Allow chrome to become the os default handler for arbitrary protocols on mac/win.

chrome/browser/shell_integration.h

Index: chrome/browser/shell_integration.h
diff --git a/chrome/browser/shell_integration.h b/chrome/browser/shell_integration.h
index 575575e9175ecc92cc9f805e1c3f5acca2e4febd..bad39a280b7f06c782bf99ac64ac0e774ca8f16b 100644
--- a/chrome/browser/shell_integration.h
+++ b/chrome/browser/shell_integration.h
@@ -30,26 +30,35 @@ class ShellIntegration {
   // this operation fails.
   static bool SetAsDefaultBrowser();
 
+  // Sets Chrome as client application for the given protocol (only for

[Mark Mentovai, 2011/05/24 16:28:53]

as the client application

[benwells, 2011/05/25 08:07:19]

Done.

+  // current user). Returns false if this operation fails.

[Mark Mentovai, 2011/05/24 16:28:53]

for the current user

[benwells, 2011/05/25 08:07:19]

Done.

+  static bool SetAsDefaultProtocolClient(const std::string& protocol);
+
   // On Linux, it may not be possible to determine or set the default browser
   // on some desktop environments or configurations. So, we use this enum and
   // not a plain bool. (Note however that if used like a bool, this enum will
   // have reasonable behavior.)
-  enum DefaultBrowserState {
-    NOT_DEFAULT_BROWSER = 0,
-    IS_DEFAULT_BROWSER,
-    UNKNOWN_DEFAULT_BROWSER
+  enum DefaultWebClientState {
+    NOT_DEFAULT_WEB_CLIENT = 0,
+    IS_DEFAULT_WEB_CLIENT,
+    UNKNOWN_DEFAULT_WEB_CLIENT = -1
   };
 
   // Attempt to determine if this instance of Chrome is the default browser and
   // return the appropriate state. (Defined as being the handler for HTTP/HTTPS
   // protocols; we don't want to report "no" here if the user has simply chosen
   // to open HTML files in a text editor and FTP links with an FTP client.)
-  static DefaultBrowserState IsDefaultBrowser();
+  static DefaultWebClientState IsDefaultBrowser();
 
   // Returns true if Firefox is likely to be the default browser for the current
   // user. This method is very fast so it can be invoked in the UI thread.
   static bool IsFirefoxDefaultBrowser();
 
+  // Attempt to determine if this instance of Chrome is the default client
+  // application for the given protocol and return the appropriate state.
+  static DefaultWebClientState
+      IsDefaultProtocolClient(const std::string& protocol);
+
   struct ShortcutInfo {
     ShortcutInfo();
     ~ShortcutInfo();
@@ -123,66 +132,121 @@ class ShellIntegration {
   static void MigrateChromiumShortcuts();
 #endif  // defined(OS_WIN)
 
-  // The current default browser UI state
-  enum DefaultBrowserUIState {
+  // The current default browser / client application UI state

[xiyuan, 2011/05/24 17:55:20]

nit: did you mean "web client application"?

[benwells, 2011/05/25 08:07:19]

Done.

+  enum DefaultWebClientUIState {
     STATE_PROCESSING,
     STATE_NOT_DEFAULT,
     STATE_IS_DEFAULT,
     STATE_UNKNOWN
   };
 
-  class DefaultBrowserObserver {
+  class DefaultWebClientObserver {
    public:
     // Updates the UI state to reflect the current default browser state.
-    virtual void SetDefaultBrowserUIState(DefaultBrowserUIState state) = 0;
-    virtual ~DefaultBrowserObserver() {}
+    virtual void SetDefaultWebClientUIState(DefaultWebClientUIState state) = 0;
+    virtual ~DefaultWebClientObserver() {}

[Mark Mentovai, 2011/05/24 16:28:53]

Nit (to fix the existing code): within public, private, and protected, the
destructor should precede any methods.

http://google-styleguide.googlecode.com/svn/trunk/cppguide.xml?showone=Declar...

[benwells, 2011/05/25 08:07:19]

Done.

   };
-  //  A helper object that handles checking if Chrome is the default browser on
-  //  Windows and also setting it as the default browser. These operations are
-  //  performed asynchronously on the file thread since registry access is
-  //  involved and this can be slow.
-  //
-  class DefaultBrowserWorker
-      : public base::RefCountedThreadSafe<DefaultBrowserWorker> {
+
+  //  Helper objects that handle checking if Chrome is the default browser
+  //  or application for a url protocol on Windows and Linux, and also setting
+  //  it as the default. These operations are performed asynchronously on the
+  //  file thread since registry access (on Windows) or the preference database
+  //  (on Linux) are involved and this can be slow.
+  class DefaultWebClientWorker
+      : public base::RefCountedThreadSafe<DefaultWebClientWorker> {
    public:
-    explicit DefaultBrowserWorker(DefaultBrowserObserver* observer);
+    explicit DefaultWebClientWorker(DefaultWebClientObserver* observer);
 
-    // Checks if Chrome is the default browser.
-    void StartCheckDefaultBrowser();
+    // Checks to see if Chrome is the default web client application.

[Mark Mentovai, 2011/05/24 16:28:53]

For this and the next “Start” call, the header comment should say how the
observer gets called.

[benwells, 2011/05/25 08:07:19]

Done.

+    void StartCheckIsDefault();
 
-    // Sets Chrome as the default browser.
-    void StartSetAsDefaultBrowser();
+    // Sets Chrome as the default web client application.
+    void StartSetAsDefault();
 
     // Called to notify the worker that the view is gone.
     void ObserverDestroyed();
 
+   protected:
+    friend class base::RefCountedThreadSafe<DefaultWebClientWorker>;
+
+    virtual ~DefaultWebClientWorker() {}
+
    private:
-    friend class base::RefCountedThreadSafe<DefaultBrowserWorker>;
+    // Function that performs the check.
+    virtual DefaultWebClientState CheckIsDefault() = 0;
 
-    virtual ~DefaultBrowserWorker() {}
+    // Function that sets Chrome as the default web client.
+    virtual void SetAsDefault() = 0;
+
+    // Function that handles performing the check on the file thread. This
+    // function is posted as a task onto the file thread, where it performs
+    // the check and sends the result back to the UI thread.

[Mark Mentovai, 2011/05/24 16:28:53]

Instead of “sends the result back to the UI thread,” this should say what
function gets posted to the UI thread.

[benwells, 2011/05/25 08:07:19]

Done.

+    void ExecuteCheckIsDefault();
+
+    // Function that handles setting Chrome as the default web client on the
+    // file thread. This function is posted as a task onto the file thread.
+    // Once it is finished it posts a task back to the UI thread to complete

[Mark Mentovai, 2011/05/24 16:28:53]

Same: say what will be called on the UI thread.

[benwells, 2011/05/25 08:07:19]

Done.

+    // the job.
+    void ExecuteSetAsDefault();
+
+    // Communicate results to the observer. This function is posted as a task
+    // back to the UI thread from the file thread.

[Mark Mentovai, 2011/05/24 16:28:53]

And again, for this and the next one, it’s more useful to say where the call
comes from, not just the thread.

[benwells, 2011/05/25 08:07:19]

Done.

+    void CompleteCheckIsDefault(DefaultWebClientState state);
+
+    // When the action to set Chrome as the default has completed this function
+    // is posted as a task back to the UI thread. If an observer is present
+    // it will execute a check, which will report the status of Chrome as the
+    // default web client back to the observer.
+    void CompleteSetAsDefault();
+
+    // Updates the UI in our associated view with the current default web
+    // client state.
+    void UpdateUI(DefaultWebClientState state);
+
+    DefaultWebClientObserver* observer_;
+
+    DISALLOW_COPY_AND_ASSIGN(DefaultWebClientWorker);
+  };
 
-    // Functions that track the process of checking if Chrome is the default
-    // browser.  |ExecuteCheckDefaultBrowser| checks the registry on the file
-    // thread.  |CompleteCheckDefaultBrowser| notifies the view to update on the
-    // UI thread.
-    void ExecuteCheckDefaultBrowser();
-    void CompleteCheckDefaultBrowser(DefaultBrowserState state);
+  // Worker for checking and setting the default browser.
+  class DefaultBrowserWorker : public DefaultWebClientWorker {
+   public:
+    explicit DefaultBrowserWorker(DefaultWebClientObserver* observer);
 
-    // Functions that track the process of setting Chrome as the default
-    // browser.  |ExecuteSetAsDefaultBrowser| updates the registry on the file
-    // thread.  |CompleteSetAsDefaultBrowser| notifies the view to update on the
-    // UI thread.
-    void ExecuteSetAsDefaultBrowser();
-    void CompleteSetAsDefaultBrowser();
+   private:
+    virtual ~DefaultBrowserWorker() {}
 
-    // Updates the UI in our associated view with the current default browser
-    // state.
-    void UpdateUI(DefaultBrowserState state);
+    // Check if Chrome is the default browser.
+    virtual DefaultWebClientState CheckIsDefault();
 
-    DefaultBrowserObserver* observer_;
+    // Set Chrome as the default browser.
+    virtual void SetAsDefault();
 
     DISALLOW_COPY_AND_ASSIGN(DefaultBrowserWorker);
   };
+
+  // Worker for checking and setting the default client application
+  // for a given protocol. A different worker instance is needed for each
+  // protocol you are interested in, so to check or set the default for
+  // multiple protocols you should use multiple worker objects.
+  class DefaultProtocolClientWorker : public DefaultWebClientWorker {
+   public:
+    DefaultProtocolClientWorker(DefaultWebClientObserver* observer,
+                                const std::string& protocol);
+
+   private:
+    virtual ~DefaultProtocolClientWorker() {}
+
+    // Check is Chrome is the default handler for this protocol.
+    virtual DefaultWebClientState CheckIsDefault();
+
+    // Set Chrome as the default handler for this protocol.
+    virtual void SetAsDefault();
+
+    std::string protocol_;
+
+    DISALLOW_COPY_AND_ASSIGN(DefaultProtocolClientWorker);
+  };
 };
 
 #endif  // CHROME_BROWSER_SHELL_INTEGRATION_H_