I have a custom UIView. Dead simple, just always wants to be 300x30 if possible.
class MyVoo: UIView {
override func sizeThatFits(size: CGSize) -> CGSize {
return CGSize(width: 300, height: 30)
}
}
I then set it to the navigationItem's titleView property like so:
let voo = MyVoo()
voo.backgroundColor = .magentaColor()
navigationItem.titleView = voo
voo.sizeToFit()
But when I run it, it looks like this:
As you can see width is weird. It's set to 246 for some reason, which is just slightly too much and causes the back button text to be cut off. I don't mind it being cut off, but it should occupy the space to the left better, or be the proper size and allow the back button text to show.
Basically my question is: how do I have this custom UIView be properly sized in the navigation bar? Right now it's very clearly "off", and I'd like it to effectively behave as if I just navigationItem.title (instead of titleView) to 300px worth of text. Properly shortened, the back button has proper text, etc. Rather than this weird solution where it's not properly sized for anything at all. How do I properly size it and how does it decide its sizing?
Related
I could not find much detail about how to add a customView as decoration for UICalenderView. There are many blogs telling how to add images but could not find anyone about CustomView. In images, we can return the decoration item with size parameter however in case of customView there is no option to pass size along with customView that you are adding. So in the end, I was able to add a view with red background, but the size is wrong. I tried to create a view and give it frame but it had no effect. So im confused how to adjust its size. Here is the method in which I add customView that im creating:
func calendarView(_ calendarView: UICalendarView, decorationFor dateComponents: DateComponents) -> UICalendarView.Decoration? {
return .customView(addActivityCircle)
}
And this is my addActivityCircle method which for now just creating a view with red background color:
private func addActivityCircle() -> UIView {
let view = UIView()
view.backgroundColor = .red
view.clipsToBounds = false
view.frame = CGRect(x: 0, y: 0, width: 50, height: 50)
return view
}
When I run this code I do see a view with red color but it's like a small rectangle, not 50x50. If I pass small values like 20x20, I do see a small rectangle but anything above that I see a rectangle of fixed size. I think that's the limit of decoration item but in apps like Fitness app by apple, there are bigger activity rings than that so there should be a way to have bigger sized custom views as this is just too small. The width is fine but the height is just too less. This is what im getting and it does not get any higher than that:
I'm learning swift with cs193p and I have a problem with UITextView.sizeThatFits(...). It should return a recommended size for popover view to display an [int] array as a text. As you can see in Paul Hegarty's example (https://youtu.be/gjl2gc70YHM?t=1h43m17s), he gets perfectly-fit popover window without scrollbar. I'm using almost the same code that was in this lecture, but instead i've got this:
the text string equals [100], but the sizeThatFits() method is returning a size that is too small to display it nicely, even though there is plenty of free space.
It is getting a bit better after I've added some text, but still not precise and with the scrollbar:
Here is the part of the code where the size is being set:
override var preferredContentSize: CGSize {
get {
if textView != nil && presentingViewController != nil {
// I've added these outputs so I can see the exact numbers to try to understand how this works
print("presentingViewController!.view.bounds.size = \(presentingViewController!.view.bounds.size)")
print("sizeThatFits = \(textView.sizeThatFits(presentingViewController!.view.bounds.size))")
return textView.sizeThatFits(presentingViewController!.view.bounds.size)
} else { return super.preferredContentSize }
}
set { super.preferredContentSize = newValue }
}
What should I do so this will work in the same way as in the lecture?
It looks like there are 16 pt margins between the label and its parent view. You need to take that into account when returning the preferred size of the popover.
You should try both of the following:
Add 32 to the width that's returned from preferredContentSize
In Interface Builder, clear the layout constraints on your UILabel, then re-add top, bottom, leading, and trailing constraints and make sure that "Constrain to Margins" option is not enabled.
Finally, instead of overriding preferredContentSize, you can simply set the preferredContentSize when your view is ready to display, and you can ask Auto Layout to choose the best size:
override func viewDidLayoutSubviews() {
self.preferredContentSize = self.view.systemLayoutSizeFitting(UILayoutFittingCompressedSize)
}
If your layout is configured correctly, systemLayoutSizeFitting(UILayoutFittingCompressedSize) will return the smallest possible size for your view, taking into account all of the margins and sub-views.
I am trying to display a UILabel that may take up multiple lines but I'm having problem with how the height is resized.
Here is what it looks when I have text over a single line, displaying correctly:
When the text spans multiple lines however this happens:
Here's the interface builder settings I'm using:
Ideally I'd like the text view to remain at athe top of the screen and just take up as much space as it needs to diaplay the text but I really can't tell where I am going wrong.
The text view is a bit tricky to handle with automatic layout. If possible use an UILabel. If not then there are several issues with the text view and the most manageable solution is to add the height constraint which is then manipulated in the code.
The height of the text view content can be determined as:
let height = textView.sizeThatFits(textView.frame.size).height
It is also possible to use
let height = textView.contentSize.height
But the results are sometimes incorrect.
You do need to then set the delegate for the text view so that on change you will refresh the size of the text view.
Well you did give it permission to do so based on your constraints. Any height > 0 as long as it's 20 from the top margin. Since you don't have any other views to base your height off of you can hook up an outlet to your label and use this:
#IBOutlet weak var label: UILabel!
override func viewDidAppear(_ animated: Bool) {
super.viewDidAppear(animated)
label.sizeToFit()
}
Uncheck the "Preferred Width" explicit checkbox(In Size Inspector)
Remove the height constraint on you UILabel.
It will definitely work.
I've tried a lot of things but couldn't come up with a solution. Any words of thought can help me evaluate on this. I made a full view DrawBoard class which is inherited from a UITextView class.When the switch on the view controller is on the user can type and scroll, when it is off the user can draw on the Drawboard.
#IBAction func changeSwitch(sender: UISwitch) {
if sender.on{
drawBoard.setNeedsDisplay()
drawBoard.scrollEnabled = true
drawBoard.editable = true
drawBoard.selectable = true
drawBoard.switchBool = false
}else if !sender.on {
drawBoard.switchBool=true
let a:CGPoint = drawBoard.contentOffset
drawBoard.scrollEnabled = false
drawBoard.setContentOffset(a, animated: false)
drawBoard.editable = false
drawBoard.selectable=false
}
}
It updates the scrolling but scrollEnabled= false just saves the text that is in the first page range of the textview so that it scrolls to the top automatically and disable the scrolling there.Then when I do the setContentOffset the drawable view of the background is visible and it draws on the right place of the textview. However the text that should be on top of it is not visible. This only happens when the switch button is set to off while I am out of the first page's range.How do I also make the text at that range visible?
Sorry if it's a really easy question I'm new to programming and got stuck for a considerable amount of time for this.Thank you.
You have to update the content size of the UIScrollView.
Like this:
scrollView.contentSize = CGSize(width: 100, height: 100)
"Content Size" determines the size of scrollable content, if it's not large enough to cover new views, you won't be able to see it in your scroll view.
I am going through the Stanford Winter 2015 Swift/iOS course and while doing the assignments I run into a behavior I'd like to change.
I use Autolayout as described in the videos (making the display pin to leading and trailing view edges) and the Calculator app "Display" UILabel is fine with an initial value of 0 and whenever the value used to set it (a String) is non-nil and non "".
If it is either nil or "", the entire UILabel disappears. What I am trying to do is to "clear" the display whenever there is no value to display or an incorrect calculation resulted in nil.
Any tips on who to deal with this in general? "Clearing" a UILabel without changing it's on-screen dimensions?
Edit (thanks Rob)
The UILabel has the following constraints
1. Option-click drag-left to containing UIView, selected "leading" something (on commute to work can't check yet for exact wording.
2. Same method as (1) except that the drag is to the right edge and selecting "trailing"
3. Option click-drag up to top of view, select "vertical" menu option.
4. Same as (3) except that drag is to a UIButton underneath the UILabel on the GUI.
With those settings, the label when it contains a number is always visible and (if understand, will color it to verify) stretches across the screen even if the text doesn't.
The layout looks correct in profile and landscape as long as content of UILabel is not empty. If empty, it seems to "shrink to fit" so much that the buttons below get moved up towards the top.
I'm a C++ dev since mid 90s but I have little UI experience and no more than a couple weeks experience in iOS/Swift development.
Thanks!
You can always give the UILabel a min width and min height or constraints that holds the left and right side of the label. That should keep the label from changing it's dimensions to zero.
Use a custom UILabel class assigned in Interface Builder >> Identity inspector >> Custom Class >> Class to override UILabel intrinsic content size.
No need to create any superfluous auto-layout constraints.
Swift:
class UILabelNonCompressible: UILabel
{
private static let NonCompressibleInvisibleContent = " "
override var intrinsicContentSize: CGSize
{
if /* zero-width */ text == nil ? true : text!.isEmpty
{
// prefer mirror-and-calculate over modify-calculate-restore due to KVO
let doppelganger = createCopy()
// calculate for any non-zero -height content
doppelganger.text = UILabelNonCompressible.NonCompressibleInvisibleContent
// override
return doppelganger.intrinsicContentSize
}
else
{
return super.intrinsicContentSize
}
}
}
You will also need "How do copy for UILabel?":
extension UILabel
{
func createCopy() -> UILabel
{
let archivedData = NSKeyedArchiver.archivedData(withRootObject: self)
return NSKeyedUnarchiver.unarchiveObject(with: archivedData) as! UILabel
}
}