remember plugin-UI type (custom/basic) with session.

amend to 3.1-81-g1acf8bd

gtk2_ardour/processor_box.cc

@@ -2642,6 +2642,38 @@ ProcessorWindowProxy::session_handle()
 	return 0;
 }
 
+XMLNode&
+ProcessorWindowProxy::get_state () const
+{
+	XMLNode *node;
+	node = &ProxyBase::get_state();
+	node->add_property (X_("custom-ui"), is_custom? X_("yes") : X_("no"));
+	return *node;
+}
+
+void
+ProcessorWindowProxy::set_state (const XMLNode& node)
+{
+	XMLNodeList children = node.children ();
+	XMLNodeList::const_iterator i = children.begin ();
+	while (i != children.end()) {
+		XMLProperty* prop = (*i)->property (X_("name"));
+		if ((*i)->name() == X_("Window") && prop && prop->value() == _name) {
+			break;
+		}
+		++i;
+	}
+
+	if (i != children.end()) {
+		XMLProperty* prop;
+		if ((prop = (*i)->property (X_("custom-ui"))) != 0) {
+			want_custom = PBD::string_is_affirmative (prop->value ());
+		}
+	}
+
+	ProxyBase::set_state(node);
+}
+
 Gtk::Window*
 ProcessorWindowProxy::get (bool create)
 {

gtk2_ardour/processor_box.h

@@ -92,6 +92,9 @@ class ProcessorWindowProxy : public WM::ProxyBase
 
     bool marked;
 
+    void set_state (const XMLNode&);
+    XMLNode& get_state () const;
+
   private:
     ProcessorBox* _processor_box;
     boost::weak_ptr<ARDOUR::Processor> _processor;

gtk2_ardour/window_manager.cc

@@ -28,6 +28,7 @@
 #include "ardour_dialog.h"
 #include "ardour_window.h"
 #include "window_manager.h"
+#include "processor_box.h"
 
 #include "i18n.h"
 
@@ -106,7 +107,12 @@ Manager::add_state (XMLNode& root) const
 		if (dynamic_cast<ProxyTemporary*> (*i)) {
 			continue;
 		}
-		root.add_child_nocopy ((*i)->get_state());
+		if (dynamic_cast<ProcessorWindowProxy*> (*i)) {
+			ProcessorWindowProxy *pi = dynamic_cast<ProcessorWindowProxy*> (*i);
+			root.add_child_nocopy (pi->get_state());
+		} else {
+			root.add_child_nocopy ((*i)->get_state());
+		}
 	}
 }