Search code examples
objective-ciosuilabeluitextviewcore-text

UILables, Text Flow and Layouts

Consider the following, I have paragraph data being sent to a view which needs to be placed over a background image, which has at the top and the bottom, fixed elements (fig1)

Fig1.UIView Showing text flow and fixed elements

My thought was to split this into 4 labels (Fig1.example2) my question here is how I can get the text to flow through labels 1 - 4 given that label 1,2 & 3 ar of fixed height. I assumed here that label 3 should be populated prior to 4 hence the layout in the attached diagram.

Can someone suggest the best way of doing this with maybe an example?

Thanks

Solution

  • Wish I could help more, but I think I can at least point you in the right direction.

    First, your idea seems very possible, but would involve lots of calculations of text size that would be ugly and might not produce ideal results. The way I see it working is a binary search of testing portions of your string with sizeWithFont: until you can get the best guess for what the label will fit into that size and still look "right". Then you have to actually break up the string and track it in pieces... just seems wrong.

    In iOS 6 (unfortunately doesn't apply to you right now but I'll post it as a potential benefit to others), you could probably use one UILabel and an NSAttributed string. There would be a couple of options to go with here, (I haven't done it so I'm not sure which would be the best) but it seems that if you could format the page with html, you can initialize the attributed string that way.

    From the docs: You can create an attributed string from HTML data using the initialization methods initWithHTML:documentAttributes: and initWithHTML:baseURL:documentAttributes:. The methods return text attributes defined by the HTML as the attributes of the string. They return document-level attributes defined by the HTML, such as paper and margin sizes, by reference to an NSDictionary object, as described in “RTF Files and Attributed Strings.” The methods translate HTML as well as possible into structures of the Cocoa text system, but the Application Kit does not provide complete, true rendering of arbitrary HTML.

    An alternative here would be to just use the available attributes, setting line indents and such according to the image size. I haven't worked with attributed strings at this level, so I the best reference would be the developer videos and the programming guide for NSAttributedString. https://developer.apple.com/library/mac/#documentation/Cocoa/Conceptual/AttributedStrings/AttributedStrings.html#//apple_ref/doc/uid/10000036-BBCCGDBG

    For lesser versions of iOS, you'd probably be better off becoming familiar with CoreText. In the end you'll be rewarded with a better looking result, reusability/flexibility, the list goes on. For that, I would start with the CoreText programming guide: https://developer.apple.com/library/mac/#documentation/StringsTextFonts/Conceptual/CoreText_Programming/Introduction/Introduction.html

    Maybe someone else can provide some sample code, but I think just looking through the docs will give you less of a headache than trying to calculate 4 labels like that.

    EDIT: I changed the link for CoreText