Converting a font character number into a string - cocoa

I'd like to draw a specific character number in a font using NSString's drawAtPoint() routine.
To do this I've been casting the integer value of the specific character into an NSString:
int characterNumber = 150; //character 150 in a particular font
NSString* myString = [NSString stringWithCharacters:(const unichar*)&characterNumber length:1];
This works if the character number is less than 128. If the characterNumber is greater than that (my font contains 200+ characters) then no character prints. If the character number is 150, and I change the string length to 2, then the wrong character from the font prints.
Is this an encoding issue?

Shouldn't that be:
unichar characterNumber = 150; //character 150 in a particular font
NSString* myString = [NSString stringWithCharacters:&characterNumber length:1];

The problem, it turned out, is that character 0x007F (127) is the DEL character, and is unprintable.
Other issues I had with my custom font turned out to be issues of encoding, which had to be worked out in Fontographer, rather than in NSString.

Related

How can i write a fraction for a UILabel in interface builder?

On the left: current
On the right: this is what I need
If you are directly setting the value in Interface builder. You can simply copy this (⅓) and paste in there and adjust the font size.
If you are setting from the code, You have unicode characters for defined fractions. You can use them.
For Example, for 1/3,
const unichar third = 0x2153;
labelText = [NSString stringWithCharacters:&third length:1];
For other fractions, check this link

Displaying currency signs in UILabel on Xcode

I am trying to display the gliphs for a currencies by using either the html format or unicode one. By using the former I tried all sorts of operations including: stringWithUTF8String, decodeFromPercentEscapeString, CFURLCreateStringByReplacingPercentEscapesUsingEncoding, stringByReplacingPercentEscapesUsingEncoding but none of them succeded in turning € into a euro sign. With Unicode the issue was slightly better as:
NSString *aStr = [NSString stringWithUTF8String:[#"\u20ac" UTF8String]];
actually prints a euro sign, but for I reason I do not understand, if I provide the string as the result of a method, the unicode code gets displayed instead.
What is the standard way for displaying euro, dollar or pounds signs in a UILbel?
UILabel automatically resolves unicode strings, no need to decode:
label.text = #"\u0024"; // dollar
label.text = #"\u20ac"; // euro
Refer to fileformat.info for the encoding name.
What about directly copying and pasting those characters in your string as :
NSString *aStr = #"Euro-€, Dollar-$, Pound-£";
label.text=aStr;
I found a very simple solution:
float fareValue=/*float value*/;
NSNumber* fareNumber=[NSNumber numberWithFloat:fareValue];
NSString* formatted=[NSNumberFormatter localizedStringFromNumber:fareNumber numberStyle:NSNumberFormatterCurrencyStyle];
Thanks everyone
Swift 3
"\u{00A3}"
The '#' is no longer needed

How to change an NSString's encoding?

I have an NSArray of NStrings, I got this from NSLog when printing the array.
Here is the code I have implemented:
NSMetadataQuery *query = [[NSMetadataQuery alloc] init];
.....
NSArray *queryResults = [[query results] copy];
for (NSMetadataItem *item in queryResults)
{
id value = [item valueForAttribute: kMDItemAlbum];
[databaseArray addObject: value];
}
"The Chronicles Of Narnia: Prince Caspian",
"Taste the First Love",
"Once (Original Soundtrack)",
"430 West Presents Detroit Calling",
"O\U0308\U00d0\U00b9u\U0301\U00b0\U00aeA\U0300O\U0308A\U0300O\U0308I\U0301A\U030a-O\U0301a\U0300A\U0302\U00a1",
"\U7ea2\U96e8\U6d41\U884c\U7f51",
"I\U0300\U00ab\U00bc\U00abO\U0303A\U030aE\U0300y\U0301\U00b7a\U0301",
"A\U0303n\U0303\U00b8e\U0300\U00b2I\U0300C\U0327U\U0300",
"\U00bb\U00b3A\U0308i\U0302O\U0303\U00bdO\U0301N\U0303",
"American IV (The Man Comes Aro",
"All That We Needed",
Now how can I change the human-unreadable strings to human-readable strings? Thanks.
Looking past the escaping done by description (e.g., \U0308), the strings are wrong (e.g., “Öйú°®ÀÖÀÖÍÅ-Óà¡”) because the data you got was wrong.
That's probably not Spotlight's fault. (You could verify that by trying a different ID3-tag library.) Most probably, the files themselves contain poorly-encoded tags.
To fix this:
Encode it in the 8-bit encoding that matches the characters. You can't just pick an encoding (like “ASCII”, which Cocoa mapped to ISO Latin 1 the last time I checked) at random; you need to use the encoding that contains all of the characters in the input and encodes them correctly for what you're going to do next. Try ISO Latin 1, ISO Latin 9, Windows codepage 1252, and MacRoman, in that order.
Decode the encoded data as UTF-8. If this fails, go back to step 1 and try a different encoding.
If step 2 succeeds on any attempt, that is your valid data (unless you're very unlucky). If it fails on all attempts, the data is unrecoverable and you may want to warn the user that their input files contain bogus tags.
Parsing these kind of strings aren't particularly easy: See this SO post for background. It's got links to other SO posts with specific ways of handling this problem.
These strings are utf-8 encoded. You can decode them by:
NSString *myDecoded = [NSString stringWithUTF8String:myEscapedString];
So to process your complete array 'completeArray' you can convert to a const char* first and then back into NSString:
NSMutableArray *processed = [NSMutableArray arrayWithCapacity:completeArray.count];
for (NSString* s in completeArray) {
[processed addObject:[NSString stringWithUTF8String:[s cStringUsingEncoding:ASCIIEncoding]]];
}

ASCII to NSData

This is another crack at my MD5 problem. I know the issue is with the ASCII character © (0xa9, 169). Either it is the way I am inserting the character into the string or its a higher vs lower byte problem.
If I
NSString *source = [NSString stringWithFormat:#"%c", 0xa9];
NSData *data = [source dataUsingEncoding:NSASCIIStringEncoding];
NSLog(#"\n\n ############### source %# \ndata desc %#", source, [data description]);
CC_MD5([data bytes], [data length], result);
return [NSString stringWithFormat:
#"%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x",
result[0], result[1], result[2], result[3],
result[4], result[5], result[6], result[7],
result[8], result[9], result[10], result[11],
result[12], result[13], result[14], result[15]
];
Result:
######### source ©
[data description] = (null)
md5: d41d8cd98f00b204e9800998ecf8427e
values: int 169 char ©
When I change the encoding to
NSData *data = [NSData dataWithBytes:[source UTF8String] length:[source length]];
The result is
######### source ©
[data description] = "<"c2>
md5: 6465dad1d31752be3f3283e8f70feef7
When I change the encoding to
NSData *data = [NSData dataWithBytes:[source UTF8String] length:[source lengthOfBytesUsingEncoding:NSUTF8StringEncoding]];
The result is
############### source © len 2
[data description] = "<"c2a9>
md5: a541ecda3d4c67f1151cad5075633423
When I run the same function in Java I get
">>>>> msg## \251 \251
md5 a252c2c85a9e7756d5ba5da9949d57ed
The question is what is the best way to get the same byte in objC as I get in Java?
“ASCII to NSData” makes no sense, because ASCII is an encoding; if you have encoded characters, then you have data.
An encoding is a transformation of ideal Unicode characters (code points) into one-or-more-byte units (code units), possibly in sequences such as UTF-16's surrogate pairs.
An NSString is more or less an ideal Unicode object. It contains the characters of the string, in Unicode, irrespective of any encoding*.
ASCII is an encoding. UTF-8 is also an encoding. When you ask the string for its UTF8String, you are asking it to encode its characters as UTF-8.
NSData *data = [NSData dataWithBytes:[source UTF8String] length:[source length]];
The result is
######### source ©
[data description] = "<"c2>
That's because you passed the wrong length. The string's length (in characters) is not the same as the number of code units (bytes, in this case) in some encoding.
The correct length is strlen([source UTF8String]), but it's easier for you and faster at run time to use dataUsingEncoding: to ask the string to create the NSData object for you.
When I change the encoding to
NSData *data = [NSData dataWithBytes:[source UTF8String] length:[source lengthOfBytesUsingEncoding:NSUTF8StringEncoding]];
You didn't change the encoding. You're still encoding it as UTF-8.
Use dataUsingEncoding:.
The question is what is the best way to get the same byte in objC as I get in Java?
Use the same encoding.
There is no such thing as “extended ASCII”. There are several different encodings that are based on (or at least compatible with) ASCII, including ISO 8859-1, ISO 8859-9, MacRoman, Windows codepage 1252, and UTF-8. You need to decide which one you mean and tell the string to encode its characters with that.
Better yet, continue using UTF-8—it is almost always the right choice for mostly-ASCII text—and change your Java code instead.
NSData *data = [source dataUsingEncoding:NSASCIIStringEncoding];
Result:
[data description] = (null)
True ASCII can only encode 128 possible characters. Unicode includes all of ASCII unchanged, so the first 128 code points in Unicode are what ASCII can encode. Anything else, ASCII cannot encode.
I've seen NSASCIIStringEncoding behave as equivalent to NSISOLatin1StringEncoding before; it sounds like they might have changed it to be a pure ASCII encoding, and if that's the case, that's a good thing. There is no copyright symbol in ASCII. What you see here is the correct result.
*This is not quite true; the characters are exposed as UTF-16, so any characters outside the Basic Multilingual Plane are exposed as surrogate pairs, not whole characters as they would be in a truly ideal string object. This is a trade-off. In Swift, the built-in String type is a perfect ideal Unicode object; characters are characters, never divided until encoded. But when working with NSString (whether in Swift or in Objective-C), as far as you are concerned, you should treat it as an ideal string.
Thanks to GBegan's explanation in another post I was able to cobble this together.
for(int c = 0; c < [s length]; c++){
int number = [s characterAtIndex:c];
unsigned char c[1];
c[0] = (unsigned char)number;
NSMutableData *oneByte = [NSMutableData dataWithBytes:&c length:1];
}

How to type a square character in Xcode?

How do I type a square character in Xcode? Not as program code but in a string.
I tried to copy a character but its not working. I am still stuck with:
aCounty.area = #"301.338 km2";
const UniChar square = 0x00B2;
NSString * str = [NSString stringWithFormat:#"%C", square];
NSLog(#"301 km%#", str);
you can get the character code from OS X's "Special Characters…" menu item

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