Issue implementing Glass Button UIButton

Question

I'm a noob to iphone development and i'm having a weird issue while trying to implement Glass Buttons (found here). My build fails because I'm getting an "unexpected @ in program error" inside the MOGlassButtons.m file. I haven't been able to find anything regarding how to resolve this issue. Any help is greatly appreciated.

MOGlassButton.m

self.gradientLayer1.colors = @[(id)[MO_RGBACOLOR(255, 255, 255, 0.45) CGColor], (id)[MO_RGBACOLOR(255, 235, 255, 0.1) CGColor]]; //<--"unexpected @ in program error" 

self.gradientLayer2.colors = @[(id)[MO_RGBACOLOR(205, 205, 205, 0) CGColor], (id)[MO_RGBACOLOR(235, 215, 215, 0.2) CGColor]]; //<--"unexpected @ in program error"

EDIT

#import "MOGlassButton.h"

// Courtesy of https://github.com/facebook/three20
#ifndef MO_RGBCOLOR
#define MO_RGBCOLOR(r,g,b) [UIColor colorWithRed:r/255.0 green:g/255.0 blue:b/255.0 alpha:1]
#endif
#ifndef MO_RGBCOLOR1
#define MO_RGBCOLOR1(c) [UIColor colorWithRed:c/255.0 green:c/255.0 blue:c/255.0 alpha:1]
#endif
#ifndef MO_RGBACOLOR
#define MO_RGBACOLOR(r,g,b,a) [UIColor colorWithRed:r/255.0 green:g/255.0 blue:b/255.0 alpha:a]
#endif

Could you please show us MO_RGBACOLOR? If it, as I suppose, a macro, chances are it is the culprit. — Julius Maximilian Steen, Mar 21 '13 at 23:23
you can't just cast CGColorRef to id, why don't you just store UIColor — Bryan Chen, Mar 21 '13 at 23:53
`(id)[MO_RGBACOLOR(...) CGColor]` will cause run-time error, because `CGColorRef` is not `id` — Bryan Chen, Mar 22 '13 at 00:34
@xlc in my experience, this is no problem and I never had problems with this. This seems logical to me, as NSMutableArray and CFMutableArrayRef are toll-free bridged and the latter obviously does allow CFType data structures like CGColor. — Julius Maximilian Steen, Mar 22 '13 at 00:47
@JuliusMaximilianSteen ok, I never know `CGColorRef` can be stored in `NSArray`... there must be a reason that `UIColor` and `CGColor` are not toll-free bridged... — Bryan Chen, Mar 22 '13 at 00:55
@xlc Apple themselves do that in their documentation: `NSMutableArray *colors = [NSMutableArray arrayWithObject:(id) [[UIColor darkGrayColor] CGColor]]; [colors addObject:(id)[[UIColor lightGrayColor] CGColor]];` See here: http://developer.apple.com/library/ios/#releasenotes/ObjectiveC/RN-TransitioningToARC/Introduction/Introduction.html What do you mean by workaround? — Julius Maximilian Steen, Mar 22 '13 at 01:09

score 1 · Answer 1 · edited May 23 '17 at 12:28

Your problem is probably the outdated version of Xcode you are running. Your code uses Objective-C literals (the @[…] part) which are supported since Xcode 4.4 and thus not valid in earlier releases. (see What are the details of "Objective-C Literals" mentioned in the Xcode 4.4 release notes?)

Upgrading should fix your problem.

Edit

Alternatively, although I heavily recommend updating, you could use the following.

[NSArray arrayWithObjects: (id)[MO_RGBACOLOR(255, 255, 255, 0.45) CGColor], (id)[MO_RGBACOLOR(255, 235, 255, 0.1) CGColor], nil];

Issue implementing Glass Button UIButton

1 Answers1