For my syntax highlighting implementation, I observe changes to an NSTextView
using -[<NSTextStorageDelegate> textStorageDidProcessEditing:]
.
- (void)textStorageDidProcessEditing:(NSNotification *)notification {
if (!self.languageGrammar) return;
NSTextStorage *textStorage = self.textView.textStorage;
NSRange glyphRange = [self.textView.layoutManager glyphRangeForBoundingRect:self.scrollView.documentVisibleRect
inTextContainer:self.textView.textContainer];
NSRange editedRange = [self.textView.layoutManager characterRangeForGlyphRange:glyphRange actualGlyphRange:NULL];
[textStorage removeAttribute:NSForegroundColorAttributeName range:editedRange];
// crash is the line above ^^^^
// color text ...
}
I want to get the range of visible characters. The above code works until I hit backspace, which makes it crash:
*** -[NSConcreteTextStorage attributesAtIndex:effectiveRange:]: Range or index out of bounds
How would I get the range of visible characters so I can color them?
Check if the range is beyond the bounds of the entire string, and if it is set the range to fit the bounds of the string: