FilePathWatcher::Watch() - Listen for sub directory changes.

base/files/file_path_watcher.h

 // Copyright (c) 2012 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.
 
 // This module provides a way to monitor a file or directory for changes.
 
 #ifndef BASE_FILES_FILE_PATH_WATCHER_H_
 #define BASE_FILES_FILE_PATH_WATCHER_H_
 
 #include "base/base_export.h"
@@ skipping 41 matching lines @@
 
   // Used internally to encapsulate different members on different platforms.
   // TODO(jhawkins): Move this into its own file. Also fix the confusing naming
   // wrt Delegate vs PlatformDelegate.
   class PlatformDelegate : public base::RefCountedThreadSafe<PlatformDelegate> {
    public:
     PlatformDelegate();
 
     // Start watching for the given |path| and notify |delegate| about changes.
     virtual bool Watch(const FilePath& path,
+                       bool recursive,
                        Delegate* delegate) WARN_UNUSED_RESULT = 0;
 
     // Stop watching. This is called from FilePathWatcher's dtor in order to
     // allow to shut down properly while the object is still alive.
     // It can be called from any thread.
     virtual void Cancel() = 0;
 
    protected:
     friend class base::RefCountedThreadSafe<PlatformDelegate>;
     friend class FilePathWatcher;
@@ skipping 36 matching lines @@
   static void CancelWatch(const scoped_refptr<PlatformDelegate>& delegate);
 
   // Register interest in any changes on |path|. OnPathChanged will be called
   // back for each change. Returns true on success.
   // OnFilePathChanged() will be called on the same thread as Watch() is called,
   // which should have a MessageLoop of TYPE_IO.
   //
   // Deprecated: new code should use the callback interface, declared below.
   // The FilePathWatcher::Delegate interface will be removed once all client
   // code has been updated. http://crbug.com/130980
-  virtual bool Watch(const FilePath& path, Delegate* delegate)
+  virtual bool Watch(const FilePath& path, bool recursive, Delegate* delegate)

[Lei Zhang, 2012/11/21 03:36:49]

Do we need this? I don't think anyone will write new code with the deprecated
method and ask for recursive.

[kmadhusu, 2012/11/21 04:13:26]

bool Watch(const FilePath& path, bool recursive, const Callback& callback) calls
this function.

[Lei Zhang, 2012/11/21 04:21:02]

Maybe it's time to make the new Watch() method call impl_->Watch() directly?
We'll eventually do that anyway, since the old Watch() method will eventually go
away.

[kmadhusu, 2012/11/22 01:39:41]

Done.

       WARN_UNUSED_RESULT;
 
   // Invokes |callback| whenever updates to |path| are detected. This should be
-  // called at most once, and from a MessageLoop of TYPE_IO. The callback will
+  // called at most once, and from a MessageLoop of TYPE_IO. Set |recursive| to

[Lei Zhang, 2012/11/21 03:36:49]

"Set |recursive| to true to watch the |path| and its children."

[kmadhusu, 2012/11/21 04:13:26]

Done.

+  // true, to watch the sub trees of the specified |path|. The callback will
   // be invoked on the same loop. Returns true on success.
-  bool Watch(const FilePath& path, const Callback& callback);
+  bool Watch(const FilePath& path, bool recursive, const Callback& callback);
 
  private:
   scoped_refptr<PlatformDelegate> impl_;
 
   DISALLOW_COPY_AND_ASSIGN(FilePathWatcher);
 };
 
 }  // namespace files
 }  // namespace base
 
 #endif  // BASE_FILES_FILE_PATH_WATCHER_H_