Returns the directory where a theme should be installed.
If the theme is already installed, drupal_get_path() will return a valid path and we should install it there (although we need to use an absolute path, so we prepend DRUPAL_ROOT). If we're installing a new theme, we always want it to go into /themes, since that's where all the documentation recommends users install their themes, and there's no way that can conflict on a multi-site installation, since the Update manager won't let you install a new theme if it's already found on your system, and if there was a copy in the top-level we'd see it.
string A directory path.
Overrides UpdaterInterface::getInstallDirectory
public function getInstallDirectory() {
if ($relative_path = drupal_get_path('theme', $this->name)) {
$relative_path = dirname($relative_path);
}
else {
$relative_path = 'themes';
}
return DRUPAL_ROOT . '/' . $relative_path;
}