How to create clockwise angle text in xcode - ios

Question

I'm trying to create clockwise text in Xcode. My current coding is just displaying like that.
But I want to change outer text to as follow

Answer 1

By using this library : https://github.com/javenisme/CurvaView
CoreTextArcView * cityLabel = [[[CoreTextArcView alloc] initWithFrame:rect1
font:font1
text:#"Hello this is radious arc with text"
radius:85
arcSize:110
color:color1] autorelease];
Remove arc for one file like as follows (set -fno-objc-arc to that library's .m file from build phases of your project target) :
Output like this

Answer 2

This is my code to do this, it draw attributed strings.
I can't post images but the result it's just right.
Text is also automatically reversed if the angle is between 100° and 260°
#define degreesToRadians(degrees) (( degrees ) / 180.0 * M_PI )
#define radiansToDegrees(radians) (( radians ) * ( 180.0 / M_PI ) )
+ (void)drawCurvedStringOnLayer:(CALayer *)layer
withAttributedText:(NSAttributedString *)text
atAngle:(float)angle
withRadius:(float)radius {
// angle in radians
CGSize textSize = CGRectIntegral([text boundingRectWithSize:CGSizeMake(CGFLOAT_MAX, CGFLOAT_MAX)
options:(NSStringDrawingUsesLineFragmentOrigin|NSStringDrawingUsesFontLeading)
context:nil]).size;
float perimeter = 2 * M_PI * radius;
float textAngle = (textSize.width / perimeter * 2 * M_PI); // text curved width
float textRotation;
float textDirection;
if (angle > degreesToRadians(10) && angle < degreesToRadians(170))
{
//down
textRotation = 0.5 * M_PI ;
textDirection = - 2 * M_PI;
angle += textAngle / 2 + degreesToRadians(6);
}
else
{
//up
textRotation = 1.5 * M_PI ;
textDirection = 2 * M_PI;
angle -= textAngle / 2; // + degreesToRadians(6);
}
for (int c = 0; c < text.length; c++)
{
NSRange range = {c, 1};
NSAttributedString* letter = [text attributedSubstringFromRange:range];
CGSize charSize = CGRectIntegral([letter boundingRectWithSize:CGSizeMake(CGFLOAT_MAX, CGFLOAT_MAX)
options:(NSStringDrawingUsesLineFragmentOrigin|NSStringDrawingUsesFontLeading)
context:nil]).size;
float letterAngle = ( (charSize.width / perimeter) * textDirection );
float x = radius * cos(angle + (letterAngle/2));
float y = radius * sin(angle + (letterAngle/2));
//NSLog(#"Char %# with size: %f x %f", letter, charSize.width, charSize.height);
//NSLog(#"Char %# with angle: %f x: %f y: %f", letter, angle, x, y);
CATextLayer *text = [layers drawTextOnLayer:layer
withText:letter
frame:CGRectMake(layer.frame.size.width/2 - charSize.width/2 + x,
layer.frame.size.height/2 - charSize.height/2 + y,
charSize.width, charSize.height)
bgColor:nil
opacity:1];
text.transform = CATransform3DMakeAffineTransform( CGAffineTransformMakeRotation(angle - textRotation) );
angle += letterAngle;
}
}
+ (CATextLayer *)drawTextOnLayer:(CALayer *)layer
withText:(NSAttributedString *)text
frame:(CGRect)frame
bgColor:(UIColor *)bgColor
opacity:(float)opacity {
CATextLayer *textLayer = [[CATextLayer alloc] init];
textLayer.needsDisplayOnBoundsChange = true;
//[textLayer setFont:(__bridge CFTypeRef)(font)];
//[textLayer setFontSize:fontSize];
[textLayer setFrame:frame];
[textLayer setString:text];
[textLayer setAlignmentMode:kCAAlignmentCenter];
// [textLayer setForegroundColor:color.CGColor];
[textLayer setBackgroundColor:bgColor.CGColor];
[textLayer setContentsScale:[UIScreen mainScreen].scale];
[textLayer setOpacity:opacity];
[layer addSublayer:textLayer];
}