MiniGUI 体系结构之三 逻辑字体以及多字体和多字符集实现(转)

              魏永明

蓝点软件（北京）研发中心技术主管

图 1 逻辑字体以及相关数据结构

int GUIAPI GetFirstWord (PLOGFONT log_font, const char* mstr, int len,
                    WORDINFO* word_info)
{
    DEVFONT* sbc_devfont = log_font->sbc_devfont;
    DEVFONT* mbc_devfont = log_font->mbc_devfont;

    if (mbc_devfont) {
        int mbc_pos;

        mbc_pos = (*mbc_devfont->charset_ops->pos_first_char) (mstr, len);
        if (mbc_pos == 0) {
            len = (*mbc_devfont->charset_ops->len_first_substr) (mstr, len);

            (*mbc_devfont->charset_ops->get_next_word) (mstr, len, word_info);
            return word_info->len + word_info->nr_delimiters;
        }
        else if (mbc_pos > 0)
            len = mbc_pos;
    }

    (*sbc_devfont->charset_ops->get_next_word) (mstr, len, word_info);
    return word_info->len + word_info->nr_delimiters;
}

该函数首先判断该逻辑字体是否包含多字节设备字体（mbc_devfont是否为空），如果是，则调用多字节字符集对应的操作函 数 pos_first_char、len_first_substr、get_next_word 等函数获得第一个单词信息，并填充 word_info 结构。如果该逻辑字体只包含单字节设备字体，则直接调用单字节字符集对应的操作函数 get_next_word。一般而言，在 GetFirstWord 等函数中，我们首先要进行多字节字符集的某些判断，比如 pos_first_char 返回的是字符串中属于该字符集的第一个字符的位置。如果返回值不为零，表明第一个字符是单字节字符；如果为零，才会调用其他函数进行操作。

 250 typedef struct _CHARSETOPS
 251 {
 252     int nr_chars;    // 该字符集中字符的个数
 253     int bytes_per_char;   // 每个字符的平均字节数
 254     int bytes_maxlen_char;  // 字符的最大字节数
 255     const char* name;   // 字符集名称
 256     char def_char [MAX_LEN_MCHAR]; // 默认字符
 257 
 258     int (*len_first_char) (const unsigned char* mstr, int mstrlen);
 259     int (*char_offset) (const unsigned char* mchar);
 260 
 261     int (*nr_chars_in_str) (const unsigned char* mstr, int mstrlen);
 262 
 263     int (*is_this_charset) (const unsigned char* charset);
 264 
 265     int (*len_first_substr) (const unsigned char* mstr, int mstrlen);
 266     const unsigned char* (*get_next_word) (const unsigned char* mstr, 
 267                 int strlen, WORDINFO* word_info);
 268 
 269     int (*pos_first_char) (const unsigned char* mstr, int mstrlen);
 270 
 271 #ifndef _LITE_VERSION
 272     unsigned short (*conv_to_uc16) (const unsigned char* mchar, int len);
 273 #endif /* !LITE_VERSION */
 274 } CHARSETOPS;

 716 static CHARSETOPS* Charsets [] =
 717 {
 718     &CharsetOps_iso8859_1,
 719     &CharsetOps_iso8859_5,
 720 #ifdef _GB_SUPPORT
 721     &CharsetOps_gb2312,
 722 #endif
 723 #ifdef _BIG5_SUPPORT
 724     &CharsetOps_big5,
 725 #endif
 726 #ifdef _EUCKR_SUPPORT
 727     &CharsetOps_euckr,
 728 #endif
 729 #ifdef _UJIS_SUPPORT
 730     &CharsetOps_ujis
 731 #endif
 732 };
 733 
 734 #define NR_CHARSETS     (sizeof(Charsets)/sizeof(CHARSETOPS*))
 735 
 736 CHARSETOPS* GetCharsetOps (const char* charset_name)
 737 {
 738     int i;
 739 
 740     for (i = 0; i < NR_CHARSETS; i++) {
 741         if ((*Charsets [i]->is_this_charset) (charset_name) == 0)
 742             return Charsets [i];
 743     }
 744 
 745     return NULL;
 746 }
 747 

 468 #ifdef _EUCKR_SUPPORT
 469 /************************* EUCKR Specific Operations ************************/
 470 static int euckr_len_first_char (const unsigned char* mstr, int len)
 471 {
 472     unsigned char ch1;
 473     unsigned char ch2;
 474 
 475     if (len < 2) return 0;
 476 
 477     ch1 = mstr [0];
 478     if (ch1 == '\0')
 479         return 0;
 480 
 481     ch2 = mstr [1];
 482     if (ch1 >= 0xA1 && ch1 <= 0xFE && ch2 >= 0xA1 && ch2 <= 0xFE)
 483         return 2;
 484 
 485     return 0;
 486 }
 487 
 488 static int euckr_char_offset (const unsigned char* mchar)
 489 {
 490     if(mchar [0] > 0xAD)
 491         return ((mchar [0] - 0xA4) * 94 + mchar [1] - 0xA1 - 0x8E);
 492     else
 493         return ((mchar [0] - 0xA1) * 94 + mchar [1] - 0xA1 - 0x8E);
 494 }
 495 
 496 static int euckr_is_this_charset (const unsigned char* charset)
 497 {
 498     int i;
 499     char name [LEN_FONT_NAME + 1];
 500 
 501     for (i = 0; i < LEN_FONT_NAME + 1; i++) {
 502         if (charset [i] == '\0')
 503             break;
 504         name [i] = toupper (charset [i]);
 505     }
 506     name [i] = '\0';
 507 
 508     if (strstr (name, "EUCKR") )
 509         return 0;
 510 
 511     return 1;
 512 }
 513 
 514 static int euckr_len_first_substr (const unsigned char* mstr, int mstrlen)
 515 {
 516     unsigned char ch1;
 517     unsigned char ch2;
 518     int i, left;
 519     int sub_len = 0;
 520 
 521     left = mstrlen;
 522     for (i = 0; i < mstrlen; i += 2) {
 523         if (left < 2) return sub_len;
 524 
 525         ch1 = mstr [i];
 526         if (ch1 == '\0') return sub_len;
 527 
 528         ch2 = mstr [i + 1];
 529         if (ch1 >= 0xA1 && ch1 <= 0xFE && ch2 >= 0xA1 && ch2 <= 0xFE)
 530             sub_len += 2;
 531         else
 532             return sub_len;
 533 
 534         left -= 2;
 535     }
 536 
 537     return sub_len;
 538 }
 539 
 540 static int euckr_pos_first_char (const unsigned char* mstr, int mstrlen)
 541 {
 542     unsigned char ch1;
 543     unsigned char ch2;
 544     int i, left;
 545 
 546     i = 0;
 547     left = mstrlen;
 548     while (left) {
 549         if (left < 2) return -1;
 550 
 551         ch1 = mstr [i];
 552         if (ch1 == '\0') return -1;
 553 
 554         ch2 = mstr [i + 1];
 555         if (ch1 >= 0xA1 && ch1 <= 0xFE && ch2 >= 0xA1 && ch2 <= 0xFE)
 556             return i;
 557 
 558         i += 1;
 559         left -= 1;
 560     }
 561 
 562     return -1;
 563 }
 564 
 565 #ifndef _LITE_VERSION
 566 static unsigned short euckr_conv_to_uc16 (const unsigned char* mchar, int len)
 567 {
 568     return '?';
 569 }
 570 #endif
 571 
 572 static CHARSETOPS CharsetOps_euckr = {
 573     8836,
 574     2,
 575     2,
 576     FONT_CHARSET_EUCKR,
 577     {'\xA1', '\xA1'},
 578     euckr_len_first_char,
 579     euckr_char_offset,
 580     db_nr_chars_in_str,
 581     euckr_is_this_charset,
 582     euckr_len_first_substr,
 583     db_get_next_word,
 584     euckr_pos_first_char,
 585 #ifndef _LITE_VERSION
 586     euckr_conv_to_uc16
 587 #endif
 588 };
 589 /************************* End of EUCKR *************************************/
 590 #endif  /* _EUCKR_SUPPORT */

 319 struct _DEVFONT
 320 {
 321     char             name [LEN_DEVFONT_NAME + 1];
 322     DWORD            style;
 323     FONTOPS*         font_ops;
 324     CHARSETOPS*      charset_ops;
 325     struct _DEVFONT* sbc_next;
 326     struct _DEVFONT* mbc_next;
 327     void*            data;
 328 };

--