossible();
  80
  81   GURL alternate_nav_url_;
  82   scoped_ptr<net::URLFetcher> fetcher_;
  83   content::NavigationController* controller_;
  84   State state_;
  85   bool navigated_to_entry_;
  86
  87   content::NotificationRegistrar registrar_;
  88
  89   DISALLOW_COPY_AND_ASSIGN(AlternateNavURLFetcher);
  90 };
  91
  92 #endif  // CHROME_BROWSER_UI_OMNIBOX_ALTERNATE_NAV_URL_FETCHER_H_