1 /* PSPP - a program for statistical analysis.
2 Copyright (C) 2011 Free Software Foundation, Inc.
3
4 This program is free software: you can redistribute it and/or modify
5 it under the terms of the GNU General Public License as published by
6 the Free Software Foundation, either version 3 of the License, or
7 (at your option) any later version.
8
9 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU General Public License for more details.
13
14 You should have received a copy of the GNU General Public License
15 along with this program. If not, see <http://www.gnu.org/licenses/>. */
16
17 /* A lex_reader object to read characters directly from a GtkTextBuffer */
18
19 #include <config.h>
20
21 #include "psppire-lex-reader.h"
22 #include "src/language/lexer/lexer.h"
23
24 #include <gtk/gtk.h>
25
26
27 #include "libpspp/cast.h"
28
29 #include "gl/minmax.h"
30
31 static const struct lex_reader_class lex_gtk_text_buffer_reader_class ;
32
33
34 struct lex_gtk_text_buffer_reader
35 {
36 struct lex_reader reader;
37
38 /* The GtkTextBuffer from which we are reading. */
39 GtkTextBuffer *buffer;
40 GtkTextIter start;
41 GtkTextIter stop;
42
43 /* Text pulled from part of the GtkTextBuffer. */
44 gchar *part;
45 gsize part_len; /* Number of bytes in 'part'. */
46 gsize part_ofs; /* Current offset into 'part'. */
47 };
48
49 static struct lex_gtk_text_buffer_reader *
lex_gtk_text_buffer_reader_cast(struct lex_reader * r)50 lex_gtk_text_buffer_reader_cast (struct lex_reader *r)
51 {
52 return UP_CAST (r, struct lex_gtk_text_buffer_reader, reader);
53 }
54
55
56 struct lex_reader *
lex_reader_for_gtk_text_buffer(GtkTextBuffer * buffer,GtkTextIter start,GtkTextIter stop)57 lex_reader_for_gtk_text_buffer (GtkTextBuffer *buffer, GtkTextIter start, GtkTextIter stop)
58 {
59 struct lex_gtk_text_buffer_reader *r = xmalloc (sizeof *r);
60
61 lex_reader_init (&r->reader, &lex_gtk_text_buffer_reader_class);
62
63 r->buffer = buffer;
64 g_object_ref (buffer);
65
66 r->start = start;
67 r->stop = stop;
68
69 r->part = NULL;
70 r->part_len = 0;
71 r->part_ofs = 0;
72
73 return &r->reader;
74 }
75
76
77 static size_t
lex_gtk_text_buffer_read(struct lex_reader * r_,char * buf,size_t n,enum prompt_style prompt_style UNUSED)78 lex_gtk_text_buffer_read (struct lex_reader *r_, char *buf, size_t n,
79 enum prompt_style prompt_style UNUSED)
80 {
81 struct lex_gtk_text_buffer_reader *r = lex_gtk_text_buffer_reader_cast (r_);
82 gsize chunk;
83
84 if (r->part_ofs == r->part_len)
85 {
86 /* Read up to N characters into r->part. N characters might be more than
87 N bytes, but that's OK: we'll just buffer up some of those bytes for
88 the next read. */
89 int n_chars = n;
90
91 GtkTextIter iter = r->start ;
92
93 int offset = gtk_text_iter_get_offset (&iter);
94 int end_offset = gtk_text_iter_get_offset (&r->stop);
95
96 if (end_offset - offset < n)
97 n_chars = end_offset - offset;
98
99 gtk_text_iter_set_offset (&iter, offset + n_chars);
100
101 g_free (r->part);
102 r->part = gtk_text_iter_get_text (&r->start, &iter);
103 r->part_len = strlen (r->part);
104 r->part_ofs = 0;
105
106 r->start = iter;
107 }
108
109 chunk = MIN (r->part_len - r->part_ofs, n);
110 memcpy (buf, r->part + r->part_ofs, chunk);
111 r->part_ofs += chunk;
112
113 return chunk;
114 }
115
116
117
118 static void
lex_gtk_text_buffer_close(struct lex_reader * r_)119 lex_gtk_text_buffer_close (struct lex_reader *r_)
120 {
121 struct lex_gtk_text_buffer_reader *r = lex_gtk_text_buffer_reader_cast (r_);
122
123 g_object_unref (r->buffer);
124 g_free (r->part);
125 g_free (r);
126 }
127
128
129 static const struct lex_reader_class lex_gtk_text_buffer_reader_class =
130 {
131 lex_gtk_text_buffer_read,
132 lex_gtk_text_buffer_close
133 };
134