Adding Constraints in Interface Builder
Open BNRDetailViewController.xib. First, select the image view in the canvas and delete it from the XIB file. You will recreate the image view and add its constraints programmatically in Chapter 16.
Select the toolbar on the canvas. At the bottom righthand corner of the canvas, find the Auto Layout constraint menu (Figure 15.7).
Figure 15.7 Selecting a constraint
Click the icon (the second from the left) to reveal the Pin menu. This menu shows you the current size and position of the ...