I am trying to position a UILabel instance label next to a UITextField instance textfield like done in the iOS Settings dialogs. I'm using Auto Layout and constraints with the help of Florian Kuglers FLKAutoLayout extensions (https://github.com/dkduck/FLKAutoLayout).
When I set only a leading constraint for the label and a space constraint between label and textfield, the label and textfield widths are adjusted to their content. (bottom picture)
But when I set also a trailing constraint for the textfield, only textfields width is adjusted to its content, but label is stretched. (top picture)
I want to behave the opposite around, so that the textfield will be stretched and the label is adjusted to its content. Why does iOS decide to stretch the label instead of the textfield?
[self addSubview:self.label];
[self addSubview:self.textField];
[self.label alignLeadingEdgeWithView:self predicate:#"10"];
[self.textField constrainLeadingSpaceToView:self.label predicate:#"10"];
// difference between top and bottom pciture
// [self.textField alignTrailingEdgeWithView:self predicate:#"-25"];
EDITED: So after the comment of Rahul I played with width and priorities. Adding the following width constraint lead into the somewhat wrong direction, because of entering some very long value, the label was resized too small.
[self.label constrainWidth:#"0#1"];
So I finally read up on "Compression Resistance and Content Hugging" (http://www.objc.io/issue-3/advanced-auto-layout-toolbox.html) and the solution is to set the Horizontal Content Hugging priority of the label to a higher value.
[self.label setContentHuggingPriority:500 forAxis:UILayoutConstraintAxisHorizontal];
Then even entering big values will let the label stay as width as its content!
Solution is not adding a width constraint with priority, but to set Compression Resistance and Content Hugging properties for the intrinsic content size of the UIViews.
Following constraints which I set in the storyboard works exactly how you want.
Horizontal space constraint between label and superview.(default)
Horizontal space constraint between textfield and superview. (default)
Horizontal space constraint between textfield and label.
Related
I have a UITextView inside a UIScrollView. if I try to display a long text with a certain font size, the text is not showing. With shorter text or decreasing the font size the text shows up again. What am I doing wrong?
Screenshot of the autolayout here (the item selected is the textview):
The UITextView is inherited from UIScrollView
open class UITextView : UIScrollView, UITextInput, UIContentSizeCategoryAdjusting
So it is a bad practice to put ScrollView inside scrollView.
The reason why you don't see a long text in UITextView is that UITextView became scrollable. Also you didn't specify your scrollView content width so the with is calculated is as one line of your long text. But you can scroll it because you will scroll scrollView. Better way is to set label inside scrollview and set the label numberOfLines = 0. Make the label bottom padding to the bottom of your scrollView and top to some items in top of label and you will get a scrollable text.
I've just understood that you don't need a scrollView to place your long text.
You can use just a UITextView for your needs.
Remove your scrollView.
Add a UITextView.
Set constraints as described and math them with screenshot
Top Space to ReadingTimeLabel
Align Bottom to Superview / Bottom Layout Guide
Leading space to Superview
Trailing space to Superview
And you will get the result like on the screenshots
Scroller top:
Scrolled bottom:
Note: You can disable UITextView editing in attribute inspector.
But if you for some reason need a scroll view:
Set constrains as described, also match them as shown on screenshots.
Add scrollView constraints (Superview is the view where the scrollView is placed in):
-Top space to ReadingTimeLabel
-Align bottom to Superview/Bottom Layout Guide
-Align leading to Superview
-Align trailing to Superview
Please a UIView inside scrollView. Use it as container.
Add constraints for container. (Superview is scrollView)
-Align Leading to Superview
-Align Trailing to Superview
-Top Space to SuperView
-Bottom Space to SuperView
-Equal Width to SuperView
Add a UILabel inside container. (Superview is container).
Add constraints for UILabel.
-Align Leading to Superview
-Align Trailing to Superview
-Top Space to SuperView
-Bottom Space to SuperView
For the label set Lines = 0 in Attribute inspector or use the code
label.numberOfLines = 0
And you will get the result like on screenshots
Scrolled top
Scroller bottom
Try the below code:
textView.sizeToFit()
I have 2 UILabel side-by-side horizontally using auto-layout as following:
1st-Label is full-width (like sizeToFit)
2nd-Label has adjustsFontSizeToFitWidth = true
On launch everything is fine, when returning from landscape to portrait 1st-Label shrinks to zero width.
Constraints are following:
1st Label: H:|-0-[1stLabel], V:[1stLabel]-0-|
2nd Label: H:[2ndLabel]-0-|, V:[2ndLabel]-0-|
Leading/Trailing Relation Constraint: H:[1stLabel]-(>=1)-[2ndLabel]
set compression resistance priority of label 1 to 1000
I missed to set ContentCompressionResistancePriority on 2nd-Label:
secondLabel.setContentCompressionResistancePriority(.defaultLow, for:.horizontal)
I'm having this weird issue with my constraints which causes the UILabel (Caption Label) to be a fixed height instead of dynamically changing height depending on the text.
I have a view (Vertical View) with a top constraint on the label above it. The Vertical View contains a view (called View) which I'm using as a divider that is centered from top to bottom with a width of 1. On the left of the divider is a UIImageView (Left Image View) with constraints leading, top, bottom equal to superview and trailing equal to View. I want to do the exact same thing to the UIImageView on the right of the divider but here is where my issue comes up.
If I use a fixed height as seen below, the UILabel above Vertical View dynamically changes its height like I want but this is obviously not how I want the UIImageView on the right to appear. I want it to be similar to the UIImageView on the left of the divider with equal height and width.
If I set the top constraint of the UIImageView on the right to the superview Vertical View, similar to the UIImageView on the left of the divider, the UILabel above Vertical View doesn't dynamically change height anymore. The UILabel now has a fixed height which I believe comes from the fact that UILabel has a height of >= 14.
How can I properly set the constraints so that I can have both UIImageViews next to each other with equal and height contained within the Vertical View and still have the UILabel above Vertical View dynamically change height depending on the text that I set the UILabel to?
On the RightImageView, you first need to get rid of the "Height = 50" constraint. This is what is causing it to be small.
Next, if that alone doesn't fix you, can you try setting the following constraints instead of using the superview for the constrains (instead make it mirror the LeftImageView):
Left: Leading spacing to divider view
Top: Align top edges to LeftImageView
Right: Horizontal space to superview (your vertical container view)
Bottom: Align bottom edges to LeftImageView
This should allow the views to remain the same height and width (assuming your distances between left/right edge of vertical container view are the same, and the distances between divider are the same).
Now, ensure the size constraint for width of the divider is set to 1 and not >= 1. Also, ensure the vertical container view has a Compression lower than the Label.
One final note--your screenshot shows the result that IB is showing you (with the dotted yellow box) on the LeftImageView. One you update your constraints correctly, this yellow box should go away.
Regarding the UILabel - if you want this to grow dynamically, you need to do the following:
myUILabel.numberOfLines = 0;
myUILabel.text = #"Enter large amount of text here";
[myUILabel sizeToFit];
I have a screen layout where there are two resizable labels , which will contain multiline text. These labels are placed inside their parent views which intern are added to main contentView, main contentView is then added to scrollView ( thats what most of the solutions suggests). For both the labels (below About and Time and location labels in first image attached) I have set height constraints as "greater than or equal to" and setting the numberOfLines to 0 as well as calling SizetoFit, but actual output is not as expected (see second image attached). There are no constraints warnings. All constraints are provided for all the elements.
The code in viewDidLoad is as follows for one of the label.
self.lblAbout.text = #"this is a long two three lines about string which will have two lines this is a long two three lines about string which will have two lines";
self.lblAbout.numberOfLines = 0;
[self.lblAbout sizeToFit];
[self.lblAbout setPreferredMaxLayoutWidth:244.0];
Also
-(void)viewDidLayoutSubviews
{
[super viewDidLayoutSubviews];
scrollView.contentSize = contentView.frame.size;
}
Not if any additional constraints are needed, I have added all leading , trailing , top , bottom constrains along with height wherever needed, plus the spacing between all the views is in place.
What i want is the labels should get adjusted to number of lines and the contentView (parent view) should scroll inside ScrollView as the total height will be larger than the screen available.
*** problem I think is the outer view of the labels aren't getting resized as per the label because of which all the views below it aren't getting repositioned ****
Please try this Solution,
1. add Height Constraint to superView of your Label.
2. add IBOutlet of that Constraint
3. add this Method to find out Height of your Text
you need to give width of super view of your Label so width will be same as your super view
4. Now get Height form returned CGRect and assign it to your Constraints's constant. it should be like
heightConstraint.constant = youObject.size.height;
please Make sure you have added other Constraints accordingly this. if not than you need to also increase Height of other superviews accordingly.
(CGRect)sizeOfDetailLabelFromString:(NSString*)string maxWidth:(CGFloat)maxWidth{
NSDictionary *attributes = #{NSFontAttributeName:FONT_LIGHT};
CGRect rect = [string boundingRectWithSize:CGSizeMake(maxWidth, MAXFLOAT) options:NSStringDrawingUsesLineFragmentOrigin|NSStringDrawingUsesFontLeading attributes:attributes context:nil];
return rect;
}
Here is what worked finally.
Added ScrollView in main View
Added View as a contentView ( be sure to rename it in designer to something than just view )
pinned scrollview to main view using leading trailing top and bottom space constraints.
Pinned contentView to scrollview same as above
Added all the components with their respective constraints
Set the height of UILabel which i want to resize using "Greater than or equal to constraint (this is necessary) and set number of lines to 0 in code
The parent view of label shouldn't have any fixed height but enough constraints to calculate it at runtime.
Make sure ScrollView has no ambiguity in calculating contentSize.
imp - Add constraints to width of Main view , scrollview , contentView ( that was in my case , you may not need equal width constraint between contentView and scrollview , but between contentView and main view its necessary)
Now scrollview scrolls exactly the way it's needed.
To my belief most of the above things i already did but somehow it wasn't working ,deleted everything and did all the things again few times and it worked.
I read this answer in how to adjust the height of my label based on the text of the label:
Vertically align text to top within a UILabel
This is my code trying to set new Text and adjust the label at the same time.
But what I find out is the height of the label never get changed. It ways stays at the value I set in my xib file. I use tool, Spark to inspect the height of the label:
-(void) setNewText(NSString *)newText
{
self.myLabel.text = newText;
self.myLabel.numberOfLines = 0;
[self.myLabel sizeToFit];
[self setNeedsLayout];
}
Can you please tell me what's wrong with my code?
Thank you.
Updated:
I have tried #rdelmar suggestion. Set the width constraint for the label and num of line to 0. The height of the ui label does get adjusted. But there are extra spacing before and after the first/last line of the text.
Here is the screenshot I captured using Spark. The blue rectangle is the UILabel. As you can see, there are extra spacing before/after the first/last line. How can I remove those spacing?
You don't need to do anything in code to get your label to adjust its height. In the xib or storyboard, give the label constraints to set its position, and give it a fixed width constraint. Do not set its height. Set the numberOfLines to 0, and that's all you need to do. If you set the text with a string that's too long to fit on one line, the label will adjust its height automatically.