GET_PHONEBOOK_INDEX

http://android.git.kernel.org/?p=platform/external/sqlite.git;a=commitdiff;h=3a74962298118ee138e290c3458bccb895854b47

显示SQLite中的 GET_PHONEBOOK_INDEX 函数是在2010.3.3才加入的，也就是说，可能2.0之后的很多老机器都不支持该函数，需要自己去实现，

This function will produce a normalized upper case first letter
from a given string.

Bug: 2407129
Change-Id: Idfafca04342d43ef43cfdff0e431e0a6a8cf5c68

android/Android.mk         patch | blob | history
android/PhonebookIndex.cpp     [new file with mode: 0644]     patch | blob
android/PhonebookIndex.h     [new file with mode: 0644]     patch | blob
android/sqlite3_android.cpp         patch | blob | history

而且看了C++代码(./external/sqlite/android/PhonebookIndex.cpp)发现，有很多字符处理都是直接返回0的：

/**
 * Returns TRUE if the character belongs to a Hanzi unicode block
 */
static bool is_CJK(UChar c) {
  return
       (0x4e00 <= c && c <= 0x9fff)     // CJK_UNIFIED_IDEOGRAPHS
    || (0x3400 <= c && c <= 0x4dbf)     // CJK_UNIFIED_IDEOGRAPHS_EXTENSION_A
    || (0x3000 <= c && c <= 0x303f)     // CJK_SYMBOLS_AND_PUNCTUATION
    || (0x2e80 <= c && c <= 0x2eff)     // CJK_RADICALS_SUPPLEMENT
    || (0x3300 <= c && c <= 0x33ff)     // CJK_COMPATIBILITY
    || (0xfe30 <= c && c <= 0xfe4f)     // CJK_COMPATIBILITY_FORMS
    || (0xf900 <= c && c <= 0xfaff);    // CJK_COMPATIBILITY_IDEOGRAPHS
}

int32_t GetPhonebookIndex(UCharIterator * iter, const char * locale, UChar * out, int32_t size,
        UBool * isError)
{
  if (size < MIN_OUTPUT_SIZE) {
    *isError = TRUE;
    return 0;
  }

  *isError = FALSE;

  // Normalize the first character to remove accents using the NFD normalization
  UErrorCode errorCode = U_ZERO_ERROR;
  int32_t len = unorm_next(iter, out, size, UNORM_NFD,
          0 /* options */, TRUE /* normalize */, NULL, &errorCode);
  if (U_FAILURE(errorCode)) {
    *isError = TRUE;
    return 0;
  }

  if (len == 0) {   // Empty input string
    return 0;
  }

  UChar c = out[0];

  // We are only interested in letters
  if (!u_isalpha(c)) {
    return 0;
  }

  c = u_toupper(c);

  // Check for explicitly mapped characters
  UChar c_mapped = map_character(c, DEFAULT_CHAR_MAP, sizeof(DEFAULT_CHAR_MAP) / sizeof(UChar));
  if (c_mapped != 0) {
    out[0] = c_mapped;
    return 1;
  }

  // Convert Kanas to Hiragana
  UChar next = len > 2 ? out[1] : 0;
  c = android::GetNormalizedCodePoint(c, next, NULL);

  // Traditional grouping of Hiragana characters
  if (0x3042 <= c && c <= 0x309F) {
    if (c < 0x304B) c = 0x3042;         // a
    else if (c < 0x3055) c = 0x304B;    // ka
    else if (c < 0x305F) c = 0x3055;    // sa
    else if (c < 0x306A) c = 0x305F;    // ta
    else if (c < 0x306F) c = 0x306A;    // na
    else if (c < 0x307E) c = 0x306F;    // ha
    else if (c < 0x3084) c = 0x307E;    // ma
    else if (c < 0x3089) c = 0x3084;    // ya
    else if (c < 0x308F) c = 0x3089;    // ra
    else c = 0x308F;                    // wa
    out[0] = c;
    return 1;
  }

  if (is_CJK(c)) {
    if (strncmp(locale, "ja", 2) == 0) {
      // Japanese word meaning "misc" or "other"
      out[0] = 0x4ED6;
      return 1;
    } else {
      return 0;
    }
  }

  out[0] = c;
  return 1;
}

倒是对日语支持的很好啊。