I made a customView and I want the size of that view to be fixed.
Like UISwitch in which you can't even change the height and width value.
Or like UILabel. I want to add the view to storyboard without adding any height or width constraint with no missing constraint error.
I already override intrinsicContentSize but I still get the missing constraint error.
Is there any way to make height and width of a view constant that don't even get values?
Simple solution
You can override the intrinsicContentSize variable and return the fixed size of your view.
So something like this should work in your custom view class:
override var intrinsicContentSize: CGSize {
return CGSize(width: <Your width>, height: <Your height>)
}
More Advanced
Adding the intrinsicContentSize will work, but if a user adds a height constraint it can make the view confused or change the height of the view to match the constraint. If you Know the height of your custom view shouldn't change then you can manually change the height constraints from your view.
override func updateConstraints() {
super.updateConstraints()
if let constraint = self.constraints.first(where: { constraint in
return constraint.isActive && constraint.firstAttribute == .height
}) {
constraint.constant = <Height of View>
}
}
Ideally though, your best not adding this, but I'm just adding this here so it's an option if anyone needs it.
Related
I'm building a simple NSGridView, and want to have a custom NSView as each element of the grid. Eventually, each NSView will be a xib based label (NSTextField) centered in the NSView.
The problem I am having is with the intrinsic size of the NSView. I want to define the size of the NSView and have auto layout work based on that. I added this code to the custom view (labelView):
override var intrinsicContentSize: NSSize {
return NSSize(width:100, height:100);
};
And it is indeed called; but apparently ignored. As a test, I have on the same row some other labels, and the height for the row is always set to the largest of the row text heights (including the label in the custom view); but the length is set to the longest of column text fields, ignoring the label in the custom view. And anyway, I want to arbitrarily make the NSView a certain height and length, as I tried (but failed) to do with the intrinsicContentSize.
NSStackview seems to do the right thing; but NSGridView does not.
I can force the width of a particular column with
grid.column(at:0).width = 400;
but want I really want to do is define the size of the NSView, and let autolayout use that as a building block.
This strikes me as a conceptual error on my part, so if someone could explain these NSGridView-autolayout-NSView subtleties, I think many might benefit.
I was having the exact same issue, tried to use custom NSView's inside a NSGridView and couldn't get them to draw correctly. What finally worked for me was setting the following:
let gridSize = 5
let cellSize: CGFloat = 50
gridView.xPlacement = .fill // this was key part of the solution
gridView.yPlacement = .fill
for i in 0 ..< gridSize {
gridView.row(at: i).height = cellSize
gridView.column(at: i).width = cellSize
}
Note that I'm setting the size of each cell with the row height and column width of the NSGridView, and not using the NSView size, but this is the only way I got it working.
I have a static UITableView and I want to set the row height for three of the cells dynamically. So in viewDidLoad() I implemented the following code:
tableView.estimatedRowHeight = 100
tableView.rowHeight = UITableView.automaticDimension
I also implemented the heightForRowAt method:
(The first two cells of the first section should have a fixed height)
override func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
if indexPath.section == 0 && indexPath.row == 0 {
return CGFloat(85)
} else if indexPath.section == 0 && indexPath.row == 1 {
return CGFloat(145)
}
return UITableView.automaticDimension
}
This the result which I'm currently getting:
I changed the lines of the labels to 0, too and the constraints of the labels inside the cells are 0, 12, 0, 12 (top, right, bottom, left).
Does anybody know, why the cell in section 3 doesn't display the data in the right way?
Edit:
(How it looks after the implementation of the suggestion above)
Because sizeToFit() did not work for you, we are going to try something a little more involved.
The cell in section 3 is displaying the data the right way. This is because UILabels don't automatically adjust their height to accommodate the text inside. Here's what you need to do:
1. Create a height constraint for your UILabel In your interface builder, add a constraint for the height of the UILabel in section 3's cell. Connect this height constraint to your view controller's class via an #IBOutlet:
class YourViewController: UIViewController {
#IBOutlet var cellLabel: UILabel!
#IBOutlet var cellLabelHeight: NSLayoutConstraint!
...
}
2. Add String extension that calculates height I am unsure of where/when you are setting the text of the UILabel in question, but I know you are doing this somewhere as you have described it as being "dynamic". Whenever you do set the text of the UILabel in question, you now also need to change the constant of the height constraint that we made in order to accommodate this text. So, we need to be able to calculate the height of the UILabel based on its width and font. We can add an extension to String in order to do this:
extension String {
func height(withConstrainedWidth width: CGFloat, font: UIFont) -> CGFloat {
let constraintRect = CGSize(width: width, height: .greatestFiniteMagnitude)
let boundingBox = self.boundingRect(with: constraintRect, options: .usesLineFragmentOrigin, attributes: [.font: font], context: nil)
return ceil(boundingBox.height)
}
}
3. Set the height constraint's constant based off the UILabel's text The final step is to set the height of the UILabel height constraint we made by using the extension we just created:
cellLabel.text = "DummyDataDummyDataDummyDataDummyDataDummyDataDummyDataDummyDataDummyData"
//This will be called immediately after you set the text for the UILabel in question
cellLabelHeight.constant = cellLabel.text.height(withConstrainedWidth: cellLabel.frame.width, font: cellLabel.font)
The cell in section 3 is displaying the data the right way. Unless you tell it otherwise, a UILabel will not automatically adjust to accommodate the text within it.
What I need you to do is select the UILabel in question, then in the attributes inspector, set the Number of Lines to 0.
You also said that this UILabel is dynamic, meaning you are setting it's text somewhere in your code. Immediately after you set this UILabel's text, you are going to want to call myLabel.sizeToFit(). This should adjust the label's height to accommodate the text within.
If this doesn't work, I have another, more involved solution that should work for you.
Please look at the below;
Select your cellLabel and set the Lines value to 0:
Also apple says Self-Sizing
Summary :
lay out your table view cell’s content within the cell’s content view. To define the cell’s height, you need an unbroken chain of constraints and views (with defined heights) to fill the area between the content view’s top edge and its bottom edge. If your views have intrinsic content heights, the system uses those values. If not, you must add the appropriate height constraints, either to the views or to the content view itself.
Change the bottom constraint of the AuthorLabel from equal to Greater than or equal
I have a calendarView from the CVCalendar pod (https://github.com/CVCalendar/CVCalendar/) and an issue with the custom View is it erratically sets the height of the view after rotation. To try and resolve this I have set a height constraint for it and am trying to set the height after the rotation to properly fit the view:
override func viewDidLayoutSubviews() {
super.viewDidLayoutSubviews()
print("Before height: \(calendarViewTestHeight.constant)")
calendarViewTestHeight.constant = 500
self.calendarView.layoutIfNeeded()
print("After height: \(calendarViewTestHeight.constant)")
}
When this code is called the height within the print statement changes as expected but the views height does not update.
I have a headerview in my UITableView but I can't find a solution to make it dynamically height. In my headerview I have a UITextView which height depends on its content.
What I have tried so far.
override func viewDidLayoutSubviews() {
super.viewDidLayoutSubviews()
sizeHeaderToFit()
}
func sizeHeaderToFit() {
let headerView = mTabView.tableHeaderView!
mTxtViewDescription.sizeToFit()
mConDescriptionHeight.constant = mTxtViewDescription.frame.height
print(mContainerView.frame.maxY)
headerView.frame.size.height += mTxtViewDescription.frame.height
}
The green area is my headerview
Changing the height of the frame of a UITableView header that's already been set won't recalculate the height, meaning you can't just change the height of a tableHeaderView as its layout is managed by the tableView. You need to set the tableHeaderView again, setting the property triggers the new calculation.
There are a number of questions going into detail about this, several linked from this one.
I have an autolayouted UIView and need to know the width of it. How do I find the width the easiest way in Swift?
You can find the width of any view by
let width = yourView.bounds.width
If you have applied a width constraint to the view and you have an outlet for that constraint then you can find it by.
let width = yourWidthConstraint.constant
The right place to get the UIScreen frame data is in viewDidLayoutSubviews as it is called after the subViews have been laid out in screen also it is called after every time your device changes orientation such as your width will be different when your user goes into landscape mode.This is called after viewWillAppear:
override func viewDidLayoutSubviews() {
super.viewDidLayoutSubviews()
let viewWidth = self.myView.bounds.width
}
Inside implementation your view you can use
override func layoutSubviews() {
super.layoutSubviews()
// you can get width of view in this function
print(self.frame.size.width)
}