For a while now, I’ve wanted to add a feature to Assignment Planner that detects when you’ve typed a URL into any of the notes fields and displays the URL as a link. Coincidentally, while I was adding LRFilterBar and (the newly released) LRCalendarView to Cocoadev’s ObjectLibrary, I caught a glance of BlackHole Media’s URLTextView, which gets close to what I was looking for.

The problem is that the example will take text from an NSTextField and add it to the NSTextView, looking for URLs before it does so. But, I needed an editable NSTextView which will look for URLs as you type them in. So, I added the following code to the subclass:

- (void)didChangeText
{
  NSMutableAttributedString* inputValue = [[[NSMutableAttributedString alloc] initWithString:[NSString stringWithFormat:@"%@", [self string]]] autorelease];
  [inputValue detectURLs:[NSColor blueColor]];
  [[self textStorage] setAttributedString:inputValue];
  [super didChangeText];
}

- (void)setString:(NSString *)aString
{
  [super setString:aString];
  [self didChangeText];
}

So the didChangeText function is called whenever the text inside of the NSTextView changes. We take the text inside of the view, analyze it for URLs using the NSMutableAttributedString additions that come with the URLTextView and then replace the contents with our new attributed string.

We override the setString: function so that when we first set the string of the textbox, the contents are analyzed right off the bat. I found that without it, when an assignment was selected, the notes showed up but without all of the links. Then any one change in the box would create the links. So adding this function fixes the problem.

The only other issue that I had with the URLTextView was that the included finger pointer that should appear when the cursor hovers over the link doesn’t display. But, I don’t have a big problem with it, since it’s quite clear that the blue underlined link is clickable. Otherwise, this is the perfect solution to the problem.

URLTextView is available at BlackHole Media’s Code page.