Sets the current directory. Passing in null sets the file chooser to point to the user's default directory. This default depends on the operating system. It is typically the "My Documents" folder on Windows, and the user's home directory on Unix. If the file passed in as currentDirectory is not a directory, the parent of the file will be used as the currentDirectory. If the parent is not traversable, then it will walk up the parent tree until it finds a traversable directory, or hits the root of the file system.

Parameters:

dir the current directory to point to