How to change an UILabel/UIFont's letter spacing?

Question

I've searched loads already and couldn't find an answer.

I have a normal UILabel, defined this way:

    UILabel *totalColors = [[[UILabel alloc] initWithFrame:CGRectMake(5, 7, 120, 69)] autorelease];     totalColors.text = [NSString stringWithFormat:@"%d", total];     totalColors.font = [UIFont fontWithName:@"Arial-BoldMT" size:60];     totalColors.textColor = [UIColor colorWithRed:221/255.0 green:221/255.0 blue:221/255.0 alpha:1.0];     totalColors.backgroundColor = [UIColor clearColor];     [self addSubview:totalColors]; 

And I wanted the horizontal spacing between letters, to be tighter, whilst mantaining the font size.

Is there a way to do this? It should be a pretty basic thing to do.

Cheers guys, Andre

UPDATE:

So I was forced to do it like this:

- (void) drawRect:(CGRect)rect  {     CGContextRef context = UIGraphicsGetCurrentContext();      CGContextSelectFont (context, "Arial-BoldMT", 60, kCGEncodingMacRoman);     CGContextSetCharacterSpacing (context, -10);     CGContextSetTextDrawingMode (context, kCGTextFill);      CGContextSetRGBFillColor(context, 221/255.0, 221/255.0, 221/255.0, 221/255.0);     CGAffineTransform xform = CGAffineTransformMake(1.0, 0.0, 0.0, -1.0, 0.0, 0.0);     CGContextSetTextMatrix(context, xform);      char* result = malloc(17);     sprintf(result, "%d", totalNumber);      CGContextShowTextAtPoint (context, 0, 54, result, strlen(result)); } 

But I need to align this to the right. I could do that manually if I knew the width of the drawn text, but it's proving near impossible to find that.

I've read about ATSU, but I couldn't find any examples.

This sucks :/

Answer 1

From iOS 6 you can use NSAttributedString in UILabel.

In attributed string you can use attribute NSKernAttributeName to set letter spacing

NSMutableAttributedString* attrStr = [[NSMutableAttributedString alloc] initWithString: @"Test test test test "]; [attrStr addAttribute:NSKernAttributeName value:@(4.0) range:NSMakeRange(0, attrStr.length)];  UILabel* label = [[UILabel alloc] initWithFrame:CGRectMake(0, 300, 300, 100)]; label.attributedText = attrStr; 

Answer 2

I've extended UILabel to change the character spacing. This should work out the box and pulls font, text, color etc from the UILabel itself (proper coding!).

You may notice I draw the text twice, first with clear color. This is to auto center the text in the label. Whilst this may be inefficient - isn't it nice to be auto centered?

Enjoy!

@interface RALabel : UILabel { } @end    @implementation RALabel   - (void) drawRect:(CGRect)rect  {      // Drawing code      CGContextRef context = UIGraphicsGetCurrentContext();     CGContextSelectFont (context, [self.font.fontName cStringUsingEncoding:NSASCIIStringEncoding], self.font.pointSize, kCGEncodingMacRoman);     CGContextSetCharacterSpacing(context, 1);     CGContextSetFillColorWithColor(context, [[UIColor clearColor] CGColor]);     CGAffineTransform myTextTransform = CGAffineTransformScale(CGAffineTransformIdentity, 1.f, -1.f );     CGContextSetTextMatrix (context, myTextTransform);      // draw 1 but invisbly to get the string length.     CGPoint p =CGContextGetTextPosition(context);     float centeredY = (self.font.pointSize + (self.frame.size.height- self.font.pointSize)/2)-2;     CGContextShowTextAtPoint(context, 0, centeredY, [self.text cStringUsingEncoding:NSASCIIStringEncoding], [self.text length]);     CGPoint v =CGContextGetTextPosition(context);      // calculate width and draw second one.     float width = v.x - p.x;     float centeredX =(self.frame.size.width- width)/2;     CGContextSetFillColorWithColor(context, [self.textColor CGColor]);     CGContextShowTextAtPoint(context, centeredX, centeredY, [self.text cStringUsingEncoding:NSASCIIStringEncoding], [self.text length]);  }