UINavigationBar TitleView with subtitle

Question

I want a titleView inside my UINavigationBar which has two lines of text instead of only one

My current implementiation works well when I have a \"Back\"-Button and

Answer 1

I was using Rodrigo Pedroso's answer, but the fact that it doesn't truncate long titles became a problem. I made a version that measures how much space there is for the title between the bar button items, and then manually truncates the title to fit in that space. The truncation code was adapted from this answer, and is a bit of a mess - maybe someone can help figure out a way to use UILabel's built-in truncation methods (i.e. .ByTruncatingTail). I've already spent too much time on this though.

Here's what I've got:

extension UIViewController {

    private var availableWidthForTitle: CGFloat {
        get {
            var total = UIScreen.mainScreen().bounds.width
            if let navigationBar = navigationController?.navigationBar {
                var maxYLeft:  CGFloat = 0
                var minYRight: CGFloat = 0
                for subview in navigationBar.subviews.dropFirst()
                    where !subview.hidden {
                    if subview.frame.origin.x < total / 2 {
                        let rightEdge = subview.frame.origin.x + subview.frame.size.width
                        if rightEdge < total / 2 {
                            maxYLeft = max(maxYLeft, rightEdge)
                        }
                    } else {
                        let leftEdge = subview.frame.origin.x
                        if leftEdge > total / 2 {
                            minYRight = min(minYRight, total - leftEdge)
                        }
                    }
                }
                total = total - maxYLeft - minYRight
            }

            return total
        }
    }

    func setTitle(title:String, subtitle:String?) {
        if (subtitle == nil) {
            self.title = title.uppercaseString
        } else {
            let titleLabel = UILabel(frame: CGRectMake(0, -2, 0, 0))
            titleLabel.backgroundColor = UIColor.clearColor()
            titleLabel.textColor = MaterialColor.white
            titleLabel.font = RobotoFont.boldWithSize(17)
            titleLabel.textAlignment = .Center
            let availableWidth = availableWidthForTitle
            let titleUppercase = NSString(string: title.uppercaseString)
            if titleUppercase.boundingRectWithSize(
                // if title needs to be truncated
                CGSize(width: CGFloat.max, height: CGFloat.max),
                options: NSStringDrawingOptions.UsesLineFragmentOrigin,
                attributes: [NSFontAttributeName : titleLabel.font],
                context: nil).width > availableWidth {
                let truncTitle: NSMutableString = ""
                for nextChar in title.uppercaseString.characters {
                    if truncTitle.boundingRectWithSize(
                        CGSize(width: CGFloat.max, height: CGFloat.max),
                        options: NSStringDrawingOptions.UsesLineFragmentOrigin,
                        attributes: [NSFontAttributeName : titleLabel.font],
                        context: nil).width > availableWidth - 16 { // for ellipsis + some margin
                        truncTitle.appendString("...")
                        break
                    } else {
                        truncTitle.appendString(String(nextChar))
                    }
                }
                titleLabel.text = truncTitle as String
            } else {
                // use title as-is
                titleLabel.text = titleUppercase as String
            }
            titleLabel.sizeToFit()
            let subtitleLabel = UILabel(frame: CGRectMake(0, 18, 0, 0))
            subtitleLabel.backgroundColor = UIColor.clearColor()
            subtitleLabel.textColor = MaterialColor.white
            subtitleLabel.font = MaterialFont.italicSystemFontWithSize(10)
            subtitleLabel.text = subtitle
            subtitleLabel.sizeToFit()

            let titleView = UIView(frame: CGRectMake(0, 0, max(titleLabel.frame.size.width, subtitleLabel.frame.size.width), 30))
            // Center title or subtitle on screen (depending on which is larger)
            if titleLabel.frame.width >= subtitleLabel.frame.width {
                var adjustment = subtitleLabel.frame
                adjustment.origin.x = titleView.frame.origin.x + (titleView.frame.width/2) - (subtitleLabel.frame.width/2)
                subtitleLabel.frame = adjustment
            } else {
                var adjustment = titleLabel.frame
                adjustment.origin.x = titleView.frame.origin.x + (titleView.frame.width/2) - (titleLabel.frame.width/2)
                titleLabel.frame = adjustment
            }

            titleView.addSubview(titleLabel)
            titleView.addSubview(subtitleLabel)
            self.navigationItem.titleView = titleView
        }
    }
}