new devices are created by a (possibly externally provided) factory

4 files changed, 18 insertions, 1 deletions

diff --git a/mixlib/mix_vm.c b/mixlib/mix_vm.c
index 9a39247..39b3e6f 100644
--- a/mixlib/mix_vm.c
+++ b/mixlib/mix_vm.c
@@ -76,8 +76,10 @@ mix_vm_new (void)
     vm->devices[i] = NULL;
   
   vm->clock = mix_vm_clock_new ();
+  vm->factory = mix_device_new;
   
   vm_reset_ (vm);
+
   return vm;
 }
 
@@ -116,6 +118,15 @@ mix_vm_connect_device (mix_vm_t *vm, mix_device_t *device)
   return old;
 }
 
+/* install a device factory for automatic connection */
+void
+mix_vm_set_device_factory (mix_vm_t *vm, mix_device_factory_t factory)
+{
+  g_return_if_fail (vm != NULL);
+  g_return_if_fail (factory != NULL);
+  vm->factory = factory;
+}
+
 /* Reset a vm  (set state as of a newly created one) */
 void
 mix_vm_reset (mix_vm_t * vm)
diff --git a/mixlib/mix_vm.h b/mixlib/mix_vm.h
index b64e197..c4663bc 100644
--- a/mixlib/mix_vm.h
+++ b/mixlib/mix_vm.h
@@ -51,6 +51,11 @@ mix_vm_delete(mix_vm_t * vm);
 extern mix_device_t * /* previously connected device */
 mix_vm_connect_device (mix_vm_t *vm, mix_device_t *device);
 
+/* install a device factory for automatic connection */
+typedef mix_device_t * (* mix_device_factory_t) (mix_device_type_t device);
+extern void
+mix_vm_set_device_factory (mix_vm_t *vm, mix_device_factory_t factory);
+
 /* Reset a vm (set state as of a newly created one) */
 extern void
 mix_vm_reset(mix_vm_t * vm);
diff --git a/mixlib/xmix_vm.c b/mixlib/xmix_vm.c
index e614cb4..c810a71 100644
--- a/mixlib/xmix_vm.c
+++ b/mixlib/xmix_vm.c
@@ -52,7 +52,7 @@ get_dev_ (mix_vm_t *vm, mix_fspec_t type)
 {
   if (type >= BD_NO_) return NULL;
   if (vm->devices[type] == NULL)
-    vm->devices[type] = mix_device_new (type);
+    vm->devices[type] = vm->factory (type);
   return vm->devices[type];
 }
 
diff --git a/mixlib/xmix_vm.h b/mixlib/xmix_vm.h
index 7255d02..d5cbff4 100644
--- a/mixlib/xmix_vm.h
+++ b/mixlib/xmix_vm.h
@@ -49,6 +49,7 @@ struct mix_vm_t
   mix_vm_clock_t *clock;		/* the vm clock */
   mix_symbol_table_t *symbol_table;
   mix_src_file_t *src_file;	/* source of last loaded code file */
+  mix_device_factory_t factory; /* the factory for new devices */
 };
 
 /* Macros for accessing/modifying the above structure.