//  The implementation for a category on UIView which centers a view on its superview.
//  Make sure this method is only called AFTER the view has been added to its superview.
//
//  Created by Jonathan Ellis on 28/09/11
//

@implementation UIView (Positioning)

- (void)centerOnSuperviewHorizontally:(BOOL)horizontally vertically:(BOOL)vertically {
    NSAssert(self.superview, @"Cannot center a view on its superview if the view has no superview.");
    CGSize selfSize = self.frame.size;
    CGSize superviewSize = self.superview.frame.size;
    CGPoint origin = self.frame.origin;
    if (horizontally) origin.x = (superviewSize.width - selfSize.width)/2;
    if (vertically) origin.y = (superviewSize.height - selfSize.height)/2;
    CGRect frame = self.frame;
    frame.origin = origin;
    self.frame = frame;
}

@end