midway snapshot of work done on managing Region & Source lifetimes correctly. may...

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

diff --git a/libs/pbd/pbd/stateful.h b/libs/pbd/pbd/stateful.h
index bc32d7fd9b0df37437f0d4c0eb3b4514d32a72cf..1272a735f93d7487650ecf46795ff71a78dcc555 100644 (file)
--- a/libs/pbd/pbd/stateful.h
+++ b/libs/pbd/pbd/stateful.h
@@ -26,7 +26,7 @@
 
 #include "pbd/id.h"
 #include "pbd/xml++.h"
-#include "pbd/properties.h"
+#include "pbd/property_basics.h"
 #include "pbd/signals.h"
 
 class XMLNode;
@@ -37,6 +37,9 @@ namespace sys {
        class path;
 }
 
+class PropertyList;
+class OwnedPropertyList;
+
 /** Base class for objects with saveable and undoable state */
 class Stateful {
   public:
@@ -45,16 +48,12 @@ class Stateful {
 
        virtual XMLNode& get_state (void) = 0;
        virtual int set_state (const XMLNode&, int version) = 0;
-       /* derived types do not have to implement this, but probably should
-          give it serious attention.
-       */
-       virtual bool set_property (const PropertyBase&) { return false; }
+       virtual bool set_property (const PropertyBase&);
 
        PropertyChange set_properties (const PropertyList&);
+        const OwnedPropertyList& properties() const { return *_properties; }
 
-       void add_property (PropertyBase& s) {
-               _properties.add (s);
-       }
+       void add_property (PropertyBase& s);
 
        /* Extra XML node: so that 3rd parties can attach state to the XMLNode
           representing the state of this object.
@@ -65,9 +64,15 @@ class Stateful {
 
        const PBD::ID& id() const { return _id; }
 
+        /* history management */
+
        void clear_history ();
-       std::pair<XMLNode *, XMLNode*> diff () const;
-       void changed (PropertyChange&) const;
+        void diff (PropertyList&, PropertyList&, Command*) const;
+        bool changed() const;
+
+        /* create a property list from an XMLNode
+         */
+        virtual PropertyList* property_factory(const XMLNode&) const { return 0; }
 
        /* How stateful's notify of changes to their properties
         */
@@ -76,6 +81,12 @@ class Stateful {
        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);
@@ -85,7 +96,6 @@ class Stateful {
           to get basic property setting done.
        */
        PropertyChange set_properties (XMLNode const &);
-
        
        /* derived classes can implement this to do cross-checking
           of property values after either a PropertyList or XML 
@@ -95,10 +105,21 @@ class Stateful {
 
        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;
+       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