libsmartcols: support custom wrap and remove SCOLS_FL_WRAPNL

This new API provides full control on multi-line cells, you can wrap
text by new lines (build-in support) or by another way (after words,
commas, etc.) Changes:

* new scols_column_set_wrapfunc() sets pointers to two callback functions

   1/ chunksize() - returns largest data chunk size; used when we
                    calculate columns width
   2/ nextchunk() - terminate the current chunk and returns pointer to
                    the next; used when we print data

* remove SCOLS_FL_WRAPNL and add new functions scols_wrapnl_chunksize()
  and scols_wrapnl_nextchunk() to provide build-in functionality to
  wrap cells on \n

* remove scols_column_is_wrapnl() add scols_column_is_customwrap()
  (returns true if custom wrap functions are defined)

* add scols_column_set_safechars() and scols_column_get_safechars() to
  allow to control output encoding, safe chars are not encoded by \xFOO

* modify "fromfile" test code to use build-in scols_wrapnl_* callbacks
  for "wrapnl" tests

* add new function scols_column_get_table()

Signed-off-by: Karel Zak <kzak@redhat.com>

7 files changed, 208 insertions, 58 deletions

diff --git a/libsmartcols/docs/libsmartcols-sections.txt b/libsmartcols/docs/libsmartcols-sections.txt
index 12366bd34..f05d45479 100644
--- a/libsmartcols/docs/libsmartcols-sections.txt
+++ b/libsmartcols/docs/libsmartcols-sections.txt
@@ -21,7 +21,10 @@ libscols_column
 scols_column_get_color
 scols_column_get_flags
 scols_column_get_header
+scols_column_get_safechars;
+scols_column_get_table;
 scols_column_get_whint
+scols_column_is_customwrap;
 scols_column_is_hidden
 scols_column_is_noextremes
 scols_column_is_right
@@ -29,15 +32,18 @@ scols_column_is_strict_width
 scols_column_is_tree
 scols_column_is_trunc
 scols_column_is_wrap
-scols_column_is_wrapnl
 scols_column_set_cmpfunc
 scols_column_set_color
 scols_column_set_flags
+scols_column_set_safechars;
 scols_column_set_whint
+scols_column_set_wrapfunc;
 scols_copy_column
 scols_new_column
 scols_ref_column
 scols_unref_column
+scols_wrapnl_chunksize;
+scols_wrapnl_nextchunk;
 </SECTION>
 
 <SECTION>
diff --git a/libsmartcols/samples/fromfile.c b/libsmartcols/samples/fromfile.c
index 6d4ee4aaf..fcf01c749 100644
--- a/libsmartcols/samples/fromfile.c
+++ b/libsmartcols/samples/fromfile.c
@@ -34,7 +34,7 @@ static const struct column_flag flags[] = {
 	{ "noextremes", SCOLS_FL_NOEXTREMES },
 	{ "hidden",	SCOLS_FL_HIDDEN },
 	{ "wrap",	SCOLS_FL_WRAP },
-	{ "wrapnl",	SCOLS_FL_WRAPNL },
+	{ "wrapnl",	SCOLS_FL_WRAP },
 	{ "none",	0 }
 };
 
@@ -101,6 +101,13 @@ static struct libscols_column *parse_column(FILE *f)
 			int flags = parse_column_flags(line);
 			if (scols_column_set_flags(cl, flags))
 				goto fail;
+			if (strcmp(line, "wrapnl") == 0) {
+				scols_column_set_wrapfunc(cl,
+						scols_wrapnl_chunksize,
+						scols_wrapnl_nextchunk,
+						NULL);
+				scols_column_set_safechars(cl, "\n");
+			}
 			break;
 		}
 		case 3: /* COLOR */
diff --git a/libsmartcols/src/column.c b/libsmartcols/src/column.c
index 6f4ccc3bd..1e84a6363 100644
--- a/libsmartcols/src/column.c
+++ b/libsmartcols/src/column.c
@@ -22,6 +22,8 @@
 #include <string.h>
 #include <ctype.h>
 
+#include "mbsalign.h"
+
 #include "smartcolsP.h"
 
 /**
@@ -169,6 +171,17 @@ int scols_column_set_flags(struct libscols_column *cl, int flags)
 }
 
 /**
+ * scols_column_get_table:
+ * @cl: a pointer to a struct libscols_column instance
+ *
+ * Returns: pointer to the table where columns is used
+ */
+struct libscols_table *scols_column_get_table(struct libscols_column *cl)
+{
+	return cl->table;
+}
+
+/**
  * scols_column_get_flags:
  * @cl: a pointer to a struct libscols_column instance
  *
@@ -227,6 +240,69 @@ const char *scols_column_get_color(const struct libscols_column *cl)
 	return cl->color;
 }
 
+/**
+ * scols_wrapnl_nextchunk:
+ * @cl: a pointer to a struct libscols_column instance
+ * @data: string
+ * @userdata: any data or NULL
+ *
+ * This is build-in function for scols_column_set_wrapfunc(). This function
+ * terminates the current chunk by \0 and returns pointer to the begin of
+ * the next chunk. The chunks are based on \n.
+ *
+ * For example for data "AAA\nBBB\nCCC" the next chunk is "BBB".
+ *
+ * Returns: next chunk
+ */
+char *scols_wrapnl_nextchunk(const struct libscols_column *cl __attribute__((unused)),
+			char *data,
+			void *userdata __attribute__((unused)))
+{
+	char *p = data ? strchr(data, '\n') : NULL;
+
+	if (p) {
+		*p = '\0';
+		return p + 1;
+	}
+	return NULL;
+}
+
+/**
+ * scols_wrapnl_chunksize:
+ * @cl: a pointer to a struct libscols_column instance
+ * @data: string
+ *
+ * Analyzes @data and returns size of the largest chunk. The chunks are based
+ * on \n. For example for data "AAA\nBBB\nCCCC" the largest chunk size is 4.
+ *
+ * Note that the size has to be based on number of terminal cells rather than
+ * bytes to support multu-byte output.
+ *
+ * Returns: size of the largest chunk.
+ */
+size_t scols_wrapnl_chunksize(const struct libscols_column *cl __attribute__((unused)),
+		const char *data,
+		void *userdata __attribute__((unused)))
+{
+	size_t sum = 0;
+
+	while (data && *data) {
+		const char *p = data;
+		size_t sz;
+
+		p = strchr(data, '\n');
+		if (p) {
+			sz = mbs_safe_nwidth(data, p - data, NULL);
+			p++;
+		} else
+			sz = mbs_safe_width(data);
+
+		sum = max(sum, sz);
+		data = p;;
+	}
+
+	return sum;
+}
 
 /**
  * scols_column_set_cmpfunc:
@@ -251,6 +327,66 @@ int scols_column_set_cmpfunc(struct libscols_column *cl,
 }
 
 /**
+ * scols_column_set_wrapfunc:
+ * @cl: a pointer to a struct libscols_column instance
+ * @wrap_chunksize: function to return size of the largest chink of data
+ * @wrap_nextchunk: function to return next zero terminated data
+ *
+ * Extends SCOLS_FL_WRAP and allows to set custom wrap function. The default
+ * is to wrap by column size, but you can create functions to wrap for example
+ * after \n or after words, etc.
+ *
+ * Returns: 0, a negative value in case of an error.
+ */
+int scols_column_set_wrapfunc(struct libscols_column *cl,
+			size_t (*wrap_chunksize)(const struct libscols_column *,
+						 const char *,
+						 void *),
+			char * (*wrap_nextchunk)(const struct libscols_column *,
+						 char *,
+						 void *),
+			void *data)
+{
+	if (!cl)
+		return -EINVAL;
+
+	cl->wrap_nextchunk = wrap_nextchunk;
+	cl->wrap_chunksize = wrap_chunksize;
+	cl->wrapfunc_data = data;
+	return 0;
+}
+
+/**
+ * scols_column_set_safechars:
+ * @cl: a pointer to a struct libscols_column instance
+ * @safe: safe characters (e.g. "\n\t")
+ *
+ * Use for bytes you don't want to encode on output. This is for example
+ * necessary if you want to use custom wrap function based on \n, in this case
+ * you have to set "\n" as a safe char.
+ *
+ * Returns: 0, a negative value in case of an error.
+ */
+int scols_column_set_safechars(struct libscols_column *cl, const char *safe)
+{
+	if (!cl)
+		return -EINVAL;
+	cl->safechars = safe;
+	return 0;
+}
+
+/**
+ * scols_column_get_safechars:
+ * @cl: a pointer to a struct libscols_column instance
+ *
+ * Returns: safe chars
+ */
+const char *scols_column_get_safechars(const struct libscols_column *cl)
+{
+	return cl->safechars;
+}
+
+/**
  * scols_column_is_hidden:
  * @cl: a pointer to a struct libscols_column instance
  *
@@ -340,16 +476,16 @@ int scols_column_is_wrap(const struct libscols_column *cl)
 	return cl->flags & SCOLS_FL_WRAP ? 1 : 0;
 }
 /**
- * scols_column_is_wrapnl:
+ * scols_column_is_customwrap:
  * @cl: a pointer to a struct libscols_column instance
  *
- * Gets the value of @cl's flag wrap.
- *
  * Returns: 0 or 1
  *
  * Since: 2.29
  */
-int scols_column_is_wrapnl(const struct libscols_column *cl)
+int scols_column_is_customwrap(const struct libscols_column *cl)
 {
-	return cl->flags & SCOLS_FL_WRAPNL ? 1 : 0;
+	return (cl->flags & SCOLS_FL_WRAP)
+		&& cl->wrap_chunksize
+		&& cl->wrap_nextchunk ? 1 : 0;
 }
diff --git a/libsmartcols/src/libsmartcols.h.in b/libsmartcols/src/libsmartcols.h.in
index 22cab64a1..d6ae91f60 100644
--- a/libsmartcols/src/libsmartcols.h.in
+++ b/libsmartcols/src/libsmartcols.h.in
@@ -84,8 +84,7 @@ enum {
 	SCOLS_FL_STRICTWIDTH = (1 << 3),   /* don't reduce width if column is empty */
 	SCOLS_FL_NOEXTREMES  = (1 << 4),   /* ignore extreme fields when count column width*/
 	SCOLS_FL_HIDDEN	     = (1 << 5),   /* maintain data, but don't print */
-	SCOLS_FL_WRAP	     = (1 << 6),   /* wrap long lines to multi-line cells */
-	SCOLS_FL_WRAPNL	     = (1 << 7)    /* wrap based on '\n' char */
+	SCOLS_FL_WRAP	     = (1 << 6)    /* wrap long lines to multi-line cells */
 };
 
 /*
@@ -146,7 +145,10 @@ extern int scols_column_is_strict_width(const struct libscols_column *cl);
 extern int scols_column_is_hidden(const struct libscols_column *cl);
 extern int scols_column_is_noextremes(const struct libscols_column *cl);
 extern int scols_column_is_wrap(const struct libscols_column *cl);
-extern int scols_column_is_wrapnl(const struct libscols_column *cl);
+extern int scols_column_is_customwrap(const struct libscols_column *cl);
+
+extern int scols_column_set_safechars(struct libscols_column *cl, const char *safe);
+extern const char *scols_column_get_safechars(const struct libscols_column *cl);
 
 extern int scols_column_set_flags(struct libscols_column *cl, int flags);
 extern int scols_column_get_flags(const struct libscols_column *cl);
@@ -159,12 +161,23 @@ extern double scols_column_get_whint(const struct libscols_column *cl);
 extern struct libscols_cell *scols_column_get_header(struct libscols_column *cl);
 extern int scols_column_set_color(struct libscols_column *cl, const char *color);
 extern const char *scols_column_get_color(const struct libscols_column *cl);
+extern struct libscols_table *scols_column_get_table(struct libscols_column *cl);
 
 extern int scols_column_set_cmpfunc(struct libscols_column *cl,
 			int (*cmp)(struct libscols_cell *a,
 				   struct libscols_cell *b, void *),
 			void *data);
 
+extern int scols_column_set_wrapfunc(struct libscols_column *cl,
+			size_t (*wrap_chunksize)(const struct libscols_column *,
+					 const char *, void *),
+			char * (*wrap_nextchunk)(const struct libscols_column *,
+					 char *, void *),
+			void *data);
+
+extern char *scols_wrapnl_nextchunk(const struct libscols_column *cl, char *data, void *userdata);
+extern size_t scols_wrapnl_chunksize(const struct libscols_column *cl, const char *data, void *userdata);
+
 /* line.c */
 extern struct libscols_line *scols_new_line(void);
 extern void scols_ref_line(struct libscols_line *ln);
diff --git a/libsmartcols/src/libsmartcols.sym b/libsmartcols/src/libsmartcols.sym
index aca648b63..d5c3674b8 100644
--- a/libsmartcols/src/libsmartcols.sym
+++ b/libsmartcols/src/libsmartcols.sym
@@ -139,15 +139,21 @@ global:
 
 SMARTCOLS_2.29 {
 global:
-	scols_column_is_wrapnl;
+	scols_column_get_safechars;
+	scols_column_get_table;
+	scols_column_is_customwrap;
+	scols_column_set_safechars;
+	scols_column_set_wrapfunc;
 	scols_symbols_set_cell_padding;
+	scols_table_get_name;
 	scols_table_get_symbols;
 	scols_table_get_termforce;
 	scols_table_get_termwidth;
+	scols_table_is_nolinesep;
+	scols_table_is_nowrap;
 	scols_table_set_default_symbols;
 	scols_table_set_termforce;
 	scols_table_set_termwidth;
-	scols_table_get_name;
-	scols_table_is_nowrap;
-	scols_table_is_nolinesep;
+	scols_wrapnl_chunksize;
+	scols_wrapnl_nextchunk;
 } SMARTCOLS_2.28;
diff --git a/libsmartcols/src/smartcolsP.h b/libsmartcols/src/smartcolsP.h
index 8e8bd768e..2f29c9f63 100644
--- a/libsmartcols/src/smartcolsP.h
+++ b/libsmartcols/src/smartcolsP.h
@@ -95,6 +95,14 @@ struct libscols_column {
 		       void *);			/* cells comparison function */
 	void *cmpfunc_data;
 
+	size_t (*wrap_chunksize)(const struct libscols_column *,
+			const char *, void *);
+	char *(*wrap_nextchunk)(const struct libscols_column *,
+			char *, void *);
+	void *wrapfunc_data;
+
+	const char *safechars;	/* do not encode this bytes */
+
 	struct libscols_cell	header;
 	struct list_head	cl_columns;
 
diff --git a/libsmartcols/src/table_print.c b/libsmartcols/src/table_print.c
index 5771111b3..c73154ec6 100644
--- a/libsmartcols/src/table_print.c
+++ b/libsmartcols/src/table_print.c
@@ -370,7 +370,7 @@ static int print_pending_data(
 	size_t width = cl->width, bytes;
 	size_t len = width, i;
 	char *data;
-	char *wrapnl = NULL;
+	char *nextchunk = NULL;
 
 	if (!cl->pending_data)
 		return 0;
@@ -381,10 +381,9 @@ static int print_pending_data(
 	if (!data)
 		goto err;
 
-	if (scols_column_is_wrapnl(cl) && (wrapnl = strchr(data, '\n'))) {
-		*wrapnl = '\0';
-		wrapnl++;
-		bytes = wrapnl - data;
+	if (scols_column_is_customwrap(cl)
+	    && (nextchunk = cl->wrap_nextchunk(cl, data, cl->wrapfunc_data))) {
+		bytes = nextchunk - data;
 
 		len = mbs_safe_nwidth(data, bytes, NULL);
 	} else
@@ -423,7 +422,7 @@ static int print_data(struct libscols_table *tb,
 {
 	size_t len = 0, i, width, bytes;
 	const char *color = NULL;
-	char *data, *wrapnl;
+	char *data, *nextchunk;
 	int is_last;
 
 	assert(tb);
@@ -471,21 +470,18 @@ static int print_data(struct libscols_table *tb,
 	color = get_cell_color(tb, cl, ln, ce);
 
 	/* Encode. Note that 'len' and 'width' are number of cells, not bytes.
-	 * For the columns with WRAPNL we mark \n as a safe char.
 	 */
-	data = buffer_get_safe_data(buf, &len,
-			scols_column_is_wrapnl(cl) ? "\n" : NULL);
+	data = buffer_get_safe_data(buf, &len, scols_column_get_safechars(cl));
 	if (!data)
 		data = "";
 	bytes = strlen(data);
 	width = cl->width;
 
-	/* multi-line cell based on '\n' */
-	if (*data && scols_column_is_wrapnl(cl) && (wrapnl = strchr(data, '\n'))) {
-		*wrapnl = '\0';
-		wrapnl++;
-		set_pending_data(cl, wrapnl, bytes - (wrapnl - data));
-		bytes = wrapnl - data;
+	/* custom multi-line cell based */
+	if (*data && scols_column_is_customwrap(cl)
+	    && (nextchunk = cl->wrap_nextchunk(cl, data, cl->wrapfunc_data))) {
+		set_pending_data(cl, nextchunk, bytes - (nextchunk - data));
+		bytes = nextchunk - data;
 		len = mbs_safe_nwidth(data, bytes, NULL);
 	}
 
@@ -501,8 +497,9 @@ static int print_data(struct libscols_table *tb,
 		bytes = mbs_truncate(data, &len);	/* updates 'len' */
 	}
 
-	/* multi-line cell */
-	if (len > width && scols_column_is_wrap(cl)) {
+	/* standard multi-line cell */
+	if (len > width && scols_column_is_wrap(cl)
+	    && !scols_column_is_customwrap(cl)) {
 		set_pending_data(cl, data, bytes);
 
 		len = width;
@@ -989,30 +986,6 @@ static void dbg_columns(struct libscols_table *tb)
 		dbg_column(tb, cl);
 }
 
-/* count the maximal size of \n terminated chunk in the @data
- * for example for "AAA\nBBBB\nXX" the wrap size is 4 ('BBBB').
- */
-static size_t count_wrapnl_size(const char *data)
-{
-	size_t sum = 0;
-
-	while (data && *data) {
-		const char *p = data;
-		size_t sz;
-
-		p = strchr(data, '\n');
-		if (p) {
-			sz = mbs_safe_nwidth(data, p - data, NULL);
-			p++;
-		} else
-			sz = mbs_safe_width(data);
-
-		sum = max(sum, sz);
-		data = p;;
-	}
-
-	return sum;
-}
 
 /*
  * This function counts column width.
@@ -1061,8 +1034,8 @@ static int count_column_width(struct libscols_table *tb,
 
 		if (!data)
 			len = 0;
-		else if (scols_column_is_wrapnl(cl))
-			len = count_wrapnl_size(data);
+		else if (scols_column_is_customwrap(cl))
+			len = cl->wrap_chunksize(cl, data, cl->wrapfunc_data);
 		else
 			len = mbs_safe_width(data);
 
@@ -1265,7 +1238,8 @@ static int recount_widths(struct libscols_table *tb, struct libscols_buffer *buf
 				continue;	/* never truncate columns with absolute sizes */
 			if (scols_column_is_tree(cl) && width <= cl->width_treeart)
 				continue;	/* never truncate the tree */
-			if (trunc_only && !(scols_column_is_trunc(cl) || scols_column_is_wrap(cl)))
+			if (trunc_only && !(scols_column_is_trunc(cl) ||
+					(scols_column_is_wrap(cl) && !scols_column_is_customwrap(cl))))
 				continue;
 			if (cl->width == cl->width_min)
 				continue;