add prperty changes to stuff monitored by jack_evmon (in tools)

evmon.c

@@ -23,6 +23,8 @@
 #include <stdlib.h>
 
 #include <jack/jack.h>
+#include <jack/metadata.h>
+#include <jack/uuid.h>
 
 void
 port_callback (jack_port_id_t port, int yn, void* arg)
@@ -49,6 +51,39 @@ graph_callback (void* arg)
 	return 0;
 }
 
+void
+propchange (jack_uuid_t subject, const char* key, jack_property_change_t change)
+{
+        char buf[JACK_UUID_STRING_SIZE];
+        const char* action = "";
+
+        switch (change) {
+        case PropertyCreated:
+                action = "created";
+                break;
+
+        case PropertyChanged:
+                action = "changed";
+                break;
+
+        case PropertyDeleted:
+                action = "deleted";
+                break;
+        }
+
+        if (jack_uuid_empty (subject)) {
+                printf ("All properties changed!\n");
+        } else {
+                jack_uuid_unparse (subject, buf);
+                
+                if (key) {
+                        printf ("key [%s] for %s %s\n", key, buf, action);
+                } else {
+                        printf ("all keys for %s %s\n", buf, action);
+                }
+        }
+}
+
 int
 main (int argc, char *argv[])
 {
@@ -81,6 +116,10 @@ main (int argc, char *argv[])
 		fprintf (stderr, "cannot set graph order registration callback\n");
 		return 1;
 	}
+        if (jack_set_property_change_callback (client, (JackPropertyChangeCallback) propchange, 0)) {
+                fprintf (stderr, "cannot set property change callback\n");
+                return 1;
+        }
 	if (jack_activate (client)) {
 		fprintf (stderr, "cannot activate client");
 		return 1;