UIView Resize for content - ios

Couldn't find any answer for this, or am I missing something...
In iOS with autolayout on storyboard. If I have a UIView with some controls in it, depending on what the user clicks, the subviews are resizing. Can I somehow have the superview resize to the content?
In my app I have a view, but if a button is clicked subview is hidden I want the superviews height to decrease to exclude the hidden view. I can hook up the height constraint and handle it programatically, but it would be nice to handle it automatically....
Is there a way?

Can I assume that you have some constraint that relates the size of your superview to the size of your subview?
If so, all you will need to do to resize your superview when you hide the subview, is change the height constraint of your subview to 0 (auto layout won't care if your subview is hidden or not, it only takes into account constraints).

you can try something like this:
You can try putting this code to your buttonAction
yourView.frame = CGRect(x: anotherView.bounds.minX, y: anotherView.bounds.min, width: anotherView.bounds.width , height: anotherView.bounds.height)
in this case "yourView" will change its size to "anotherView".
yourView.frame = CGRect(x: anotherView.bounds.minX, y: anotherView.bounds.min, width: anotherView.bounds.width , height: anotherView.bounds.height / 2)
This example will change the height to 1/2 of "anotherView" frame.
Hope it will help you a little bit.

I was missing something.. 😄
What I didn't get was that the view will resize for its contents if you don't set a height for it and have the content have a constraint for the bottom of the view.
So I ended up setting the height of the hidden control to 0, and the bottom control constraint to parent bottom.

Related

how to resize scroll view after remove subview swift?

I have subview in a scrollview and after I remove some subview from the bottom there is a blank space and the scroll view still keeps height, not resizing. How to fix this?
Scrollview's contentHeight & contentWidth is calculated from its subviews(if used auto layout). If autolayout is not used then you need to set its content size.
So whenever you are adding or removing subviews in scrollview you need to take care of its contentHeight and contentWidth.
If you're using auto layout, you need to add constraints to newly added view in such a way that scroll view can calculate its contentHeight from it.(in auto layouts you don't need to explicitly set the content height to scroll view)
If you're using frame base layout, you need to set the contentHeight explicitly to the scroll view. In frame base layout, you need to take care of scrollviews content size.
Why is there blank space in scrollview?
When a subview is removed from scrollview, its content size need to be adjusted. It means it is not able to calculate its content size.
you can use this line
self.scrollView.contentSize = CGSize(width: self.view.frame.width, height: (YOURVIEW) - (THEREMOVEDVIEW))
I recommend you that you must save the height before remove view for later you can adjust.
UIScrollView doesn't know the height of its content automatically. You must calculate the height and width for yourself like below:
scrollView.contentSize = CGSize(width: self.view.frame.size.width, height: 700)
note: change width and height as you want.
you can try this also:
let content: CGRect = scrollView.subviews.reduce(into: .zero) { rect, view in
rect = rect.union(view.frame)
}
scrollView.contentSize = content.size

How to set UIScrollView Height in Swift

I'm using swift to build an application. I want to add some content to my view controller using storyboard.
I already put everything inside the scrollview and set the specific height, but however when I run the application, the scrollview always set longer than the button in the bottom of the view
I want the scroll view stop right after the button
Please kindly help me how to solve this problem
thank you
after scrolling
for your information, please ignore the white space between 'critics' and submit button, because actually there's UITextView between them but not visible (still try to add some border)
these are my storyboard preview
1) ScrollView Contraints
2) ScrollView -> contentView Constraints to scroll View same as above image
3) now ContentView width and Height Constraints to main View [SuperView in which ScrollView is embedded] and constraints will be as follows.
4) now click on the EqualWidth to View [Third constraint from top]and edit it as in step 6
5) contentView Width Contraint
6) ContentView Height Constraint // set priority [must] . here you need to change the first item and second item in the menu to as shown First as - ContentView.Height and second as - View.height and set priority to 250 after this a dotted line will appear in storyboard along the contentView
7) now add the content like [UIView, labels, textfields] in contentView and add constraints as Top upperMost view top space to contentView [like I have]DoubleRight imageView
and constraints for my DoubleRight imageView are
look for the Top space margin its given a top space 20 points
and same you need to do for the last item you will be adding in ContentView like I have uiView
add bottom space from this respective view to your superView[ContentView] and my constraints are:
after you had initialed all these steps results will be as Expected for every Screen size no need to change height additionally for screen sizes
Note : - [all the views must be connected to each other with top and bottom parameter]
like Flow will be
View1 - top to contentView and bottom to View2
View2 - top to View1 and bottom to view3
View3 [Last view] - top to View2 and bottom to contentView as shown
using uiView, uiimageViews their heights must be fixed
It may be helped
your_scrollView.frame = CGRect(x: 0, y: 0, width: 375, height: 667)
your_scrollView.contentSize = CGSize(width: 375, height: 1000) // You can set height, whatever you want.
You can try :
your_scrollView.frame = CGRect(x: 0, y: 0, width: 375, height: 667)
your_scrollView.contentSize = CGSize(width: 375, height: self.view.frame.size.hight)

Adding subview to scrollview

I'm trying to add a subview to a scrollview I have in my view controller:
let size:CGSize = self.view.bounds.size;
self.scrollview.contentSize.width = size.width
pageMenu = CAPSPageMenu(viewControllers: controllerArray, frame: CGRectMake(0.0, self.tableView.frame.origin.y + 130, size.width, size.height), pageMenuOptions: parameters)
self.scrollview.addSubview(pageMenu!.view)
It works to the extent that it adds it in the correct position and height I want it. But for some reason, right now it only expands to about 60% the width of the screen (I need it to be full screen).
Things I've tried
1) Setting it so self.view.frame.width
2) Setting it to the width of another full screen element.
3) Setting it to UIScreen.mainScreen().bounds
I checked the constraints of the scrollview in storyboard and it's configured to be full screen...so I'm not sure why this wont work.
This issue is related to the constraints that need to be set to the scroll view. I have answered a similar question here. Basically you need to specify a constraint for the scroll view's content view's width. See my answer in above link for a detailed description. The problem is that the scrollview adjusts its size to its content view's size even after we provide proper constraints to the scroll view. So we need to specify the constraints of the content view of the scroll view with respect to the scrollview and its superview so that the content in the scrollview fits our requirement.
One thing I noticed was that in your CGRectMake code you are specifying your y origin to be tableViews y value + 130. That seems like the problem to me.

How to change the position and size of a UIScrollView?

I got frustrated with AutoLayout so I decided to disable it and just set the positions and sizes of the elements in my view programatically. I tried this:
func setScrollViewBounds() {
var windowFrame = self.view.frame;
var scrollerHeigth = (windowFrame.height/100)*15
BottomScroll.frame = CGRect(x: CGFloat(10), y: windowFrame.height-scrollerHeigth, width: windowFrame.width-20, height: scrollerHeigth);
TopScroll.frame = CGRect(x: CGFloat(10), y: BottomScroll.frame.maxY-10, width: windowFrame.width-20, height: scrollerHeigth)
}
Im trying to set the two scroll views (TopScroll and BottomScroll) to be at the bottom of the page and have one be on top of the other. This however doesn't seem to do anything. Any ideas why?
I'm calling the function in ViewDidLoad().
TopScroll and BottomScroll are IBOutlets.
Apply constraint following order
Put your subviews in UIView Object(Which will subview of ScrollView).
Select Both ScrollView and UIView
Go->Pin->Equal Width.(Not Equal Height)
Select UIScrollView Go-> Pin uncheck Constraint to Margin and give Top,Bottom,Left,Right constraint.
Now Select UIView(Subview of UIScrollview say contentView) control click contentView to Main View(Default controller's View) and select Leading,Trailing,Top,Bottom constraint.
Finally Select contentView Go-> Resolve Auto-layOut issue -> Reset to Suggested constraints.
Constraints for subview of ContentView as usual with respect to contentView. use viewDidLayoutSubview for setting content-size to UIScrollView.

How do I get auto layout to reposition a view when it's sibling view changes size?

I have a view controller with two views (greenView, redView) and a switch:
I have a constraint on the redView top space of 50px from greenView. Here are all the constraints on redView:
I have a switch that when tapped toggles the height of greenView from 50px to 100px.
When I launch the app, the views are laid out as I want, but when the switch is tapped, the greenView frame changes from a height of 50 to 100, the redView doesn't do what I would expect - which is to shift it's y position 50px down to maintain the top space constraint it was assigned. I have an inequality constraint put on the bottom space of redView so there are no conflicts, and I am also calling [self.redView layoutIfNeeded].
Here's the relevant code:
- (IBAction)switchTapped {
if (theSwitch.isOn) {
greenView.frame = CGRectMake(0, 30, 320, 100);
[redView layoutIfNeeded];
} else {
greenView.frame = CGRectMake(0, 30, 320, 50);
[redView layoutIfNeeded];
}
Why isn't redView's y position being updated?
I have watched WWDC videos, but they seem to mention calling layoutIfNeeded in passing. What am I missing?
Here's what it looks like when launched:
And here it is when the switch is tapped:
A couple of pointers:
layoutIfNeeded assumes that you have previously called setNeedsLayout. Use setNeedsLayout instead and your app will update the layout as soon as appropriate.
Setting a frame generally does not work with autolayout. Set or change a height constraint instead. This is something you should do in code, mros had a good suggestion for this.
I find that inequality constraints are usually not the best solution, since they often lead to ambiguous layout. Instead, set an equality constraint, but lower the priority (e.g. to 500). The autolayout system will try to honor the constraint as much as possible, but will prioritize other constraints. (By default, all constraints have 1000 priority.)
There are a couple things that are causing problems. The first thing is that autolayout is supposed to ignore the object's frame. If you want to change the height of something, you change its height constraint, not the frame height. This is because constraints are applied after your layout and would override any frame changes. In addition, the red view looks like it is constrained to your superview "view" not "greenView". As far as editing the constraints, you can set up an IBOutlet and then modify the constant property of the UILayoutConstraint object.

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