fltk/fluid/undo.cxx

193 lines
5.2 KiB
C++

//
// "$Id$"
//
// FLUID undo support for the Fast Light Tool Kit (FLTK).
//
// Copyright 1998-2009 by Bill Spitzak and others.
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Library General Public
// License as published by the Free Software Foundation; either
// version 2 of the License, or (at your option) any later version.
//
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
// Library General Public License for more details.
//
// You should have received a copy of the GNU Library General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
// USA.
//
// Please report all bugs and problems on the following page:
//
// http://www.fltk.org/str.php
//
#include <FL/Fl.H>
#include "Fl_Type.h"
#include "undo.h"
#include <FL/Fl_Preferences.H>
#include "../src/flstring.h"
#if defined(WIN32) && !defined(__CYGWIN__)
# include <io.h>
# include <windows.h>
# define getpid (int)GetCurrentProcessId
# ifndef __WATCOMC__
// Visual C++ 2005 incorrectly displays a warning about the use of POSIX APIs
// on Windows, which is supposed to be POSIX compliant...
# define unlink _unlink
# endif // !__WATCOMC__
#else
# include <unistd.h>
#endif // WIN32 && !__CYGWIN__
extern Fl_Preferences fluid_prefs; // FLUID preferences
extern Fl_Menu_Item Main_Menu[]; // Main menu
#define UNDO_ITEM 25 // Undo menu item index
#define REDO_ITEM 26 // Redo menu item index
//
// This file implements an undo system using temporary files; ideally
// we'd like to do this in memory, however the current data structures
// and design aren't well-suited... Instead, we save and restore
// checkpoint files.
//
int undo_current = 0; // Current undo level in buffer
int undo_last = 0; // Last undo level in buffer
int undo_max = 0; // Maximum undo level used
int undo_save = -1; // Last undo level that was saved
static int undo_paused = 0; // Undo checkpointing paused?
// Return the undo filename
static char *undo_filename(int level, char *buf, int bufsize) {
static char undo_path[1024] = ""; // Undo path
if (!undo_path[0]) fluid_prefs.getUserdataPath(undo_path, sizeof(undo_path));
snprintf(buf, bufsize, "%sundo_%d_%d.fl", undo_path, getpid(), level);
return buf;
}
// Redo menu callback
void redo_cb(Fl_Widget *, void *) {
char filename[1024]; // Undo checkpoint file
if (undo_current >= undo_last) return;
undo_suspend();
if (!read_file(undo_filename(undo_current + 1, filename, sizeof(filename)), 0)) {
// Unable to read checkpoint file, don't redo...
undo_resume();
return;
}
undo_current ++;
// Update modified flag...
set_modflag(undo_current != undo_save);
// Update undo/redo menu items...
if (undo_current >= undo_last) Main_Menu[REDO_ITEM].deactivate();
Main_Menu[UNDO_ITEM].activate();
}
// Undo menu callback
void undo_cb(Fl_Widget *, void *) {
char filename[1024]; // Undo checkpoint file
if (undo_current <= 0) return;
if (undo_current == undo_last) {
write_file(undo_filename(undo_current, filename, sizeof(filename)));
}
undo_suspend();
if (!read_file(undo_filename(undo_current - 1, filename, sizeof(filename)), 0)) {
// Unable to read checkpoint file, don't undo...
undo_resume();
return;
}
undo_current --;
// Update modified flag...
set_modflag(undo_current != undo_save);
// Update undo/redo menu items...
if (undo_current <= 0) Main_Menu[UNDO_ITEM].deactivate();
Main_Menu[REDO_ITEM].activate();
undo_resume();
}
// Save current file to undo buffer
void undo_checkpoint() {
char filename[1024]; // Undo checkpoint filename
// printf("undo_checkpoint(): undo_current=%d, undo_paused=%d, modflag=%d\n",
// undo_current, undo_paused, modflag);
// Don't checkpoint if undo_suspend() has been called...
if (undo_paused) return;
// Save the current UI to a checkpoint file...
if (!write_file(undo_filename(undo_current, filename, sizeof(filename)))) {
// Don't attempt to do undo stuff if we can't write a checkpoint file...
perror(filename);
return;
}
// Update the saved level...
if (modflag && undo_current <= undo_save) undo_save = -1;
else if (!modflag) undo_save = undo_current;
// Update the current undo level...
undo_current ++;
undo_last = undo_current;
if (undo_current > undo_max) undo_max = undo_current;
// Enable the Undo and disable the Redo menu items...
Main_Menu[UNDO_ITEM].activate();
Main_Menu[REDO_ITEM].deactivate();
}
// Clear undo buffer
void undo_clear() {
char filename[1024]; // Undo checkpoint filename
// Remove old checkpoint files...
for (int i = 0; i <= undo_max; i ++) {
unlink(undo_filename(i, filename, sizeof(filename)));
}
// Reset current, last, and save indices...
undo_current = undo_last = undo_max = 0;
if (modflag) undo_save = -1;
else undo_save = 0;
}
// Resume undo checkpoints
void undo_resume() {
undo_paused = 0;
}
// Suspend undo checkpoints
void undo_suspend() {
undo_paused = 1;
}
//
// End of "$Id$".
//