From 45a608f07d66c70fd0d7296e7732215fdd606fb8 Mon Sep 17 00:00:00 2001
From: Yang Liu <yaliu@linkedin.com>
Date: Sun, 8 Feb 2015 16:12:29 -0800
Subject: [PATCH] Added a property "linkCornerRadius" to allow rounded rect

Draw a rounded rect around link text when tapped, similar to the
original iOS design.
---
 .../CCHLinkTextView Example/ViewController.m  |  4 ++-
 CCHLinkTextView/CCHLinkTextView.h             |  3 ++
 CCHLinkTextView/CCHLinkTextView.m             | 36 +++++++++++++++++++
 README.md                                     |  2 ++
 4 files changed, 44 insertions(+), 1 deletion(-)

diff --git a/CCHLinkTextView Example/CCHLinkTextView Example/ViewController.m b/CCHLinkTextView Example/CCHLinkTextView Example/ViewController.m
index 46a042c..a3449f4 100644
--- a/CCHLinkTextView Example/CCHLinkTextView Example/ViewController.m	
+++ b/CCHLinkTextView Example/CCHLinkTextView Example/ViewController.m	
@@ -85,7 +85,9 @@
     [self.longPressGestureRecognizer requireGestureRecognizerToFail:linkTextView.linkGestureRecognizer];
     linkTextView.linkDelegate = self;
     linkTextView.linkTextAttributes = @{NSForegroundColorAttributeName : [UIColor blueColor]};
-    linkTextView.linkTextTouchAttributes = @{NSForegroundColorAttributeName : [UIColor orangeColor]};
+    linkTextView.linkTextTouchAttributes = @{NSForegroundColorAttributeName : [UIColor orangeColor],
+                                             NSBackgroundColorAttributeName: [UIColor darkGrayColor]};
+    linkTextView.linkCornerRadius = 4.0f;
 }
 
 - (void)linkTextView:(CCHLinkTextView *)linkTextView didTapLinkWithValue:(id)value
diff --git a/CCHLinkTextView/CCHLinkTextView.h b/CCHLinkTextView/CCHLinkTextView.h
index fcd87ab..7efccc2 100644
--- a/CCHLinkTextView/CCHLinkTextView.h
+++ b/CCHLinkTextView/CCHLinkTextView.h
@@ -53,6 +53,9 @@ extern NSString *const CCHLinkAttributeName;
 /** The gesture recognizer used to detect links in this text view. */
 @property (nonatomic, readonly) CCHLinkGestureRecognizer *linkGestureRecognizer;
 
+/** The corner radius of the rounded rectangle that is shown when link touched. (default = 0 point) */
+@property (nonatomic) CGFloat linkCornerRadius;
+
 /** 
  For the given ranges, enumerates all view rectangles that cover each range.
  @param ranges array of ranges.
diff --git a/CCHLinkTextView/CCHLinkTextView.m b/CCHLinkTextView/CCHLinkTextView.m
index 584ae6e..7c7be8a 100644
--- a/CCHLinkTextView/CCHLinkTextView.m
+++ b/CCHLinkTextView/CCHLinkTextView.m
@@ -200,6 +200,36 @@ NSString *const CCHLinkAttributeName = @"CCHLinkAttributeName";
     return linkFound;
 }
 
+- (void)drawRoundedCornerForRange:(NSRange)range
+{
+    CALayer * layer = [[CALayer alloc] init];
+    layer.frame = self.bounds;
+    layer.backgroundColor = [[UIColor clearColor] CGColor];
+    
+    UIGraphicsBeginImageContextWithOptions(layer.bounds.size, NO, 0.0);
+    CGContextRef context = UIGraphicsGetCurrentContext();
+    CGContextSetFillColorWithColor(context, [[UIColor whiteColor] CGColor]);
+    CGContextFillRect(context, layer.bounds); // Unmask the whole text area
+    
+    NSRange glyphRange = [self.layoutManager glyphRangeForCharacterRange:range actualCharacterRange:NULL];
+    [self.layoutManager enumerateEnclosingRectsForGlyphRange:glyphRange withinSelectedGlyphRange:NSMakeRange(NSNotFound, 0) inTextContainer:self.textContainer usingBlock:^(CGRect rect, BOOL *stop) {
+        rect.origin.x += self.textContainerInset.left;
+        rect.origin.y += self.textContainerInset.top;
+        
+        CGContextClearRect(context, CGRectInset(rect, -1, -1)); // Mask the rectangle of the range
+        
+        CGContextAddPath(context, [UIBezierPath bezierPathWithRoundedRect:rect cornerRadius:self.linkCornerRadius].CGPath);
+        CGContextSetFillColorWithColor(context, [[UIColor whiteColor] CGColor]);  // Unmask the rounded area inside the rectangle
+        CGContextFillPath(context);
+    }];
+    
+    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
+    UIGraphicsEndImageContext();
+
+    [layer setContents:(id)[image CGImage]];
+    self.layer.mask = layer;
+}
+
 #pragma mark Gesture recognition
 
 - (void)linkAction:(CCHLinkGestureRecognizer *)recognizer
@@ -241,6 +271,10 @@ NSString *const CCHLinkAttributeName = @"CCHLinkAttributeName";
         }
         [attributedText addAttributes:self.linkTextTouchAttributes range:range];
         [super setAttributedText:attributedText];
+
+        if (self.linkCornerRadius > 0) {
+          [self drawRoundedCornerForRange:range];
+        }
     }];
 }
 
@@ -253,6 +287,8 @@ NSString *const CCHLinkAttributeName = @"CCHLinkAttributeName";
         }
         [attributedText addAttributes:self.linkTextAttributes range:range];
         [super setAttributedText:attributedText];
+
+        self.layer.mask = nil;
     }];
 }
 
diff --git a/README.md b/README.md
index 63afbb4..546c4ba 100644
--- a/README.md
+++ b/README.md
@@ -64,6 +64,8 @@ The first method is called for taps, the second for long presses.
 
 To style the links, use `linkTextAttributes` and `linkTextTouchAttributes`. These dictionaries contain `NSAttributedString` attributes applied to links as they appear normally and when touched. By default, `linkTextAttributes` sets the tint color as foreground color and `linkTextTouchAttributes` a light gray background. 
 
+Use `linkCornerRadius` to make the background on touch as a rounded rectangle.
+
 ### Advanced settings
 
 There are a few settings to allow you to adjust `CCHLinkTextView`'s behavior: