Autolayout - intrinsic size of UIButton does not include title insets

Question

If I have a UIButton arranged using autolayout, its size adjusts nicely to fit its content.

If I set an image as button.image, the instrinsic size again

Answer 1

You can solve this without having to override any methods or set an arbitrary width constraint. You can do it all in Interface Builder as follows.

• Intrinsic button width is derived from the title width plus the icon width plus the left and right content edge insets.

• If a button has both an image and text, they’re centered as a group, with no padding between.

• If you add a left content inset, it’s calculated relative to the text, not the text + icon.

• If you set a negative left image inset, the image is pulled out to the left but the overall button width is unaffected.

• If you set a negative left image inset, the actual layout uses half that value. So to get a -20 point left inset, you must use a -40 point left inset value in Interface Builder.

So you provide a big enough left content inset to create space for both the desired left inset and the inner padding between the icon and the text, and then shift the icon left by doubling the amount of padding you want between the icon and the text. The result is a button with equal left and right content insets, and a text and icon pair that are centered as a group, with a specific amount of padding between them.

Some example values:

// Produces a button with the layout:
// |-20-icon-10-text-20-|
// AutoLayout intrinsic width works as you'd desire.
button.contentEdgeInsets = UIEdgeInsetsMake(10, 30, 10, 20)
button.imageEdgeInsets = UIEdgeInsetsMake(0, -20, 0, 0)