Change attributes of one link in UITextView - ios

Question

I have a UITextView with multiple URLs that I activate by setting the dataDetectorTypes property to UIDataDetectorTypeLink. I then use the linkTextAttributes property to set the color of the links. Now when the user taps on one of the links (using a UITapGestureRecognizer), I'd like to change the color of that link only. If I change linkTextAttributes, all the links will change color.
How can I change just the color of the link that was tapped on?

Answer 1

If these urls are fixed.
For example:
I have the following urls:
http://www.123.com
http://www.456.com
http://www.789.com
I would put them to an NSAttributedString
Use NSMutableAttributedString to combine them all
NSMutableAttributedString *urlsAttributedText = [[NSMutableAttributedString alloc]init];
NSAttributedString *url1 = [[NSAttributedString alloc]initWithString:NSLocalizedString(#"http://www.123.com\n", nil) attributes:#{NSForegroundColorAttributeName : [UIColor whiteColor], NSFontAttributeName : [UIFont systemFontOfSize:15.0f]}];
NSAttributedString *url2 = [[NSAttributedString alloc]initWithString:NSLocalizedString(#"http://www.456.com\n", nil) attributes:#{NSForegroundColorAttributeName : [UIColor greenColor], NSFontAttributeName : [UIFont systemFontOfSize:15.0f]}];
NSAttributedString *url3 = [[NSAttributedString alloc]initWithString:NSLocalizedString(#"http://www.789.com\n", nil) attributes:#{NSForegroundColorAttributeName : [UIColor redColor], NSFontAttributeName : [UIFont systemFontOfSize:15.0f]}];
[urlsAttributedText url1];
[urlsAttributedText appendAttributedString:url2];
[urlsAttributedText appendAttributedString:url3];
self.texView.attributedText = urlsAttributedText;
Cheers!

Answer 2

I think I solved it, using a subclass of UITextView called which has a rangeOfLink property.
First, in my UIViewController viewDidLoad:, I add
self.textView.dataDetectorTypes = UIDataDetectorTypeLink; // change for other link types
self.textView.selectable = YES;
self.textView.userInteractionEnabled = YES;
UITapGestureRecognizer *tapGesture = [[UITapGestureRecognizer alloc] initWithTarget: self action: #selector(handleTap:)];
tapGesture.cancelsTouchesInView = YES;
[self.textView addGestureRecognizer: tapGesture];
[self.textView setNeedsDisplay]; // force a redraw so that drawRect is called
Then in handleTap, I do this:
MyTextViewWithLink *aTextView = (IDTextViewWithLink *) recognizer.view;
if (aTextView != self.textView)
return;
if (recognizer.state == UIGestureRecognizerStateEnded)
{
CGPoint location = [recognizer locationInView: aTextView];
// this returns an NSTextCheckingResult if location is inside a link
NSTextCheckingResult *result = [self textCheckingResultAtPoint: location inTextView: aTextView];
if (result)
{
aTextView.rangeOfLink = result.range;
[aTextView setNeedsDisplay]; // this will force the color change
// open url
}
}
Finally I override drawRect in my UITextView subclass:
self.linkTextAttributes = [NSDictionary dictionary];
NSError *error = nil;
NSDataDetector *dataDetector = [NSDataDetector dataDetectorWithTypes: NSTextCheckingTypeLink error: &error]; // change for other link types
if (!error && dataDetector)
{
NSArray* resultString = [dataDetector matchesInString: self.text
options: NSMatchingReportProgress
range: NSMakeRange(0, [self.text length])];
if (resultString.count > 0)
{
NSMutableAttributedString *mas = [self.attributedText mutableCopy];
for (NSTextCheckingResult* result in resultString)
{
if (result.resultType == NSTextCheckingTypeLink)
{
NSRange intersection = NSIntersectionRange(result.range, self.rangeOfLink);
if (intersection.length <= 0) // no match
[mas addAttribute: NSForegroundColorAttributeName
value: [UIColor blueColor]
range: self.rangeOfLink];
else
[mas addAttribute: NSForegroundColorAttributeName
value: [UIColor redColor]
range: self.rangeOfLink];
}
}
self.attributedText = mas;
}
}
[super drawRect: rect];
Now if the textView has more than one link, only the selected one will change color.