I'm manually adding a subview to a view and am positioning it with constraints...
UIView *superview = self.view;
UIView *subview = self.subview;
NSDictionary *viewsDictionary = NSDictionaryOfVariableBindings(superview, subview);
[self.superview addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:#"H:|-(0)-[subview]-(0)-|" options:NSLayoutFormatAlignAllBaseline metrics:nil views:viewsDictionary]];
[self.superview addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:#"V:|-(0)-[subview]-(0)-|" options:NSLayoutFormatAlignAllBaseline metrics:nil views:viewsDictionary]];
This positions my subview neatly in the superview. However, at a later time I would like to apply a margin around my subview (with animation) so that it is inset by 100. So in effect, my constraints in visual format language would be...
"H:|-(100)-[subview]-(100)-|"
"V:|-(100)-[subview]-(100)-|"
How can I attach variables to my 'margin' value so that I can transition between the two types of display for the subview?
[NSLayoutConstraint constraintsWithVisualFormat:#"H:|-(0)-[subview]-(0)-|" options:NSLayoutFormatAlignAllBaseline metrics:nil views:viewsDictionary]
Will return an array with the constraints in the same order that they were specified, you can look for it inside the array and then change its constant value.
But I think the easiest way is to create a reference to it like so (you can store it in an internal variable or property):
NSLayoutConstraint* space = [NSLayoutConstraint constraintWithItem:self.button1 attribute:NSLayoutAttributeRight
relatedBy:NSLayoutRelationEqual toItem:self.button2
attribute:NSLayoutAttributeLeft multiplier:1.0 constant:12.0];
and add it like this:
[self.view addConstraints:#[space]];
then you can change space.constant to some value. and animate it like so:
[UIView animateWithDuration:1.0 animations:^{
// Make all constraint changes here
[self.view layoutIfNeeded];}];
Other approach would be to remove all constraints and add VFL constraints with updated values, and then perform layoutIfNeeded inside the animation block as above.
Related
This is my very first program in autolayout.
Basic problem: i am not able to add subviews(a uibutton and a uilabel) to a superview(a containerview).Subviews are just out of bond of superview or say not clipped.
I have added commented in detail to be better understanding of code.
What i want:
i dont care whereever containerview is but i want both subviews to be add in containerview with 0 padding from all sides.
- (void)viewDidLoad {
[super viewDidLoad];
**//create a uibutton with dynamic text(MAX_WIDTH=500, height = 60) and uilabel of fixed size(60, 60).Done
//create pin of fixed 2 pixes between UIButton and UILabel.Done
//put above created views in container view, it will max to 562 width and fix 60 height, so UIButton and UIlabel should fill container view with no top, bottom, left and right.Fail**
//this will be containing my button and my label
UIView *superview = self.view;
UIView *containerView = [UIView new];
[containerView setBackgroundColor:[UIColor blackColor]];
[containerView setTranslatesAutoresizingMaskIntoConstraints:NO];
[superview addSubview:containerView];
//this will be containing my button and my label
UILabel *mylabel = [[UILabel alloc]init];
[mylabel setBackgroundColor:[UIColor redColor]];
[mylabel setTranslatesAutoresizingMaskIntoConstraints:NO];
mylabel.text = #"MyLabel";
UIButton *mybutton = [UIButton
buttonWithType:UIButtonTypeRoundedRect];
[mybutton setTitle:#"My Button ye ye yey yeyeyye yeyey"
forState:UIControlStateNormal];
[mybutton setTranslatesAutoresizingMaskIntoConstraints:NO];
[mybutton setBackgroundColor:[UIColor greenColor]];
[containerView addSubview:mylabel];
[containerView addSubview:mybutton];
NSDictionary * views = NSDictionaryOfVariableBindings(mybutton,mylabel);
//create pin of fixed 2 pixes between UIButton and UILabel.Done
NSArray * horizontalConstraintsforbuttons = [NSLayoutConstraint constraintsWithVisualFormat:#"H:[mybutton(<=500)]-2-[mylabel(60)]" options:0 metrics:nil views:views];
NSArray * heightConstraintforbutton = [NSLayoutConstraint constraintsWithVisualFormat:#"V:[mybutton(==60)]" options:0 metrics:nil views:views];
NSArray * heightConstraintforLabel = [NSLayoutConstraint constraintsWithVisualFormat:#"V:[mylabel(==60)]" options:0 metrics:nil views:views];
[containerView addConstraints:horizontalConstraintsforbuttons];
[containerView addConstraints:heightConstraintforbutton];
[containerView addConstraints:heightConstraintforLabel];
//container view specific constraints//**it must be ideally <=562, but then this container view disappears, please hep to fix**
NSArray *widthConstraintForConstraint = [NSLayoutConstraint constraintsWithVisualFormat:#"H:[containerView(==560)]" options:0 metrics:nil views:NSDictionaryOfVariableBindings(containerView)];
NSArray *heightConstraint = [NSLayoutConstraint constraintsWithVisualFormat:#"V:[containerView(==60)]" options:0 metrics:nil views:NSDictionaryOfVariableBindings(containerView)];
[superview addConstraints:widthConstraintForConstraint];
[superview addConstraints:heightConstraint];
[superview addConstraint:[NSLayoutConstraint constraintWithItem:containerView attribute:NSLayoutAttributeCenterX relatedBy:NSLayoutRelationEqual toItem:superview attribute:NSLayoutAttributeCenterX multiplier:1.0f constant:0.0]];
[superview addConstraint:[NSLayoutConstraint constraintWithItem:containerView attribute:NSLayoutAttributeCenterY relatedBy:NSLayoutRelationEqual toItem:superview attribute:NSLayoutAttributeCenterY multiplier:1.0f constant:0.0]];
}
Any suggestion? :)
The VFL for each of your subviews is missing a relationship with the parent view. Autolayout is assuming your constraints should be in relation to the top-level view — what you've defined as self.view.
Here's where your problem is.
NSDictionary * views = NSDictionaryOfVariableBindings(mybutton,mylabel);
//create pin of fixed 2 pixes between UIButton and UILabel.Done
NSArray * horizontalConstraintsforbuttons = [NSLayoutConstraint constraintsWithVisualFormat:#"H:[mybutton(<=500)]-2-[mylabel(60)]" options:0 metrics:nil views:views];
NSArray * heightConstraintforbutton = [NSLayoutConstraint constraintsWithVisualFormat:#"V:[mybutton(==60)]" options:0 metrics:nil views:views];
NSArray * heightConstraintforLabel = [NSLayoutConstraint constraintsWithVisualFormat
First, add your containerView to that dictionary so you can refer to it in VFL:
NSDictionary *views = NSDictionaryOfVariableBindings(mybutton,
mylabel,
containerView);
Then in your VFL, use the pipe operator (|) to tell autolayout to place your subviews in relation to their immediate parent.
NSArray * horizontalConstraintsforbuttons = [NSLayoutConstraint constraintsWithVisualFormat:#"H:|[mybutton(<=500)]-2-[mylabel(60)]" options:0 metrics:nil views:views];
NSArray * heightConstraintforbutton = [NSLayoutConstraint constraintsWithVisualFormat:#"V:[mybutton(==60)]|" options:0 metrics:nil views:views];
NSArray * heightConstraintforLabel = [NSLayoutConstraint constraintsWithVisualFormat:#"V:|[mylabel(==60)]|" options:0 metrics:nil views:views];
I'm not entirely sure what you're trying to do with the horizontal placement of those views, but this should get you back on track. I recommend reading this post on VFL, too.
Edit
I sort of see what you're trying to do now. First, base your values at 1x when working with VFL and autolayout. As an example, a width of 560 is larger than the largest possible iPhone screen:
NSArray *widthConstraintForConstraint = [NSLayoutConstraint constraintsWithVisualFormat:#"H:[containerView(==560)]" options:0 metrics:nil views:NSDictionaryOfVariableBindings(containerView)];
Let's pretend you just wanted containerView to match the width of the device. That would look like this:
#"H:|[containerView]|"
Those pipe operators outside the containerView are saying that you want the leading (left side) and trailing (right side) space of containerView to be flush with the superview.
Alternatively, let's say you wanted your view to be slightly smaller than the width of the device (560/2).
#"H:[containerView(==280)]"
You're already horizontally centering containerView elsewhere, so it'll appear in the center of it's superview.
Let's then assume you want your red label to (actually) have a width of 60 and your green button to have a width less than or equal to 250 (500/2). That would look like this:
#"H:|[mybutton(<=250)]-2-[mylabel(==60)]|"
Since these are subviews of containerView (and we told that to autolayout earlier), the pipe operators are saying you want
the leading space (left side) of mybutton to be flush with containerView.
the trailing space (right side) of mylabel to be flush with containerView.
Since mylabel has a width of 60, mybutton will be narrower (thanks to <=) to satisfy constraints, depending on the width of containerView.
I tried to place a UIView which is 3x the screen width (or 3x UIScrollView's width) in UIScrollView.
UIScrollView's width equal to the screen width.
How do I do this in AutoLayout?
If you want to do it in code via pure AutoLayout, here's how you'd do it:
- (void)layoutUserInterface {
// Placing the scrollView using AutoLayout
[self.view addSubview:self.scrollView];
// Note: The "H:" is optional, but I like to be clear
[self.view addConstraints:
[NSLayoutConstraint
constraintsWithVisualFormat:#"H:|[scrollview]|"
options:0
metrics:nil
views:#{#"scrollview": self.scrollView}]];
[self.view addConstraints:
[NSLayoutConstraint
constraintsWithVisualFormat:#"V:|[scrollview]|"
options:0
metrics:nil
views:#{#"scrollview": self.scrollView}]];
// Placing the "wideView" using AutoLayout
[self.scrollView addConstraints:
[NSLayoutConstraint
constraintsWithVisualFormat:#"H:|[wideView]"
options:0
metrics:nil
views:#{#"wideView": self.wideView}]];
[self.scrollView addConstraints:
[NSLayoutConstraint
constraintsWithVisualFormat:#"V:|[wideView]"
options:0
metrics:nil
views:#{#"wideView": self.wideView}]];
// Setting up the 3x width constraint
[self.scrollView addConstraint:
[NSLayoutConstraint
constraintWithItem:self.wideView
attribute:NSLayoutAttributeWidth
relatedBy:NSLayoutRelationEqual
toItem:self.view
attribute:NSLayoutAttributeWidth
multiplier:3.0f
constant:0.0f]];
// Figure out your "wideView's" height requirements
}
Assign a value for your views's width constraint and make an IBOutlet for this in your header file.
In your m file's viewDidLoad method get the width of the current device's screen, multiply by 3 and assign to your constraint's constant. And finally call your view's layoutIfNeeded method.
Is this clear enough or do you want me to make it more clear?
I'm building a comment input control for an app. This control consists of a UITextView embedded in a UIView. All constraints are being handled programatically. What happens is when the user taps the UITextView, the keyboard will open. This calls the keyboard observer methods and I then adjust the bottom constraint for the comment input control to move up with the keyboard. However, I am also trying to increase the height of the input control at the same time so the user has more room to type. I'm having trouble achieving this.
-(void)updateViewConstraints
{
NSDictionary *views = #{
#"table" : self.commentsTableView,
#"seeMoreComments" : self.seeMoreCommentsView,
#"commentInput" : self.commentEntryInput
};
//See More Comments Constraints
[self.view addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:#"H:|-0-[seeMoreComments]-0-|" options:0 metrics:nil views:views]];
[self.view addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:#"V:[seeMoreComments(45)]" options:0 metrics:nil views:views]];
//Table view constraints
[self.view addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:#"H:|-0-[table]-0-|" options:0 metrics:nil views:views]];
[self.view addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:#"V:|-0-[seeMoreComments]-0-[table]-0-|" options:0 metrics:nil views:views]];
//Comment entry input
[self.view addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:#"H:|-0-[commentInput]-0-|" options:0 metrics:nil views:views]];
commentInputVerticalConstraint = [NSLayoutConstraint constraintWithItem:self.commentEntryInput
attribute:NSLayoutAttributeHeight
relatedBy:NSLayoutRelationEqual
toItem:nil
attribute:NSLayoutAttributeHeight
multiplier:1.0
constant:commentInputHeight];
if(commentInputBottomConstraint == nil)
{
commentInputBottomConstraint =
[NSLayoutConstraint constraintWithItem:self.commentEntryInput
attribute:NSLayoutAttributeBottom
relatedBy:NSLayoutRelationEqual
toItem:self.view
attribute:NSLayoutAttributeBottom multiplier:1.0
constant:0.0];
}
[self.view addConstraint:commentInputVerticalConstraint];
[self.view addConstraint:commentInputBottomConstraint];
[super updateViewConstraints];
}
Now I have a method that is called when keyBoardWillShow is called. This method animates the comment input control up when the keyboard appears.
(void)animateContentWithKeyboardInfo:(NSDictionary *)keyboardInfo
{
NSNumber *animationDuration = keyboardInfo[ UIKeyboardAnimationDurationUserInfoKey ];
NSValue *keyboardFrameValue = keyboardInfo[ UIKeyboardFrameEndUserInfoKey ];
CGRect keyboardFrame = [keyboardFrameValue CGRectValue];
UIViewAnimationCurve animationCurve = [keyboardInfo[ UIKeyboardAnimationCurveUserInfoKey ] intValue];
UIViewAnimationOptions animationOptions = animationOptionWithCurve(animationCurve);
commentInputBottomConstraint.constant = (keyboardFrame.origin.y - [UIScreen mainScreen].bounds.size.height);
//Increase the veritcal height of the comment input control
commentInputVerticalConstraint.constant = 125;
//Takes into account that the Tab Bar is 50 points, and adjust for this
//value.
if(keyboardAppeared == YES)
{
commentInputBottomConstraint.constant += TAB_BAR_OFFSET;
}
else
{
commentInputBottomConstraint.constant -= TAB_BAR_OFFSET;
}
[self.view layoutIfNeeded];
[self.view setNeedsUpdateConstraints];
[UIView animateWithDuration:[animationDuration floatValue] delay:0.0 options:animationOptions animations:
^{
[self.view layoutIfNeeded];
} completion:nil];
}
However, when I try to adjust the constant of the of the commentInputVerticalConstraint I receive this error message:
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:0x1899fcb0 V:[CommentEntryInput:0x176e5160(50)]>",
"<NSLayoutConstraint:0x1899e5c0 V:[CommentEntryInput:0x176e5160(125)]>"
)
I'm not sure if there is a way for me to "reset" or adjust the constraint to handle when the keyboard appears and then put it back to normal when the keyboard disappears. Any help would be appreciated.
Your problem is that -(void)updateViewConstraints is getting called more than once. So you are creating a new constraint and adding it to the view twice. Try checking if the constraint is nil or not.
I also don't think you need the first [self.view layoutIfNeeded] before the animation change of the constant. When changing constant, just set it then wrap the [self.view layoutIfNeeded] in a animation block to animate to that new value.
I am trying to programatically setup some constraints. I have one container view UIView which holds three subviews.
UIView - circleView
UILabel - label1
UILabel - label2
The circleview is shown at the top of the container at (0,0,width,80). The label1 is shown underneath the circleview with 5.0 padding.
I am now trying to add the label2 to be in the center of the circleView. How do I do this with AutoLayout programatically.
This is what I currently do.
NSDictionary *views = NSDictionaryOfVariableBindings(circleView,labelView, iconLbl);
[self addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:#"|[circleView(circleSize)]|" options:0 metrics:metrics views:views]];
[self addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:#"|[labelView]|" options:0 metrics:metrics views:views]];
[self addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:#"V:|[circleView(circleSize)]-(padding)-[labelView]-|" options:0 metrics:metrics views:views]];
The label2 is the iconLbl view in the dictionary.
This should be relatively straightforward - it helps to use xib to see how many constraints you actually need to get the effect you want. Constraining a label to be in the center of another view, both of which are in a parentView, only requires 2 constraints to be fully constrained. If this were a regular UIView, you'd need 4 constraints (x,y,width,height), but the label will automatically determine it's width and height from it's content, so it's not ambiguous. This is of course if you other views are all properly constrained, but you only asked about the label2 in the circle view.
I prefer to use the non-visual form for defining constraints because they read like mathematical equations. What you want is:
label2.centerX = circleView.centerX*1 + 0;
label2.centerY = circleView.centerY*1 + 0;
Since these are siblings with a common parent, the constraints are added to the parentView. So you get the following two constraints.
[parentView addConstraint:[NSLayoutConstraint constraintWithItem:label2 attribute:NSLayoutAttributeCenterX relatedBy:NSLayoutRelationEqual toItem:circleView attribute:NSLayoutAttributeCenterX multiplier:1.0 constant:0.0]];
[parentView addConstraint:[NSLayoutConstraint constraintWithItem:label2 attribute:NSLayoutAttributeCenterY relatedBy:NSLayoutRelationEqual toItem:circleView attribute:NSLayoutAttributeCenterY multiplier:1.0 constant:0.0]];
This is sufficient for getting label2 centered in the parentView. Any issues you get will likely be due to other constraints between your views not being properly specified.
Can you try this?
[self addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:#"|[circleView(circleSize)]" options:0 metrics:metrics views:views]]; //Dont link to both the sides. Dock to the left edge
[self addConstraint:[NSLayoutConstraint constraintWithItem:self.view attribute:NSLayoutAttributeCenterX relatedBy:NSLayoutRelationEqual toItem:self. labelView attribute:NSLayoutAttributeCenterX multiplier:1.0 constant:0.0 ]]; //Specify the X
[self addConstraint:[NSLayoutConstraint constraintWithItem:self.view attribute:NSLayoutAttributeCenterY relatedBy:NSLayoutRelationEqual toItem:self. labelView attribute:NSLayoutAttributeCenterY multiplier:1.0 constant:0.0 ]]; //Specify Y
[self addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:#"V:|[circleView(circleSize)]" options:0 metrics:metrics views:views]]; //Dock the circle to the top
With Masonry library
[view1 mas_makeConstraints:^(MASConstraintMaker *make) {
make.center.equalTo(view);
}];
I've decided to programmatically create my own UITableView separator lines because I need fine control over displaying a separator above and/or below each individual UITableViewCell. My tableView has static cells, so I do not create the separators in cellForRowAtIndexPath. Instead, I have propertys for each cell and in viewDidLoad, I add a top and/or bottom separator as needed. It's working, until I rotate to landscape and then the separator line does not stretch to fill the screen - it of course remains the same width it was when created. I'm not seeing how I can automatically adjust them to fit the width of the screen.
I tried adding Auto Layout constraints (leading, trailing, top/bottom), but for some reason it's not working - the width does not change, but there are no error messages logged to indicate anything is wrong with the constraints. The separator lines also sometimes disappear upon scroll or rotate, and if I comment out the auto layout constraints then they do not disappear.
So how can I make my custom cell separators always stretch to fill the device width upon rotation, and how do I prevent them from disappearing?
If it would be easier/better to create my custom cell separators in a different way, I am willing to do that. I just don't know how this can be done aside from my approach when the cells are static. I considered creating the views in the Storyboard, and setting up the constraints visually, but would that not be the equivalent of what I'm doing programmatically? If they were dynamic cells I would do it in cellForRowAtIndexPath.
//In viewDidLoad:
[self addTopSeparatorForCell:self.myCell];
//Helper method
- (void)addTopSeparatorForCell:(UITableViewCell *)cell {
UIView *topSeparator = [[UIView alloc] initWithFrame:CGRectMake(15, 1, cell.contentView.frame.size.width, 0.5)];
//add CALayer to preserve line separator visibility when row is highlighted
CALayer *backgroundColorLayer = [CALayer layer];
backgroundColorLayer.frame = topSeparator.bounds;
backgroundColorLayer.backgroundColor = [UIColor colorWithWhite:204/255.0f alpha:1].CGColor;
[topSeparator.layer addSublayer:backgroundColorLayer];
[cell.contentView addSubview:topSeparator];
//add auto layout constraints
topSeparator.translatesAutoresizingMaskIntoConstraints = NO;
NSLayoutConstraint *cn = nil;
cn = [NSLayoutConstraint constraintWithItem:topSeparator
attribute:NSLayoutAttributeLeading
relatedBy:NSLayoutRelationEqual
toItem:cell.contentView
attribute:NSLayoutAttributeLeading
multiplier:1.0
constant:15];
[cell.contentView addConstraint:cn];
cn = [NSLayoutConstraint constraintWithItem:topSeparator
attribute:NSLayoutAttributeTrailing
relatedBy:NSLayoutRelationEqual
toItem:cell.contentView
attribute:NSLayoutAttributeTrailing
multiplier:1.0
constant:0];
[cell.contentView addConstraint:cn];
cn = [NSLayoutConstraint constraintWithItem:topSeparator
attribute:NSLayoutAttributeTop
relatedBy:NSLayoutRelationEqual
toItem:cell.contentView
attribute:NSLayoutAttributeTop
multiplier:1.0
constant:1];
[cell.contentView addConstraint:cn];
}
EDIT: Thanks to # user1966109, we've been able to solve the issue with the lines not extending to fill the width, and now they are preserved when highlighting a cell. But one issue still remains that I haven't been able to solve, since I'm not sure why it's occurring. The separator lines disappear after scrolling down the scrolling back up. It's related to the auto layout constraints though because a previous solution which had other issues did not exhibit this problem. Here's the current solution that causes the lines to disappear. I'd appreciate it if someone knows how to prevent this problem (and preserve the other issues already resolved).
[self.cell addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:#"H:|-(15#750)-[myView]-(-47#750)-|" options:0 metrics:0 views:viewsDictionary]];
[self.cell addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:#"V:[myView(2)]-(-2#750)-|" options:0 metrics:0 views:viewsDictionary]];
You should not mix initWithFrame and Auto Layout. You can have a good result with a few lines using Visual Format Language for Auto layout:
//#interface TableViewController ()
#property (weak, nonatomic) IBOutlet UITableViewCell *cell;
//#implementation TableViewController
- (void)viewDidLoad
{
[super viewDidLoad];
UIView *myView = [[UIView alloc] init];
myView.backgroundColor = [UIColor redColor];
[self.cell.contentView addSubview:myView];
myView.translatesAutoresizingMaskIntoConstraints = NO;
NSDictionary *viewsDictionary = NSDictionaryOfVariableBindings(myView);
[self.cell.contentView addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:#"H:|-[myView]|" options:0 metrics:0 views:viewsDictionary]];
[self.cell.contentView addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:#"V:|[myView(2)]" options:0 metrics:0 views:viewsDictionary]];
}
This handles rotation perfectly.
Edit!
Set the following constraints if using a accessory view:
//Set a negative value to the trailing space in order to display myView under the accessory view
//Those constraints work for both self.cell and self.cell.contentView (kind of odd)
[self.cell addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:#"H:|-(15#750)-[myView]-(-47#750)-|" options:0 metrics:0 views:viewsDictionary]];
[self.cell addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:#"V:[myView(2)]-(-2#750)-|" options:0 metrics:0 views:viewsDictionary]];
With the initial help of user1966109, I have figured out constraints that address all of the problems and are working well:
[cell addConstraint:[NSLayoutConstraint constraintWithItem:imageView
attribute:NSLayoutAttributeLeading
relatedBy:NSLayoutRelationEqual
toItem:cell
attribute:NSLayoutAttributeLeading
multiplier:1.0
constant:indent]];
[cell addConstraint:[NSLayoutConstraint constraintWithItem:imageView
attribute:NSLayoutAttributeTrailing
relatedBy:NSLayoutRelationEqual
toItem:cell
attribute:NSLayoutAttributeTrailing
multiplier:1.0
constant:0.0]];
[cell addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:#"V:|[imageView(0.5)]" options:0 metrics:0 views:viewsDictionary]];