sfundo.c

A GTK sound font editor. Sound font files are used to synthesize instruments from audio samples for

/*==================================================================
 * sfundo.c - Sound font undo/redo routines
 *
 * Smurf Sound Font Editor
 * Copyright (C) 1999-2001 Josh Green
 *
 * 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 the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
 * 02111-1307, USA or point your web browser to http://www.gnu.org.
 *
 * To contact the author of this program:
 * Email: Josh Green <[e-mail]>
 * Smurf homepage: http://smurf.sourceforge.net
 *==================================================================*/
#include "config.h"

#include <stdio.h>
#include <glib.h>
#include "sfundo.h"
#include "sfdofunc.h"
#include "uif_sfundo.h"

static SFDoItem *sfdo_new_item (void);
static void sfdo_free_item (SFDoItem *doitem);
static void sfdo_new_entry (void);
static void sfdo_remove_curpos_entry ();

#define ENTRY_CHUNK_OPTIMUM_AREA	64
#define ITEM_CHUNK_OPTIMUM_AREA		128

static GMemChunk *entry_chunk;
static GMemChunk *item_chunk;

/* the do tree */
SFDoTree sfdo_tree;

/* if TRUE then undo system is active, else calls to sfdofuncs are ignored */
gboolean sfdo_active = FALSE;
gboolean sfdo_running = FALSE;

/* initialize sfdo_tree */
void
sfdo_init (void)
{
  entry_chunk =
    g_mem_chunk_create (SFDoEntry, ENTRY_CHUNK_OPTIMUM_AREA,
    G_ALLOC_AND_FREE);
  item_chunk =
    g_mem_chunk_create (SFDoItem, ITEM_CHUNK_OPTIMUM_AREA, G_ALLOC_AND_FREE);

  sfdo_tree.root = g_node_new (NULL);	/* root node is a dummy */
  sfdo_tree.curpos = sfdo_tree.root;
  sfdo_tree.groups = NULL;

  sfdo_active = TRUE;
}

/* dump undo tree for debugging purposes */
void
sfdo_debug_dump (GNode *start, gint sibling, gboolean traverse, gboolean detail)
{
  GList *l = NULL, *p, *p2;
  GNode *n;
  SFDoEntry *entry;
  SFDoItem *item;
  gint prev, next;

  if (!start)
    start = sfdo_tree.curpos;	/* no start specified, set to current pos */
  else if (sibling >= 0)
    {				/* start from the 'sibling' index of 'start' */
      n = start->parent;	/* get parent of 'start' */
      if (n)
	{
	  n = g_node_nth_child (n, sibling); /* find the sibling by index */
	  if (n) start = n;
	}
    }

  if (traverse)
    {
      /* traverse up the tree */
      n = start;
      while (n && n->data)
	{
	  entry = (SFDoEntry *)(n->data);
	  l = g_list_prepend (l, n);
	  n = n->parent;
	}

      /* traverse down the tree via the default redo path */
      n = start;
      if (n) n = n->children;
      while (n && n->data)
	{
	  entry = (SFDoEntry *)(n->data);
	  l = g_list_append (l, n);
	  n = n->children;
	}
    }
  else l = g_list_append (l, start); /* !traverse, show just one node */

  printf ("   %c    ROOT\n", (sfdo_tree.curpos == sfdo_tree.root) ? '+' : '/');

  p = l;
  prev = 0;
  next = 0;
  while (p)
    {
      n = (GNode *)(p->data);
      p = g_list_next (p);

      entry = (SFDoEntry *)(n->data);

      if (n->parent)
	{
	  prev = g_node_child_position (n->parent, n);
	  next = g_node_n_children (n->parent) - prev - 1;
	}

      printf ("%c%-2d%c%2d%c (%lx) %s\n",
	      prev ? '<' : ' ', prev,
	      (n == sfdo_tree.curpos) ? '+' : '|',
	       next, next ? '>' : ' ',
	      (long)(n), entry->descr);

      if (!detail) continue;

      p2 = g_list_last (entry->items);

      if (!p2) printf ("\t<EMPTY>\n");

      while (p2)
	{
	  item = (SFDoItem *)(p2->data);

	  printf ("\t| (state = %lx) %s\n", (long)(item->state),
		  sfdofuncs[item->type].descr);

	  p2 = g_list_previous (p2);
	}
    }
}

/* open curpos entry to group do items into (nested grouping is allowed but
   they are only visable while open) */
void
sfdo_group (gchar *descr)
{
  GList *p;
  SFDoEntry *entry;

  if (!sfdo_active || sfdo_running) return;

  if (sfdo_tree.groups)  /* sub group? */
    {				/* ? grouping already active? */
      /* ?: yes, get last GList * SFDoItem of last group */
      entry = (SFDoEntry *) (sfdo_tree.curpos->data);
      p = entry->items;		/* first (most recent) group item */
    }
  else  /* top level group */
    {
      sfdo_new_entry ();	/* ?: no, create new entry */
      p = NULL;			/* last GList * of previous group is NULL */

      /* copy the description to the entry if provided */
      if (descr)
	((SFDoEntry *)(sfdo_tree.curpos->data))->descr = g_strdup (descr);
    }

  sfdo_tree.groups = g_list_prepend (sfdo_tree.groups, p);
}

/* close group */
void
sfdo_done (void)
{
  GList *p;

  if (!sfdo_active || sfdo_running) return;

  g_return_if_fail (sfdo_tree.groups != NULL);

  p = sfdo_tree.groups;	/* first (most recent) group item */

  /* remove and free group node */
  sfdo_tree.groups = g_list_remove_link (sfdo_tree.groups, p);
  g_list_free_1 (p);

  /* hack to update user interface after a toplevel group is closed */
  if (!sfdo_tree.groups)
    uido_toplevel_group_done ();
}

/* add an item to the active open group entry */
void
sfdo_add (guint16 type, gpointer state)
{
  SFDoEntry *entry;
  SFDoItem *item;

  if (!sfdo_active) return;

  g_return_if_fail (sfdo_tree.groups != NULL);
  g_return_if_fail (type != DOFUNC_INVALID);
  g_return_if_fail (type < DOFUNC_LAST);

  /* create and load the SFDoItem */
  item = sfdo_new_item ();
  item->type = type;
  item->state = state;

  entry = (SFDoEntry *) (sfdo_tree.curpos->data);
  entry->items = g_list_prepend (entry->items, item);
}

/* undo all items in current open group and delete it */
void
sfdo_retract (void)
{
  GList *p, *p2;
  SFDoEntry *entry;
  SFDoItem *doitem;

  if (!sfdo_active) return;

  g_return_if_fail (sfdo_tree.groups != NULL);  /* fail if no groups? */

  sfdo_running = TRUE;		/* to stop recursive undo calls */

  entry = (SFDoEntry *)(sfdo_tree.curpos->data);  /* current entry */
  p = entry->items;  /* first item of current entry */

  /* loop while items and item isn't the last item of the previous group */
  while (p && p->data != sfdo_tree.groups->data)
    {
      doitem = (SFDoItem *)(p->data);
      (*sfdofuncs[doitem->type].restore) (doitem);  /* call undo function */
      if (sfdofuncs[doitem->type].free) /* call free state function */
	(*sfdofuncs[doitem->type].free) (doitem);

      p2 = p;
      p = g_list_next (p);  /* must advance here, as p will be removed */

      /* remove SFDoItem GList node */
      entry->items = g_list_remove_link (entry->items, p2);
      g_list_free_1 (p2);

      sfdo_free_item (doitem);  /* free the SFDoItem structure */
    }

  /* free last group SFDoItem pointer, thereby destroying the group */
  sfdo_tree.groups = g_list_remove_link (sfdo_tree.groups,
					  sfdo_tree.groups);

  if (!sfdo_tree.groups)
    sfdo_remove_curpos_entry ();

  sfdo_running = FALSE;
}

/* undo all sub groups in current entry and delete it */
void
sfdo_retract_all (void)
{
  if (!sfdo_active) return;

  g_return_if_fail (sfdo_tree.groups != NULL);  /* fail if no groups? */

  while (sfdo_tree.groups)
    sfdo_retract ();
}

/* undo an entry from the tree
   Steps: save redo entry state, restore undo entry state, remove undo entry,
   replace undo entry with redo, and move curpos up the tree */
void
sfdo_undo (void)
{
  GList *p;
  SFDoEntry *entry;
  SFDoItem *undoitem, *newitem;

  if (!sfdo_active) return;

  /* groups should not be active */
  g_return_if_fail (sfdo_tree.groups == NULL);

  /* return if no entries to undo */
  if (sfdo_tree.curpos == sfdo_tree.root)
    return;

  sfdo_running = TRUE;		/* to stop recursive undo calls */

  entry = (SFDoEntry *)(sfdo_tree.curpos->data);  /* current entry */
  p = entry->items;  /* first item of current entry */

  /* loop while items */
  while (p)
    {
      undoitem = (SFDoItem *)(p->data);  /* item to undo */
      newitem = sfdo_new_item ();  /* new item to store redo state data */

      /* load redo item using undo item as reference */
      (*sfdofuncs[undoitem->type].restate) (undoitem, newitem);

      /* restore state from undo item */
      (*sfdofuncs[undoitem->type].restore) (undoitem);

      /* free old undo item state and structure */
      if (sfdofuncs[undoitem->type].free)
	(*sfdofuncs[undoitem->type].free) (undoitem);
      sfdo_free_item (undoitem);

      p->data = newitem;  /* replace old undo GList data ptr with redo ptr */

      p = g_list_next (p);  /* advance forward in list (backwards in time) */
    }

  /* advance curpos up the tree */
  sfdo_tree.curpos = sfdo_tree.curpos->parent;

  sfdo_running = FALSE;
}

/* redo an entry from the sfdo_tree
   node is a GNode ptr to a child of curpos or NULL to redo most recent undo
   Steps: save undo state, restore redo state, free redo item, move curpos
   to redone node */
void
sfdo_redo (GNode *node)
{
  GList *p;
  GNode *n;
  SFDoEntry *entry;
  SFDoItem *redoitem, *newitem;

  if (!sfdo_active) return;

  /* groups should not be active */
  g_return_if_fail (sfdo_tree.groups == NULL);

  /* return if no entries to redo */
  if (sfdo_tree.curpos->children == NULL)
    return;

  n = sfdo_tree.curpos->children;

  if (node)  /* redo node specified? */
    {
      /* look for child node matching "node" */
      while (n && n != node)
	n = g_node_next_sibling (n);

      g_return_if_fail (n != NULL);  /* fail if no match found */
    }

  sfdo_running = TRUE;		/* to stop recursive undo calls */

  entry = (SFDoEntry *)(n->data);  /* entry to redo */
  p = g_list_last (entry->items);  /* last item of entry to redo */

  /* loop while items */
  while (p)
    {
      redoitem = (SFDoItem *)(p->data);  /* item to redo */
      newitem = sfdo_new_item ();  /* new item to store undo state data */

      /* load undo item using redo item as reference */
      (*sfdofuncs[redoitem->type].restate) (redoitem, newitem);

      /* restore state from redo item */
      (*sfdofuncs[redoitem->type].restore) (redoitem);

      /* free old redo item state and structure */
      if (sfdofuncs[redoitem->type].free)
	(*sfdofuncs[redoitem->type].free) (redoitem);
      sfdo_free_item (redoitem);

      p->data = newitem;  /* replace old redo GList data ptr with undo ptr */

      p = g_list_previous (p);  /* advance back in list (forwards in time) */
    }

  /* advance curpos to redone node */
  sfdo_tree.curpos = n;

  sfdo_running = FALSE;
}

/* jump to specified state (undo/redo from curpos to 'node') */
void
sfdo_jump (GNode *node)
{
  GNode *n;
  GSList *srclist = NULL, *dstlist = NULL;
  GSList *srcp, *dstp;
  gint i;

  if (!sfdo_active) return;

  /* groups should not be active */
  g_return_if_fail (sfdo_tree.groups == NULL);

  n = sfdo_tree.curpos;
  while (n)			/* make a list of curpos ancestry */
    {
      srclist = g_slist_prepend (srclist, n);
      n = n->parent;
    }

  n = node;
  while (n)			/* make a list of destination ancestry */
    {
      dstlist = g_slist_prepend (dstlist, n);
      n = n->parent;
    }

  srcp = srclist;
  dstp = dstlist;
  i = 0;
  while (srcp && dstp)		/* skip common ancestry */
    {
      if (srcp->data != dstp->data) break;
      srcp = g_slist_next (srcp);
      dstp = g_slist_next (dstp);
      i++;
    }

  while (srcp)			/* undo from curpos up to common parent */
    {
      sfdo_undo ();
      srcp = g_slist_next (srcp);
    }

  while (dstp)			/* redo from common parent to destination */
    {
      sfdo_redo ((GNode *)(dstp->data));
      dstp = g_slist_next (dstp);
    }

  g_slist_free (srclist);
  g_slist_free (dstlist);
}

/* allocate a new SFDoItem and initialize to a NULL state */
static SFDoItem *
sfdo_new_item (void)
{
  SFDoItem *item;
  item = g_chunk_new (SFDoItem, item_chunk);
  item->type = DOFUNC_INVALID;
  item->state = NULL;
  return (item);
}

static void
sfdo_free_item (SFDoItem *doitem)
{
  g_mem_chunk_free (item_chunk, doitem);
}

/* appends a new entry onto the curpos node, and makes it the curpos */
static void
sfdo_new_entry (void)
{
  SFDoEntry *entry;

  /* grouping should not be active! */
  g_return_if_fail (sfdo_tree.groups == NULL);

  entry = g_chunk_new (SFDoEntry, entry_chunk);
  entry->descr = NULL;
  entry->items = NULL;
  sfdo_tree.curpos = g_node_prepend_data (sfdo_tree.curpos, entry);
}

/* removes the current entry which must have NO SFDoItems and NO children
   (i.e. bottom of the tree) */
static void
sfdo_remove_curpos_entry ()
{
  GNode *n;
  SFDoEntry *entry;

  /* curpos should be the bottom of the tree (no GNode children!) */
  g_return_if_fail (sfdo_tree.curpos->children == NULL);

  n = sfdo_tree.curpos;  /* current position GNode */
  entry = (SFDoEntry *)(n->data);  /* get current entry */

  g_return_if_fail (entry->items == NULL);  /* fail if it has SFDoItems */

  sfdo_tree.curpos = sfdo_tree.curpos->parent;  /* move curpos to parent */

  /* if this entry has a description, free it */
  if (entry->descr)
    g_free (entry->descr);

  g_mem_chunk_free (entry_chunk, entry);  /* free the SFDoEntry atom */
  g_node_unlink (n);  /* unlink the node from the tree */
  g_node_destroy (n);  /* destroy node */
}