How do I find the width of a string (CGFloat) given the font name and font size?
(The goal is to set the width of a UIView to be just wide enough to hold the string.)
I have two strings: one with "1" repeated 36 times, the other with "M" repeated 36 times. These both fill the width (359.0) of the screen (give or take a little for margins).
I am using using Courier 16, which is monospaced, so I expect the width of both strings to be equal (as they in fact do appear on the screen).
However, using https://stackoverflow.com/a/58782429/8635708 :
the width of the string with the "1"s is 257.34375
the width of the string with the "M"s is 492.1875.
The first is does not fill the screen, the other is way too long.
And using https://stackoverflow.com/a/58795998/8635708 :
the width of each string is 249.640625.
At least here, they are the same, but that value clearly does not fill the screen.
I think you could create a label and call label.sizeToFit():
let label = UILabel()
label.font = UIFont.init(name: "Courier", size: 16)
label.text = "mmmmmmmmmmmmmmmm"//"1111111111111111"
label.sizeToFit()
print("Width: \(label.frame.size.width)") //153.66666666666666 -> For both strings
Related
In a very simple single screen app, I have a single-line UILabel going from left edge to right edge of the screen.
The text of the label is dynamically updated at runtime. The length of the text varies, as it contains a number in the range 0...100, and I am neither using a monospaced font nor leading zeroes.
Here is an illustration:
|<--------- Screen width --------------->|
|<----- UILabel "Some value = 0" ------->|
|<----- UILabel "Some value = 50" ------>|
|<----- UILabel "Some value = 100" ----->|
I would like the label to always use the maximum width for any device (i.e. screen size). This can be achieved by using auto-layout, suitable leading and trailing constraints, a large font size and the "auto-shrink" property for the label.
The problem is, that this approach will make the font size also vary depending on the value displayed, which is not what I want. It should only vary with the width of the screen, but not with the length of the label text.
In the example above, a large font size would be used for the value 0, a medium one for 50 and a small one for 100. I want it to adjust to the worst-case (100) and use the resulting size for any text afterwards.
Is it possible to achieve this using Interface-Builder properties and auto-layout constraints only?
I can think of ways how to calculate sizes in code, but I think there must be an easier way.
You cannot express font size as a proportion of view width in interface builder but you can do it very easily in code:
override func viewDidLayoutSubviews() {
super.viewDidLayoutSubviews()
let textSize = Constant.baseFontSize * bounds.size.width / Constant.baseViewWidth
label.font = .systemFont(ofSize: textSize)
}
I'm building my first real-world app after going through some tutorials and I've come across a layout issue. It is quite simple to adjust UI layout to different screen size classes, but I haven't found any information on how to adjust layout within same size class.
For example, I have a label whose Top Space constraint is set to 40 pt form top of view. It looks neat on a large iPhone 8 Plus screen:
But on a smaller iPhone SE screen (which is confusingly of same size class) this constraint of 40 pt pushes the label halfway through to the center, leaving reasonably less useful space below it:
So I was wondering if there's a way to set different constraints for different iPhones: say, 40 pt for iPhone 8 Plus, 30 pt for iPhone 8 and 20 pt for iPhone SE. Same goes about positioning other views below the label: I want them more compact vertical-wise on a small iPhone screen, and having more space between them on large screen. I know this last part can be solved with a stack view, but it's not always convenient to use.
UPD. Here is a full layout of the view on 8 Plus screen:
It has 3 fixed constraints:
1. From 'Title' label to top of the view - 50 pt
2. From 'Percent' label to bottom of 'Title' label - 60 pt
3. From 'Details' label to bottom of the view - 80 pt.
I've used text autoshrink in all labels + height of each label is proportional to view's height. This made layout a bit more flexible, but still there's a noticible issue on small SE screen:
As you can see, 'Details' is squeezed to 'Percent' label. At this point it would be great to move 'Percent' label higher up and closer to 'Title', but unlike heights constraints cannot be set in proportion (not in IB at least) to Superview height.
One of the options I see is to put a blank view between top and mid labels, making its height proportional and setting 'Percent' label top constraint at 0 to this blank view. Not sure though using such a "crutch" is a good practice.
You may get your most satisfactory results by using a single UILabel and setting the Attributed Text, instead of trying to get multiple labels and font sizes to cooperate.
Try this:
Create a new View Controller
add a normal UILabel
set constraints to 85% of width and 80% of height, and centered both ways
connect the label to an IBOutlet
then:
class ScalingViewController: UIViewController {
#IBOutlet weak var theLabel: UILabel!
override func viewDidLoad() {
super.viewDidLoad()
let titleFont = UIFont.systemFont(ofSize: 80.0, weight: UIFontWeightThin)
let pctFont = UIFont.systemFont(ofSize: 100.0, weight: UIFontWeightThin)
let paraFont = UIFont.systemFont(ofSize: 30.0, weight: UIFontWeightLight)
// for blank lines between Title and Percent and between Percent and Body
let blankLineFont = UIFont.systemFont(ofSize: 36.0, weight: UIFontWeightLight)
let sTitle = "Title"
let sPct = "78%"
let sBody = "A detailed text explaining the meaning of percentage above and what a person should do to make it lower or higher."
// create the Attributed String by combining Title, Percent and Body, plus blank lines
let attText = NSMutableAttributedString()
attText.append(NSMutableAttributedString(string: sTitle, attributes: [NSFontAttributeName: titleFont]))
attText.append(NSMutableAttributedString(string: "\n\n", attributes: [NSFontAttributeName: blankLineFont]))
attText.append(NSMutableAttributedString(string: sPct, attributes: [NSFontAttributeName: pctFont]))
attText.append(NSMutableAttributedString(string: "\n\n", attributes: [NSFontAttributeName: blankLineFont]))
attText.append(NSMutableAttributedString(string: sBody, attributes: [NSFontAttributeName: paraFont]))
// these properties can be set in Interface Builder... or set them here to make sure.
theLabel.textAlignment = .center
theLabel.numberOfLines = 0
theLabel.adjustsFontSizeToFitWidth = true
theLabel.minimumScaleFactor = 0.05
// set the label content
theLabel.attributedText = attText
}
}
This gives me these results for 7+, 6s and SE:
And, just for demonstration's sake, how it looks with additional text in the "body" paragraph:
I have a UILabel carefully laid out in Interface Builder with proper height and width constraints. The number of lines is set to 4. The wrapping is set to word wrap. The text is "CHECKED". The font size is very large and thus it only fits "CHECKE" and the "D" is on the second line. Writing "Checked" instead of "CHECKED" lets the font shrink (as intended) so that the whole word fits. But (the text is user given and it can be expected that the user writes fully uppercase words) having uppercase words the label does not break it/shrink the font as expected.
Do you have a suggestion as to what I might have missed? Capitalising the words (thusly only having the first letter uppercase) does work, but is not what the client wants.
Updated question
The problem seems to be unrelated to having uppercase or lowercase text. My problem could be solved by an answer to the following question:
How to make (ideally with the help of only Interface Builder) the UILabel text shrink trying to fit full words within all available lines without wrapping the text mid-word?
If the text "CHECKED" is too wide for a label (with more than 1 line available) it should shrink the font size instead of breaking the "D" and wrapping the single letter to the next line.
If the text is "one CHECKED two" and the single word "CHECKED" is already too wide for a label (with more than 1 line available) it should break between all words and shrinking the font size so that "CHECKED" still fits the middle line.
Avoiding:
one
CHECKE
D two
Thank you very much!
Here is a UILabel subclass that will find the largest word in the labels text, use the boundingRect function of NSString to see how large that one word will be with the current font, and drop the font size until it fits the width.
class AutosizingMultilineLabel: UILabel {
override func layoutSubviews() {
super.layoutSubviews()
self.adjustFontToFitWidth()
}
func adjustFontToFitWidth() {
guard let currentFont = self.font else { return }
let minimumFontSize: CGFloat = floor(self.minimumScaleFactor * currentFont.pointSize)
var newFontSize = currentFont.pointSize
var theNewFont = currentFont
if let text = self.text, let longestWord = text.components(separatedBy: " ").max(by: {$1.count > $0.count})?.replacingOccurrences(of: "\n", with: "") {
let nsString = longestWord as NSString
while newFontSize > minimumFontSize {
theNewFont = currentFont.withSize(newFontSize)
let boundingRect = nsString.boundingRect(with: CGSize(width: CGFloat.greatestFiniteMagnitude, height: CGFloat.greatestFiniteMagnitude),
options: NSStringDrawingOptions.usesLineFragmentOrigin,
attributes: [.font: theNewFont],
context: nil)
if ceil(boundingRect.size.width) <= self.bounds.size.width {
break
}
newFontSize -= 1
}
self.font = theNewFont
}
}
}
When the word is bigger than the line, word wrap doesn't work. If it doesn't fit on this line, it won't fit on the next line. (same word, same size, same line size). To make it fit, the label will start putting letters on the next line.
If you allow multiple lines on your label, the OS will try to fill the lines before adjusting the font size.
I think you're just running into a limitation on Autoshrink.
In Interface Builder:
add a new UILabel with Width: 230 and Height: 280
set the Font to System 44.0
set Line Break: Truncate Tail
set Autoshrink: Minimum Font Scale at 0.15
set the text of the label to test CHECKED lines
Now, drag the handle on the right edge of the label left and right... when it gets too narrow, the word CHECKED will break onto the next line.
Change CHECKED to checked and do the same thing. You should see the same behavior.
Now, try dragging the Bottom edge up and down. With either CHECKED or checked, you should see the Font Size auto shrink.
So... to do what you're trying to do, you might have to skip Autoshrink and instead do some code calculations.
Edit: further visual of what goes on...
Start with above values, but set the Height of the label to 170 - gives it just a little vertical padding.
Now, drag the left edge to make it narrower.
When you reach the end of the word CHECKED, and keep going, you will see the font shrink until it gets small enough that there is space for it to wrap to a 4th line.
I think you're going to need some code to get exactly what you need.
I'm trying to automatically layout text on a UILabel view.
The text (such as "abcdefghij") contains ten characters. I want to display it in one single line.
I turned off the Size Class and Auto Layout for convenience, and added following codes to layout the text on the UILabel. It should be ten characters in one line, and the width of the UILabel is equal to the width of the device.
let screenWidth = UIScreen.mainScreen().bounds.width
labelView.frame = CGRect(x: labelView.frame.origin.x, y: labelView.frame.origin.y, width: screenWidth, height: labelView.frame.height)
let string = "abcdefghij"
let stringLength = CGFloat(string.characters.count)
let characterSize = keyboardView.font.pointSize
let characterSpacing = (screenWidth - characterSize * stringLength) / stringLength
let content = NSAttributedString(string: string, attributes: [NSKernAttributeName: characterSpacing])
keyboardView.attributedText = content
But it turns out like this. The width of string is not equal to the screen
I think, the only could be wrong here is the pointSize. It equals to 13.8 while I set the font size to 17.
I don't understand it.
Give me some hints, please.
Thanks for your attention. 😄
By using sizeWithAttributes and boundingRectWithSize(_:options:context:), I finally figured out how it works. But my origin purpose is fitting the 10 characters in one line. The code should calculate the space between the characters, and all the space is same size. Could you give me some advices?
This is what I want to make
Each character occupies different amount of space depending on the character, font and size of the font.
Hence, you can use boundingRectWithSize(_:options:context:) to predict size of the string at runtime, and then take action according to your requirements.
I have a multi line label with a set size (300 x 300).
I want to adjust the label's font size programmatically according to how long the label's text is and how big the label is.
Here are 2 examples of the same sized labels with different length text strings
Refer to NSString.boundingRectWithSize:options:attributes:. Here you need to decrement the font size stepwise until the string will fit into the original frame.
var paragraph = NSMutableParagraphStyle()
let layout = [NSFontAttributeName:NSFont.systemFontOfSize(0), NSParagraphStyleAttributeName: paragraph, ]
paragraph.lineBreakMode = NSLineBreakMode.ByWordWrapping
var a = NSString(string: "My long text")
let rect = NSMakeSize(30, 20)
let bb = a.boundingRectWithSize(rect, options: NSStringDrawingOptions.UsesLineFragmentOrigin, attributes: layout)
Place the above in Playground and modify rect and the font to see what happens.
I know the Question is old but....
Just use the option AutoShrink and set the minimum font size/scale in the Attributes Inspector, it will scale the font as large as possible to fit the size of the label.