]> git.xonotic.org Git - xonotic/netradiant.git/blobdiff - radiant/undo.cpp
radiant/texwindow: test .wad file extension case-insensitively on all systems, fix...
[xonotic/netradiant.git] / radiant / undo.cpp
index d576f82bf862ea8dbdd8926c5a7af2c0ee4797cb..fb741abdd9db93059102f34a1ced0a595a78d531 100644 (file)
@@ -1,6 +1,6 @@
 /*
-   Copyright (C) 1999-2007 id Software, Inc. and contributors.
-   For a list of contributors, see the accompanying CONTRIBUTORS file.
+   Copyright (C) 2001-2006, William Joseph.
+   All Rights Reserved.
 
    This file is part of GtkRadiant.
 
    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  */
 
+#include "undo.h"
 
-/*
-
-   QERadiant Undo/Redo
-
+#include "debugging/debugging.h"
+#include "warnings.h"
 
-   basic setup:
+#include "iundo.h"
+#include "preferencesystem.h"
+#include "string/string.h"
+#include "generic/callback.h"
+#include "preferences.h"
+#include "stringio.h"
 
-   <-g_undolist---------g_lastundo> <---map data---> <-g_lastredo---------g_redolist->
+#include <list>
+#include <map>
+#include <set>
 
+#include "timer.h"
 
-   undo/redo on the world_entity is special, only the epair changes are remembered
-   and the world entity never gets deleted.
-
-   FIXME: maybe reset the Undo system at map load
-         maybe also reset the entityId at map load
- */
-
-#include "stdafx.h"
-
-typedef struct undo_s
+class DebugScopeTimer
 {
-       double time;                //time operation was performed
-       int id;                     //every undo has an unique id
-       int done;                   //true when undo is build
-       const char *operation;          //name of the operation
-       brush_t brushlist;          //deleted brushes
-       entity_t entitylist;        //deleted entities
-       struct undo_s *prev, *next; //next and prev undo in list
-} undo_t;
-
-undo_t *g_undolist;                     //first undo in the list
-undo_t *g_lastundo;                     //last undo in the list
-undo_t *g_redolist;                     //first redo in the list
-undo_t *g_lastredo;                     //last undo in list
-int g_undoMaxSize = 64;                 //maximum number of undos
-int g_undoSize = 0;                     //number of undos in the list
-int g_undoMaxMemorySize = 2 * 1024 * 1024;  //maximum undo memory (default 2 MB)
-int g_undoMemorySize = 0;               //memory size of undo buffer
-int g_undoId = 1;                       //current undo ID (zero is invalid id)
-int g_redoId = 1;                       //current redo ID (zero is invalid id)
-
-/*
-   =============
-   Undo_MemorySize
-   =============
- */
-int Undo_MemorySize( void ){
-       return g_undoMemorySize;
+Timer m_timer;
+const char* m_operation;
+public:
+DebugScopeTimer( const char* operation )
+       : m_operation( operation ){
+       m_timer.start();
 }
-
-/*
-   =============
-   Undo_ClearRedo
-   =============
- */
-void Undo_ClearRedo( void ){
-       undo_t *redo, *nextredo;
-       brush_t *pBrush, *pNextBrush;
-       entity_t *pEntity, *pNextEntity;
-
-       for ( redo = g_redolist; redo; redo = nextredo )
-       {
-               nextredo = redo->next;
-               for ( pBrush = redo->brushlist.next ; pBrush != NULL && pBrush != &redo->brushlist ; pBrush = pNextBrush )
-               {
-                       pNextBrush = pBrush->next;
-                       Brush_Free( pBrush );
-               }
-               for ( pEntity = redo->entitylist.next; pEntity != NULL && pEntity != &redo->entitylist; pEntity = pNextEntity )
-               {
-                       pNextEntity = pEntity->next;
-                       Entity_Free( pEntity );
-               }
-               free( redo );
+~DebugScopeTimer(){
+       unsigned int elapsed = m_timer.elapsed_msec();
+       if ( elapsed > 0 ) {
+               globalOutputStream() << m_operation << ": " << elapsed << " msec\n";
        }
-       g_redolist = NULL;
-       g_lastredo = NULL;
-       g_redoId = 1;
 }
+};
 
-/*
-   =============
-   Undo_Clear
 
-   Clears the undo buffer.
-   =============
- */
-void Undo_Clear( void ){
-       undo_t *undo, *nextundo;
-       brush_t *pBrush, *pNextBrush;
-       entity_t *pEntity, *pNextEntity;
+class RadiantUndoSystem : public UndoSystem
+{
+UINT_CONSTANT( MAX_UNDO_LEVELS, 1024 );
 
-       Undo_ClearRedo();
-       for ( undo = g_undolist; undo; undo = nextundo )
-       {
-               nextundo = undo->next;
-               for ( pBrush = undo->brushlist.next ; pBrush != NULL && pBrush != &undo->brushlist ; pBrush = pNextBrush )
-               {
-                       pNextBrush = pBrush->next;
-                       g_undoMemorySize -= Brush_MemorySize( pBrush );
-                       Brush_Free( pBrush );
-               }
-               for ( pEntity = undo->entitylist.next; pEntity != NULL && pEntity != &undo->entitylist; pEntity = pNextEntity )
-               {
-                       pNextEntity = pEntity->next;
-                       g_undoMemorySize -= Entity_MemorySize( pEntity );
-                       Entity_Free( pEntity );
-               }
-               g_undoMemorySize -= sizeof( undo_t );
-               free( undo );
-       }
-       g_undolist = NULL;
-       g_lastundo = NULL;
-       g_undoSize = 0;
-       g_undoMemorySize = 0;
-       g_undoId = 1;
+class Snapshot
+{
+class StateApplicator
+{
+public:
+Undoable* m_undoable;
+private:
+UndoMemento* m_data;
+public:
+
+StateApplicator( Undoable* undoable, UndoMemento* data )
+       : m_undoable( undoable ), m_data( data ){
 }
-
-/*
-   =============
-   Undo_SetMaxSize
-   =============
- */
-void Undo_SetMaxSize( int size ){
-       Undo_Clear();
-       if ( size < 1 ) {
-               g_undoMaxSize = 1;
-       }
-       else{g_undoMaxSize = size; }
+void restore(){
+       m_undoable->importState( m_data );
 }
-
-/*
-   =============
-   Undo_GetMaxSize
-   =============
- */
-int Undo_GetMaxSize( void ){
-       return g_undoMaxSize;
+void release(){
+       m_data->release();
 }
+};
 
-/*
-   =============
-   Undo_SetMaxMemorySize
-   =============
- */
-void Undo_SetMaxMemorySize( int size ){
-       Undo_Clear();
-       if ( size < 1024 ) {
-               g_undoMaxMemorySize = 1024;
-       }
-       else{g_undoMaxMemorySize = size; }
-}
+typedef std::list<StateApplicator> states_t;
+states_t m_states;
 
-/*
-   =============
-   Undo_GetMaxMemorySize
-   =============
- */
-int Undo_GetMaxMemorySize( void ){
-       return g_undoMaxMemorySize;
+public:
+bool empty() const {
+       return m_states.empty();
 }
-
-/*
-   =============
-   Undo_FreeFirstUndo
-   =============
- */
-void Undo_FreeFirstUndo( void ){
-       undo_t *undo;
-       brush_t *pBrush, *pNextBrush;
-       entity_t *pEntity, *pNextEntity;
-
-       //remove the oldest undo from the undo buffer
-       undo = g_undolist;
-       g_undolist = g_undolist->next;
-       g_undolist->prev = NULL;
-       //
-       for ( pBrush = undo->brushlist.next ; pBrush != NULL && pBrush != &undo->brushlist ; pBrush = pNextBrush )
+std::size_t size() const {
+       return m_states.size();
+}
+void save( Undoable* undoable ){
+       m_states.push_front( StateApplicator( undoable, undoable->exportState() ) );
+}
+void restore(){
+       for ( states_t::iterator i = m_states.begin(); i != m_states.end(); ++i )
        {
-               pNextBrush = pBrush->next;
-               g_undoMemorySize -= Brush_MemorySize( pBrush );
-               Brush_Free( pBrush );
+               ( *i ).restore();
        }
-       for ( pEntity = undo->entitylist.next; pEntity != NULL && pEntity != &undo->entitylist; pEntity = pNextEntity )
+}
+void release(){
+       for ( states_t::iterator i = m_states.begin(); i != m_states.end(); ++i )
        {
-               pNextEntity = pEntity->next;
-               g_undoMemorySize -= Entity_MemorySize( pEntity );
-               Entity_Free( pEntity );
+               ( *i ).release();
        }
-       g_undoMemorySize -= sizeof( undo_t );
-       free( undo );
-       g_undoSize--;
 }
+};
 
-/*
-   =============
-   Undo_GeneralStart
-   =============
- */
-void Undo_GeneralStart( const char *operation ){
-       undo_t *undo;
-       brush_t *pBrush;
-       entity_t *pEntity;
-
-
-       if ( g_lastundo ) {
-               if ( !g_lastundo->done ) {
-                       Sys_Printf( "Undo_Start: WARNING last undo not finished.\n" );
-               }
-       }
+struct Operation
+{
+       Snapshot m_snapshot;
+       CopiedString m_command;
 
-       undo = (undo_t *) malloc( sizeof( undo_t ) );
-       if ( !undo ) {
-               return;
-       }
-       memset( undo, 0, sizeof( undo_t ) );
-       undo->brushlist.next = &undo->brushlist;
-       undo->brushlist.prev = &undo->brushlist;
-       undo->entitylist.next = &undo->entitylist;
-       undo->entitylist.prev = &undo->entitylist;
-       if ( g_lastundo ) {
-               g_lastundo->next = undo;
+       Operation( const char* command )
+               : m_command( command ){
        }
-       else{
-               g_undolist = undo;
+       ~Operation(){
+               m_snapshot.release();
        }
-       undo->prev = g_lastundo;
-       undo->next = NULL;
-       g_lastundo = undo;
-
-       undo->time = Sys_DoubleTime();
-       //
-       if ( g_undoId > g_undoMaxSize * 2 ) {
-               g_undoId = 1;
-       }
-       if ( g_undoId <= 0 ) {
-               g_undoId = 1;
-       }
-       undo->id = g_undoId++;
-       undo->done = false;
-       undo->operation = operation;
-       //reset the undo IDs of all brushes using the new ID
-       for ( pBrush = active_brushes.next; pBrush != NULL && pBrush != &active_brushes; pBrush = pBrush->next )
-       {
-               if ( pBrush->undoId == undo->id ) {
-                       pBrush->undoId = 0;
+};
+
+
+class UndoStack
+{
+//! Note: using std::list instead of vector/deque, to avoid copying of undos
+typedef std::list<Operation*> Operations;
+
+Operations m_stack;
+Operation* m_pending;
+
+public:
+UndoStack() : m_pending( 0 ){
+}
+~UndoStack(){
+       clear();
+}
+bool empty() const {
+       return m_stack.empty();
+}
+std::size_t size() const {
+       return m_stack.size();
+}
+Operation* back(){
+       return m_stack.back();
+}
+const Operation* back() const {
+       return m_stack.back();
+}
+Operation* front(){
+       return m_stack.front();
+}
+const Operation* front() const {
+       return m_stack.front();
+}
+void pop_front(){
+       delete m_stack.front();
+       m_stack.pop_front();
+}
+void pop_back(){
+       delete m_stack.back();
+       m_stack.pop_back();
+}
+void clear(){
+       if ( !m_stack.empty() ) {
+               for ( Operations::iterator i = m_stack.begin(); i != m_stack.end(); ++i )
+               {
+                       delete *i;
                }
+               m_stack.clear();
        }
-       for ( pBrush = selected_brushes.next; pBrush != NULL && pBrush != &selected_brushes; pBrush = pBrush->next )
-       {
-               if ( pBrush->undoId == undo->id ) {
-                       pBrush->undoId = 0;
-               }
+}
+void start( const char* command ){
+       if ( m_pending != 0 ) {
+               delete m_pending;
+       }
+       m_pending = new Operation( command );
+}
+bool finish( const char* command ){
+       if ( m_pending != 0 ) {
+               delete m_pending;
+               m_pending = 0;
+               return false;
        }
-       //reset the undo IDs of all entities using thew new ID
-       for ( pEntity = entities.next; pEntity != NULL && pEntity != &entities; pEntity = pEntity->next )
+       else
        {
-               if ( pEntity->undoId == undo->id ) {
-                       pEntity->undoId = 0;
-               }
+               ASSERT_MESSAGE( !m_stack.empty(), "undo stack empty" );
+               m_stack.back()->m_command = command;
+               return true;
        }
-       g_undoMemorySize += sizeof( undo_t );
-       g_undoSize++;
-       //undo buffer is bound to a max
-       if ( g_undoSize > g_undoMaxSize ) {
-               Undo_FreeFirstUndo();
+}
+void save( Undoable* undoable ){
+       if ( m_pending != 0 ) {
+               m_stack.push_back( m_pending );
+               m_pending = 0;
        }
+       back()->m_snapshot.save( undoable );
 }
+};
 
-/*
-   =============
-   Undo_BrushInUndo
-   =============
- */
-int Undo_BrushInUndo( undo_t *undo, brush_t *brush ){
-/*     brush_t *b;
+UndoStack m_undo_stack;
+UndoStack m_redo_stack;
+
+class UndoStackFiller : public UndoObserver
+{
+UndoStack* m_stack;
+public:
 
-    for (b = undo->brushlist.next; b != &undo->brushlist; b = b->next)
-    {
-    // Arnout: NOTE - can't do a pointer compare as the brushes get cloned into the undo brushlist, and not just referenced from it
-    // For entities we have a unique ID, for brushes we have numberID - but brush full clone increases that anyway so it's useless right now.
-        if (b == brush) return true;
-    }*/
-       // Arnout: function is pointless right now, see above explanation
-       return false;
+UndoStackFiller()
+       : m_stack( 0 ){
 }
+void save( Undoable* undoable ){
+       ASSERT_NOTNULL( undoable );
 
-/*
-   =============
-   Undo_EntityInUndo
-   =============
- */
-int Undo_EntityInUndo( undo_t *undo, entity_t *ent ){
-       entity_t *e;
+       if ( m_stack != 0 ) {
+               m_stack->save( undoable );
+               m_stack = 0;
+       }
+}
+void setStack( UndoStack* stack ){
+       m_stack = stack;
+}
+};
 
-       for ( e = undo->entitylist.next; e != &undo->entitylist; e = e->next )
+typedef std::map<Undoable*, UndoStackFiller> undoables_t;
+undoables_t m_undoables;
+
+void mark_undoables( UndoStack* stack ){
+       for ( undoables_t::iterator i = m_undoables.begin(); i != m_undoables.end(); ++i )
        {
-               // Arnout: NOTE - can't do a pointer compare as the entities get cloned into the undo entitylist, and not just referenced from it
-               //if (e == ent) return true;
-               if ( e->entityId == ent->entityId ) {
-                       return true;
-               }
+               ( *i ).second.setStack( stack );
        }
-       return false;
 }
 
-/*
-   =============
-   Undo_Start
-   =============
- */
-void Undo_Start( const char *operation ){
-       // spog - disable undo if undo levels = 0
-       if ( g_PrefsDlg.m_nUndoLevels == 0 ) {
-#ifdef DBG_UNDO
-               Sys_Printf( "Undo_Start: undo is disabled.\n" );
-#endif
-               return;
-       }
+std::size_t m_undo_levels;
 
-       Undo_ClearRedo();
-       Undo_GeneralStart( operation );
+typedef std::set<UndoTracker*> Trackers;
+Trackers m_trackers;
+public:
+RadiantUndoSystem()
+       : m_undo_levels( 64 ){
 }
+~RadiantUndoSystem(){
+       clear();
+}
+UndoObserver* observer( Undoable* undoable ){
+       ASSERT_NOTNULL( undoable );
 
-/*
-   =============
-   Undo_AddBrush
-   =============
- */
-void Undo_AddBrush( brush_t *pBrush ){
-       // spog - disable undo if undo levels = 0
-       if ( g_PrefsDlg.m_nUndoLevels == 0 ) {
-#ifdef DBG_UNDO
-               Sys_Printf( "Undo_AddBrush: undo is disabled.\n" );
-#endif
-               return;
+       return &m_undoables[undoable];
+}
+void release( Undoable* undoable ){
+       ASSERT_NOTNULL( undoable );
+
+       m_undoables.erase( undoable );
+}
+void setLevels( std::size_t levels ){
+       if ( levels > MAX_UNDO_LEVELS() ) {
+               levels = MAX_UNDO_LEVELS();
        }
 
-       if ( !g_lastundo ) {
-               Sys_Printf( "Undo_AddBrushList: no last undo.\n" );
-               return;
+       while ( m_undo_stack.size() > levels )
+       {
+               m_undo_stack.pop_front();
        }
-       if ( g_lastundo->entitylist.next != &g_lastundo->entitylist ) {
-               Sys_Printf( "Undo_AddBrushList: WARNING adding brushes after entity.\n" );
+       m_undo_levels = levels;
+}
+std::size_t getLevels() const {
+       return m_undo_levels;
+}
+std::size_t size() const {
+       return m_undo_stack.size();
+}
+void startUndo(){
+       m_undo_stack.start( "unnamedCommand" );
+       mark_undoables( &m_undo_stack );
+}
+bool finishUndo( const char* command ){
+       bool changed = m_undo_stack.finish( command );
+       mark_undoables( 0 );
+       return changed;
+}
+void startRedo(){
+       m_redo_stack.start( "unnamedCommand" );
+       mark_undoables( &m_redo_stack );
+}
+bool finishRedo( const char* command ){
+       bool changed = m_redo_stack.finish( command );
+       mark_undoables( 0 );
+       return changed;
+}
+void start(){
+       m_redo_stack.clear();
+       if ( m_undo_stack.size() == m_undo_levels ) {
+               m_undo_stack.pop_front();
        }
-       //if the brush is already in the undo
-       if ( Undo_BrushInUndo( g_lastundo, pBrush ) ) {
-               return;
+       startUndo();
+       trackersBegin();
+}
+void finish( const char* command ){
+       if ( finishUndo( command ) ) {
+               globalOutputStream() << command << '\n';
        }
-       //clone the brush
-       brush_t* pClone = Brush_FullClone( pBrush );
-       //save the ID of the owner entity
-       pClone->ownerId = pBrush->owner->entityId;
-       //save the old undo ID for previous undos
-       pClone->undoId = pBrush->undoId;
-       Brush_AddToList( pClone, &g_lastundo->brushlist );
-       //
-       g_undoMemorySize += Brush_MemorySize( pClone );
 }
-
-/*
-   =============
-   Undo_AddBrushList
-   TTimo: some brushes are just there for UI, and the information is somewhere else
-   for patches it's in the patchMesh_t structure, so when we clone the brush we get that information (brush_t::pPatch)
-   but: models are stored in pBrush->owner->md3Class, and owner epairs and origin parameters are important
-   so, we detect models and push the entity in the undo session (as well as it's BBox brush)
-    same for other items like weapons and ammo etc.
-   =============
- */
-void Undo_AddBrushList( brush_t *brushlist ){
-       // spog - disable undo if undo levels = 0
-       if ( g_PrefsDlg.m_nUndoLevels == 0 ) {
-#ifdef DBG_UNDO
-               Sys_Printf( "Undo_AddBrushList: undo is disabled.\n" );
-#endif
-               return;
+void undo(){
+       if ( m_undo_stack.empty() ) {
+               globalOutputStream() << "Undo: no undo available\n";
        }
+       else
+       {
+               Operation* operation = m_undo_stack.back();
+               globalOutputStream() << "Undo: " << operation->m_command.c_str() << "\n";
 
-       brush_t *pBrush;
-
-       if ( !g_lastundo ) {
-               Sys_Printf( "Undo_AddBrushList: no last undo.\n" );
-               return;
+               startRedo();
+               trackersUndo();
+               operation->m_snapshot.restore();
+               finishRedo( operation->m_command.c_str() );
+               m_undo_stack.pop_back();
        }
-       if ( g_lastundo->entitylist.next != &g_lastundo->entitylist ) {
-               Sys_Printf( "Undo_AddBrushList: WARNING adding brushes after entity.\n" );
+}
+void redo(){
+       if ( m_redo_stack.empty() ) {
+               globalOutputStream() << "Redo: no redo available\n";
        }
-       //copy the brushes to the undo
-       for ( pBrush = brushlist->next ; pBrush != NULL && pBrush != brushlist; pBrush = pBrush->next )
+       else
        {
-               //if the brush is already in the undo
-               //++timo FIXME: when does this happen?
-               if ( Undo_BrushInUndo( g_lastundo, pBrush ) ) {
-                       continue;
-               }
-               // do we need to store this brush's entity in the undo?
-               // if it's a fixed size entity, the brush that reprents it is not really relevant, it's used for selecting and moving around
-               // what we want to store for undo is the owner entity, epairs and origin/angle stuff
-               //++timo FIXME: if the entity is not fixed size I don't know, so I don't do it yet
-               if ( pBrush->owner->eclass->fixedsize == 1 ) {
-                       Undo_AddEntity( pBrush->owner );
-               }
-               // clone the brush
-               brush_t* pClone = Brush_FullClone( pBrush );
-               // save the ID of the owner entity
-               pClone->ownerId = pBrush->owner->entityId;
-               // save the old undo ID from previous undos
-               pClone->undoId = pBrush->undoId;
-               Brush_AddToList( pClone, &g_lastundo->brushlist );
-               // track memory size used by undo
-               g_undoMemorySize += Brush_MemorySize( pClone );
+               Operation* operation = m_redo_stack.back();
+               globalOutputStream() << "Redo: " << operation->m_command.c_str() << "\n";
+
+               startUndo();
+               trackersRedo();
+               operation->m_snapshot.restore();
+               finishUndo( operation->m_command.c_str() );
+               m_redo_stack.pop_back();
        }
 }
-
-/*
-   =============
-   Undo_EndBrush
-   =============
- */
-void Undo_EndBrush( brush_t *pBrush ){
-       // spog - disable undo if undo levels = 0
-       if ( g_PrefsDlg.m_nUndoLevels == 0 ) {
-#ifdef DBG_UNDO
-               Sys_Printf( "Undo_EndBrush: undo is disabled.\n" );
-#endif
-               return;
+void clear(){
+       mark_undoables( 0 );
+       m_undo_stack.clear();
+       m_redo_stack.clear();
+       trackersClear();
+}
+void trackerAttach( UndoTracker& tracker ){
+       ASSERT_MESSAGE( m_trackers.find( &tracker ) == m_trackers.end(), "undo tracker already attached" );
+       m_trackers.insert( &tracker );
+}
+void trackerDetach( UndoTracker& tracker ){
+       ASSERT_MESSAGE( m_trackers.find( &tracker ) != m_trackers.end(), "undo tracker cannot be detached" );
+       m_trackers.erase( &tracker );
+}
+void trackersClear() const {
+       for ( Trackers::const_iterator i = m_trackers.begin(); i != m_trackers.end(); ++i )
+       {
+               ( *i )->clear();
        }
-
-
-       if ( !g_lastundo ) {
-               //Sys_Printf("Undo_End: no last undo.\n");
-               return;
+}
+void trackersBegin() const {
+       for ( Trackers::const_iterator i = m_trackers.begin(); i != m_trackers.end(); ++i )
+       {
+               ( *i )->begin();
        }
-       if ( g_lastundo->done ) {
-               //Sys_Printf("Undo_End: last undo already finished.\n");
-               return;
+}
+void trackersUndo() const {
+       for ( Trackers::const_iterator i = m_trackers.begin(); i != m_trackers.end(); ++i )
+       {
+               ( *i )->undo();
        }
-       pBrush->undoId = g_lastundo->id;
 }
-
-/*
-   =============
-   Undo_EndBrushList
-   =============
- */
-void Undo_EndBrushList( brush_t *brushlist ){
-       // spog - disable undo if undo levels = 0
-       if ( g_PrefsDlg.m_nUndoLevels == 0 ) {
-#ifdef DBG_UNDO
-               Sys_Printf( "Undo_EndBrushList: undo is disabled.\n" );
-#endif
-               return;
+void trackersRedo() const {
+       for ( Trackers::const_iterator i = m_trackers.begin(); i != m_trackers.end(); ++i )
+       {
+               ( *i )->redo();
        }
+}
+};
 
 
-       if ( !g_lastundo ) {
-               //Sys_Printf("Undo_End: no last undo.\n");
-               return;
-       }
-       if ( g_lastundo->done ) {
-               //Sys_Printf("Undo_End: last undo already finished.\n");
-               return;
-       }
-       for ( brush_t* pBrush = brushlist->next; pBrush != NULL && pBrush != brushlist; pBrush = pBrush->next )
-       {
-               pBrush->undoId = g_lastundo->id;
-               // http://github.com/mfn/GtkRadiant/commit/ee1ef98536470d5680bd9bfecc5b5c9a62ffe9ab
-               if ( pBrush->owner->eclass->fixedsize == 1 ) {
-                       pBrush->owner->undoId = pBrush->undoId;
-               }
-       }
+
+void UndoLevels_importString( RadiantUndoSystem& undo, const char* value ){
+       int levels;
+       PropertyImpl<int, const char *>::Import( levels, value );
+       undo.setLevels( levels );
+}
+typedef ReferenceCaller<RadiantUndoSystem, void(const char*), UndoLevels_importString> UndoLevelsImportStringCaller;
+void UndoLevels_exportString( const RadiantUndoSystem& undo, const Callback<void(const char *)> & importer ){
+       PropertyImpl<int, const char *>::Export( static_cast<int>( undo.getLevels() ), importer );
 }
+typedef ConstReferenceCaller<RadiantUndoSystem, void(const Callback<void(const char *)> &), UndoLevels_exportString> UndoLevelsExportStringCaller;
 
-/*
-   =============
-   Undo_AddEntity
-   =============
- */
-void Undo_AddEntity( entity_t *entity ){
-       // spog - disable undo if undo levels = 0
-       if ( g_PrefsDlg.m_nUndoLevels == 0 ) {
-#ifdef DBG_UNDO
-               Sys_Printf( "Undo_AddEntity: undo is disabled.\n" );
-#endif
-               return;
-       }
+#include "generic/callback.h"
 
+struct UndoLevels {
+    static void Export(const RadiantUndoSystem &self, const Callback<void(int)> &returnz) {
+        returnz(static_cast<int>(self.getLevels()));
+    }
 
-       entity_t* pClone;
+    static void Import(RadiantUndoSystem &self, int value) {
+        self.setLevels(value);
+    }
+};
 
-       if ( !g_lastundo ) {
-               Sys_Printf( "Undo_AddEntity: no last undo.\n" );
-               return;
-       }
-       //if the entity is already in the undo
-       if ( Undo_EntityInUndo( g_lastundo, entity ) ) {
-               return;
-       }
-       //clone the entity
-       pClone = Entity_Clone( entity );
-       //save the old undo ID for previous undos
-       pClone->undoId = entity->undoId;
-       //save the entity ID (we need a full clone)
-       pClone->entityId = entity->entityId;
-       //
-       Entity_AddToList( pClone, &g_lastundo->entitylist );
-       //
-       g_undoMemorySize += Entity_MemorySize( pClone );
+void Undo_constructPreferences( RadiantUndoSystem& undo, PreferencesPage& page ){
+    page.appendSpinner("Undo Queue Size", 64, 0, 1024, make_property<UndoLevels>(undo));
+}
+void Undo_constructPage( RadiantUndoSystem& undo, PreferenceGroup& group ){
+       PreferencesPage page( group.createPage( "Undo", "Undo Queue Settings" ) );
+       Undo_constructPreferences( undo, page );
+}
+void Undo_registerPreferencesPage( RadiantUndoSystem& undo ){
+       PreferencesDialog_addSettingsPage( ReferenceCaller<RadiantUndoSystem, void(PreferenceGroup&), Undo_constructPage>( undo ) );
 }
 
-/*
-   =============
-   Undo_EndEntity
-   =============
- */
-void Undo_EndEntity( entity_t *entity ){
-       // spog - disable undo if undo levels = 0
-       if ( g_PrefsDlg.m_nUndoLevels == 0 ) {
-#ifdef DBG_UNDO
-               Sys_Printf( "Undo_EndEntity: undo is disabled.\n" );
-#endif
-               return;
-       }
+class UndoSystemDependencies : public GlobalPreferenceSystemModuleRef
+{
+};
 
+class UndoSystemAPI
+{
+RadiantUndoSystem m_undosystem;
+public:
+typedef UndoSystem Type;
+STRING_CONSTANT( Name, "*" );
 
-       if ( !g_lastundo ) {
-#ifdef _DEBUG
-               Sys_Printf( "Undo_End: no last undo.\n" );
-#endif
-               return;
-       }
-       if ( g_lastundo->done ) {
-#ifdef _DEBUG
-               Sys_Printf( "Undo_End: last undo already finished.\n" );
-#endif
-               return;
-       }
-       if ( entity == world_entity ) {
-               //Sys_Printf("Undo_AddEntity: undo on world entity.\n");
-               //NOTE: we never delete the world entity when undoing an operation
-               //              we only transfer the epairs
-               return;
-       }
-       entity->undoId = g_lastundo->id;
+UndoSystemAPI(){
+    GlobalPreferenceSystem().registerPreference("UndoLevels", make_property_string<UndoLevels>(m_undosystem));
+
+       Undo_registerPreferencesPage( m_undosystem );
 }
+UndoSystem* getTable(){
+       return &m_undosystem;
+}
+};
 
-/*
-   =============
-   Undo_End
-   =============
- */
-void Undo_End( void ){
-       // spog - disable undo if undo levels = 0
-       if ( g_PrefsDlg.m_nUndoLevels == 0 ) {
-#ifdef DBG_UNDO
-               Sys_Printf( "Undo_End: undo is disabled.\n" );
-#endif
-               return;
-       }
+#include "modulesystem/singletonmodule.h"
+#include "modulesystem/moduleregistry.h"
 
+typedef SingletonModule<UndoSystemAPI, UndoSystemDependencies> UndoSystemModule;
+typedef Static<UndoSystemModule> StaticUndoSystemModule;
+StaticRegisterModule staticRegisterUndoSystem( StaticUndoSystemModule::instance() );
 
-       if ( !g_lastundo ) {
-               //Sys_Printf("Undo_End: no last undo.\n");
-               return;
-       }
-       if ( g_lastundo->done ) {
-               //Sys_Printf("Undo_End: last undo already finished.\n");
-               return;
-       }
-       g_lastundo->done = true;
 
-       //undo memory size is bound to a max
-       while ( g_undoMemorySize > g_undoMaxMemorySize )
-       {
-               //always keep one undo
-               if ( g_undolist == g_lastundo ) {
-                       break;
-               }
-               Undo_FreeFirstUndo();
-       }
-       //
-       //Sys_Printf("undo size = %d, undo memory = %d\n", g_undoSize, g_undoMemorySize);
-}
 
-/*
-   =============
-   Undo_Undo
-   =============
- */
-void Undo_Undo( boolean bSilent ){
-       // spog - disable undo if undo levels = 0
-       if ( g_PrefsDlg.m_nUndoLevels == 0 ) {
-               Sys_Printf( "Undo_Undo: undo is disabled.\n" );
-               return;
-       }
 
-       undo_t *undo, *redo;
-       brush_t *pBrush, *pNextBrush;
-       entity_t *pEntity, *pNextEntity, *pUndoEntity;
 
-       if ( !g_lastundo ) {
-               Sys_Printf( "Nothing left to undo.\n" );
-               return;
-       }
-       if ( !g_lastundo->done ) {
-               Sys_Printf( "Undo_Undo: WARNING: last undo not yet finished!\n" );
-       }
-       // get the last undo
-       undo = g_lastundo;
-       if ( g_lastundo->prev ) {
-               g_lastundo->prev->next = NULL;
-       }
-       else{g_undolist = NULL; }
-       g_lastundo = g_lastundo->prev;
 
-       //allocate a new redo
-       redo = (undo_t *) malloc( sizeof( undo_t ) );
-       if ( !redo ) {
-               return;
-       }
-       memset( redo, 0, sizeof( undo_t ) );
-       redo->brushlist.next = &redo->brushlist;
-       redo->brushlist.prev = &redo->brushlist;
-       redo->entitylist.next = &redo->entitylist;
-       redo->entitylist.prev = &redo->entitylist;
-       if ( g_lastredo ) {
-               g_lastredo->next = redo;
-       }
-       else{g_redolist = redo; }
-       redo->prev = g_lastredo;
-       redo->next = NULL;
-       g_lastredo = redo;
-       redo->time = Sys_DoubleTime();
-       redo->id = g_redoId++;
-       redo->done = true;
-       redo->operation = undo->operation;
-
-       //reset the redo IDs of all brushes using the new ID
-       for ( pBrush = active_brushes.next; pBrush != NULL && pBrush != &active_brushes; pBrush = pBrush->next )
-       {
-               if ( pBrush->redoId == redo->id ) {
-                       pBrush->redoId = 0;
-               }
-       }
-       for ( pBrush = selected_brushes.next; pBrush != NULL && pBrush != &selected_brushes; pBrush = pBrush->next )
-       {
-               if ( pBrush->redoId == redo->id ) {
-                       pBrush->redoId = 0;
-               }
-       }
-       //reset the redo IDs of all entities using thew new ID
-       for ( pEntity = entities.next; pEntity != NULL && pEntity != &entities; pEntity = pEntity->next )
-       {
-               if ( pEntity->redoId == redo->id ) {
-                       pEntity->redoId = 0;
-               }
-       }
 
-       // deselect current sutff
-       Select_Deselect();
-       // move "created" brushes to the redo
-       for ( pBrush = active_brushes.next; pBrush != NULL && pBrush != &active_brushes; pBrush = pNextBrush )
-       {
-               pNextBrush = pBrush->next;
-               if ( pBrush->undoId == undo->id ) {
-                       //Brush_Free(pBrush);
-                       //move the brush to the redo
-                       Brush_RemoveFromList( pBrush );
-                       Brush_AddToList( pBrush, &redo->brushlist );
-                       //make sure the ID of the owner is stored
-                       pBrush->ownerId = pBrush->owner->entityId;
-                       //unlink the brush from the owner entity
-                       Entity_UnlinkBrush( pBrush );
-               }
-       }
-       // move "created" entities to the redo
-       for ( pEntity = entities.next; pEntity != NULL && pEntity != &entities; pEntity = pNextEntity )
-       {
-               pNextEntity = pEntity->next;
-               if ( pEntity->undoId == undo->id ) {
-                       // check if this entity is in the undo
-                       for ( pUndoEntity = undo->entitylist.next; pUndoEntity != NULL && pUndoEntity != &undo->entitylist; pUndoEntity = pUndoEntity->next )
-                       {
-                               // move brushes to the undo entity
-                               if ( pUndoEntity->entityId == pEntity->entityId ) {
-                                       pUndoEntity->brushes.next = pEntity->brushes.next;
-                                       pUndoEntity->brushes.prev = pEntity->brushes.prev;
-                                       pEntity->brushes.next = &pEntity->brushes;
-                                       pEntity->brushes.prev = &pEntity->brushes;
-                               }
-                       }
-                       //
-                       //Entity_Free(pEntity);
-                       //move the entity to the redo
-                       Entity_RemoveFromList( pEntity );
-                       Entity_AddToList( pEntity, &redo->entitylist );
-               }
-       }
-       // add the undo entities back into the entity list
-       for ( pEntity = undo->entitylist.next; pEntity != NULL && pEntity != &undo->entitylist; pEntity = undo->entitylist.next )
-       {
-               g_undoMemorySize -= Entity_MemorySize( pEntity );
-               //if this is the world entity
-               if ( pEntity->entityId == world_entity->entityId ) {
-                       epair_t* tmp = world_entity->epairs;
-                       world_entity->epairs = pEntity->epairs;
-                       pEntity->epairs = tmp;
-                       Entity_Free( pEntity );
-               }
-               else
-               {
-                       Entity_RemoveFromList( pEntity );
-                       Entity_AddToList( pEntity, &entities );
-                       pEntity->redoId = redo->id;
-               }
-       }
-       // add the undo brushes back into the selected brushes
-       for ( pBrush = undo->brushlist.next; pBrush != NULL && pBrush != &undo->brushlist; pBrush = undo->brushlist.next )
-       {
-               //Sys_Printf("Owner ID: %i\n",pBrush->ownerId);
-               g_undoMemorySize -= Brush_MemorySize( pBrush );
-               Brush_RemoveFromList( pBrush );
-               Brush_AddToList( pBrush, &active_brushes );
-               for ( pEntity = entities.next; pEntity != NULL && pEntity != &entities; pEntity = pEntity->next ) // fixes broken undo on entities
-               {
-                       //Sys_Printf("Entity ID: %i\n",pEntity->entityId);
-                       if ( pEntity->entityId == pBrush->ownerId ) {
-                               Entity_LinkBrush( pEntity, pBrush );
-                               break;
-                       }
-               }
-               //if the brush is not linked then it should be linked into the world entity
-               //++timo FIXME: maybe not, maybe we've lost this entity's owner!
-               if ( pEntity == NULL || pEntity == &entities ) {
-                       Entity_LinkBrush( world_entity, pBrush );
-               }
-               //build the brush
-               //Brush_Build(pBrush);
-               Select_Brush( pBrush );
-               pBrush->redoId = redo->id;
-       }
-       if ( !bSilent ) {
-               Sys_Printf( "%s undone.\n", undo->operation );
-       }
-       // free the undo
-       g_undoMemorySize -= sizeof( undo_t );
-       free( undo );
-       g_undoSize--;
-       g_undoId--;
-       if ( g_undoId <= 0 ) {
-               g_undoId = 2 * g_undoMaxSize;
-       }
-       //
-       g_bScreenUpdates = true;
-       UpdateSurfaceDialog();
-       Sys_UpdateWindows( W_ALL );
-}
 
-/*
-   =============
-   Undo_Redo
-   =============
- */
-void Undo_Redo( void ){
-       // spog - disable undo if undo levels = 0
-       if ( g_PrefsDlg.m_nUndoLevels == 0 ) {
-               Sys_Printf( "Undo_Redo: undo is disabled.\n" );
-               return;
-       }
 
-       undo_t *redo;
-       brush_t *pBrush, *pNextBrush;
-       entity_t *pEntity, *pNextEntity, *pRedoEntity;
 
-       if ( !g_lastredo ) {
-               Sys_Printf( "Nothing left to redo.\n" );
-               return;
-       }
-       if ( g_lastundo ) {
-               if ( !g_lastundo->done ) {
-                       Sys_Printf( "WARNING: last undo not finished.\n" );
-               }
-       }
-       // get the last redo
-       redo = g_lastredo;
-       if ( g_lastredo->prev ) {
-               g_lastredo->prev->next = NULL;
-       }
-       else{g_redolist = NULL; }
-       g_lastredo = g_lastredo->prev;
-       //
-       Undo_GeneralStart( redo->operation );
-       // remove current selection
-       Select_Deselect();
-       // move "created" brushes back to the last undo
-       for ( pBrush = active_brushes.next; pBrush != NULL && pBrush != &active_brushes; pBrush = pNextBrush )
-       {
-               pNextBrush = pBrush->next;
-               if ( pBrush->redoId == redo->id ) {
-                       //move the brush to the undo
-                       Brush_RemoveFromList( pBrush );
-                       Brush_AddToList( pBrush, &g_lastundo->brushlist );
-                       g_undoMemorySize += Brush_MemorySize( pBrush );
-                       pBrush->ownerId = pBrush->owner->entityId;
-                       Entity_UnlinkBrush( pBrush );
-               }
-       }
-       // move "created" entities back to the last undo
-       for ( pEntity = entities.next; pEntity != NULL && pEntity != &entities; pEntity = pNextEntity )
-       {
-               pNextEntity = pEntity->next;
-               if ( pEntity->redoId == redo->id ) {
-                       // check if this entity is in the redo
-                       for ( pRedoEntity = redo->entitylist.next; pRedoEntity != NULL && pRedoEntity != &redo->entitylist; pRedoEntity = pRedoEntity->next )
-                       {
-                               // move brushes to the redo entity
-                               if ( pRedoEntity->entityId == pEntity->entityId ) {
-                                       pRedoEntity->brushes.next = pEntity->brushes.next;
-                                       pRedoEntity->brushes.prev = pEntity->brushes.prev;
-                                       pEntity->brushes.next = &pEntity->brushes;
-                                       pEntity->brushes.prev = &pEntity->brushes;
-                               }
-                       }
-                       //
-                       //Entity_Free(pEntity);
-                       //move the entity to the redo
-                       Entity_RemoveFromList( pEntity );
-                       Entity_AddToList( pEntity, &g_lastundo->entitylist );
-                       g_undoMemorySize += Entity_MemorySize( pEntity );
-               }
+class undoable_test : public Undoable
+{
+struct state_type : public UndoMemento
+{
+       state_type() : test_data( 0 ){
        }
-       // add the undo entities back into the entity list
-       for ( pEntity = redo->entitylist.next; pEntity != NULL && pEntity != &redo->entitylist; pEntity = redo->entitylist.next )
-       {
-               //if this is the world entity
-               if ( pEntity->entityId == world_entity->entityId ) {
-                       epair_t* tmp = world_entity->epairs;
-                       world_entity->epairs = pEntity->epairs;
-                       pEntity->epairs = tmp;
-                       Entity_Free( pEntity );
-               }
-               else
-               {
-                       Entity_RemoveFromList( pEntity );
-                       Entity_AddToList( pEntity, &entities );
-               }
+       state_type( const state_type& other ) : UndoMemento( other ), test_data( other.test_data ){
        }
-       // add the redo brushes back into the selected brushes
-       for ( pBrush = redo->brushlist.next; pBrush != NULL && pBrush != &redo->brushlist; pBrush = redo->brushlist.next )
-       {
-               Brush_RemoveFromList( pBrush );
-               Brush_AddToList( pBrush, &active_brushes );
-               for ( pEntity = entities.next; pEntity != NULL && pEntity != &entities; pEntity = pEntity->next ) // fixes broken undo on entities
-               {
-                       if ( pEntity->entityId == pBrush->ownerId ) {
-                               Entity_LinkBrush( pEntity, pBrush );
-                               break;
-                       }
-               }
-               //if the brush is not linked then it should be linked into the world entity
-               if ( pEntity == NULL || pEntity == &entities ) {
-                       Entity_LinkBrush( world_entity, pBrush );
-               }
-               //build the brush
-               //Brush_Build(pBrush);
-               Select_Brush( pBrush );
+       void release(){
+               delete this;
        }
-       //
-       Undo_End();
-       //
-       Sys_Printf( "%s redone.\n", redo->operation );
-       //
-       g_redoId--;
-       // free the undo
-       free( redo );
-       //
-       g_bScreenUpdates = true;
-       UpdateSurfaceDialog();
-       Sys_UpdateWindows( W_ALL );
+
+       int test_data;
+};
+state_type m_state;
+UndoObserver* m_observer;
+public:
+undoable_test()
+       : m_observer( GlobalUndoSystem().observer( this ) ){
 }
+~undoable_test(){
+       GlobalUndoSystem().release( this );
+}
+UndoMemento* exportState() const {
+       return new state_type( m_state );
+}
+void importState( const UndoMemento* state ){
+       ASSERT_NOTNULL( state );
 
-/*
-   =============
-   Undo_RedoAvailable
-   =============
- */
-int Undo_RedoAvailable( void ){
-       if ( g_lastredo ) {
-               return true;
-       }
-       return false;
+       m_observer->save( this );
+       m_state = *( static_cast<const state_type*>( state ) );
 }
 
-int Undo_GetUndoId( void ){
-       if ( g_lastundo ) {
-               return g_lastundo->id;
-       }
-       return 0;
+void mutate( unsigned int data ){
+       m_observer->save( this );
+       m_state.test_data = data;
 }
+};
 
-/*
-   =============
-   Undo_UndoAvailable
-   =============
- */
-int Undo_UndoAvailable( void ){
-       if ( g_lastundo ) {
-               if ( g_lastundo->done ) {
-                       return true;
-               }
-       }
-       return false;
+#if 0
+
+class TestUndo
+{
+public:
+TestUndo(){
+       undoable_test test;
+       GlobalUndoSystem().begin( "bleh" );
+       test.mutate( 3 );
+       GlobalUndoSystem().begin( "blah" );
+       test.mutate( 4 );
+       GlobalUndoSystem().undo();
+       GlobalUndoSystem().undo();
+       GlobalUndoSystem().redo();
+       GlobalUndoSystem().redo();
 }
+};
+
+TestUndo g_TestUndo;
+
+#endif