iOS: Draw NSString and border on UIImage - iphone

Question

I am wanting to draw an NSString and a border onto a UIImage that I already have. I found a method that will draw an NSString as a UIImage, but I need it to draw on an image that I provide.
-(UIImage *)imageFromText:(NSString *)text
{
// set the font type and size
UIFont *font = [UIFont systemFontOfSize:20.0];
CGSize size = [text sizeWithFont:font];
// check if UIGraphicsBeginImageContextWithOptions is available (iOS is 4.0+)
if (UIGraphicsBeginImageContextWithOptions != NULL)
UIGraphicsBeginImageContextWithOptions(size,NO,0.0);
else
// iOS is < 4.0
UIGraphicsBeginImageContext(size);
// optional: add a shadow, to avoid clipping the shadow you should make the context size bigger
//
// CGContextRef ctx = UIGraphicsGetCurrentContext();
// CGContextSetShadowWithColor(ctx, CGSizeMake(1.0, 1.0), 5.0, [[UIColor grayColor] CGColor]);
// draw in context, you can use also drawInRect:withFont:
[text drawAtPoint:CGPointMake(0.0, 0.0) withFont:font];
// transfer image
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return image;
}
How would I modify this method to provide my own background image, as well as adding a border?

Answer 1

If you are displaying the UIImage in a UIImageView you can set the UIImageView.layer.delegate and use something like:
- (void) drawLayer:(CALayer *)layer inContext:(CGContextRef)ctx {
CGContextSetFillColorWithColor(ctx, [[UIColor darkTextColor] CGColor]);
UIGraphicsPushContext(ctx);
[word drawAtPoint:CGPointMake(30.0f, 30.0f)
forWidth:200.0f
withFont:[UIFont boldSystemFontOfSize:32]
lineBreakMode:UILineBreakModeClip];
UIGraphicsPopContext();
}
Code from Add text to CALayer
The border is easy, just use the CALayer properties:
imageview.layer.borderColor = [UIColor blackColor].CGColor;
imageview.sublayer.borderWidth = 2.0;

Answer 2

You are looking for CALayers.
Here is very good tutorial how to create and use them.
So basically you will add new CALayer with image as a background and then draw on it text.
http://www.raywenderlich.com/2502/introduction-to-calayers-tutorial

Answer 3

Use this function to Draw NSString and border on UIImage
For border check CGContextSetRGBStrokeColor
-(UIImage *)imageFromText:(NSString *)text
{
// set the font type and size
UIFont *font = [UIFont systemFontOfSize:20.0];
CGSize size = [text sizeWithFont:font];
// check if UIGraphicsBeginImageContextWithOptions is available (iOS is 4.0+)
if (UIGraphicsBeginImageContextWithOptions != NULL)
UIGraphicsBeginImageContextWithOptions(size,NO,0.0);
else
// iOS is < 4.0
UIGraphicsBeginImageContext(size);
// optional: add a shadow, to avoid clipping the shadow you should make the context size bigger
//
CGContextRef ctx = UIGraphicsGetCurrentContext();
CGContextSetShadowWithColor(ctx, CGSizeMake(1.0, 1.0), 5.0, [[UIColor brownColor] CGColor]);
// draw in context, you can use also drawInRect:withFont:
[text drawAtPoint:CGPointMake(0.0, 0.0) withFont:font];
//CGImageRef cimg = UIGraphicsGetCurrentContext();
// transfer image
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
CGRect rect = CGRectMake(0, 0, image.size.width, image.size.height);
[image drawInRect:rect blendMode:kCGBlendModeNormal alpha:1.0];
//CGContextRef context = UIGraphicsGetCurrentContext();
CGContextSetRGBStrokeColor(ctx, 2.0, 3.5, 5.0, 1.0);
CGContextStrokeRect(ctx, rect);
UIImage *testImg = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return testImg;
}