Re: Code points on Windows

From: Philippe Verdy (
Date: Wed Jan 14 2004 - 15:18:51 EST

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    Code points on WindowsFrom: Mike Ayers
    > On Windows, it is well known that you can generate a character from its
    code point
    > by holding down the alt key and typing the code point in decimal, with a
    leading 0,
    > on the numeric keypad.

    Correction: what you generate is not the (Unicode) code point but only the
    code position in your current Windows ANSI code page (even if the characters
    generated will be coded with Unicode). The reason for that is that Windows
    must be able to return WM_CHAR events to applications that are not prepared
    to recveive something else than ANSI characters, if these applications use
    the legacy ANSI API.

    But if the application uses the Unicode version of the
    GetMessage()/TranslateMessage() API, it will receive WM_CHAR events
    containing the Unicode codepoints (in fact only UTF-16 code units)
    corresponding to keyboard input events.

    You can't use that input method to enter any Unicode code point (the user
    has no way to determine whever the application uses the Unicode API or the
    ANSI API internally, so the input sequence should be consistent across
    multiple applications for the same input sequence defined for only ANSI
    characters), and there are lots of difference between the ANSI code page and
    Unicode code points in the range 128 to 159 as well as on all other higher
    codes if your Windows code page is not 1252 (Western European, based on

    There's nothing in the default keyboard drivers to allow you input directly
    from the keyboard, characters that are not in your current Windows code page
    (the default keyboard drivers will not return characters outside of this

    When this support is added, it does not come from the keyboard driver
    itself, but from GUI input components like rich-edit controls, which will
    remap the keyboard events using alternate conversion rules to generate
    characters outside of the current Windows ANSI codepage (for example by
    mapping AltGr+x followed by hexadecimal Unicode code point).

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