iOS Autolayout: Issue with UILabels in a resizing parent view

Question

I\'ve got a view that contains only a UILabel. This label contains multiline text. The parent has a variable width that can be resized with a pan gesture. My problem is t

Answer 1

I've fixed this issue after raising a bug with Apple. The issue that multiline text requires a two-pass approach to layout and it all relies on the property preferredMaxLayoutWidth

Here is the relevant code that needs to be added to a view controller that contains a multiline label:

- (void)viewWillLayoutSubviews
{
    // Clear the preferred max layout width in case the text of the label is a single line taking less width than what would be taken from the constraints of the left and right edges to the label's superview
    [self.label setPreferredMaxLayoutWidth:0.];
}

- (void)viewDidLayoutSubviews
{
    // Now that you know what the constraints gave you for the label's width, use that for the preferredMaxLayoutWidth—so you get the correct height for the layout
    [self.label setPreferredMaxLayoutWidth:[self.label bounds].size.width];

    // And then layout again with the label's correct height.
    [self.view layoutSubviews];
}