/*
* UNDO system
* Copyright
* (C) 1992 Joseph H. Allen
*
* This file is part of JOE (Joe's Own Editor)
*/
struct undorec {
LINK(UNDOREC) link; /* Doubly-linked list of undo records */
UNDOREC *unit; /* If this is first record of a unit: points to last. If this is last record of a unit: points to first. */
int min; /* Set to allow merging of undo information with this record (like to small inserts) */
int changed; /* Status of modified flag before this record */
off_t where; /* Buffer address of this record */
off_t len; /* Length of insert or delete */
int del; /* Set if this is a delete */
B *big; /* Set to buffer containing a large amount of deleted data */
char *small; /* Set to malloc block containg a small amount of deleted data */
};
struct undo {
LINK(UNDO) link;
B *b;
ptrdiff_t nrecs; /* Number of units */
UNDOREC recs; /* The undo records: recs.link.prev is latest */
UNDOREC *ptr; /* Pointer to latest "undone" record. */
UNDOREC *first; /* Pointers to first and last records of a group. The group is */
UNDOREC *last; /* treated as a single undo record. */
};
extern int inundo; /* Set if inserts/deletes are part of an undo operation */
extern int justkilled; /* Last edit was a delete, so store data in yank buffer */
UNDO *undomk(B *b);
void undorm(UNDO *undo);
int uundo(W *w, int k);
int uredo(W *w, int k);
void umclear(void); /* Call this to finalize current undo records. New changes will create new records. */
void undomark(void);
void undoins(UNDO *undo, P *p, off_t size);
void undodel(UNDO *undo, off_t where, B *b);
int uyank(W *w, int k);
int uyankpop(W *w, int k);
int uyapp(W *w, int k);
int unotmod(W *w, int k);
int ucopy(W *w, int k);
void load_yank(FILE *f);
void save_yank(FILE *f);
void bw_unlock(BW *bw);
extern int undo_keep;
