--- /dev/null
+<?php
+
+namespace Drupal\libraries\ExternalLibrary\Local;
+
+/**
+ * Provides an interface for library locators.
+ *
+ * Because determining the installation status and library path of a library
+ * is not specific to any library or even any library type, this logic can be
+ * implemented generically in form of a locator.
+ */
+interface LocatorInterface {
+
+ /**
+ * Locates a library.
+ *
+ * @param \Drupal\libraries\ExternalLibrary\Local\LocalLibraryInterface $library
+ * The library to locate.
+ */
+ public function locate(LocalLibraryInterface $library);
+
+}