xref: /freebsd/contrib/dialog/columns.c (revision 7431dfd4580e850375fe5478d92ec770344db098)
1 /*
2  *  $Id: columns.c,v 1.10 2011/10/20 20:53:55 tom Exp $
3  *
4  *  columns.c -- implements column-alignment
5  *
6  *  Copyright 2008-2010,2011	Thomas E. Dickey
7  *
8  *  This program is free software; you can redistribute it and/or modify
9  *  it under the terms of the GNU Lesser General Public License, version 2.1
10  *  as published by the Free Software Foundation.
11  *
12  *  This program is distributed in the hope that it will be useful, but
13  *  WITHOUT ANY WARRANTY; without even the implied warranty of
14  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15  *  Lesser General Public License for more details.
16  *
17  *  You should have received a copy of the GNU Lesser General Public
18  *  License along with this program; if not, write to
19  *	Free Software Foundation, Inc.
20  *	51 Franklin St., Fifth Floor
21  *	Boston, MA 02110, USA.
22  */
23 
24 #include <dialog.h>
25 
26 #define each(row, data) \
27  		row = 0, data = target; \
28  		row < num_rows; \
29 		++row, data = next_row(data, per_row)
30 
31 static char *
32 column_separator(void)
33 {
34     char *result = 0;
35 
36     if ((result = dialog_vars.column_separator) != 0) {
37 	if (*result == '\0')
38 	    result = 0;
39     }
40     return result;
41 }
42 
43 static char **
44 next_row(char **target, int per_row)
45 {
46     char *result = (char *) target;
47     result += per_row;
48     return (char **) (void *) result;
49 }
50 
51 static char *
52 next_col(char *source, unsigned offset)
53 {
54     char *mark = column_separator();
55     char *result = source + offset;
56     if (offset)
57 	result += strlen(mark);
58     return strstr(result, mark);
59 }
60 
61 /*
62  * Parse the source string, storing the offsets and widths of each column in
63  * the corresponding arrays.  Return the number of columns.
64  */
65 static unsigned
66 split_row(char *source, unsigned *offsets, unsigned *widths)
67 {
68     int mark = (int) strlen(column_separator());
69     char *next = 0;
70     unsigned result = 0;
71     unsigned offset = 0;
72 
73     do {
74 	if (result) {
75 	    offset = (unsigned) (mark + next - source);
76 	    widths[result - 1] = offset - offsets[result - 1] - (unsigned) mark;
77 	}
78 	offsets[result] = offset;
79 	++result;
80     } while ((next = next_col(source, offset)) != 0);
81 
82     offset = (unsigned) strlen(source);
83     widths[result - 1] = offset - offsets[result - 1];
84 
85     return result;
86 }
87 
88 /*
89  * The caller passes a pointer to a struct or array containing pointers
90  * to strings that we may want to copy and reformat according to the column
91  * separator.
92  */
93 void
94 dlg_align_columns(char **target, int per_row, int num_rows)
95 {
96     int row;
97 
98     if (column_separator()) {
99 	char **value;
100 	unsigned numcols = 1;
101 	size_t maxcols = 0;
102 	unsigned *widths;
103 	unsigned *offsets;
104 	unsigned *maxwidth;
105 	unsigned realwidth;
106 	unsigned n;
107 
108 	/* first allocate arrays for workspace */
109 	for (each(row, value)) {
110 	    size_t len = strlen(*value);
111 	    if (maxcols < len)
112 		maxcols = len;
113 	}
114 	++maxcols;
115 	widths = dlg_calloc(unsigned, maxcols);
116 	offsets = dlg_calloc(unsigned, maxcols);
117 	maxwidth = dlg_calloc(unsigned, maxcols);
118 
119 	assert_ptr(widths, "dlg_align_columns");
120 	assert_ptr(offsets, "dlg_align_columns");
121 	assert_ptr(maxwidth, "dlg_align_columns");
122 
123 	/* now, determine the number of columns and the column-widths */
124 	for (each(row, value)) {
125 	    unsigned cols = split_row(*value, offsets, widths);
126 	    if (numcols < cols)
127 		numcols = cols;
128 	    for (n = 0; n < cols; ++n) {
129 		if (maxwidth[n] < widths[n])
130 		    maxwidth[n] = widths[n];
131 	    }
132 	}
133 	realwidth = numcols - 1;
134 	for (n = 0; n < numcols; ++n) {
135 	    realwidth += maxwidth[n];
136 	}
137 
138 	/* finally, construct reformatted strings */
139 	for (each(row, value)) {
140 	    unsigned cols = split_row(*value, offsets, widths);
141 	    unsigned offset = 0;
142 	    char *text = dlg_malloc(char, realwidth + 1);
143 
144 	    assert_ptr(text, "dlg_align_columns");
145 
146 	    memset(text, ' ', (size_t) realwidth);
147 	    for (n = 0; n < cols; ++n) {
148 		memcpy(text + offset, *value + offsets[n], (size_t) widths[n]);
149 		offset += maxwidth[n] + 1;
150 	    }
151 	    text[realwidth] = 0;
152 	    *value = text;
153 	}
154 
155 	free(widths);
156 	free(offsets);
157 	free(maxwidth);
158     }
159 }
160 
161 /*
162  * Free temporary storage used while making column-aligned data.
163  */
164 void
165 dlg_free_columns(char **target, int per_row, int num_rows)
166 {
167     int row;
168     char **value;
169 
170     if (column_separator()) {
171 	for (each(row, value)) {
172 	    free(*value);
173 	}
174     }
175 }
176