UITextView underlined text - ios7

Question

I have UITextView and want to underline selected text.
It is working by this code
NSRange range = selectedTextView.selectedRange;
NSTextStorage *textStorage = selectedTextView.textStorage;
[textStorage addAttribute: NSUnderlineStyleAttributeName
value:[NSNumber numberWithInt:NSUnderlineStyleSingle]
range:range];
But letters which have "a tail" under baseline (as q y g p) are not underlined (screenshot: http://i.stack.imgur.com/dRrEH.png).
Also I noticed that space between baseline and underline depends on font.
How can I underline text without any breakings/spacing?

Answer 1

#import <UIKit/UIKit.h>
#interface TextViewWithUnderline : UITextView
#end
#import "TextViewWithUnderline.h"
#implementation TextViewWithUnderline
- (id)initWithFrame:(CGRect)frame {
self = [super initWithFrame:frame];
if (self) {
//self.contentMode = UIViewContentModeRedraw;
}
return self;
}
- (void)drawRect:(CGRect)rect {
//Get the current drawing context
CGContextRef context = UIGraphicsGetCurrentContext();
//Set the line color and width
CGContextSetStrokeColorWithColor(context, [UIColor lightGrayColor].CGColor);
CGContextSetLineWidth(context, 1.0f);
//Start a new Path
CGContextBeginPath(context);
//Find the number of lines in our textView + add a bit more height to draw lines in the empty part of the view
NSUInteger numberOfLines = (self.contentSize.height + self.bounds.size.height) / self.font.leading;
//Set the line offset from the baseline. (I'm sure there's a concrete way to calculate this.)
CGFloat baselineOffset = 6.0f;
//iterate over numberOfLines and draw each line
for (int x = 1; x < numberOfLines; x++) {
//0.5f offset lines up line with pixel boundary
CGContextMoveToPoint(context, self.bounds.origin.x + 10, self.font.leading*x + 0.5f + baselineOffset);
CGContextAddLineToPoint(context, self.bounds.size.width - 10, self.font.leading*x + 0.5f + baselineOffset);
}
//Close our Path and Stroke (draw) it
CGContextClosePath(context);
CGContextStrokePath(context);
}
#end
#import <UIKit/UIKit.h>
#import "TextViewWithUnderline.h"
#interface CustomTextView : UIViewController
#property (weak, nonatomic) IBOutlet TextViewWithUnderline *textView;
#end
#import "CustomTextView.h"
#interface CustomTextView ()
#end
#implementation CustomTextView
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self) {
// Custom initialization
}
return self;
}
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view.
self.textView.contentMode = UIViewContentModeRedraw;
}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
#end