Rounded corners and gradients in NSTextView

Question

I'm using NSAttributedString inside a NSTextView to highlight certain areas within the text. I found it easy to change the background color and the text color, but I don't even know where to start on drawing more sophisticated things like rounded corners or background gradients, or borders.

Here's a picture of what I'm trying to achieve:

This is totally doable in a web view, but that seems like overkill for just a few extra graphic flourishes.

Answer 1

I've created an NSTextView implementation that achieves very similar look to the one you're looking to create (only the gradient is missing), the implementation is available here: http://github.com/aiman86/ANTaggedTextView :

And here's a blog post explaining my approach: http://aimannajjar.com/blog/1-How-to-Create-NSTextView-with-Facebook-like-Tags-Mentions.html#post

Answer 2

You can do rounded corner with Quartz lib :

[view.layer setCornerRadius:7.0];

Everyting is possible but not as easy as a stylesheet !

Answer 3

You can set attributes on the range of text you want to highlight in one of two ways:

NSTextView *textView = ...;
NSRange rangeToHighlight = ...; // Range of characters in textView's textStorage
NSColor *highlightColor = ...;

// Method 1: less efficient
[textView.textStorage setAttributes:@{ NSForegroundColorAttributeName : highlightColor } range:rangeToHighlight];

// Method 2: more efficient but only works for attributes that don't affect layout, e.g. color, underline etc.
[textView.layoutManager addTemporaryAttribute:NSForegroundColorAttributeName value:highlightColor forCharacterRange:rangeToHighlight];

I'm not sure if you can use a gradient color, but solid colors certainly work.

This won't get you the rounded corners though.

You might try an NSTextAttachmentCell so you can custom render the corners.

Answer 4

有一些解决这个问题的方法可能对你有所帮助，创建一个带圆角的UIView，然后尝试在其中绘制NSTextView，它应该可以工作。