Sets the Application visual style.

        :param full_screen_style: Use fullscreen stylesheet file.
        :type full_screen_style: bool
        :return: Method success.
        :rtype: bool

def set_visual_style(self, full_screen_style=False):
        """
        Sets the Application visual style.

        :param full_screen_style: Use fullscreen stylesheet file.
        :type full_screen_style: bool
        :return: Method success.
        :rtype: bool
        """

        LOGGER.debug("> Setting Application visual style.")
        platform_styles = {"Windows": (("Windows", "Microsoft"),
                                       UiConstants.windows_style,
                                       UiConstants.windows_stylesheet_file,
                                       UiConstants.windows_full_screen_stylesheet_file),
                           "Darwin": (("Darwin",),
                                      UiConstants.darwin_style,
                                      UiConstants.darwin_stylesheet_file,
                                      UiConstants.darwin_full_screen_stylesheet_file),
                           "Linux": (("Linux",),
                                     UiConstants.linux_style,
                                     UiConstants.linux_stylesheet_file,
                                     UiConstants.linux_full_screen_stylesheet_file)}

        style_sheet_file = None
        for platform_style, settings in platform_styles.iteritems():
            LOGGER.debug("> Setting '{0}' visual style.".format(platform_style))
            platform_systems, style, styleSheeFile, full_screen_style_sheet_file = settings
            if platform.system() in platform_systems:
                RuntimeGlobals.application.setStyle(style)
                style_sheet_path = umbra.ui.common.get_resource_path(styleSheeFile)
                if full_screen_style:
                    full_screen_style_sheet_path = umbra.ui.common.get_resource_path(full_screen_style_sheet_file,
                                                                                     raise_exception=False)
                    style_sheet_path = full_screen_style_sheet_path or style_sheet_path
                style_sheet_file = foundations.io.File(style_sheet_path)
                break

        if not style_sheet_file:
            raise foundations.exceptions.FileExistsError(
                "{0} | No stylesheet file found, visual style will not be applied!".format(self.__class__.__name__))

        if foundations.common.path_exists(style_sheet_file.path):
            LOGGER.debug("> Reading style sheet file: '{0}'.".format(style_sheet_file.path))
            style_sheet_file.cache()
            for i, line in enumerate(style_sheet_file.content):
                search = re.search(r"url\((?P<url>.*)\)", line)
                if not search:
                    continue

                style_sheet_file.content[i] = line.replace(search.group("url"),
                                                           foundations.strings.to_forward_slashes(
                                                               umbra.ui.common.get_resource_path(search.group("url"))))
            RuntimeGlobals.application.setStyleSheet(QString("".join(style_sheet_file.content)))
            return True
        else:
            raise foundations.exceptions.FileExistsError(
                "{0} | '{1}' stylesheet file is not available, visual style will not be applied!".format(
                    self.__class__.__name__, style_sheet_file.path))