Debug constraints when setting view programmatically - ios

I have a complex set of labels and buttons. I set everything programmatically using mainly visual format language. The UILabels are created with the following method:
-(UILabel*)createLabelWithPlaceHolder:(NSString*)placeHolder{
UILabel *provisionalLabel=[[UILabel alloc] init];
provisionalLabel =[[UILabel alloc] init];
provisionalLabel.translatesAutoresizingMaskIntoConstraints=NO;
provisionalLabel.text=placeHolder;
provisionalLabel.font=[UIFont systemFontOfSize:12.0f];
provisionalLabel.backgroundColor=[UIColor greenColor];
provisionalLabel.textAlignment=NSTextAlignmentCenter;
[provisionalLabel setContentHuggingPriority:200 forAxis:UILayoutConstraintAxisHorizontal];
[provisionalLabel setContentCompressionResistancePriority:900 forAxis:UILayoutConstraintAxisHorizontal];
return provisionalLabel;
}
and the labels are displayed according to the following VLF code:
gap=(self.vistaGris.bounds.size.width*secondRowFactor)/7;
labelWidth=(self.vistaGris.bounds.size.width*(1-secondRowFactor))/6;
gapN=[NSNumber numberWithFloat:gap];
labelWidthN=[NSNumber numberWithFloat:labelWidth];
constraints = [NSLayoutConstraint
constraintsWithVisualFormat:#"H:|-gap-[solution4(width)]-gap-[solution5(width)]-gap-[solution6(width)]-gap-[solution7(width)]-gap-[solution8(width)]-gap-[solution9(width)]-gap-|"
options:NSLayoutFormatAlignAllBaseline
metrics:#{#"gap":gapN, #"width":labelWidthN}
views:viewsDictionary];
[self.vistaGris addConstraints:constraints];
Basically what it does is to display 6 labels on the bottom of the view. With equal spaces between them and same width. The device orientation is always landscape all the time.
The code does what I want it to do and everything is displayed OK. However I got a console warning telling me that the system cannot satisfy simultaneous constraints:
2014-04-19 09:59:48.749 Concentrations[431:60b] 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)
(
"<NSLayoutConstraint:0x8d6cd70 Linees:0x8c82d70.width == UIView:0x8c41c40.width>",
"<NSLayoutConstraint:0x8d84480 H:|-(6.85714)-[UILabel:0x8d65460] (Names: '|':Linees:0x8c82d70 )>",
"<NSLayoutConstraint:0x8d844d0 H:[UILabel:0x8d65460(72)]>",
"<NSLayoutConstraint:0x8d84500 H:[UILabel:0x8d65460]-(6.85714)-[UILabel:0x8d73890]>",
"<NSLayoutConstraint:0x8d84550 H:[UILabel:0x8d73890(72)]>",
"<NSLayoutConstraint:0x8d845b0 H:[UILabel:0x8d73890]-(6.85714)-[UILabel:0x8d731b0]>",
"<NSLayoutConstraint:0x8d845e0 H:[UILabel:0x8d731b0(72)]>",
"<NSLayoutConstraint:0x8d84640 H:[UILabel:0x8d731b0]-(6.85714)-[UILabel:0x8d734e0]>",
"<NSLayoutConstraint:0x8d84690 H:[UILabel:0x8d734e0(72)]>",
"<NSLayoutConstraint:0x8d84700 H:[UILabel:0x8d734e0]-(6.85714)-[UILabel:0x8d741b0]>",
"<NSLayoutConstraint:0x8d84730 H:[UILabel:0x8d741b0(72)]>",
"<NSLayoutConstraint:0x8d847d0 H:[UILabel:0x8d741b0]-(6.85714)-[UILabel:0x8d744d0]>",
"<NSLayoutConstraint:0x8d84800 H:[UILabel:0x8d744d0(72)]>",
"<NSLayoutConstraint:0x8d84860 H:[UILabel:0x8d744d0]-(6.85714)-| (Names: '|':Linees:0x8c82d70 )>",
"<NSAutoresizingMaskLayoutConstraint:0x8c8aef0 h=--& v=--& V:[UIView:0x8c41c40(480)]>"
)
Will attempt to recover by breaking constraint
<NSLayoutConstraint:0x8d847d0 H:[UILabel:0x8d741b0]-(6.85714)-[UILabel:0x8d744d0]>
The thing is that I don't set constraints for these labels anywhere else on my code and this debugger warning could not be less explanatory.

The warning says that you have an NSAutoresizingMaskLayoutConstraint (it derives from the autoresize automatically translated to constraints). Probably you want to set translatesAutoresizingMaskIntoConstraints=NO not only on the labels but on the vistaGris too.

Related

Dynamic UIScrollView content: Unable to simultaneously satisfy constraints

I'm attempting to set up autolayout for a paging scroll view with a dynamic number of pages (one primary subview per page). My view hierarchy is set up as follows:
Main view
Scroll view
UIView (fits content)
TutorialSubview
...
After adding all the views to an array, I have the following code to dynamically generate constraints:
self.iphoneSVContentWConstr.constant = (self.subVWidth * self.contentSV.frame.size.width);
NSMutableDictionary *views = [NSMutableDictionary new];
NSLayoutFormatOptions formatForVert = (NSLayoutFormatAlignAllTop | NSLayoutFormatAlignAllBottom);
NSMutableString *format = [NSMutableString stringWithString:#"|"];
int idx = 0; for (UIView *v in self.viewArr) {
NSString *key = [NSString stringWithFormat:#"View%i", idx];
[views setObject:v forKey:key];
[format appendFormat:#"[%#(%.f)]", key, self.subVWidth];
idx++;
}
[format appendString:#"|"];
NSLog(#"%#", format);
//Update the content view
[self.iphoneSVContent addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:format options:formatForVert metrics:nil views:views]];
[self.contentSV layoutIfNeeded];
This ends up outputting:
|[View0(320)][View1(320)][View2(320)][View3(320)]|
Which seems correct. However, I'm getting the following errors thrown:
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)
(
"<NSLayoutConstraint:0x17409f1d0 H:[UIView:0x174197c40(102400)]>",
"<NSLayoutConstraint:0x1742811d0 H:|-(0)-[TutorialSubview:0x1743a1960] (Names: '|':UIView:0x174197c40 )>",
"<NSLayoutConstraint:0x170287490 H:[TutorialSubview:0x1743a1960(320)]>",
"<NSLayoutConstraint:0x1702873f0 H:[TutorialSubview:0x1743a1960]-(0)-[TutorialSubview:0x1743a3100]>",
"<NSLayoutConstraint:0x1702871c0 H:[TutorialSubview:0x1743a3100(320)]>",
"<NSLayoutConstraint:0x1702872b0 H:[TutorialSubview:0x1743a3100]-(0)-[TutorialSubview:0x1743a3480]>",
"<NSLayoutConstraint:0x170287210 H:[TutorialSubview:0x1743a3480(320)]>",
"<NSLayoutConstraint:0x170286fe0 H:[TutorialSubview:0x1743a3480]-(0)-[TutorialSubview:0x1703a31e0]>",
"<NSLayoutConstraint:0x170287080 H:[TutorialSubview:0x1703a31e0(320)]>",
"<NSLayoutConstraint:0x170286f40 H:[TutorialSubview:0x1703a31e0]-(0)-| (Names: '|':UIView:0x174197c40 )>"
)
Will attempt to recover by breaking constraint
<NSLayoutConstraint:0x170286fe0 H:[TutorialSubview:0x1743a3480]-(0)-[TutorialSubview:0x1703a31e0]>
I have the following constraints set up on self.iphoneSVContent (the view they're all being added to within the scroll view):
At this point, I'm just unsure as to what's causing the issue. Any insight is much appreciated!
The problem seems to be the first constraint you are changing the constant
self.iphoneSVContentWConstr.constant = (self.subVWidth * self.contentSV.frame.size.width);
The value for the view's width you set with this constraint (which is 102400, from the conflicting constraints output) is not the same as 4* 320 (which is the width of the views inside it).
If the width of the UIView inside the scrollview is defined completely by the number of subviews it has inside (which already have defined width), you should not need this constraint self.iphoneSVContentWConstr, because you have enough constraints for the width to be calculated unambiguously.
If you still want to keep this width constraint, make sure you set the constant to the correct value, with something like:
self.iphoneSVContentWConstr.constant = (self.subVWidth * self.viewArr.count);
I suppose the width/height of the scrollview you set in the storyboard. That should be enough for it to work and for the constraints to not crash anymore.
I really liked the way you constructed the visual format string! Cool :)
Let me know how it went. Good luck!

Change Auto Constraint height of UIView

I have a UIView in a UITableViewCell. in the view, I have a UITextView and a UIView. They are both auto constraint on all 4 sides.
The UIView has a height constraint. I would like to update the height constraint prorrammatically. I made a outlet of the height constraint so I can change it.
Here is my code:
CGRect frame = self.myView.frame;
frame.size.height = 50;
frame.size.width = self.myView.frame.size.width;
self.myView.frame = frame;
self.viewHeight.constant = 50;
[myTableView reloadData];
When I run this code, it works perfectly, but I get an error: (I'm pretty new to objective c, so I don't understand what it's trying to say.)
2015-01-26 15:25:43.408 myApp[1449:55334] 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)
(
"<NSLayoutConstraint:0x7fb07853ac20 V:[UIView:0x7fb0784dbb80(50)]>",
"<NSLayoutConstraint:0x7fb0785bd170 V:|-(0)-[UITextView:0x7fb07896de00] (Names: '|':UIView:0x7fb07857fb70 )>",
"<NSLayoutConstraint:0x7fb0785bd260 V:[UITextView:0x7fb07896de00]-(3)-[UIView:0x7fb0784dbb80]>",
"<NSLayoutConstraint:0x7fb0785bd350 V:[UIView:0x7fb0784dbb80]-(0)-| (Names: '|':UIView:0x7fb07857fb70 )>",
"<NSLayoutConstraint:0x7fb0785bd5b0 UILabel:0x7fb0785150f0'info:'.top == UITableViewCellContentView:0x7fb078581400.topMargin>",
"<NSLayoutConstraint:0x7fb0785bd650 UITableViewCellContentView:0x7fb078581400.bottomMargin == UIView:0x7fb07857fb70.bottom + 1>",
"<NSLayoutConstraint:0x7fb0785bd6f0 V:[UILabel:0x7fb0785150f0'info:']-(8)-[UIView:0x7fb07857fb70]>",
"<NSLayoutConstraint:0x7fb078704f20 'UIView-Encapsulated-Layout-Height' V:[UITableViewCellContentView:0x7fb078581400(77)]>"
)
Will attempt to recover by breaking constraint
<NSLayoutConstraint:0x7fb07853ac20 V:[UIView:0x7fb0784dbb80(50)]>
Make a symbolic breakpoint at UIViewAlertForUnsatisfiableConstraints to catch this in the debugger.
The methods in the UIConstraintBasedLayoutDebugging category on UIView listed in <UIKit/UIView.h> may also be helpful.
You programmaticlly change the height constraint to 50. It is unsatisfied with UIView-Encapsulated-Layout-Height constraint(77), which is set by iOS for UITableViewCellContentView.

Custom UITableViewCell vertical layout constraints causing error

when I run my app on an iPhone I get the following errors. When I run it in the simulator I do not. If I take the -12-| away then the cell's height collapses to something like 30 pixels. And the UI breaks.
Can someone help me and tell me why?
Thanks
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)
(
"<NSLayoutConstraint:0x170285ff0 V:|-(12)-[UIImageView:0x1741ec200] (Names: '|':UITableViewCellContentView:0x17419c7d0 )>",
"<NSLayoutConstraint:0x170286040 V:[UIImageView:0x1741ec200(200)]>",
"<NSLayoutConstraint:0x170286090 V:[UIImageView:0x1741ec200]-(12)-| (Names: '|':UITableViewCellContentView:0x17419c7d0 )>",
"<NSLayoutConstraint:0x174881f40 'UIView-Encapsulated-Layout-Height' V:[UITableViewCellContentView:0x17419c7d0(224)]>"
)
Will attempt to recover by breaking constraint
<NSLayoutConstraint:0x170286090 V:[UIImageView:0x1741ec200]-(12)-| (Names: '|':UITableViewCellContentView:0x17419c7d0 )>
Make a symbolic breakpoint at UIViewAlertForUnsatisfiableConstraints to catch this in the debugger.
The methods in the UIConstraintBasedLayoutDebugging category on UIView listed in <UIKit/UIView.h> may also be helpful.
Warning once only: Detected a case where constraints ambiguously suggest a height of zero for a tableview cell's content view. We're considering the collapse unintentional and using standard height instead.
Unable to simultaneously satisfy constraints.
In a custom UITableViewCell I defined the Layout Constraints as follows:
_imgView.translatesAutoresizingMaskIntoConstraints = NO;
[self.contentView addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:#"H:|-15-[imageView]-15-|" options:0 metrics:nil views:#{ #"imageView": _imgView }]];
[self.contentView addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:#"V:|-12-[imageView(200)]-12-|" options:0 metrics:metrics views:#{ #"imageView" : _imgView }]];
--- EDIT ---
In response to the contentView.bounds suggestion:
In my UITableViewController I implement the following:
_tableView.rowHeight = UITableViewAutomaticDimension;
_tableView.estimatedRowHeight = 30.0f;
So a zero height, should not be an issue.
The initial height of the cell is likely smaller than the vertical constraints. This creates an initial height conflict until the contentView's frame changes.
You can work around this issue using one of the following approaches:
Increase the cell's height in the storyboard to initially fit the content.
Change the bounds of the cell's contentView to a larger size:
self.contentView.bounds = CGRectMake(0, 0, 99999, 99999);
You'll find more details in the answers to this auto layout question.
Update:
The "Unable to simultaneously satisfy constraints" conflict is between the imageView constraints trying to set the cell's height to 225 points, and the fixed height trying to set the cell height to 224 points.
Your imageView vertical constraints use 224 (12 + 200 + 12) points. The tableView separator uses 1 point. So the cell height needs to be 225 points for all constraints to be met.

Why aren't these constraints working?

I am programatically setting the following constraints on three views inside a UIView:
UIView *view1 = ((UIViewController *)[self.viewControllers objectAtIndex:0]).view;
UIView *view2 = ((UIViewController *)[self.viewControllers objectAtIndex:1]).view;
UIView *view3 = ((UIViewController *)[self.viewControllers objectAtIndex:2]).view;
NSDictionary *viewsDictionary = NSDictionaryOfVariableBindings(view1, view2, view3);
[self.contentView addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:#"H:|-0-[view1(==320)]-0-[view2(==320)]-0-[view3(==320)]|" options:0 metrics:0 views:viewsDictionary]];
My intention is that each view is 320px wide, sitting flush against one-another with no gap, and view one up against the left edge of the containing UIView.
However, when compiled, the views are laid out on-top of one-another and I get the following in the console:
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)
(
"<NSLayoutConstraint:0x211811c0 H:|-(0)-[UIView:0xc683790] (Names: '|':UIView:0xc683320 )>",
"<NSAutoresizingMaskLayoutConstraint:0x21179820 h=-&- v=-&- UIView:0xc683790.midX == UIView:0xc683320.midX - 340>",
"<NSLayoutConstraint:0x211793d0 H:[UIView:0xc6a50c0]-(0)-| (Names: '|':UIView:0xc683320 )>",
"<NSLayoutConstraint:0x21179390 H:[UIView:0xc6a50c0(320)]>",
"<NSLayoutConstraint:0x21179350 H:[UIView:0xc6a05f0]-(0)-[UIView:0xc6a50c0]>",
"<NSLayoutConstraint:0x211563d0 H:[UIView:0xc6a05f0(320)]>",
"<NSLayoutConstraint:0x21156390 H:[UIView:0xc683790]-(0)-[UIView:0xc6a05f0]>"
)
Will attempt to recover by breaking constraint
<NSLayoutConstraint:0x21179350 H:[UIView:0xc6a05f0]-(0)-[UIView:0xc6a50c0]>
Try setting
[view setTranslatesAutoresizingMaskIntoConstraints:NO];
for all of your views, it usually is enough to solve this kind of problem.

Autolayout constraint conflict when I specified just one constraint

I have the following simple test code in my controller:
- (void)loadView
{
UIView *view = [UIView new];
[self setView:view];
UILabel *label = [UILabel new];
[label setText:#"Hello World!"];
[view addSubview:label];
[view addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:#"|-[label]"
options:0 metrics:nil views:NSDictionaryOfVariableBindings(label)]];
}
The code fails with the following exception and I can't figure out why. Any help would be greatly appreciated:
2013-04-15 14:15:47.880 libmarkup-test[1072:c07] 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)
(
"<NSLayoutConstraint:0x753eb60 H:|-(NSSpace(20))-[UILabel:0x7536b60] (Names: '|':UIView:0x75376a0 )>",
"<NSAutoresizingMaskLayoutConstraint:0x712a2c0 h=--& v=--& UILabel:0x7536b60.midX ==>"
)
Will attempt to recover by breaking constraint
<NSLayoutConstraint:0x753eb60 H:|-(NSSpace(20))-[UILabel:0x7536b60] (Names: '|':UIView:0x75376a0 )>
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.
The "unable to simultaneously satisfy constraints" message is especially confusing since, as far as I can tell, I'm only specifying one constraint.
It looks like you forgot to set translatesAutoresizingMaskIntoConstraints on the UILabel. By default it will be YES. So the autoresizing mask on that label are translated to additional constraints, which are then conflicting with the one you specified.
Adding this should fix the constraint issue:
label.translatesAutoresizingMaskIntoConstraints = NO;
You should probably think about a vertical constraints on that label as well.
please adjust the constraint priority( default is 1000) and hugging priority(default is 250)

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