|
|
This Technical Note contains a collection of archived Q&As relating to a specific topic--questions sent the Developer Support Center (DSC)
along with answers from the DSC engineers. Current Q&As can be found on the Macintosh Technical Q&As web site.
[Oct 01 1990]
|
String2Date and Date2Secs conversion surprises
Date Written: 8/19/91
Last reviewed: 6/14/93
String2Date and Date2Secs treat all dates with the year 04 to 10 as 2004 to
2010 instead of 1904 to 1910.
___
This is correct; the Script Manager treats two-digit years less than or
equal to 10 as 20xx dates if the current year is between 1990 and 1999, inclusive.
Basically, it just assumes that you're talking about 1-20 years in the future, rather
than 80-100 years in the past. The same is true of two-digit 9x dates, when the current
year is less than or equal to xx10. Thus, in 2003, the date returned when 3/7/94 is converted
will be 1994, not 2094. This is all documented in "Worldwide Development: Guide to System Software".
Back to top Using FormatXToStr and FormatStrToX with Pascal switches
Date Written: 12/10/90
Last reviewed: 6/14/93
Why do the FormatXToStr and FormatStrToX Script Manager routines stop working
when I use the Pascal -MC68881 switch?
___
Regular SANE extended numbers are 10 bytes long while MC68881 extended numbers
are 12 bytes long, and the extra two bytes are right in the middle of every
68881 extended number. Appendix G "The SANE Library" in the Macintosh
Programmer's Workshop (MPW) Object Pascal version 3.1 manual goes into detail
about this. The FormatX2Str and FormatStr2X parse the extended number you pass
them directly, and they can only parse 10-byte extended numbers. Fortunately,
you can still use the -mc68881 option with these routines as long as you
convert any extended numbers to 80-bit extended numbers before passing them to
FormatX2Str and FormatStr2X. The SANE.p unit has routines to do this called
X96toX80 and X80toX96 (incorrectly documented as X96to80 and X80to96 in the MPW
Object Pascal manual). Because the extended80 and extended96 types aren't
equivalent to the extended type as far as Object Pascal is concerned, you have
to redeclare FormatX2Str and FormatStr2X to take these types. You can do this
as follows:
FUNCTION FormatX2Str80 (x: extended80;
myCanonical: NumFormatString;
partsTable: NumberParts;
VAR outString: Str255): FormatStatus;
INLINE $2F3C,$8210,$FFE8,$A8B5;
FUNCTION FormatStr2X80 (source: Str255;
myCanonical: NumFormatString;
partsTable: NumberParts;
VAR x: extended80): FormatStatus;
INLINE $2F3C,$8210,$FFE6,$A8B5;
|
Call these routines instead of the originals. To call FormatX2Str80, all you
have to do is this:
VAR
x: extended80; {96-bit extended number}
myCanonical: NumFormatString;
partsTable: NumberParts;
outString: Str255
result := FormatX2Str80 (X96toX80 (x), myCanonical, partsTable, outString);
|
Calling FormatStr2X80 is just slightly more complicated because the extended
number is passed by reference:
VAR
x: extended; {96-bit extended number}
x80: extended80; {80-bit extended number}
source: Str255;
myCanonical: NumFormatString;
partsTable: NumberParts;
x80 := X96toX80 (x);
result := FormatStr2X80 (theString, realCanon, PartsTable, x80);
x := X80toX96 (x80);
|
You should find that these calls now work properly with the -mc68881 option
set. This of course means that you'll need two versions of the source code; one
with the calls to convert between 96-bit and 80-bit extended numbers for use
with the -mc68881 option and another one which just uses plain old 80-bit
extended numbers for use when the -mc68881 option is turned off.
Back to top FormatX2Str strings
Date Written: 10/9/91
Last reviewed: 6/14/93
Using the Script Manager to convert numbers to strings and vice versa, in any
language, what's the best way to create the string to pass to FormatX2Str? Will
strings using the characters: "#" or "0" or "." or "," work no matter what
script is currently running, and if not, what can I do?
___
The number format string and canonical number format string mechanisms that you
use with FormatX2Str and its kin is a strange design, for exactly the reason
that you asked about. The number format string (the one with the characters
such as "#" and "0") does not necessarily work right regardless of the current
script. In fact, it doesn't even necessarily work right between localized
versions within one script system. The canonical number format string does work
between localized systems and between script systems. The strange thing is
there's an easy way to store number format strings (usually in a 'STR '
resource), but no obvious way to store canonical number format strings. Here's
what you can do when converting between numbers and strings:
When you convert a number format string to a canonical number format string
with Str2Format on a U.S. system, it converts it from something like "###.###"
to a canonical number format string that looks something like, "three digits, a
decimal point, and three digits." On a German system, that same number format
string would be converted to "three digits, a thousands separator, and three
digits."
What you can do to get around this is to save the canonical number format
string in a resource instead of the number format string. The canonical string
stores things in a language- and script-independent way. Create this resource
by writing a trivial utility program that takes a number format string and
calls Str2Format to convert it into a canonical number format string, and then
copy this into a handle and save it as a resource of a custom type, like
'NUMF'. In your real program, load the 'NUMF' resource, lock it, and then pass
the dereferenced handle to FormatX2Str and FormatStr2X.
You can see this done in the ProcDoggie Process Manager sample from the 7.0
Golden Master CD. Take a look at the SetUpProcessInfoItems procedure in
UProcessGuts.inc1.p file. You'll see that the 'NUMF' resource is loaded,
locked, and then passed to FormatX2Str. The result is displayed in the Process
Information window.
If your program is localized by nonprogrammers, then you might want to provide
the utility that converts a number format string to a canonical number format
string resource just in case they have to change the entire format of the
string. Then they can install the new 'NUMF' (or whatever you choose) resource
as part of the localization process.
Back to top Code for truncating a multi-byte character string
Date Written: 1/24/92
Last reviewed: 6/14/93
I create a Macintosh file name from another file name. Since I am adding
information to the name, I must make sure that it is within the 31 chars
maximum allowed by the operating system. What I need is the equivalent of the
TruncText command, except instead of dealing with pixel width, I want the width
to be number of characters (31). I can trunc myself, but I'd rather do a proper
smTruncMiddle and have it nicely internationalized.
___
If you're going to be adding a set number of bytes to the end of a existing
string and you don't want the localized ellipsis (from the 'itl4' resource)
between the truncated string and your bytes, then you can use this routine:
PROCEDURE TruncPString (VAR theString: Str255; maxLength: Integer);
{ This procedure truncates a Pascal string to be of length maxLength or }
{ shorter. It uses the Script Manager charByte function to make sure }
{ the string is not broken in the middle of a multi-byte character. }
VAR
charType: Integer;
BEGIN
IF Length(theString) > maxLength THEN
BEGIN
charType := CharByte(@theString[1], maxLength);
WHILE ((charType < 0) OR (charType > 1)) AND (maxLength <> 0) DO
BEGIN
maxLength := maxLength - 1;
charType := CharByte(@theString[1], maxLength);
END;
theString[0] := chr(maxLength);
END;
END;
|
If you want the localized ellipsis (from the 'itl4' resource) between the
truncated string and your bytes, or you want the localized ellipsis in the
middle of the combined strings truncated to a specific length, then you can use
this routine:
FUNCTION TruncPString (maxLength: Integer; VAR theString: Str255;
truncWhere: TruncCode): Integer;
{ This function truncates a Pascal String to be of length maxLength or }
{ shorter. It uses the Script Manager TruncString function which adds }
{ the correct tokenEllipsis to the middle or end of the string. See }
{ Inside Macintosh Volume VI, pages 14-59 and14-60 for more info. }
VAR
found: Boolean;
first, midPoint, last: Integer;
tempString: Str255;
whatHappened: Integer;
BEGIN
found := FALSE;
first := 0;
last := TextWidth(@theString[1], 0, Length(theString));
IF Length(theString) > maxLength THEN
BEGIN
WHILE (first <= last) AND NOT found DO
BEGIN
tempString := theString; { tempString gets destroyed every }
{ time through }
midPoint := (first + last) DIV 2;
whatHappened := TruncString(midPoint, tempString, truncWhere);
IF whatHappened < smNotTruncated THEN
BEGIN { ERROR, bail out now }
TruncPString := whatHappened; { return error }
Exit(TruncPString);
END
ELSE IF Length(tempString) = maxLength THEN
found := TRUE
ELSE IF Length(tempString) > maxLength THEN
last := midPoint - 1
ELSE
first := midPoint + 1;
END;
theString := tempString;
TruncPString := whatHappened; { will always be smTruncated }
{ in this case }
END
ELSE
TruncPString := smNotTruncated; { the string wasn't too long }
END;
|
Back to top Character type and subtype values within the Kanji system
Date Written: 11/17/89
Last reviewed: 12/17/90
What are the values of character type and subtype with the Macintosh Kanji system?
___
For Roman, these are the values of character type:
Punctuation 0
ASCII 1
European 7
|
For KanjiTalk, the values are the same as Roman, with the addition of:
Katakana 2
Hiragana 3
Kanji 4
Greek 5
Russian (Cyrillic) 6
|
In Roman, the subtype field is interpreted as:
Normal punctuation 0
Numeric 1
Symbols 2
Blanks 3
|
The KanjiTalk subtype values are the same as Roman except if the character type
is Kanji, in which case the subtype field takes these values:
JIS Level 1 0
JIS Level 2 1
JIS User Character 2
|
Finally, for KanjiTalk, the character direction field is replaced by the In-ROM
field. It is 1 if the character is in the ROM card and 0 otherwise.
Back to top
Downloadables
|
|
Acrobat version of this Note (36K)
|
Download
|
Back to top
|
