chrome/common/navigation_types.h

// Copyright (c) 2006-2008 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.

#ifndef CHROME_COMMON_NAVIGATION_TYPES_H_
#define CHROME_COMMON_NAVIGATION_TYPES_H_

#include "base/basictypes.h"

// Indicates different types of navigations that can occur that we will handle
// separately.
class NavigationType {
 public:
  enum Type {
    // Unknown type.
    UNKNOWN,

    // A new page was navigated in the main frame.
    NEW_PAGE,

    // Renavigating to an existing navigation entry. The entry is guaranteed to
    // exist in the list, or else it would be a new page or IGNORE navigation.
    EXISTING_PAGE,

    // The same page has been reloaded as a result of the user requesting
    // navigation to that same page (like pressing Enter in the URL bar). This
    // is not the same as an in-page navigation because we'll actually have a
    // pending entry for the load, which is then meaningless.
    SAME_PAGE,

    // In page navigations are when the reference fragment changes. This will
    // be in the main frame only (we won't even get notified of in-page
    // subframe navigations). It may be for any page, not necessarily the last
    // committed one (for example, whey going back to a page with a ref).
    IN_PAGE,

    // A new subframe was manually navigated by the user. We will create a new
    // NavigationEntry so they can go back to the previous subframe content
    // using the back button.
    NEW_SUBFRAME,

    // A subframe in the page was automatically loaded or navigated to such that
    // a new navigation entry should not be created. There are two cases:
    //  1. Stuff like iframes containing ads that the page loads automatically.
    //     The user doesn't want to see these, so we just update the existing
    //     navigation entry.
    //  2. Going back/forward to previous subframe navigations. We don't create
    //     a new entry here either, just update the last committed entry.
    // These two cases are actually pretty different, they just happen to
    // require almost the same code to handle.
    AUTO_SUBFRAME,

    // Nothing happened. This happens when we get information about a page we
    // don't know anything about. It can also happen when an iframe in a popup
    // navigated to about:blank is navigated. Nothing needs to be done.
    NAV_IGNORE,
  };

 private:
  // This class is for scoping only, so you shouldn't create an instance of it.
  NavigationType() {}

  DISALLOW_COPY_AND_ASSIGN(NavigationType);
};

#endif  // CHROME_COMMON_NAVIGATION_TYPES_H_