How to create percentage of total width using autolayout?
I need to create three dynamic columns, each with a fixed percentage of the total width. Not thirds, but different values. For example, the following illustration shows three columns: the first being 42% wide, the second being 25% wide, and the third being 33% wide.
For a 600 pixel across viewcontroller, that would be 252, 150, and 198 pixels respectively.
However, for any subsequent display sizes (i.e. iPhone 4 landscape (960 wide) or iPad 2 portrait (768 wide), I would like the relative percentages to be the same (not the pixel widths quoted above).
Is there a way to do this using Storyboards (i.e. without code)? I can do this easily in code, but my goal is to put as much of this display logic as possible into the Storyboard.
Answer
If, as you say, you know how to do it in code, then you already know how to do it in the storyboard. It's exactly the same constraints, but you are creating them visually rather than in code.
Select both a view and its superview.
Choose Editor -> Pin -> Widths Equally to constrain the width to be equal to the superview's width (actually the "pin" popup dialog at the bottom of the canvas works best here).
Edit the constraint and set the Multiplier to the desired fraction, e.g. 0.42. And so too for the other views.