clear_history -> clear_changes and some comments.

[ardour.git] / libs / pbd / pbd / stateful.h

diff --git a/libs/pbd/pbd/stateful.h b/libs/pbd/pbd/stateful.h
index 0204c8084a9e3d0d7d25ba7cf32431d9bc8e7999..5c1f079bc6d47240e1d9b0d47a9882dbd6545502 100644 (file)
--- a/libs/pbd/pbd/stateful.h
+++ b/libs/pbd/pbd/stateful.h
@@ -1,5 +1,5 @@
 /*
-    Copyright (C) 2000 Paul Davis 
+    Copyright (C) 2000-2010 Paul Davis 
 
     This program is free software; you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
@@ -21,7 +21,13 @@
 #define __pbd_stateful_h__
 
 #include <string>
+#include <list>
+#include <cassert>
+
 #include "pbd/id.h"
+#include "pbd/xml++.h"
+#include "pbd/property_basics.h"
+#include "pbd/signals.h"
 
 class XMLNode;
 
@@ -31,33 +37,90 @@ namespace sys {
        class path;
 }
 
+class PropertyList;
+class OwnedPropertyList;
+
+/** Base class for objects with saveable and undoable state */
 class Stateful {
   public:
-       Stateful();
+       Stateful ();
        virtual ~Stateful();
 
        virtual XMLNode& get_state (void) = 0;
-
        virtual int set_state (const XMLNode&, int version) = 0;
 
-       /* Extra XML nodes */
+       virtual bool apply_changes (PropertyBase const &);
+       PropertyChange apply_changes (PropertyList const &);
+       
+        const OwnedPropertyList& properties() const { return *_properties; }
+
+       void add_property (PropertyBase& s);
+
+       /* Extra XML node: so that 3rd parties can attach state to the XMLNode
+          representing the state of this object.
+        */
 
        void add_extra_xml (XMLNode&);
        XMLNode *extra_xml (const std::string& str);
 
        const PBD::ID& id() const { return _id; }
 
+        /* history management */
+
+       void clear_changes ();
+       virtual void clear_owned_changes ();
+        PropertyList* get_changes_as_properties (Command *) const;
+       virtual void rdiff (std::vector<StatefulDiffCommand*> &) const;
+        bool changed() const;
+
+        /* create a property list from an XMLNode
+         */
+        virtual PropertyList* property_factory (const XMLNode&) const;
+
+       /* How stateful's notify of changes to their properties
+        */
+       PBD::Signal1<void,const PropertyChange&> PropertyChanged;
+
        static int current_state_version;
        static int loading_state_version;
 
+       virtual void suspend_property_changes ();
+       virtual void resume_property_changes ();
+
+       void unlock_property_changes () { _no_property_changes = false; }
+       void block_property_changes () { _no_property_changes = true; }
+       
   protected:
 
        void add_instant_xml (XMLNode&, const sys::path& directory_path);
        XMLNode *instant_xml (const std::string& str, const sys::path& directory_path);
+       void add_properties (XMLNode &);
+
+       PropertyChange set_values (XMLNode const &);
+       
+       /* derived classes can implement this to do cross-checking
+          of property values after either a PropertyList or XML 
+          driven property change.
+       */
+       virtual void post_set () { };
 
        XMLNode *_extra_xml;
        XMLNode *_instant_xml;
-       PBD::ID _id;
+       PBD::ID  _id;
+        int32_t  _frozen;
+        bool     _no_property_changes;
+       PBD::PropertyChange     _pending_changed;
+        Glib::Mutex _lock;
+
+       std::string _xml_node_name; ///< name of node to use for this object in XML
+       OwnedPropertyList* _properties;
+
+        virtual void send_change (const PropertyChange&);
+        /** derived classes can implement this in order to process a property change
+            within thaw() just before send_change() is called.
+        */
+        virtual void mid_thaw (const PropertyChange&) { }
+        bool property_changes_suspended() const { return g_atomic_int_get (&_frozen) > 0; }
 };
 
 } // namespace PBD