Add a DirectoryWatcher class, allowing objects to be notified whenever...

base/directory_watcher.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.
+
+// This module provides a way to monitor a directory for changes.
+
+#ifndef BASE_DIRECTORY_WATCHER_H_
+#define BASE_DIRECTORY_WATCHER_H_
+
+#include <string>
+#include "base/basictypes.h"
+#include "base/ref_counted.h"
+
+class FilePath;
+
+// This class lets you register interest in changes on a directory.
+// The delegate will get called whenever a file is added or changed in the
+// directory.
+class DirectoryWatcher {
+ public:
+  class Delegate {
+   public:
+    virtual void OnDirectoryChanged(const FilePath& path) = 0;
+  };
+
+  DirectoryWatcher();
+  ~DirectoryWatcher();
+
+  // Register interest in any changes in the directory |path|.
+  // OnDirectoryChanged will be called back for each change within the dir.
+  // Returns false on error.
+  bool Watch(const FilePath& path, Delegate* delegate);
+
+ private:
+  class Impl;
+  friend class Impl;
+  scoped_refptr<Impl> impl_;
+
+  DISALLOW_COPY_AND_ASSIGN(DirectoryWatcher);
+};
+
+#endif  // BASE_DIRECTORY_WATCHER_H_