This interface lets a user list files and directories in a directory. If there are no additions to or deletions from a directory between the first and last call to readEntries, and no errors occur, then:
Read the next block of entries from this directory.
Called once per successful call to readEntries to deliver the next previously-unreported set of Entries in the associated Directory. If all Entries have already been returned from previous invocations of readEntries, successCallback must be called with a zero-length array as an argument.
A callback indicating that there was an error reading from the Directory.