// 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 "base/basictypes.h"
#include "base/ref_counted.h"
class FilePath;
class MessageLoop;
// 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 ~Delegate() {}
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.
// Any background operations will be ran on |backend_loop|, or inside Watch
// if |backend_loop| is NULL. If |recursive| is true, the delegate will be
// notified for each change within the directory tree starting at |path|.
// Returns false on error.
//
// Note: on Windows you may got more notifications for non-recursive watch
// than you expect, especially on versions earlier than Vista. The behavior
// is consistent on any particular version of Windows, but not across
// different versions.
bool Watch(const FilePath& path, Delegate* delegate,
MessageLoop* backend_loop, bool recursive) {
return impl_->Watch(path, delegate, backend_loop, recursive);
}
// Used internally to encapsulate different members on different platforms.
class PlatformDelegate : public base::RefCounted<PlatformDelegate> {
public:
virtual bool Watch(const FilePath& path, Delegate* delegate,
MessageLoop* backend_loop, bool recursive) = 0;
protected:
friend class base::RefCounted<PlatformDelegate>;
virtual ~PlatformDelegate() {}
};
private:
scoped_refptr<PlatformDelegate> impl_;
DISALLOW_COPY_AND_ASSIGN(DirectoryWatcher);
};
#endif // BASE_DIRECTORY_WATCHER_H_