Display an error message when the JACK transport is broken.

jack.C

@@ -368,7 +368,10 @@ midi_init ( void )
 {
     MESSAGE( "Initializing Jack MIDI" );
 
-    if (( client = jack_client_new ( APP_NAME )) == 0 )
+/*     if (( client = jack_client_new ( APP_NAME )) == 0 ) */
+/*         return 0; */
+
+    if (( client = jack_client_open ( APP_NAME, (jack_options_t)0, NULL )) == 0 )
         return 0;
 
     /* create output ports */
@@ -406,9 +409,6 @@ midi_init ( void )
 //1    jack_set_buffer_size_callback( client, bufsize, 0 );
     jack_set_process_callback( client, process, 0 );
 
-    jack_activate( client );
-
-    sample_rate = jack_get_sample_rate( client );
 
 /*     /\* initialize buffer size *\/ */
 /*     transport_poll(); */
@@ -422,6 +422,16 @@ midi_init ( void )
     else
         WARNING( "could not take over as timebase master" );
 
+    jack_activate( client );
+
+    sample_rate = jack_get_sample_rate( client );
+
+    /* FIXME: hack! we need to wait until jack finally calls our
+     * timebase and process callbacks in order to be able to test for
+     * valid transport info. */
+    MESSAGE( "Waiting for JACK..." );
+    usleep( 500000 );
+
     return 1;
 }
 

main.C

@@ -164,6 +164,9 @@ main ( int argc, char **argv )
     if ( ! midi_init() )
         ASSERTION( "Could not initialize MIDI system! (is Jack running and with MIDI ports enabled?)" );
 
+    if ( ! transport.valid )
+        ASSERTION( "The version of JACK you are using does not appear to be capable of passing BBT positional information." );
+
     MESSAGE( "Initializing GUI" );
 
     init_colors();

transport.C

@@ -33,7 +33,7 @@ extern jack_client_t *client;
 
 Transport transport;
 
-static bool _done;
+static volatile bool _done;
 
 /** callback for when we're Timebase Master, mostly taken from
  * transport.c in Jack's example clients. */
@@ -100,7 +100,9 @@ Transport::poll ( void )
     ts = jack_transport_query( client, &pos );
 
     rolling = ts == JackTransportRolling;
-    valid = pos.valid == JackPositionBBT;
+
+    valid = pos.valid & JackPositionBBT;
+
     bar = pos.bar;
     beat = pos.beat;
     tick = pos.tick;