Add basic UTF-8 helper functions

Add utf8_width() and utf8_strwidth() which can be used to calculate the
display width of a single character or a string, respectively. A lookup
table is used to spot double width characters, as well as composing
characters. There currently isn't any code to deal with ambigious
characters.

Signed-off-by: Lukas Fleischer <calcurse@cryptocrack.de>

3 files changed, 338 insertions, 0 deletions

diff --git a/src/Makefile.am b/src/Makefile.am
index faacf46..b24a51d 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -22,6 +22,7 @@ calcurse_SOURCES = \
 	recur.c \
 	sigs.c \
 	todo.c \
+	utf8.c \
 	utils.c \
 	vars.c \
 	wins.c \
diff --git a/src/calcurse.h b/src/calcurse.h
index d7fa770..52e3498 100644
--- a/src/calcurse.h
+++ b/src/calcurse.h
@@ -832,6 +832,10 @@ void          todo_view_note (char *);
 void          todo_init_list (void);
 void          todo_free_list (void);
 
+/* utf8.c */
+int           utf8_width (char *);
+int           utf8_strwidth (char *);
+
 /* utils.c */
 void         exit_calcurse (int) __attribute__((__noreturn__));
 void         free_user_data (void);
diff --git a/src/utf8.c b/src/utf8.c
new file mode 100644
index 0000000..3ce85d5
--- /dev/null
+++ b/src/utf8.c
@@ -0,0 +1,333 @@
+/*
+ * Calcurse - text-based organizer
+ *
+ * Copyright (c) 2004-2011 calcurse Development Team <misc@calcurse.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ *      - Redistributions of source code must retain the above
+ *        copyright notice, this list of conditions and the
+ *        following disclaimer.
+ *
+ *      - Redistributions in binary form must reproduce the above
+ *        copyright notice, this list of conditions and the
+ *        following disclaimer in the documentation and/or other
+ *        materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * Send your feedback or comments to : misc@calcurse.org
+ * Calcurse home page : http://calcurse.org
+ *
+ */
+
+#include "calcurse.h"
+
+struct utf8_range {
+  int min, max, width;
+};
+
+static const struct utf8_range utf8_widthtab[] = {
+  { 0x00300, 0x0036f, 0 },
+  { 0x00483, 0x00489, 0 },
+  { 0x00591, 0x005bd, 0 },
+  { 0x005bf, 0x005bf, 0 },
+  { 0x005c1, 0x005c2, 0 },
+  { 0x005c4, 0x005c5, 0 },
+  { 0x005c7, 0x005c7, 0 },
+  { 0x00610, 0x0061a, 0 },
+  { 0x0064b, 0x0065e, 0 },
+  { 0x00670, 0x00670, 0 },
+  { 0x006d6, 0x006dc, 0 },
+  { 0x006de, 0x006e4, 0 },
+  { 0x006e7, 0x006e8, 0 },
+  { 0x006ea, 0x006ed, 0 },
+  { 0x00711, 0x00711, 0 },
+  { 0x00730, 0x0074a, 0 },
+  { 0x007a6, 0x007b0, 0 },
+  { 0x007eb, 0x007f3, 0 },
+  { 0x00816, 0x00819, 0 },
+  { 0x0081b, 0x00823, 0 },
+  { 0x00825, 0x00827, 0 },
+  { 0x00829, 0x0082d, 0 },
+  { 0x00900, 0x00903, 0 },
+  { 0x0093c, 0x0093c, 0 },
+  { 0x0093e, 0x0094e, 0 },
+  { 0x00951, 0x00955, 0 },
+  { 0x00962, 0x00963, 0 },
+  { 0x00981, 0x00983, 0 },
+  { 0x009bc, 0x009bc, 0 },
+  { 0x009be, 0x009c4, 0 },
+  { 0x009c7, 0x009c8, 0 },
+  { 0x009cb, 0x009cd, 0 },
+  { 0x009d7, 0x009d7, 0 },
+  { 0x009e2, 0x009e3, 0 },
+  { 0x00a01, 0x00a03, 0 },
+  { 0x00a3c, 0x00a3c, 0 },
+  { 0x00a3e, 0x00a42, 0 },
+  { 0x00a47, 0x00a48, 0 },
+  { 0x00a4b, 0x00a4d, 0 },
+  { 0x00a51, 0x00a51, 0 },
+  { 0x00a70, 0x00a71, 0 },
+  { 0x00a75, 0x00a75, 0 },
+  { 0x00a81, 0x00a83, 0 },
+  { 0x00abc, 0x00abc, 0 },
+  { 0x00abe, 0x00ac5, 0 },
+  { 0x00ac7, 0x00ac9, 0 },
+  { 0x00acb, 0x00acd, 0 },
+  { 0x00ae2, 0x00ae3, 0 },
+  { 0x00b01, 0x00b03, 0 },
+  { 0x00b3c, 0x00b3c, 0 },
+  { 0x00b3e, 0x00b44, 0 },
+  { 0x00b47, 0x00b48, 0 },
+  { 0x00b4b, 0x00b4d, 0 },
+  { 0x00b56, 0x00b57, 0 },
+  { 0x00b62, 0x00b63, 0 },
+  { 0x00b82, 0x00b82, 0 },
+  { 0x00bbe, 0x00bc2, 0 },
+  { 0x00bc6, 0x00bc8, 0 },
+  { 0x00bca, 0x00bcd, 0 },
+  { 0x00bd7, 0x00bd7, 0 },
+  { 0x00c01, 0x00c03, 0 },
+  { 0x00c3e, 0x00c44, 0 },
+  { 0x00c46, 0x00c48, 0 },
+  { 0x00c4a, 0x00c4d, 0 },
+  { 0x00c55, 0x00c56, 0 },
+  { 0x00c62, 0x00c63, 0 },
+  { 0x00c82, 0x00c83, 0 },
+  { 0x00cbc, 0x00cbc, 0 },
+  { 0x00cbe, 0x00cc4, 0 },
+  { 0x00cc6, 0x00cc8, 0 },
+  { 0x00cca, 0x00ccd, 0 },
+  { 0x00cd5, 0x00cd6, 0 },
+  { 0x00ce2, 0x00ce3, 0 },
+  { 0x00d02, 0x00d03, 0 },
+  { 0x00d3e, 0x00d44, 0 },
+  { 0x00d46, 0x00d48, 0 },
+  { 0x00d4a, 0x00d4d, 0 },
+  { 0x00d57, 0x00d57, 0 },
+  { 0x00d62, 0x00d63, 0 },
+  { 0x00d82, 0x00d83, 0 },
+  { 0x00dca, 0x00dca, 0 },
+  { 0x00dcf, 0x00dd4, 0 },
+  { 0x00dd6, 0x00dd6, 0 },
+  { 0x00dd8, 0x00ddf, 0 },
+  { 0x00df2, 0x00df3, 0 },
+  { 0x00e31, 0x00e31, 0 },
+  { 0x00e34, 0x00e3a, 0 },
+  { 0x00e47, 0x00e4e, 0 },
+  { 0x00eb1, 0x00eb1, 0 },
+  { 0x00eb4, 0x00eb9, 0 },
+  { 0x00ebb, 0x00ebc, 0 },
+  { 0x00ec8, 0x00ecd, 0 },
+  { 0x00f18, 0x00f19, 0 },
+  { 0x00f35, 0x00f35, 0 },
+  { 0x00f37, 0x00f37, 0 },
+  { 0x00f39, 0x00f39, 0 },
+  { 0x00f3e, 0x00f3f, 0 },
+  { 0x00f71, 0x00f84, 0 },
+  { 0x00f86, 0x00f87, 0 },
+  { 0x00f90, 0x00f97, 0 },
+  { 0x00f99, 0x00fbc, 0 },
+  { 0x00fc6, 0x00fc6, 0 },
+  { 0x0102b, 0x0103e, 0 },
+  { 0x01056, 0x01059, 0 },
+  { 0x0105e, 0x01060, 0 },
+  { 0x01062, 0x01064, 0 },
+  { 0x01067, 0x0106d, 0 },
+  { 0x01071, 0x01074, 0 },
+  { 0x01082, 0x0108d, 0 },
+  { 0x0108f, 0x0108f, 0 },
+  { 0x0109a, 0x0109d, 0 },
+  { 0x0135f, 0x0135f, 0 },
+  { 0x01712, 0x01714, 0 },
+  { 0x01732, 0x01734, 0 },
+  { 0x01752, 0x01753, 0 },
+  { 0x01772, 0x01773, 0 },
+  { 0x017b6, 0x017d3, 0 },
+  { 0x017dd, 0x017dd, 0 },
+  { 0x0180b, 0x0180d, 0 },
+  { 0x018a9, 0x018a9, 0 },
+  { 0x01920, 0x0192b, 0 },
+  { 0x01930, 0x0193b, 0 },
+  { 0x019b0, 0x019c0, 0 },
+  { 0x019c8, 0x019c9, 0 },
+  { 0x01a17, 0x01a1b, 0 },
+  { 0x01a55, 0x01a5e, 0 },
+  { 0x01a60, 0x01a7c, 0 },
+  { 0x01a7f, 0x01a7f, 0 },
+  { 0x01b00, 0x01b04, 0 },
+  { 0x01b34, 0x01b44, 0 },
+  { 0x01b6b, 0x01b73, 0 },
+  { 0x01b80, 0x01b82, 0 },
+  { 0x01ba1, 0x01baa, 0 },
+  { 0x01c24, 0x01c37, 0 },
+  { 0x01cd0, 0x01cd2, 0 },
+  { 0x01cd4, 0x01ce8, 0 },
+  { 0x01ced, 0x01ced, 0 },
+  { 0x01cf2, 0x01cf2, 0 },
+  { 0x01dc0, 0x01de6, 0 },
+  { 0x01dfd, 0x01dff, 0 },
+  { 0x020d0, 0x020f0, 0 },
+  { 0x02cef, 0x02cf1, 0 },
+  { 0x02de0, 0x02dff, 0 },
+  { 0x0302a, 0x0302f, 0 },
+  { 0x03099, 0x0309a, 0 },
+  { 0x0a66f, 0x0a672, 0 },
+  { 0x0a67c, 0x0a67d, 0 },
+  { 0x0a6f0, 0x0a6f1, 0 },
+  { 0x0a802, 0x0a802, 0 },
+  { 0x0a806, 0x0a806, 0 },
+  { 0x0a80b, 0x0a80b, 0 },
+  { 0x0a823, 0x0a827, 0 },
+  { 0x0a880, 0x0a881, 0 },
+  { 0x0a8b4, 0x0a8c4, 0 },
+  { 0x0a8e0, 0x0a8f1, 0 },
+  { 0x0a926, 0x0a92d, 0 },
+  { 0x0a947, 0x0a953, 0 },
+  { 0x0a980, 0x0a983, 0 },
+  { 0x0a9b3, 0x0a9c0, 0 },
+  { 0x0aa29, 0x0aa36, 0 },
+  { 0x0aa43, 0x0aa43, 0 },
+  { 0x0aa4c, 0x0aa4d, 0 },
+  { 0x0aa7b, 0x0aa7b, 0 },
+  { 0x0aab0, 0x0aab0, 0 },
+  { 0x0aab2, 0x0aab4, 0 },
+  { 0x0aab7, 0x0aab8, 0 },
+  { 0x0aabe, 0x0aabf, 0 },
+  { 0x0aac1, 0x0aac1, 0 },
+  { 0x0abe3, 0x0abea, 0 },
+  { 0x0abec, 0x0abed, 0 },
+  { 0x0fb1e, 0x0fb1e, 0 },
+  { 0x0fe00, 0x0fe0f, 0 },
+  { 0x0fe20, 0x0fe26, 0 },
+  { 0x101fd, 0x101fd, 0 },
+  { 0x10a01, 0x10a03, 0 },
+  { 0x10a05, 0x10a06, 0 },
+  { 0x10a0c, 0x10a0f, 0 },
+  { 0x10a38, 0x10a3a, 0 },
+  { 0x10a3f, 0x10a3f, 0 },
+  { 0x11080, 0x11082, 0 },
+  { 0x110b0, 0x110ba, 0 },
+  { 0x1d165, 0x1d169, 0 },
+  { 0x1d16d, 0x1d172, 0 },
+  { 0x1d17b, 0x1d182, 0 },
+  { 0x1d185, 0x1d18b, 0 },
+  { 0x1d1aa, 0x1d1ad, 0 },
+  { 0x1d242, 0x1d244, 0 },
+  { 0xe0100, 0xe01ef, 0 },
+  { 0x01100, 0x0115f, 2 },
+  { 0x011a3, 0x011a7, 2 },
+  { 0x011fa, 0x011ff, 2 },
+  { 0x02329, 0x0232a, 2 },
+  { 0x02e80, 0x02e99, 2 },
+  { 0x02e9b, 0x02ef3, 2 },
+  { 0x02f00, 0x02fd5, 2 },
+  { 0x02ff0, 0x02ffb, 2 },
+  { 0x03000, 0x03029, 2 },
+  { 0x03030, 0x0303e, 2 },
+  { 0x03041, 0x03096, 2 },
+  { 0x0309b, 0x030ff, 2 },
+  { 0x03105, 0x0312d, 2 },
+  { 0x03131, 0x0318e, 2 },
+  { 0x03190, 0x031b7, 2 },
+  { 0x031c0, 0x031e3, 2 },
+  { 0x031f0, 0x0321e, 2 },
+  { 0x03220, 0x03247, 2 },
+  { 0x03250, 0x032fe, 2 },
+  { 0x03300, 0x04dbf, 2 },
+  { 0x04e00, 0x0a48c, 2 },
+  { 0x0a490, 0x0a4c6, 2 },
+  { 0x0a960, 0x0a97c, 2 },
+  { 0x0ac00, 0x0d7a3, 2 },
+  { 0x0d7b0, 0x0d7c6, 2 },
+  { 0x0d7cb, 0x0d7fb, 2 },
+  { 0x0f900, 0x0faff, 2 },
+  { 0x0fe10, 0x0fe19, 2 },
+  { 0x0fe30, 0x0fe52, 2 },
+  { 0x0fe54, 0x0fe66, 2 },
+  { 0x0fe68, 0x0fe6b, 2 },
+  { 0x0ff01, 0x0ff60, 2 },
+  { 0x0ffe0, 0x0ffe6, 2 },
+  { 0x1f200, 0x1f200, 2 },
+  { 0x1f210, 0x1f231, 2 },
+  { 0x1f240, 0x1f248, 2 },
+  { 0x20000, 0x2fffd, 2 },
+  { 0x30000, 0x3fffd, 2 }
+};
+
+/* Get the width of a UTF-8 character. */
+int
+utf8_width (char *s)
+{
+  int val, i;
+
+  if (UTF8_ISCONT (*s))
+    return 0;
+
+  switch (UTF8_LENGTH (*s))
+    {
+      case 1:
+        val = s[0];
+        break;
+      case 2:
+        val = (s[1] & 0x3f) | (s[0] & 0x1f) << 6;
+        break;
+      case 3:
+        val = ((s[2] & 0x3f) | (s[1] & 0x3f) << 6) |
+            (s[0] & 0x0f) << 12;
+        break;
+      case 4:
+        val = (((s[3] & 0x3f) | (s[2] & 0x3f) << 6) |
+            (s[1] & 0x3f) << 12) | (s[0] & 0x3f) << 18;
+        break;
+      case 5:
+        val = ((((s[4] & 0x3f) | (s[3] & 0x3f) << 6) |
+            (s[2] & 0x3f) << 12) | (s[1] & 0x3f) << 18) |
+            (s[0] & 0x3f) << 24;
+        break;
+      case 6:
+        val = (((((s[5] & 0x3f) | (s[4] & 0x3f) << 6) |
+            (s[3] & 0x3f) << 12) | (s[2] & 0x3f) << 18) |
+            (s[1] & 0x3f) << 24) | (s[0] & 0x3f) << 30;
+        break;
+      default:
+        return 0;
+    }
+
+  for (i = 0; i < sizeof(utf8_widthtab) / sizeof(utf8_widthtab[0]); i++)
+    {
+      if (val >= utf8_widthtab[i].min && val <= utf8_widthtab[i].max)
+        return utf8_widthtab[i].width;
+    }
+
+  return 1;
+}
+
+/* Get the width of a UTF-8 string. */
+int
+utf8_strwidth (char *s)
+{
+  int width = 0;
+
+  for (; s && *s; s++)
+    {
+      if (!UTF8_ISCONT (*s))
+        width += utf8_width (s);
+    }
+
+  return width;
+}