Add BPackageRoster::GetActivePackages()

The implementation is temporary. Currently it reads through the packages
in the respective packages directory and checks against the package
links. Once package activation is tracked explicitly we'll use the
activation file/directory.

headers/build/os/package/PackageDefs.h

@@ -0,0 +1,2 @@
+#include <../os/package/PackageDefs.h>
+

headers/os/package/PackageDefs.h

@@ -0,0 +1,24 @@
+/*
+ * Copyright 2011, Haiku, Inc.
+ * Distributed under the terms of the MIT License.
+ */
+#ifndef _PACKAGE__PACKAGE_DEFS_H_
+#define _PACKAGE__PACKAGE_DEFS_H_
+
+
+namespace BPackageKit {
+
+
+enum BPackageInstallationLocation {
+	B_PACKAGE_INSTALLATION_LOCATION_SYSTEM,
+	B_PACKAGE_INSTALLATION_LOCATION_COMMON,
+	B_PACKAGE_INSTALLATION_LOCATION_HOME,
+
+	B_PACKAGE_INSTALLATION_LOCATION_ENUM_COUNT
+};
+
+
+}	// namespace BPackageKit
+
+
+#endif // _PACKAGE__PACKAGE_DEFS_H_

headers/os/package/PackageRoster.h

@@ -10,6 +10,8 @@
 #include <FindDirectory.h>
 #include <Path.h>
 
+#include <package/PackageDefs.h>
+
 
 class BStringList;
 
@@ -26,6 +28,7 @@ struct BRepositoryConfigVisitor {
 };
 
 
+class BPackageInfoSet;
 class BRepositoryCache;
 class BRepositoryConfig;
 
@@ -56,12 +59,16 @@ public:
 									BRepositoryCache* repositoryCache);
 			status_t			GetRepositoryConfig(const BString& name,
 									BRepositoryConfig* repositoryConfig);
+
+			status_t			GetActivePackages(
+									BPackageInstallationLocation location,
+									BPackageInfoSet& packageInfos);
+
 private:
 			status_t			_GetRepositoryPath(BPath* path, bool create,
 									directory_which whichDir) const;
 			status_t			_VisitRepositoryConfigs(const BPath& path,
 									BRepositoryConfigVisitor& visitor);
-
 };