content/public/browser/browser_url_handler.h

   1 // Copyright (c) 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 CONTENT_PUBLIC_BROWSER_BROWSER_URL_HANDLER_H_
   6 #define CONTENT_PUBLIC_BROWSER_BROWSER_URL_HANDLER_H_
   7
   8 #include "content/common/content_export.h"
   9
  10 class GURL;
  11
  12 namespace content {
  13 class BrowserContext;
  14
  15 // We handle some special browser-level URLs (like "about:version")
  16 // before they're handed to a renderer.  This lets us do the URL handling
  17 // on the browser side (which has access to more information than the
  18 // renderers do) as well as sidestep the risk of exposing data to
  19 // random web pages (because from the resource loader's perspective, these
  20 // URL schemes don't exist).
  21 // BrowserURLHandler manages the list of all special URLs and manages
  22 // dispatching the URL handling to registered handlers.
  23 class CONTENT_EXPORT BrowserURLHandler {
  24  public:
  25   // The type of functions that can process a URL.
  26   // If a handler handles |url|, it should :
  27   // - optionally modify |url| to the URL that should be sent to the renderer
  28   // If the URL is not handled by a handler, it should return false.
  29   typedef bool (*URLHandler)(GURL* url,
  30                              BrowserContext* browser_context);
  31
  32   // Returns the null handler for use with |AddHandlerPair()|.
  33   static URLHandler null_handler();
  34
  35   // Returns the singleton instance.
  36   static  BrowserURLHandler* GetInstance();
  37
  38   // RewriteURLIfNecessary gives all registered URLHandlers a shot at processing
  39   // the given URL, and modifies it in place.
  40   // If the original URL needs to be adjusted if the modified URL is redirected,
  41   // this function sets |reverse_on_redirect| to true.
  42   virtual void RewriteURLIfNecessary(GURL* url,
  43                                      BrowserContext* browser_context,
  44                                      bool* reverse_on_redirect) = 0;
  45
  46   // Set the specified handler as a preliminary fixup phase to be done before
  47   // rewriting.  This allows minor cleanup for the URL without having it affect
  48   // the virtual URL.
  49   virtual void SetFixupHandler(URLHandler handler) = 0;
  50
  51   // Add the specified handler pair to the list of URL handlers.
  52   //
  53   // Note that normally, the reverse handler is only used if the modified URL is
  54   // not modified, e.g., by adding a hash fragment. To support this behavior,
  55   // register the forward and reverse handlers separately, each with a
  56   // null_handler() for the opposite direction.
  57   virtual void AddHandlerPair(URLHandler handler,
  58                               URLHandler reverse_handler) = 0;
  59
  60  protected:
  61   virtual ~BrowserURLHandler() {}
  62 };
  63
  64 }  // namespace content
  65
  66 #endif  // CONTENT_PUBLIC_BROWSER_BROWSER_URL_HANDLER_H_