chrome/browser/external_protocol/external_protocol_handler.h

   1 // Copyright (c) 2011 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_EXTERNAL_PROTOCOL_EXTERNAL_PROTOCOL_HANDLER_H_
   6 #define CHROME_BROWSER_EXTERNAL_PROTOCOL_EXTERNAL_PROTOCOL_HANDLER_H_
   7
   8 #include <string>
   9
  10 #include "chrome/browser/shell_integration.h"
  11
  12 class GURL;
  13 class PrefRegistrySimple;
  14
  15 namespace base {
  16 class DictionaryValue;
  17 }
  18
  19 class ExternalProtocolHandler {
  20  public:
  21   enum BlockState {
  22     DONT_BLOCK,
  23     BLOCK,
  24     UNKNOWN,
  25   };
  26
  27   // Delegate to allow unit testing to provide different behavior.
  28   class Delegate {
  29    public:
  30     virtual ShellIntegration::DefaultProtocolClientWorker* CreateShellWorker(
  31         ShellIntegration::DefaultWebClientObserver* observer,
  32         const std::string& protocol) = 0;
  33     virtual BlockState GetBlockState(const std::string& scheme) = 0;
  34     virtual void BlockRequest() = 0;
  35     virtual void RunExternalProtocolDialog(const GURL& url,
  36                                            int render_process_host_id,
  37                                            int routing_id) = 0;
  38     virtual void LaunchUrlWithoutSecurityCheck(const GURL& url) = 0;
  39     virtual void FinishedProcessingCheck() = 0;
  40     virtual ~Delegate() {}
  41   };
  42
  43   // Returns whether we should block a given scheme.
  44   static BlockState GetBlockState(const std::string& scheme);
  45
  46   // Sets whether we should block a given scheme.
  47   static void SetBlockState(const std::string& scheme, BlockState state);
  48
  49   // Checks to see if the protocol is allowed, if it is whitelisted,
  50   // the application associated with the protocol is launched on the io thread,
  51   // if it is blacklisted, returns silently. Otherwise, an
  52   // ExternalProtocolDialog is created asking the user. If the user accepts,
  53   // LaunchUrlWithoutSecurityCheck is called on the io thread and the
  54   // application is launched.
  55   // Must run on the UI thread.
  56   static void LaunchUrl(const GURL& url,
  57                         int render_process_host_id,
  58                         int tab_contents_id) {
  59     LaunchUrlWithDelegate(url, render_process_host_id, tab_contents_id, NULL);
  60   }
  61
  62   // Version of LaunchUrl allowing use of a delegate to facilitate unit
  63   // testing.
  64   static void LaunchUrlWithDelegate(const GURL& url,
  65                                     int render_process_host_id,
  66                                     int tab_contents_id,
  67                                     Delegate* delegate);
  68
  69   // Creates and runs a External Protocol dialog box.
  70   // |url| - The url of the request.
  71   // |render_process_host_id| and |routing_id| are used by
  72   // tab_util::GetWebContentsByID to aquire the tab contents associated with
  73   // this dialog.
  74   // NOTE: There is a race between the Time of Check and the Time Of Use for
  75   //       the command line. Since the caller (web page) does not have access
  76   //       to change the command line by itself, we do not do anything special
  77   //       to protect against this scenario.
  78   // This is implemented separately on each platform.
  79   static void RunExternalProtocolDialog(const GURL& url,
  80                                         int render_process_host_id,
  81                                         int routing_id);
  82
  83   // Register the ExcludedSchemes preference.
  84   static void RegisterPrefs(PrefRegistrySimple* registry);
  85
  86   // Starts a url using the external protocol handler with the help
  87   // of shellexecute. Should only be called if the protocol is whitelisted
  88   // (checked in LaunchUrl) or if the user explicitly allows it. (By selecting
  89   // "Launch Application" in an ExternalProtocolDialog.) It is assumed that the
  90   // url has already been escaped, which happens in LaunchUrl.
  91   // NOTE: You should Not call this function directly unless you are sure the
  92   // url you have has been checked against the blacklist, and has been escaped.
  93   // All calls to this function should originate in some way from LaunchUrl.
  94   static void LaunchUrlWithoutSecurityCheck(const GURL& url,
  95                                             int render_process_host_id,
  96                                             int tab_contents_id);
  97
  98   // Prepopulates the dictionary with known protocols to deny or allow, if
  99   // preferences for them do not already exist.
 100   static void PrepopulateDictionary(base::DictionaryValue* win_pref);
 101
 102   // Allows LaunchUrl to proceed with launching an external protocol handler.
 103   // This is typically triggered by a user gesture, but is also called for
 104   // each extension API function. Note that each call to LaunchUrl resets
 105   // the state to false (not allowed).
 106   static void PermitLaunchUrl();
 107
 108  private:
 109   DISALLOW_COPY_AND_ASSIGN(ExternalProtocolHandler);
 110 };
 111
 112 #endif  // CHROME_BROWSER_EXTERNAL_PROTOCOL_EXTERNAL_PROTOCOL_HANDLER_H_