upnp/Discovery: add listener interface

src/lib/upnp/Discovery.cxx

@@ -53,6 +53,24 @@ isMSDevice(const char *st)
 	return memcmp(MediaServerDType, st, sz) == 0;
 }
 
+static void
+AnnounceFoundUPnP(UPnPDiscoveryListener &listener, const UPnPDevice &device)
+{
+	for (const auto &service : device.services)
+		if (isCDService(service.serviceType.c_str()))
+			listener.FoundUPnP(ContentDirectoryService(device,
+								   service));
+}
+
+static void
+AnnounceLostUPnP(UPnPDiscoveryListener &listener, const UPnPDevice &device)
+{
+	for (const auto &service : device.services)
+		if (isCDService(service.serviceType.c_str()))
+			listener.LostUPnP(ContentDirectoryService(device,
+								  service));
+}
+
 inline void
 UPnPDeviceDirectory::LockAdd(ContentDirectoryDescriptor &&d)
 {
@@ -66,6 +84,9 @@ UPnPDeviceDirectory::LockAdd(ContentDirectoryDescriptor &&d)
 	}
 
 	directories.emplace_back(std::move(d));
+
+	if (listener != nullptr)
+		AnnounceFoundUPnP(*listener, directories.back().device);
 }
 
 inline void
@@ -76,6 +97,9 @@ UPnPDeviceDirectory::LockRemove(const std::string &id)
 	for (auto i = directories.begin(), end = directories.end();
 	     i != end; ++i) {
 		if (i->id == id) {
+			if (listener != nullptr)
+				AnnounceLostUPnP(*listener, i->device);
+
 			directories.erase(i);
 			break;
 		}
@@ -208,8 +232,10 @@ UPnPDeviceDirectory::expireDevices(Error &error)
 	return true;
 }
 
-UPnPDeviceDirectory::UPnPDeviceDirectory(LibUPnP *_lib)
+UPnPDeviceDirectory::UPnPDeviceDirectory(LibUPnP *_lib,
+					 UPnPDiscoveryListener *_listener)
 	:lib(_lib),
+	 listener(_listener),
 	 discoveredQueue("DiscoveredQueue"),
 	 m_searchTimeout(2), m_lastSearch(0)
 {

src/lib/upnp/Discovery.hxx

@@ -34,6 +34,12 @@
 class LibUPnP;
 class ContentDirectoryService;
 
+class UPnPDiscoveryListener {
+public:
+	virtual void FoundUPnP(const ContentDirectoryService &service) = 0;
+	virtual void LostUPnP(const ContentDirectoryService &service) = 0;
+};
+
 /**
  * Manage UPnP discovery and maintain a directory of active devices. Singleton.
  *
@@ -86,6 +92,7 @@ class UPnPDeviceDirectory {
 	};
 
 	LibUPnP *const lib;
+	UPnPDiscoveryListener *const listener;
 
 	Mutex mutex;
 	std::list<ContentDirectoryDescriptor> directories;
@@ -104,7 +111,8 @@ class UPnPDeviceDirectory {
 	unsigned m_lastSearch;
 
 public:
-	UPnPDeviceDirectory(LibUPnP *_lib);
+	UPnPDeviceDirectory(LibUPnP *_lib,
+			    UPnPDiscoveryListener *_listener=nullptr);
 	~UPnPDeviceDirectory();
 
 	UPnPDeviceDirectory(const UPnPDeviceDirectory &) = delete;