public FileBrowserView setDefaultDirectory(File directory) throws IllegalArgumentException {
        if (directory == null || !directory.isDirectory())
            throw new IllegalArgumentException("You must use a File object that points to a valid, " +
                    "accessible directory.");
        if (!directory.canRead())
            throw new IllegalArgumentException("Could not read the specified default directory. Make " +
                    "sure you have permission to read the directory.");
        mDefaultDir = directory;
        return this;
    }
Sets the default directory to show when the FileBrowserView is initialized.

@param directory The file that points to the default directory to display.
@return An instance of this FileBrowserView to allow method chaining.
@throws IllegalArgumentException Thrown if the input File argument doesn't
                                 point to a valid directory or the directory can't be read.
core/src/main/java/com/filebrowser/View/FileBrowserView.java