Multiline balance UILabel

When I create UILabel

with textAlignement

set to NSTextAlignmentCenter

, lineBreakMode

to NSLineBreakByWordWrapping

and long text, it breaks like this:

+------------------------------------+
| Text that does not fit on a single |
|                line                |
+------------------------------------+

      

But I really want something like this:

+------------------------------------+
|       Text that does not fit       |
|          on a single line          |
+------------------------------------+

      

Of course I don't want to handle the line break manually. I want the label to automatically balance the lines so that their lengths are as close as possible.

+3


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4 answers


I had the same problem and inspired by this question, I found a solution by simply overriding - (void)drawTextInRect:(CGRect)rect

You can see it in this GitHub project

The method itself, if you just want to copy / read it, here



- (void)drawTextInRect:(CGRect)rect {
    if (self.textAlignment == NSTextAlignmentCenter) {
        CGRect oneLineRect = [self textRectForBounds:CGRectInfinite limitedToNumberOfLines:1];
        NSInteger numberOfLines = ceil(oneLineRect.size.width / self.bounds.size.width);
        CGFloat betterWidth = (oneLineRect.size.width / numberOfLines);
        if (betterWidth < rect.size.width) {
            CGRect check = CGRectZero;
            do {
                betterWidth *= 1.1;
                CGRect b = CGRectMake(0, 0, betterWidth, CGRectInfinite.size.height);
                check = [self textRectForBounds:b limitedToNumberOfLines:0];
            } while (check.size.height > rect.size.height && betterWidth < rect.size.width);

            if (betterWidth < rect.size.width) {
                CGFloat difference = rect.size.width - betterWidth;
                rect = CGRectMake(rect.origin.x + difference/2.0, rect.origin.y, betterWidth, rect.size.height);
            }
        }
    }
    [super drawTextInRect:rect];
}

      

PR, forks, comments are welcome!

+3


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I'm working in Swift 3 (iOS 10), so I've converted dev_jac's answer for those who need it:



override func drawText(in rect: CGRect) {
    var newRect = rect

    if (textAlignment == .center) {
        let oneLineRect = self.textRect(forBounds: CGRect.infinite, limitedToNumberOfLines: 1)
        let numLines = ceil(oneLineRect.size.width / self.bounds.size.width)
        var betterWidth : CGFloat = oneLineRect.size.width / numLines
        if (betterWidth < rect.size.width) {
            var check = CGRect.zero
            repeat {
                betterWidth *= 1.1
                let b = CGRect(x: 0, y: 0, width: betterWidth, height: CGRect.infinite.size.height)
                check = self.textRect(forBounds: b, limitedToNumberOfLines: 0)
            } while (check.size.height > rect.size.height && betterWidth < rect.size.width)

            if betterWidth < rect.size.width {
                let difference : CGFloat = rect.size.width - betterWidth
                newRect = CGRect(x: rect.origin.x + difference/2, y: rect.origin.y, width: betterWidth, height: rect.size.height)
            }
        }
    }

    super.drawText(in: newRect)
}

      

+1


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There is no built-in support for what you need. You will need to do your own calculations with NSString boundingRectWithSize:options:attributes:context:

. You will need to go through different sizes to find the best width to get two filled lines. Then use that width for the size UILabel

.

0


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If you are using automatic layout, the UILabel property preferredMaxLayoutWidth

might come in handy.

-1


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