Unify string stepping delimiter code for text buttons, text editor and console (all had duplicate code).

this is also a step toward the console working with utf8 though many todo's remain.

source/blender/blenlib/intern/string_cursor_utf8.c

@@ -0,0 +1,181 @@
+/*
+ * ***** BEGIN GPL LICENSE BLOCK *****
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * The Original Code is Copyright (C) 2011 Blender Foundation.
+ * All rights reserved.
+ *
+ * Contributor(s): Campbell Barton.
+ *
+ * ***** END GPL LICENSE BLOCK *****
+ *
+ */
+
+/** \file blender/blenlib/intern/string_cursor_utf8.c
+  *  \ingroup bli
+  */
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "BLI_utildefines.h"
+#include "BLI_string_utf8.h"
+
+#include "BLI_string_cursor_utf8.h" /* own include */
+
+
+/* return 1 if char ch is special character, otherwise return 0 */
+static strCursorDelimType test_special_char(const char ch)
+{
+	/* TODO - use BLI_str_utf8_as_unicode rather then assuming ascii */
+
+	if ((ch >= 'a' && ch <= 'z') ||
+	    (ch >= 'A' && ch <= 'Z') ||
+	    (ch == '_') /* not quite correct but allow for python, could become configurable */
+	    )
+	{
+		return STRCUR_DELIM_ALPHA;
+	}
+
+	switch (ch) {
+		case ',':
+		case '.':
+			return STRCUR_DELIM_PUNCT;
+
+		case '{':
+		case '}':
+		case '[':
+		case ']':
+		case '(':
+		case ')':
+			return STRCUR_DELIM_BRACE;
+
+		case '+':
+		case '-':
+		case '=':
+		case '~':
+		case '%':
+		case '/':
+		case '<':
+		case '>':
+		case '^':
+		case '*':
+		case '&':
+			return STRCUR_DELIM_OPERATOR;
+
+		case '\'':
+		case '\"': // " - an extra closing one for Aligorith's text editor
+			return STRCUR_DELIM_QUOTE;
+
+		case ' ':
+			return STRCUR_DELIM_WHITESPACE;
+
+		case '\\':
+		case '!':
+		case '@':
+		case '#':
+		case '$':
+		case ':':
+		case ';':
+		case '?':
+		/* case '_': */ /* special case, for python */
+			return STRCUR_DELIM_OTHER;
+
+		default:
+			break;
+	}
+	return STRCUR_DELIM_NONE;
+}
+
+int BLI_str_cursor_step_next_utf8(const char *str, size_t maxlen, short *pos)
+{
+	const char *str_end= str + (maxlen + 1);
+	const char *str_pos= str + (*pos);
+	const char *str_next= BLI_str_find_next_char_utf8(str_pos, str_end);
+	if (str_next) {
+		(*pos) += (str_next - str_pos);
+		if((*pos) > maxlen) (*pos)= maxlen;
+		return TRUE;
+	}
+
+	return FALSE;
+}
+
+int BLI_str_cursor_step_prev_utf8(const char *str, size_t UNUSED(maxlen), short *pos)
+{
+	if((*pos) > 0) {
+		const char *str_pos= str + (*pos);
+		const char *str_prev= BLI_str_find_prev_char_utf8(str, str_pos);
+		if (str_prev) {
+			(*pos) -= (str_pos - str_prev);
+			return TRUE;
+		}
+	}
+
+	return FALSE;
+}
+
+void BLI_str_cursor_step_utf8(const char *str, size_t maxlen,
+                              short *pos, strCursorJumpDirection direction,
+                              strCursorJumpType jump)
+{
+	const short pos_prev= *pos;
+
+	if (direction == STRCUR_DIR_NEXT) {
+		BLI_str_cursor_step_next_utf8(str, maxlen, pos);
+
+		if (jump != STRCUR_JUMP_NONE) {
+			const strCursorDelimType is_special= (*pos) < maxlen ? test_special_char(str[(*pos)]) : STRCUR_DELIM_NONE;
+			/* jump between special characters (/,\,_,-, etc.),
+			 * look at function test_special_char() for complete
+			 * list of special character, ctr -> */
+			while ((*pos) < maxlen) {
+				if (BLI_str_cursor_step_next_utf8(str, maxlen, pos)) {
+					if ((jump != STRCUR_JUMP_ALL) && (is_special != test_special_char(str[(*pos)]))) break;
+				}
+				else {
+					break; /* unlikely but just incase */
+				}
+			}
+		}
+	}
+	else if (direction == STRCUR_DIR_PREV) {
+		BLI_str_cursor_step_prev_utf8(str, maxlen, pos);
+
+		if(jump != STRCUR_JUMP_NONE) {
+			const strCursorDelimType is_special= (*pos) > 1 ? test_special_char(str[(*pos) - 1]) : STRCUR_DELIM_NONE;
+			/* jump between special characters (/,\,_,-, etc.),
+			 * look at function test_special_char() for complete
+			 * list of special character, ctr -> */
+			while ((*pos) > 0) {
+				if (BLI_str_cursor_step_prev_utf8(str, maxlen, pos)) {
+					if ((jump != STRCUR_JUMP_ALL) && (is_special != test_special_char(str[(*pos)]))) break;
+				}
+				else {
+					break;
+				}
+			}
+
+			/* left only: compensate for index/change in direction */
+			if (((*pos) != 0) && ABS(pos_prev - (*pos)) >= 1) {
+				BLI_str_cursor_step_next_utf8(str, maxlen, pos);
+			}
+		}
+	}
+	else {
+		BLI_assert(0);
+	}
+}