Constraints making UITextView smaller - ios

I just put constraints into my ViewController, and I set the UITextView so that it keeps its height and width, yet at runtime it shrinks to only cover the text inside of it. How can I avoid this?
Thank you!

In my opinion, at the run time, the size of your TextView has changed because of the content, I mean the text set to it. To prevent this kind of issue, I would suggest some options which will be regarding your UI
At first, if you intend to fix size of the TextView, so from the constraints or Interface Builder, please create width and height constraints then fix the value. For example
If you wish your text view will be dynamically in size based on contents, you can set width and height values are greater than or equal a minimum value as it will not break your UI
I hope this would be helpful.

I assume you're using Interface Builder. Check the value for Content Hugging Priority that IB set for the text view. If it's too high, it may be overriding your constraints.

Related

Greater than or equal constraint not working correctly

I have a UIView with 3 UIViews inside, I need every UIView to define it's one height depending of its contents and at the same time, the parent view should change its size depending of its children. But I'm having this issue:
I need the first UIView from the second column's height to always stick to its content and leave the remaining space in the end of the column. In other words, what I want is the second column's first UIView to shrink.
Here's my IB, the greater than or equal constraints are not working as I expected (I highlighted the relevant constraints):
I've tried changing priorities but nothing's working, hope you can help me out, thanks.
EDIT: I forgot to show what's going on inside each UIView. The image might be present or not so if it's not I remove it and "pass" the UIView's height responsibility to the label, just that:
A greater than or equal constraint will always be as small as possible while satisfying all other constraints. So in this case it is correct...
The reason it is correct is because the label you are using will allow its frame to grow beyond its content.
To fix this you need to change the content hugging priority on the two labels on the right hand side.
To do this, select the label and go to the measurements section in Interface Builder property inspector.
Near the bottom you will see "Content Hugging Priority". Change the vertical value of this to 1000 (a.k.a. required).
This will tell the label to keep its frame as small as possible to fit the content. And so, the greater than constraint will have to be taller to satisfy this.
I got it working by extending the labels to the bottom of each UIView, now the UIViews have no excuse to expand more than the label's height.

Allow UILabel to grow dynamically using auto layout

I have a label which is going to contain a big description. I want the label to continue growing on new lines. In the image, its the label which starts with event_venue.....
The even_venue.. label has 3 constraints for now:
Vertical space with eventt_title
a horizantal space with the leading of the superview
a width constraints which defines that the label width is always less than the superview.width.
What I want to acheive is to make the event_venue.width less than superview.width, but if it has more text, it should display in new lines. Is this possible using autolayout?
This are possible steps which can create expandable UILabel
Set layouts for UILabel fixing its position
Set number of lines = 0
Set content vertical compression resistance to 1000 (this will allow text to push the label)
Since you want UILabel to expand you cannot give it fixed height constraint or its parent fixed height constraint. Sometimes depending upon condition giving height constraint is necessary to avoid error then you need to set its priority lower than vertical compression resistance
Yes, this totally is possible. I see answers here that are close to solution but not complete. Here is a solution which works with auto layout in Storyboard, no coding of sizeToFit or anything. Your modified steps would be:
Vertical space with eventt_title
A horizontal space with the leading of the superview
A horizontal space with the trailing of the superview
Set UILabel's Line Breaks as Word Wrap.
Set UILabel's lines property as 0.
I have solved a similar problem. I had to make a label that had a variable amount of text. Here's what I did:
In the storyboard, place your label with the origin where you want it.
In the Attributes Inspector, "Label" section, set the Line Breaks = Word Wrap
Fill the label with random placeholder text to the maximum shape you want. For example, if you wanted to fill the whole width and have room for a maximum of three lines of text, you could do:
abcdefghijklmnopqrstu
abcdefghijklmnopqrstu
abcdefghijklmnopqrstu
In the code, set the text of the label using setText:
[self.myLabel setText:#"MyLabelText"];
This did it for me. Your situation may be a little different in that I wasn't changing the width of the superview and it sounds like you might be. But if the width constraint is set on the label then I would expect this to work in your case, too.
I had a similar question about label resizing, and the answer that I found that was useful to me is here: UILabel Auto Size Label to Fit Text. This is a good starting source for code on how to resize your label programmatically.
I would recommend that you also add a horizontal trailing auto layout constraint from the label to the edge of the superview. Do that and you can then get rid of your current width constraint.
AutoLayout facilitate you for orientation purpose. I don think it will give you automatic expansion. You have to define label with width and height completely, otherwise you will see dots at the end of label. So you may use UITextView expanding it all over the screen. And set textView.backgroundcolot = clearColor.

Using autolayout to manage height of UILabel within a subview

Using Xcode 5, interface builder and developing for iOS 7.
Within my content view I have 2 additional sub views, one on top of another. Within the upper subview I have a UILabel. I would like for that UILabel to expand in height when the content exceeds the first line, but I can't seem to get the height increase of the UILabel to increase the height of the subview, thus pushing the bottom subview down the main content view.
Additionally, I would assume the content view would need some sort of a constraint that reflects the overall height of the two subviews?
Perhaps this the question has already been answered somewhere, but I've searched everywhere and can't seem to come up with a solution.
Any help would be hugely appreciated! Thanks in advance.
There is a couple of steps that you have to do to achieve this using autolayout.
Set layout constrains for the label.
Set height constraint with low priority.
Set numberOfLines to 0 to allow multiline text.
Set preferredMaxLayoutWidth for the label.
The preferredMaxLayoutWidth is used by label to calculate its height.
This property affects the size of the label when layout constraints
are applied to it. During layout, if the text extends beyond the width
specified by this property, the additional text is flowed to one or
more new lines, thereby increasing the height of the label.
Also, have a look here.

resize superview after subviews change dynamically using autolayout

I cant for the love of god the the hang of this resizing superview.
I have a UIView *superview with 4 UILabels. 2 function as header for the 2 others.
The content in all 4 are dynamic coming from database.
SizeToFit vs SizeThatFits:(CGSize) vs UIView systemLayoutSizeFittingSize:, passing either UILayoutFittingCompressedSize or UILayoutFittingExpandedSize.
I use autolayout programatically and have set the superview height to be equal or greater to a dummy number.
where and how do I use these SizeToFit vs sizeThatFits:(CGSize) vs UIView systemLayoutSizeFittingSize:, passing either UILayoutFittingCompressedSize or UILayoutFittingExpandedSize. I have read a lot of tips here on stack but ended up with nothing.
DO I need to recalculate the constraints for the superview somewhere specific. Maby setting the height to be ยด#property` in its controller class and remove and readd it?
Atm I have tried to put everything everywhere and then some. Still I get the same size end result with the dummy height and text floating outside. Even after setting clipsToBound on subview.
I am scratching my hair of.. help
If you're using Auto Layout, here's what you need to do:
Make sure you aren't adding fixed width and/or height constraints to any of your subviews (depending on which dimension(s) you want to dynamically size). The idea is to let the intrinsic content size of each subview determine the subview's height. UILabels come with 4 automatic implicit constraints which will (with less than Required priority) attempt to keep the label's frame at the exact size required to fit all the text inside.
Make sure that the edges of each label are connected rigidly (with Required priority constraints) to the edges of each other and their superview. You want to make sure that if you imagine one of the labels growing in size, this would force the other labels to make room for it and most importantly force the superview to expand as well.
Only add constraints to the superview to set its position, not size (at least, not for the dimension(s) you want it to size dynamically). Remember that if you set the internal constraints up correctly, its size will be determined by the sizes of all the subviews, since its edges are connected to theirs in some fashion.
That's it. You don't need to call sizeToFit or systemLayoutSizeFittingSize: to get this to work, just load your views and set the text and that should be it. The system layout engine will do the calculations for you to solve your constraints. (If anything, you might need to call setNeedsLayout on the superview...but this shouldn't be required.)
Use container views
In the following example I have a 30x30 image, and the UILabel is smaller than the containing view with the placeholder text. I needed the containing view to be at least as big as the image, but it needed to grow to contain multi-line text.
In visual format the inner container looks like this:
H:|-(15.0)-[image(30.0)]-(15.0)-[label]-(15.0)-|
V:|[image(30.0)]|
V:|[label(>=30.0)]|
Then, set the containing view to match the height of the label. Now the containing view will ride the size of the label.
As #smileyborg pointed out in his answer, connecting the content rigidly to the superview informs the layout engine that the simple container view should cause it to grow.
Yellow alignment rectangles
If you want the yellow alignment rectangles add -UIViewShowAlignmentRects YES in your scheme's list of run arguments.
This almost follows #smileyborg answer and comes with a concrete example.
Won't describe all constraints, but those related to the calculation of the height of UI objects.
[Label] Labels must not have a fixed height constraint, in this case, AutoLayout won't resize labels to fit the text, so setting edge constraints is the key. (green arrows)
[Subview] Steps 1 and 3 are very easy to follow, but this step can be misunderstood. As in the case with labels, subviews must not have height constraint set. All subviews must have top constraint set, ignoring bottom constraint, which can make you think will trigger unsatisfied constraint exception at runtime, but it won't if you set bottom constraint for the last subview. Missing to do so will blow the layout. (red arrows)
[Superview] Set all constraints the way you need, but pay big attention to the
height constraint. Assign it a random value, but make it optional, AutoLayout will set the height exactly to fit the subviews. (blue arrows)
This works perfectly, there is no need to call any additional system-layout update methods.
This was made dramatically easier with the introduction of Stack Views in iOS 9. Use a stack view inside your view to contain all your content that resizes, and then simply call
view.setNeedsUpdateConstraints()
view.updateConstraintsIfNeeded()
view.setNeedsLayout()
view.layoutIfNeeded()
after changing your content. Then you can get your new size by calling
view.systemLayoutSizeFittingSize(UILayoutFittingCompressedSize)
if you ever need to calculate the exact size required for a view.

Set height constraint for UITextView

I'm fairly new to iOS development and am having a hard time sizing a UITextView to it's content. I've found several examples of calculating a strings render size and/or updating the frame size of a textview, however I can't seem to get those to work.
When I add a UITextView to my view it adds a Height constraint which I think is locking it to a specific height. How can I work around it, update the constraint via code, and/or get my UITextView to resize vertically to show my content?
You can create an outlet to the vertical size constraint, and then adjust the .constant property of the constraint to amend the height of your text view.
A UITextView inherits from UIScrollView. As part of it's logic, it changes the height of its contentSize property to allow the user to scroll vertically to any portion of the TextView's content.
I would recommend using the ContentSize property of your UITextView to figure out how "tall" your content really is. You can then set the frame of your UITextView accordingly.
OR: You could figure out the size of your text using the right method from the NSString+UIKitAdditions category.
If you don't want autolayout then disable it in the xib file.
If you want to change the contraint and it's value this tutorial will help you to deal with autolayout.

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