Add implementations of various extension related methods (derived from file_u...

base/file_path.h

 // Copyright (c) 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.
 
 // FilePath is a container for pathnames stored in a platform's native string
 // type, providing containers for manipulation in according with the
 // platform's conventions for pathnames.  It supports the following path
 // types:
 //
 //                   POSIX            Windows
@@ skipping 91 matching lines @@
   // but kSeparators[0] is treated as the canonical separator and will be used
   // when composing pathnames.
   static const CharType kSeparators[];
 
   // A special path component meaning "this directory."
   static const CharType kCurrentDirectory[];
 
   // A special path component meaning "the parent directory."
   static const CharType kParentDirectory[];
 
+  // The character used to identify a file extension.
+  static const CharType kExtensionSeparator;
+
   FilePath() {}
   FilePath(const FilePath& that) : path_(that.path_) {}
   explicit FilePath(const StringType& path) : path_(path) {}
 
   FilePath& operator=(const FilePath& that) {
     path_ = that.path_;
     return *this;
   }
 
   bool operator==(const FilePath& that) const {
@@ skipping 18 matching lines @@
   // kCurrentDirectory.  If this object already refers to the root directory,
   // returns a FilePath identifying the root directory.
   FilePath DirName() const;
 
   // Returns a FilePath corresponding to the last path component of this
   // object, either a file or a directory.  If this object already refers to
   // the root directory, returns a FilePath identifying the root directory;
   // this is the only situation in which BaseName will return an absolute path.
   FilePath BaseName() const;
 
+  // Returns ".jpg" for path "C:\pics\jojo.jpg", or an empty string if
+  // the file has no extension.  If non-empty, Extension() will always start
+  // with precisely one ".".  The following code should always work regardless
+  // of the value of path.
+  // new_path = path.RemoveExtension().value().append(path.Extension());
+  // ASSERT(new_path == path.value());
+  // NOTE: this is different from the original file_util implementation which
+  // returned the extension without a leading "." ("jpg" instead of ".jpg")
+  StringType Extension() const;
+
+  // Returns "C:\pics\jojo" for path "C:\pics\jojo.jpg"
+  // NOTE: this is slightly different from the similar file_util implementation
+  // which returned simply 'jojo'.
+  FilePath RemoveExtension() const;
+
+  // Inserts |suffix| after the file name portion of |path| but before the
+  // extension.  Returns "" if BaseName() == "." or "..".
+  // Examples:
+  // path == "C:\pics\jojo.jpg" suffix == " (1)", returns "C:\pics\jojo (1).jpg"
+  // path == "jojo.jpg"         suffix == " (1)", returns "jojo (1).jpg"
+  // path == "C:\pics\jojo"     suffix == " (1)", returns "C:\pics\jojo (1)"
+  // path == "C:\pics.old\jojo" suffix == " (1)", returns "C:\pics.old\jojo (1)"
+  FilePath InsertBeforeExtension(const StringType& suffix) const;
+
+  // Replaces the extension of |file_name| with |extension|.  If |file_name|
+  // does not have an extension, them |extension| is added.  If |extension| is
+  // empty, then the extension is removed from |file_name|.
+  // Returns "" if BaseName() == "." or "..".
+  FilePath ReplaceExtension(const StringType& extension) const;
+
   // Returns a FilePath by appending a separator and the supplied path
   // component to this object's path.  Append takes care to avoid adding
   // excessive separators if this object's path already ends with a separator.
   // If this object's path is kCurrentDirectory, a new FilePath corresponding
   // only to |component| is returned.  |component| must be a relative path;
   // it is an error to pass an absolute path.
   FilePath Append(const StringType& component) const WARN_UNUSED_RESULT;
   FilePath Append(const FilePath& component) const WARN_UNUSED_RESULT;
 
   // Returns true if this FilePath contains an absolute path.  On Windows, an
@@ skipping 59 matching lines @@
 namespace stdext {
 
 inline size_t hash_value(const FilePath& f) {
   return hash_value(f.value());
 }
 
 }  // namespace stdext
 #endif  // COMPILER
 
 #endif  // BASE_FILE_PATH_H_