How do I flip a UILabel horizontally?

Question

I want to develop an iPhone application using the utility template, where the flip side is semi-transparent displaying the contents of the main view, flipped horizontally.

Edit: To create the illusion of semi-transparent flip side, I'd display the same content on the flip view as in the main view, but mirror the content and lower the alpha.

Is it possible to display a text using an UILabel, but mirror the text, ie flip it horizontally? Apple dev pages does not give me any help in this issue.

Answer 1

As August said, I'm not sure of your use case on this, but there's a reasonably straightforward way to do it using Core Animation. First, you'll need to add the QuartzCore framework to your project and do a

#import <QuartzCore/QuartzCore.h>

somewhere in your headers.

Then, you can apply a rotational transform to your UILabel's underlying layer using the following:

yourLabel.layer.transform = CATransform3DMakeRotation(M_PI, 0.0f, 1.0f, 0.0f);

which will rotate the label's CALayer by 180 degrees (pi radians) about the Y axis, producing the mirror effect you're looking for.