#define __pbd_stateful_h__
#include <string>
+#include <list>
#include <cassert>
+
#include "pbd/id.h"
#include "pbd/xml++.h"
-#include "pbd/enumwriter.h"
+#include "pbd/property_basics.h"
+#include "pbd/signals.h"
class XMLNode;
class path;
}
-enum Change {
- range_guarantee = ~0
-};
-
-Change new_change ();
-
-/** Base (non template) part of State */
-class StateBase
-{
-public:
- StateBase (std::string const & p, Change c)
- : _have_old (false)
- , _xml_property_name (p)
- , _change (c)
- {
-
- }
-
- /** Forget about any old value for this state */
- void clear_history () {
- _have_old = false;
- }
-
- virtual void diff (XMLNode *, XMLNode *) const = 0;
- virtual Change set_state (XMLNode const &) = 0;
- virtual void add_state (XMLNode &) const = 0;
-
-protected:
- bool _have_old;
- std::string _xml_property_name;
- Change _change;
-};
-
-/** Parent class for classes which represent a single piece of state in a Stateful object */
-template <class T>
-class StateTemplate : public StateBase
-{
-public:
- StateTemplate (std::string const & p, Change c, T const & v)
- : StateBase (p, c)
- , _current (v)
- {
-
- }
-
- StateTemplate<T> & operator= (StateTemplate<T> const & s) {
- /* XXX: isn't there a nicer place to do this? */
- _have_old = s._have_old;
- _xml_property_name = s._xml_property_name;
- _change = s._change;
-
- _current = s._current;
- _old = s._old;
- return *this;
- }
-
- T & operator= (T const & v) {
- set (v);
- return _current;
- }
-
- T & operator+= (T const & v) {
- set (_current + v);
- return _current;
- }
-
- bool operator== (const T& other) const {
- return _current == other;
- }
-
- bool operator!= (const T& other) const {
- return _current != other;
- }
-
- operator T const & () const {
- return _current;
- }
-
- T const & val () const {
- return _current;
- }
-
- void diff (XMLNode* old, XMLNode* current) const {
- if (_have_old) {
- old->add_property (_xml_property_name.c_str(), to_string (_old));
- current->add_property (_xml_property_name.c_str(), to_string (_current));
- }
- }
-
- /** Try to set state from the property of an XML node.
- * @param node XML node.
- * @return Change effected, or 0.
- */
- Change set_state (XMLNode const & node) {
- XMLProperty const * p = node.property (_xml_property_name.c_str());
-
- if (p) {
- T const v = from_string (p->value ());
-
- if (v == _current) {
- return Change (0);
- }
-
- set (v);
- return _change;
- }
-
- return Change (0);
- }
-
- void add_state (XMLNode & node) const {
- node.add_property (_xml_property_name.c_str(), to_string (_current));
- }
-
-protected:
- void set (T const & v) {
- _old = _current;
- _have_old = true;
- _current = v;
- }
-
- virtual std::string to_string (T const & v) const = 0;
- virtual T from_string (std::string const & s) const = 0;
-
- T _current;
- T _old;
-};
-
-template<class T>
-std::ostream& operator<< (std::ostream& os, StateTemplate<T> const & s)
-{
- os << s.val();
- return os;
-}
-
-/** Representation of a single piece of state in a Stateful; for use
- * with types that can be written to / read from stringstreams.
- */
-template <class T>
-class State : public StateTemplate<T>
-{
-public:
- State (std::string const & p, Change c, T const & v)
- : StateTemplate<T> (p, c, v)
- {
-
- }
-
- T & operator= (T const & v) {
- this->set (v);
- return this->_current;
- }
-
-private:
- std::string to_string (T const & v) const {
- std::stringstream s;
- s.precision (12); // in case its floating point
- s << v;
- return s.str ();
- }
-
- T from_string (std::string const & s) const {
- std::stringstream t (s);
- T v;
- t.precision (12); // in case its floating point
- t >> v;
- return v;
- }
-};
-
-template <class T>
-class EnumState : public StateTemplate<T>
-{
-public:
- EnumState (std::string const & p, Change c, T const & v)
- : StateTemplate<T> (p, c, v)
- {
-
- }
-
- T & operator= (T const & v) {
- this->set (v);
- return this->_current;
- }
-
-private:
- std::string to_string (T const & v) const {
- return enum_2_string (v);
- }
-
- T from_string (std::string const & v) const {
- return T (string_2_enum (v, this->_current));
- }
-};
+class PropertyList;
+class OwnedPropertyList;
/** Base class for objects with saveable and undoable state */
class Stateful {
virtual ~Stateful();
virtual XMLNode& get_state (void) = 0;
-
virtual int set_state (const XMLNode&, int version) = 0;
- void add_state (StateBase & s) {
- _states.push_back (&s);
- }
+ virtual bool apply_changes (PropertyBase const &);
+ PropertyChange apply_changes (PropertyList const &);
+
+ const OwnedPropertyList& properties() const { return *_properties; }
+
+ void add_property (PropertyBase& s);
- /* Extra XML nodes */
+ /* 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);
+ XMLNode *extra_xml (const std::string& str, bool add_if_missing = false);
+ void save_extra_xml (const XMLNode&);
const PBD::ID& id() const { return _id; }
+ bool set_id (const XMLNode&);
+ void set_id (const std::string&);
+ void reset_id ();
+
+ /* history management */
+
+ void clear_changes ();
+ virtual void clear_owned_changes ();
+ PropertyList* get_changes_as_properties (Command *) const;
+ virtual void rdiff (std::vector<Command*> &) const;
+ bool changed() const;
- void clear_history ();
- std::pair<XMLNode *, XMLNode*> diff ();
+ /* 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 ();
+
+ bool property_changes_suspended() const { return g_atomic_int_get (const_cast<gint*>(&_stateful_frozen)) > 0; }
+
protected:
- void add_instant_xml (XMLNode&, const sys::path& directory_path);
- XMLNode *instant_xml (const std::string& str, const sys::path& directory_path);
- Change set_state_using_states (XMLNode const &);
- void add_states (XMLNode &);
+ void add_instant_xml (XMLNode&, const std::string& directory_path);
+ XMLNode *instant_xml (const std::string& str, const std::string& 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 (const PropertyChange&) { };
XMLNode *_extra_xml;
XMLNode *_instant_xml;
- PBD::ID _id;
+ PBD::PropertyChange _pending_changed;
+ Glib::Threads::Mutex _lock;
std::string _xml_node_name; ///< name of node to use for this object in XML
- std::list<StateBase*> _states; ///< state variables that this object has
+ 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&) { }
+
+ private:
+ PBD::ID _id;
+ gint _stateful_frozen;
};
} // namespace PBD