Syntax highlighting with attributed strings on UITextView

Question

There is an excellent project to add syntax highlighting and line numbers to your project: https://github.com/illyabusigin/CYRTextView

But it has one critical issue described here: https://github.com/illyabusigin/CYRTextView/issues/16

The project is dead on github. Can anybody help to fix the issue? I've tried to analyze code but didn't find it yet.

Didn't see all the code in GitHub, but I faced an issue similar I guess: The issue is that a some point, since you do a `[yourCustomTextView setText:ZzZ]` (or `setAttributedText:`), it causes the scroll to top. And I saw an issue with `scrollRectToVisible:animated`, if `animated` parameter was `FALSE`, then it didn't scroll. Didn't had time to find out a solution (personal project). So the only way was to set the `animated` to `TRUE` but there is indeed the effect. — Larme, Jun 08 '14 at 12:32
Larme, there is no `scrollRectToVisible:animated` call on the code. The issue happens only on **the last empty** line. — Dmitry, Jun 08 '14 at 12:55
Maybe it's because of `handleTextViewDidChangeNotification:` method in `CRTextView` — Larme, Jun 08 '14 at 18:26

score 0 · Accepted Answer · edited May 23 '17 at 11:43

The issue is described and fixed here: iOS 7.1 UITextView still not scrolling to cursor/caret after new line

#define SYSTEM_VERSION_GREATER_THAN_OR_EQUAL_TO(v) ([[[UIDevice currentDevice] systemVersion] compare:v options:NSNumericSearch] != NSOrderedAscending)
#define is_iOS7 SYSTEM_VERSION_GREATER_THAN_OR_EQUAL_TO(@"7.0")
#define is_iOS8 SYSTEM_VERSION_GREATER_THAN_OR_EQUAL_TO(@"8.0")
@implementation CYRTextView {
    ...old code...
    BOOL settingText;
}

- (id)initWithFrame:(CGRect)frame {
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(handleTextViewDidChangeNotification:) name:UITextViewTextDidChangeNotification object:self];
}

- (void)scrollToCaretInTextView:(UITextView *)textView animated:(BOOL)animated {
    CGRect rect = [textView caretRectForPosition:textView.selectedTextRange.end];
    rect.size.height += textView.textContainerInset.bottom;
    [textView scrollRectToVisible:rect animated:animated];
}

- (void)handleTextViewDidChangeNotification:(NSNotification *)notification {
    if (notification.object == self && is_iOS7 && !is_iOS8 && !settingText) {
        UITextView *textView = self;
        if ([textView.text hasSuffix:@"\n"]) {
            [CATransaction setCompletionBlock:^{
                [self scrollToCaretInTextView:textView animated:NO];
            }];
        } else {
            [self scrollToCaretInTextView:textView animated:NO];
        }
    }
}

- (void)setText:(NSString *)text {
    settingText = YES;
    ...old code...
    settingText = NO;
}

Syntax highlighting with attributed strings on UITextView

1 Answers1