X-Git-Url: https://pd.if.org/git/?p=pd_readline;a=blobdiff_plain;f=mg%2Fundo.c;fp=mg%2Fundo.c;h=1efd2a1851c45e6ad06247650c3703d880fbb328;hp=0000000000000000000000000000000000000000;hb=a9843085ec916c175bd245a8398f30e6cc03f984;hpb=26fe4e09c6c3c250334fdeed60ce3061febecde2

diff --git a/mg/undo.c b/mg/undo.c
new file mode 100644
index 0000000..1efd2a1
--- /dev/null
+++ b/mg/undo.c
@@ -0,0 +1,585 @@
+/* $OpenBSD: undo.c,v 1.50 2010/06/30 19:12:54 oga Exp $ */
+/*
+ * This file is in the public domain
+ */
+
+#include "def.h"
+#include "kbd.h"
+
+#define MAX_FREE_RECORDS	32
+
+/*
+ * Local variables
+ */
+static struct undoq		 undo_free;
+static int			 undo_free_num;
+static int			 boundary_flag = TRUE;
+static int			 undo_enable_flag = TRUE;
+
+/*
+ * Local functions
+ */
+static int find_dot(struct line *, int);
+static int find_lo(int, struct line **, int *, int *);
+static struct undo_rec *new_undo_record(void);
+static int drop_oldest_undo_record(void);
+
+/*
+ * find_dot, find_lo()
+ *
+ * Find an absolute dot in the buffer from a line/offset pair, and vice-versa.
+ *
+ * Since lines can be deleted while they are referenced by undo record, we
+ * need to have an absolute dot to have something reliable.
+ */
+static int
+find_dot(struct line *lp, int off)
+{
+	int	 count = 0;
+	struct line	*p;
+
+	for (p = curbp->b_headp; p != lp; p = lforw(p)) {
+		if (count != 0) {
+			if (p == curbp->b_headp) {
+				ewprintf("Error: Undo stuff called with a"
+				    "nonexistent line");
+				return (FALSE);
+			}
+		}
+		count += llength(p) + 1;
+	}
+	count += off;
+
+	return (count);
+}
+
+static int
+find_lo(int pos, struct line **olp, int *offset, int *lnum)
+{
+	struct line *p;
+	int lineno;
+
+	p = curbp->b_headp;
+	lineno = 0;
+	while (pos > llength(p)) {
+		pos -= llength(p) + 1;
+		if ((p = lforw(p)) == curbp->b_headp) {
+			*olp = NULL;
+			*offset = 0;
+			return (FALSE);
+		}
+		lineno++;
+	}
+	*olp = p;
+	*offset = pos;
+	*lnum = lineno;
+
+	return (TRUE);
+}
+
+static struct undo_rec *
+new_undo_record(void)
+{
+	struct undo_rec *rec;
+
+	rec = TAILQ_FIRST(&undo_free);
+	if (rec != NULL) {
+		/* Remove it from the free-list */
+		TAILQ_REMOVE(&undo_free, rec, next);
+		undo_free_num--;
+	} else {
+		if ((rec = malloc(sizeof(*rec))) == NULL)
+			panic("Out of memory in undo code (record)");
+	}
+	memset(rec, 0, sizeof(struct undo_rec));
+
+	return (rec);
+}
+
+void
+free_undo_record(struct undo_rec *rec)
+{
+	static int initialised = 0;
+
+	/*
+	 * On the first run, do initialisation of the free list.
+	 */
+	if (initialised == 0) {
+		TAILQ_INIT(&undo_free);
+		initialised = 1;
+	}
+	if (rec->content != NULL) {
+		free(rec->content);
+		rec->content = NULL;
+	}
+	if (undo_free_num >= MAX_FREE_RECORDS) {
+		free(rec);
+		return;
+	}
+	undo_free_num++;
+
+	TAILQ_INSERT_HEAD(&undo_free, rec, next);
+}
+
+/*
+ * Drop the oldest undo record in our list. Return 1 if we could remove it,
+ * 0 if the undo list was empty.
+ */
+static int
+drop_oldest_undo_record(void)
+{
+	struct undo_rec *rec;
+
+	rec = TAILQ_LAST(&curbp->b_undo, undoq);
+	if (rec != NULL) {
+		undo_free_num--;
+		TAILQ_REMOVE(&curbp->b_undo, rec, next);
+		free_undo_record(rec);
+		return (1);
+	}
+	return (0);
+}
+
+static int
+lastrectype(void)
+{
+	struct undo_rec *rec;
+
+	if ((rec = TAILQ_FIRST(&curbp->b_undo)) != NULL)
+		return (rec->type);
+	return (0);
+}
+
+/*
+ * Returns TRUE if undo is enabled, FALSE otherwise.
+ */
+int
+undo_enabled(void)
+{
+	return (undo_enable_flag);
+}
+
+/*
+ * undo_enable: toggle undo_enable.
+ * Returns the previous value of the flag.
+ */
+int
+undo_enable(int f, int n)
+{
+	int pon = undo_enable_flag;
+
+	if (f & (FFARG | FFRAND))
+		undo_enable_flag = n > 0;
+	else
+		undo_enable_flag = !undo_enable_flag;
+
+	if (!(f & FFRAND))
+		ewprintf("Undo %sabled", undo_enable_flag ? "en" : "dis");
+
+	return (pon);
+}
+
+/*
+ * If undo is enabled, then:
+ *  Toggle undo boundary recording.
+ *  If called with an argument, (n > 0) => enable. Otherwise disable.
+ * In either case, add an undo boundary
+ * If undo is disabled, this function has no effect.
+ */
+int
+undo_boundary_enable(int f, int n)
+{
+	int bon = boundary_flag;
+
+	if (!undo_enable_flag)
+		return (FALSE);
+
+	undo_add_boundary(FFRAND, 1);
+
+	if (f & (FFARG | FFRAND))
+		boundary_flag = n > 0;
+	else
+		boundary_flag = !boundary_flag;
+
+	if (!(f & FFRAND))
+		ewprintf("Undo boundaries %sabled",
+		    boundary_flag ? "en" : "dis");
+
+	return (bon);
+}
+
+/*
+ * Record an undo boundary, unless boundary_flag == FALSE.
+ * Does nothing if previous undo entry is already a boundary or 'modified' flag.
+ */
+int
+undo_add_boundary(int f, int n)
+{
+	struct undo_rec *rec;
+	int last;
+
+	if (boundary_flag == FALSE)
+		return (FALSE);
+
+	last = lastrectype();
+	if (last == BOUNDARY || last == MODIFIED)
+		return (TRUE);
+
+	rec = new_undo_record();
+	rec->type = BOUNDARY;
+
+	TAILQ_INSERT_HEAD(&curbp->b_undo, rec, next);
+
+	return (TRUE);
+}
+
+/*
+ * Record an undo "modified" boundary
+ */
+void
+undo_add_modified(void)
+{
+	struct undo_rec *rec;
+
+	rec = new_undo_record();
+	rec->type = MODIFIED;
+
+	TAILQ_INSERT_HEAD(&curbp->b_undo, rec, next);
+
+	return;
+}
+
+int
+undo_add_insert(struct line *lp, int offset, int size)
+{
+	struct region	reg;
+	struct	undo_rec *rec;
+	int	pos;
+
+	if (!undo_enable_flag)
+		return (TRUE);
+	reg.r_linep = lp;
+	reg.r_offset = offset;
+	reg.r_size = size;
+
+	pos = find_dot(lp, offset);
+
+	/*
+	 * We try to reuse the last undo record to `compress' things.
+	 */
+	rec = TAILQ_FIRST(&curbp->b_undo);
+	if (rec != NULL && rec->type == INSERT) {
+		if (rec->pos + rec->region.r_size == pos) {
+			rec->region.r_size += reg.r_size;
+			return (TRUE);
+		}
+	}
+
+	/*
+	 * We couldn't reuse the last undo record, so prepare a new one.
+	 */
+	rec = new_undo_record();
+	rec->pos = pos;
+	rec->type = INSERT;
+	memmove(&rec->region, &reg, sizeof(struct region));
+	rec->content = NULL;
+
+	undo_add_boundary(FFRAND, 1);
+
+	TAILQ_INSERT_HEAD(&curbp->b_undo, rec, next);
+
+	return (TRUE);
+}
+
+/*
+ * This of course must be done _before_ the actual deletion is done.
+ */
+int
+undo_add_delete(struct line *lp, int offset, int size, int isreg)
+{
+	struct region	reg;
+	struct	undo_rec *rec;
+	int	pos;
+
+	if (!undo_enable_flag)
+		return (TRUE);
+
+	reg.r_linep = lp;
+	reg.r_offset = offset;
+	reg.r_size = size;
+
+	pos = find_dot(lp, offset);
+
+	if (offset == llength(lp))	/* if it's a newline... */
+		undo_add_boundary(FFRAND, 1);
+	else if ((rec = TAILQ_FIRST(&curbp->b_undo)) != NULL) {
+		/*
+		 * Separate this command from the previous one if we're not
+		 * just before the previous record...
+		 */
+		if (!isreg && rec->type == DELETE) {
+			if (rec->pos - rec->region.r_size != pos)
+				undo_add_boundary(FFRAND, 1);
+		}
+	}
+	rec = new_undo_record();
+	rec->pos = pos;
+	if (isreg)
+		rec->type = DELREG;
+	else
+		rec->type = DELETE;
+	memmove(&rec->region, &reg, sizeof(struct region));
+	do {
+		rec->content = malloc(reg.r_size + 1);
+	} while ((rec->content == NULL) && drop_oldest_undo_record());
+
+	if (rec->content == NULL)
+		panic("Out of memory");
+
+	region_get_data(&reg, rec->content, reg.r_size);
+
+	if (isreg || lastrectype() != DELETE)
+		undo_add_boundary(FFRAND, 1);
+
+	TAILQ_INSERT_HEAD(&curbp->b_undo, rec, next);
+
+	return (TRUE);
+}
+
+/*
+ * This of course must be called before the change takes place.
+ */
+int
+undo_add_change(struct line *lp, int offset, int size)
+{
+	if (!undo_enable_flag)
+		return (TRUE);
+	undo_add_boundary(FFRAND, 1);
+	boundary_flag = FALSE;
+	undo_add_delete(lp, offset, size, 0);
+	undo_add_insert(lp, offset, size);
+	boundary_flag = TRUE;
+	undo_add_boundary(FFRAND, 1);
+
+	return (TRUE);
+}
+
+/*
+ * Show the undo records for the current buffer in a new buffer.
+ */
+/* ARGSUSED */
+int
+undo_dump(int f, int n)
+{
+	struct	 undo_rec *rec;
+	struct buffer	*bp;
+	struct mgwin	*wp;
+	char	 buf[4096], tmp[1024];
+	int	 num;
+
+	/*
+	 * Prepare the buffer for insertion.
+	 */
+	if ((bp = bfind("*undo*", TRUE)) == NULL)
+		return (FALSE);
+	bp->b_flag |= BFREADONLY;
+	bclear(bp);
+	popbuf(bp, WNONE);
+
+	for (wp = wheadp; wp != NULL; wp = wp->w_wndp) {
+		if (wp->w_bufp == bp) {
+			wp->w_dotp = bp->b_headp;
+			wp->w_doto = 0;
+		}
+	}
+
+	num = 0;
+	TAILQ_FOREACH(rec, &curbp->b_undo, next) {
+		num++;
+		snprintf(buf, sizeof(buf),
+		    "%d:\t %s at %d ", num,
+		    (rec->type == DELETE) ? "DELETE":
+		    (rec->type == DELREG) ? "DELREGION":
+		    (rec->type == INSERT) ? "INSERT":
+		    (rec->type == BOUNDARY) ? "----" :
+		    (rec->type == MODIFIED) ? "MODIFIED": "UNKNOWN",
+		    rec->pos);
+
+		if (rec->content) {
+			(void)strlcat(buf, "\"", sizeof(buf));
+			snprintf(tmp, sizeof(tmp), "%.*s", rec->region.r_size,
+			    rec->content);
+			(void)strlcat(buf, tmp, sizeof(buf));
+			(void)strlcat(buf, "\"", sizeof(buf));
+		}
+		snprintf(tmp, sizeof(tmp), " [%d]", rec->region.r_size);
+		if (strlcat(buf, tmp, sizeof(buf)) >= sizeof(buf)) {
+			ewprintf("Undo record too large. Aborted.");
+			return (FALSE);
+		}
+		addlinef(bp, "%s", buf);
+	}
+	return (TRUE);
+}
+
+/*
+ * After the user did action1, then action2, then action3:
+ *
+ *	[action3] <--- Undoptr
+ *	[action2]
+ *	[action1]
+ *	 ------
+ *	 [undo]
+ *
+ * After undo:
+ *
+ *	[undo of action3]
+ *	[action2] <--- Undoptr
+ *	[action1]
+ *	 ------
+ *	 [undo]
+ *
+ * After another undo:
+ *
+ *
+ *	[undo of action2]
+ *	[undo of action3]
+ *	[action1]  <--- Undoptr
+ *	 ------
+ *	 [undo]
+ *
+ * Note that the "undo of actionX" have no special meaning. Only when
+ * we undo a deletion, the insertion will be recorded just as if it
+ * was typed on the keyboard. Resulting in the inverse operation being
+ * saved in the list.
+ *
+ * If undoptr reaches the bottom of the list, or if we moved between
+ * two undo actions, we make it point back at the topmost record. This is
+ * how we handle redoing.
+ */
+/* ARGSUSED */
+int
+undo(int f, int n)
+{
+	struct undo_rec	*ptr, *nptr;
+	int		 done, rval;
+	struct line	*lp;
+	int		 offset, save, dot;
+	static int	 nulled = FALSE;
+	int		 lineno;
+
+	if (n < 0)
+		return (FALSE);
+
+	dot = find_dot(curwp->w_dotp, curwp->w_doto);
+
+	ptr = curbp->b_undoptr;
+
+	/* first invocation, make ptr point back to the top of the list */
+	if ((ptr == NULL && nulled == TRUE) ||  rptcount == 0) {
+		ptr = TAILQ_FIRST(&curbp->b_undo);
+		nulled = TRUE;
+	}
+
+	rval = TRUE;
+	while (n--) {
+		/* if we have a spurious boundary, free it and move on.... */
+		while (ptr && ptr->type == BOUNDARY) {
+			nptr = TAILQ_NEXT(ptr, next);
+			TAILQ_REMOVE(&curbp->b_undo, ptr, next);
+			free_undo_record(ptr);
+			ptr = nptr;
+		}
+		/*
+		 * Ptr is NULL, but on the next run, it will point to the
+		 * top again, redoing all stuff done in the buffer since
+		 * its creation.
+		 */
+		if (ptr == NULL) {
+			ewprintf("No further undo information");
+			rval = FALSE;
+			nulled = TRUE;
+			break;
+		}
+		nulled = FALSE;
+
+		/*
+		 * Loop while we don't get a boundary specifying we've
+		 * finished the current action...
+		 */
+
+		undo_add_boundary(FFRAND, 1);
+
+		save = boundary_flag;
+		boundary_flag = FALSE;
+
+		done = 0;
+		do {
+			/*
+			 * Move to where this has to apply
+			 *
+			 * Boundaries (and the modified flag)  are put as
+			 * position 0 (to save lookup time in find_dot)
+			 * so we must not move there...
+			 */
+			if (ptr->type != BOUNDARY && ptr->type != MODIFIED) {
+				if (find_lo(ptr->pos, &lp,
+				    &offset, &lineno) == FALSE) {
+					ewprintf("Internal error in Undo!");
+					rval = FALSE;
+					break;
+				}
+				curwp->w_dotp = lp;
+				curwp->w_doto = offset;
+				curwp->w_markline = curwp->w_dotline;
+				curwp->w_dotline = lineno;
+			}
+
+			/*
+			 * Do operation^-1
+			 */
+			switch (ptr->type) {
+			case INSERT:
+				ldelete(ptr->region.r_size, KNONE);
+				break;
+			case DELETE:
+				lp = curwp->w_dotp;
+				offset = curwp->w_doto;
+				region_put_data(ptr->content,
+				    ptr->region.r_size);
+				curwp->w_dotp = lp;
+				curwp->w_doto = offset;
+				break;
+			case DELREG:
+				region_put_data(ptr->content,
+				    ptr->region.r_size);
+				break;
+			case BOUNDARY:
+				done = 1;
+				break;
+			case MODIFIED:
+				curbp->b_flag &= ~BFCHG;
+				break;
+			default:
+				break;
+			}
+
+			/* And move to next record */
+			ptr = TAILQ_NEXT(ptr, next);
+		} while (ptr != NULL && !done);
+
+		boundary_flag = save;
+		undo_add_boundary(FFRAND, 1);
+
+		ewprintf("Undo!");
+	}
+	/*
+	 * Record where we are. (we have to save our new position at the end
+	 * since we change the dot when undoing....)
+	 */
+	curbp->b_undoptr = ptr;
+
+	curbp->b_undopos = find_dot(curwp->w_dotp, curwp->w_doto);
+
+	return (rval);
+}