diff options
Diffstat (limited to 'driver/mlstring.c')
| -rw-r--r-- | driver/mlstring.c | 229 |
1 files changed, 229 insertions, 0 deletions
diff --git a/driver/mlstring.c b/driver/mlstring.c new file mode 100644 index 0000000..fdba1ee --- /dev/null +++ b/driver/mlstring.c @@ -0,0 +1,229 @@ +/* + * (c) 2007, Quest Software, Inc. All rights reserved. + * + * This file is part of XScreenSaver, + * Copyright (c) 1993-2009 Jamie Zawinski <jwz@jwz.org> + * + * Permission to use, copy, modify, distribute, and sell this software and its + * documentation for any purpose is hereby granted without fee, provided that + * the above copyright notice appear in all copies and that both that + * copyright notice and this permission notice appear in supporting + * documentation. No representations are made about the suitability of this + * software for any purpose. It is provided "as is" without express or + * implied warranty. + */ + +#include <stdlib.h> +#include <ctype.h> + +#include <X11/Xlib.h> + +#include "mlstring.h" + +#define LINE_SPACING 1.2 + +static mlstring * +mlstring_allocate(const char *msg); + +static void +mlstring_calculate(mlstring *str, XFontStruct *font); + +mlstring* +mlstring_new(const char *msg, XFontStruct *font, Dimension wrap_width) +{ + mlstring *newstr; + + if (!(newstr = mlstring_allocate(msg))) + return NULL; + + newstr->font_id = font->fid; + + mlstring_wrap(newstr, font, wrap_width); + + return newstr; +} + +mlstring * +mlstring_allocate(const char *msg) +{ + const char *s; + mlstring *ml; + struct mlstr_line *cur, *prev = NULL; + size_t linelength; + int the_end = 0; + + if (!msg) + return NULL; + + ml = calloc(1, sizeof(mlstring)); + + if (!ml) + return NULL; + + for (s = msg; !the_end; msg = ++s) + { + /* New string struct */ + cur = calloc(1, sizeof(struct mlstr_line)); + if (!cur) + goto fail; + + if (!ml->lines) + ml->lines = cur; + + /* Find the \n or end of string */ + while (*s != '\n') + { + if (*s == '\0') + { + the_end = 1; + break; + } + + ++s; + } + + linelength = s - msg; + + /* Duplicate the string */ + cur->line = malloc(linelength + 1); + if (!cur->line) + goto fail; + + strncpy(cur->line, msg, linelength); + cur->line[linelength] = '\0'; + + if (prev) + prev->next_line = cur; + prev = cur; + } + + return ml; + +fail: + + if (ml) + mlstring_free(ml); + + return NULL; +} + + +/* + * Frees an mlstring. + * This function does not have any unit tests. + */ +void +mlstring_free(mlstring *str) { + struct mlstr_line *cur, *next; + + for (cur = str->lines; cur; cur = next) { + next = cur->next_line; + free(cur->line); + free(cur); + } + + free(str); +} + + +void +mlstring_wrap(mlstring *mstring, XFontStruct *font, Dimension width) +{ + short char_width = font->max_bounds.width; + int line_length, wrap_at; + struct mlstr_line *mstr, *newml; + + /* An alternative implementation of this function would be to keep trying + * XTextWidth() on space-delimited substrings until the longest one less + * than 'width' is found, however there shouldn't be much difference + * between that, and this implementation. + */ + + for (mstr = mstring->lines; mstr; mstr = mstr->next_line) + { + if (XTextWidth(font, mstr->line, strlen(mstr->line)) > width) + { + /* Wrap it */ + line_length = width / char_width; + if (line_length == 0) + line_length = 1; + + /* First try to soft wrap by finding a space */ + for (wrap_at = line_length; wrap_at >= 0 && !isspace(mstr->line[wrap_at]); --wrap_at); + + if (wrap_at == -1) /* No space found, hard wrap */ + wrap_at = line_length; + else + wrap_at++; /* Leave the space at the end of the line. */ + + newml = calloc(1, sizeof(*newml)); + if (!newml) /* OOM, don't bother trying to wrap */ + break; + + if (NULL == (newml->line = strdup(mstr->line + wrap_at))) + { + /* OOM, jump ship */ + free(newml); + break; + } + + /* Terminate the existing string at its end */ + mstr->line[wrap_at] = '\0'; + + newml->next_line = mstr->next_line; + mstr->next_line = newml; + } + } + + mlstring_calculate(mstring, font); +} + +#undef MAX +#define MAX(x, y) ((x) > (y) ? (x) : (y)) + +/* + * Calculates the overall extents (width + height of the multi-line string). + * This function is called as part of mlstring_new(). + * It does not have any unit testing. + */ +void +mlstring_calculate(mlstring *str, XFontStruct *font) { + struct mlstr_line *line; + + str->font_height = font->ascent + font->descent; + str->overall_height = 0; + str->overall_width = 0; + + /* XXX: Should there be some baseline calculations to help XDrawString later on? */ + str->font_ascent = font->ascent; + + for (line = str->lines; line; line = line->next_line) + { + line->line_width = XTextWidth(font, line->line, strlen(line->line)); + str->overall_width = MAX(str->overall_width, line->line_width); + /* Don't add line spacing for the first line */ + str->overall_height += (font->ascent + font->descent) * + (line == str->lines ? 1 : LINE_SPACING); + } +} + +void +mlstring_draw(Display *dpy, Drawable dialog, GC gc, mlstring *string, int x, int y) { + struct mlstr_line *line; + + if (!string) + return; + + y += string->font_ascent; + + XSetFont(dpy, gc, string->font_id); + + for (line = string->lines; line; line = line->next_line) + { + XDrawString(dpy, dialog, gc, x, y, line->line, strlen(line->line)); + y += string->font_height * LINE_SPACING; + } +} + +/* vim:ts=8:sw=2:noet + */ |