Question

If I have a string that I am going to load into a TextField how can I make a line break \n occur every 10 characters (including spaces and whatnot) but not go to the next line mid-word… Like wrap the text with a max of 10 characters? But I’m not just wrapping in a UITextField I actually need the \n’s entered because it will be used in something else as well… (This is for iOS if that matters) any help is appreciated I’m really stuck!

Answer 1

You might want to make use of NSScanner in a loop to put together this kind of thing, but to figure out the precise algorithm you’d need to clarify exactly how you want it to work. Here are questions that you would need to answer:

1. Should sequence of more than one whitespace between words be “collapsed” into a single whitespace for the purpose of wrapping text, or should a sequence of 5 consecutive whitespaces be counted as 5 characters against your 10 character per line? I will assume you want multiple spaces to be collapsed rather than preserved
2. How do you want it to work if you have a single word that is greater than 10 characters? Do you want it to end up with a line that is greater than 10 characters, or would you prefer the newline to be inserted and force a mid-word line break in that situation? I will assume you want to allow words longer than 10 characters to expand beyond the 10 character limit.

With these assumptions about your problem in mind, I would code it like this:

NSMutableString *resultString = [[NSMutableString alloc] init];
NSMutableString *currentLine = [[NSMutableString alloc] init];
NSScanner *scanner = [NSScanner scannerWithString:sourceString];
NSString *scannedString = nil;
while ([scanner scanUpToCharactersFromSet:[NSCharacterSet whitespaceCharacterSet] intoString: &scannedString]) {
    if ([currentLine length] + [scannedString length] <= 10) {
        [currentLine appendFormat:@"%@ ", scannedString];
    }
    else if ([currentLine length] == 0) { // Newline but next word > 10
        [resultString appendFormat:@"%@\n", scannedString];
    }
    else { // Need to break line and start new one
        [resultString appendFormat:@"%@\n", currentLine];
        [currentLine setString:[NSString stringWithFormat:@"%@ ", scannedString]];
    }
    [scanner scanCharactersFromSet:[NSCharacterSet whitespaceCharacterSet] intoString:NULL];
}