Archive for April 2014

Unable to simultaneously satisfy constraints

All of a sudden, I started getting this error popping up in the console while developing my iOS 7 app:

2014-04-30 11:32:27.199 MyApp[4495:60b] Unable to simultaneously satisfy constraints.
	Probably at least one of the constraints in the following list is one you don't want. Try this: (1) look at each constraint and try to figure out which you don't expect; 
	(2) find the code that added the unwanted constraint or constraints and fix it. (Note: If you're seeing NSAutoresizingMaskLayoutConstraints that you don't
	understand, refer to the documentation for the UIView property translatesAutoresizingMaskIntoConstraints) 
    "<NSAutoresizingMaskLayoutConstraint:0x1946a510 h=-&- v=-&- DetailTableView:0xe39ce00.width == UIView:0x2613afd0.width - 293>",
    "<NSAutoresizingMaskLayoutConstraint:0x12ccfd50 h=--& v=-&- H:[UITransitionView:0x12ca7570(768)]>",
    "<NSAutoresizingMaskLayoutConstraint:0xcf18c40 h=-&- v=-&- UIView:0x2613afd0.width == ADTransitionView:0xcf16f20.width - 768>",
    "<NSAutoresizingMaskLayoutConstraint:0xcf19bb0 h=-&- v=-&- ADTransitionView:0xcf16f20.width == UITransitionView:0x12ca7570.width>"
Will attempt to recover by breaking constraint 
<NSAutoresizingMaskLayoutConstraint:0x1946a510 h=-&- v=-&- DetailTableView:0xe39ce00.width == UIView:0x2613afd0.width - 293>
Break on objc_exception_throw to catch this in the debugger.
The methods in the UIConstraintBasedLayoutDebugging category on UIView listed in <UIKit/UIView.h> may also be helpful.

A few notes about the app:

1. I am still a noob when it comes to Auto Layout, so I have been kind of easing into it on some of the less critical areas of the app, but the part of the app in question is still all springs and struts.
2. I am using the ADTransitionView library to do customized view controller transitions.
3. It did not do this until this morning.

If I hit continue a couple of times on the debug console, the app moves along as if there is no problem, so this is not a critical issue, but I still wanted to find out how to take care of this issue first, and then try to figure out what triggered it.

The way that I was able to get around the issue was to look at all of the nib files that make up my view controller, table view, and cells. I found that one of the component nib files was still flagged to use Auto Layout, even though there were no constraints of any kind in that nib file. When I turned off the Auto Layout flag on that file and ran the app, it started to transition between view controllers without the ‘Unable to simultaneously satisfy constraints’ message.

BTW, Happy Birthday to Phil “Scrap Iron” Garner, who was an infielder for the Pittsburgh Pirates in the late 70’s and early 80’s.

Windows 8.1 Update 1 error 80073712

It can be very frustrating when you end up searching for help with a Windows Update issue. There are so many moving parts on a Windows system that it is next to impossible to track everything reliably.

While trying to put the Windows 8.1 Update 1 on my Windows 8 virtual machine inside of Parallels Desktop on my iMac, I was getting error 80073712 in the update settings control panel. There is no shortage of materials to look at if you search for that particular error code, the tricky part is finding which one will help solve the particular problem with my installation.

I was finally able to find this procedure, and it did the job as I am now running Windows 8.1 Update 1. I will abbreviate it here, for the full source material click on the link below the list:

  • Get an administrator command prompt
  • Enter this command (I am running the 64 bit version, you will need a different command to work with 32-bit or Win 8 RT, see the link for more information):
    dism /online /remove-package /packagename:Package_for_KB2919355~31bf3856ad364e35~amd64~~
  • Enter this command:
    DISM.exe /Online /Cleanup-image /Restorehealth
  • Enter this command:
    dism /online /cleanup-image /startcomponentcleanup
  • Exit the command prompt and attempt to run the update again

Even though the 2nd command above gave me an error, I went through the whole procedure, and it worked correctly. Here is the link to the forum posting on Microsoft’s web site with the full message:

Windows 8.1 Update 1 Failing to Install with errors 80070020, 80073712 and 0x800f081f

BTW, a posthumous Happy Birthday to Bruno Kirby, who played the limo driver in This Is Spinal Tap.

NSString to UIImage

I had the need to take a regular old NSString and get a UIImage representation of that text. It seems like a relatively straightforward thing to do, so here is the code that I put together:

+ (UIImage *)imageWithView:(UIView *)view
    UIGraphicsBeginImageContextWithOptions(view.bounds.size, NO, 0.0);
    [view.layer renderInContext:UIGraphicsGetCurrentContext()];
    UIImage *img = UIGraphicsGetImageFromCurrentImageContext();
    return img;
+ (UIImage *)imageWithString:(NSString *)theString font:(UIFont *)theFont color:(UIColor *)theColor
    UILabel *tempLabel = [[UILabel alloc] initWithFrame:CGRectZero];
    tempLabel.backgroundColor = [UIColor clearColor];
    tempLabel.textColor = theColor;
    tempLabel.font = theFont;
    tempLabel.text = theString;
    [tempLabel sizeToFit];
    return [self imageWithView:tempLabel];

As an added bonus, if you happen to be using Font Awesome in your iOS project (and let’s be honest, if you aren’t, you should be), here is a bonus method:

+ (UIImage *)imageWithFontAwesomeIcon:(NSString *)faIcon fontSize:(CGFloat)fontSize color:(UIColor *)fontColor
    return [self imageWithString:[NSString fontAwesomeIconStringForIconIdentifier:faIcon]
                            font:[UIFont fontWithName:kFontAwesomeFamilyName size:fontSize]

BTW, Happy Birthday to Brian Setzer, who is a fantastic guitar player and singer.