CODEWITHSUNDEEP
iphoneuilabel
Evgeny
Evgeny

Reputation: 121

UILabel visible part of text

Is there a way to get the visible part of text in word wrapped UILabel? I mean exactly the last visible character?

I'd like to make two labels rounding the image and would like to continue the text which was out of rect for first label on the second one.

I know [NSString sizeWithFont...] but are there something reversing like [NSString stringVisibleInRect: withFont:...] ? :-)

Thank you in advance.

Upvotes: 12

Views: 5133

Answers (2)

hpique
hpique

Reputation: 120324

Here's a O(log n) method with iOS 7 APIs. Only superficially tested, please comment if you find any bugs.

- (NSRange)hp_visibleRange
{
    NSString *text = self.text;
    NSRange visibleRange = NSMakeRange(NSNotFound, 0);
    const NSInteger max = text.length - 1;
    if (max >= 0)
    {
        NSInteger next = max;
        const CGSize labelSize = self.bounds.size;
        const CGSize maxSize = CGSizeMake(labelSize.width, CGFLOAT_MAX);
        NSMutableParagraphStyle *paragraphStyle = [[NSParagraphStyle defaultParagraphStyle] mutableCopy];
        paragraphStyle.lineBreakMode = self.lineBreakMode;
        NSDictionary * attributes = @{NSFontAttributeName:self.font, NSParagraphStyleAttributeName:paragraphStyle};
        NSInteger right;
        NSInteger best = 0;
        do
        {
            right = next;
            NSRange range = NSMakeRange(0, right + 1);
            NSString *substring = [text substringWithRange:range];
            CGSize textSize = [substring boundingRectWithSize:maxSize
                                                      options:NSStringDrawingUsesLineFragmentOrigin
                                                   attributes:attributes
                                                      context:nil].size;
            if (textSize.width <= labelSize.width && textSize.height <= labelSize.height)
            {
                visibleRange = range;
                best = right;
                next = right + (max - right) / 2;
            } else if (right > 0)
            {
                next = right - (right - best) / 2;
            }
        } while (next != right);
    }
    return visibleRange;
}

Upvotes: 0

Vertism
Vertism

Reputation: 165

You could use a category to extend NSString and create the method you mention

@interface NSString (visibleText)

- (NSString*)stringVisibleInRect:(CGRect)rect withFont:(UIFont*)font;

@end

@implementation NSString (visibleText)

- (NSString*)stringVisibleInRect:(CGRect)rect withFont:(UIFont*)font
{
    NSString *visibleString = @"";
    for (int i = 1; i <= self.length; i++)
    {
        NSString *testString = [self substringToIndex:i];
        CGSize stringSize = [testString sizeWithFont:font];
        if (stringSize.height > rect.size.height || stringSize.width > rect.size.width)
            break;

        visibleString = testString;
    }
    return visibleString;
}

@end

Upvotes: 7

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