UITextField: Leading Truncate - ios

Currently, my text within a UITextField is truncating at the tail (eg. "Hello, Wor..."). I want the to truncate the text from the leading edge (eg. "...lo, World!").

I believe using NSMutableParagraphStyle's lineBreakMode with NSMutableAttributedString might work
let longString = "Hello World"
// Just for demo purposes, you can use auto layout etc
let textfield = UITextField(frame: CGRect(x: 40, y: 200, width: 30, height: 100))
textfield.layer.borderWidth = 2
textfield.layer.borderColor = UIColor.gray.cgColor
// Use a paragraph style to define the truncation method
let paragraphStyle = NSMutableParagraphStyle()
paragraphStyle.lineBreakMode = .byTruncatingHead
// Create an attributed string and apply the paragraph style
let attributedString = NSMutableAttributedString(string: longString)
attributedString.addAttribute(.paragraphStyle,
value: paragraphStyle,
range:NSMakeRange(0, attributedString.length))
// Set the text field's attributed text as the attributed string
textfield.attributedText = attributedString
This gives something like this, which is what I think you want:

You just have to update the text attributes (e.g., defaultTextAttributes) with a .paragraphStyle with a lineBreakMode of .byTruncatingHead.
I would not just replace the .paragraphStyle, though. I would fetch it, update its lineBreakMode, and then update the text attributes with that:
let oldStyle = textField.defaultTextAttributes[.paragraphStyle, default: NSParagraphStyle()] as! NSParagraphStyle
let style = oldStyle.mutableCopy() as! NSMutableParagraphStyle
style.lineBreakMode = .byTruncatingHead
textField.defaultTextAttributes[.paragraphStyle] = style
Here it is with .byTruncatingHead, .byTruncatingMiddle and .byTruncatingTail, respectively:

Related

Can I change the location of the ellipsis on the uilabel in swift?

I used UiLabel with byTruncatingTail attribute.
I want to fix the ellipsis from the middle to the bottom vertically.
It is now stated as follows.
But I want to have the ellipsis placed on the floor as follows.
My code is as follows.
let paragraphStyle = NSMutableParagraphStyle()
let range = NSRange(location: 0, length: mutableAttributedString.length)
paragraphStyle.lineSpacing = 2
paragraphStyle.alignment = .center
paragraphStyle.lineBreakMode = .byTruncatingTail
mutableAttributedString.addAttribute(.paragraphStyle, value: paragraphStyle, range: range)
titleLabel.attributedText = mutableAttributedString
Is this possible?

Underline covers text in NSAttributedString

I'm trying to create an attributed string but the underline covers my text instead of appearing behind it:
Is there a way to fix this? I'm using the following code:
let paragraphStyle = NSMutableParagraphStyle()
paragraphStyle.lineSpacing = 10.0
let attributes = [NSForegroundColorAttributeName: UIColor.white,
NSUnderlineStyleAttributeName: NSUnderlineStyle.styleThick.rawValue,
NSUnderlineColorAttributeName: UIColor.red,
NSParagraphStyleAttributeName: paragraphStyle]
let attributedString = NSAttributedString(string: "Story", attributes: attributes)
Thanks!
EDIT:
To give more context:
I'm displaying the attributed string on a UILabel placed in a .xib file:
view.textLabel.attributedText = attributedString
The label has the following font:
System Bold 32.0
I'm running the code on iPhone 6 - iOS 10.3 simulator.
EDIT 2:
I should have mentioned that the label may, at some point, contain more than one line of text. That's why the numberOfLines is set to 0.
EDIT 3:
If anybody encounters this problem -- it seems that there is a lot of difference in how underline is drawn on iOS 9 vs 10 as well as UILabel vs UITextView. I've ended up having to draw the underline myself by subclassing NSLayoutManager.
Yes, there is such problem as you have described. It shows up when you use multiline UILabel, so not only setting numberOfLines to 0, but type more than 1 line in it.
Example
let selectedStringAttributes: [String: Any]
= [NSFontAttributeName: UIFont.boldSystemFont(ofSize: 28),
NSForegroundColorAttributeName: UIColor.green,
NSUnderlineStyleAttributeName: NSUnderlineStyle.styleSingle.rawValue,
NSUnderlineColorAttributeName: UIColor.green]
let label = UILabel(frame: CGRect(x: 100, y: 100, width: 500, height: 100))
label.numberOfLines = 0
label.attributedText = NSAttributedString(string: "String to test underline", attributes: selectedStringAttributes)
And everything will look pretty good.
But if you want to use such text:
label.attributedText = NSAttributedString(string: "String to\ntest underline", attributes: selectedStringAttributes)
or label's width is too short, than:
So the reason for such behaviour is of course bug in NSAttributedString. As it mentioned in radar there is a workaround
You should add this attribute to your NSAttributedString
NSBaselineOffsetAttributeName: 0
And magic will happen.
Instead of using NSAttributedString you can draw border below the label with x space using this.
let space:CGFloat = 10
let border = CALayer()
border.backgroundColor = UIColor.red.cgColor
border.frame = CGRect(x: 0, y: (label?.frame.size.height)! + space, width: (label?.frame.size.width)!, height: 1)
label?.layer.addSublayer(border)
On my machine, showing your attributed string in a black-backgrounded UILabel, it makes a quite nice-looking display:
The red thick underline is nicely separated from the text, and is interrupted to allow the descender of the "y" to pass through it.
NOTE You cannot combine the font of the UILabel (set in Interface Builder) with its attributedText. You must set the entire label's text formatting in the attributedText. So, my code looks like this:
let attributes : [String:Any] = [NSForegroundColorAttributeName: UIColor.white,
NSUnderlineStyleAttributeName: NSUnderlineStyle.styleThick.rawValue,
NSUnderlineColorAttributeName: UIColor.red,
NSFontAttributeName: UIFont.boldSystemFont(ofSize: 32)]
let attributedString = NSAttributedString(string: "Story", attributes: attributes)
lab.backgroundColor = .black
lab.attributedText = attributedString
(You will notice that I removed your stipulation of the paragraph line spacing; there is only one line, so this stipulation adds nothing. However, I get the same result even if I restore it.)
So this is my solution to this issue.
I think it is "cleaner" and easier.
Post me if you dont understand :)
class BottomLineTextField: UITextField {
var bottomBorder = UIView()
override func awakeFromNib() {
super.awakeFromNib()
setBottomBorder()
}
func setBottomBorder() {
self.translatesAutoresizingMaskIntoConstraints = false
bottomBorder = UIView.init(frame: CGRect(x: 0, y: 0, width: 0, height: 0))
hasError = false
bottomBorder.translatesAutoresizingMaskIntoConstraints = false
addSubview(bottomBorder)
bottomBorder.bottomAnchor.constraint(equalTo: bottomAnchor).isActive = true
bottomBorder.leftAnchor.constraint(equalTo: leftAnchor).isActive = true
bottomBorder.rightAnchor.constraint(equalTo: rightAnchor).isActive = true
bottomBorder.heightAnchor.constraint(equalToConstant: 1).isActive = true // Set underline height
}
}

NSKernAttributeName space at end of line in an NSAttributedString

When using NSKernAttributeName it puts a space at the end of each line, is there any way to fix this? I can set the attributed to be in the range of:
NSRange(location: 0, length: self.text!.characters.count-1)
But I don't want to set this for every line.
This is the test code in the a playground I am using
//: Playground - noun: a place where people can play
import UIKit
import XCPlayground
var text = "Hello, playground\nhow are you?"
let paragraphStyle = NSMutableParagraphStyle()
paragraphStyle.paragraphSpacing = 50
paragraphStyle.alignment = NSTextAlignment.Left
paragraphStyle.lineBreakMode = NSLineBreakMode.ByTruncatingTail
let attributes = [
NSParagraphStyleAttributeName: paragraphStyle
, NSKernAttributeName: 20
]
let attributedString = NSAttributedString(string: text, attributes: attributes)
let label = UILabel()
label.attributedText = attributedString
label.numberOfLines = 0
label.textColor = UIColor.greenColor()
label.backgroundColor = UIColor.orangeColor()
label.sizeToFit()
label.center = CGPoint(x: 500, y: 100)
var text2 = "What's up\nWhere are you?"
let attributedString2 = NSAttributedString(string: text2, attributes: attributes)
let label2 = UILabel()
label2.attributedText = attributedString2
label2.numberOfLines = 0
label2.textColor = UIColor.greenColor()
label2.backgroundColor = UIColor.orangeColor()
label2.sizeToFit()
label2.center = CGPoint(x: 500, y: 250)
var text3 = "Hello"
let attributedString3 = NSAttributedString(string: text3, attributes: attributes)
let label3 = UILabel()
label3.attributedText = attributedString3
label3.numberOfLines = 0
label3.textColor = UIColor.greenColor()
label3.backgroundColor = UIColor.orangeColor()
label3.sizeToFit()
label3.center = CGPoint(x: 500, y: 400)
let holderView = UIView(frame: CGRect(x: 0, y: 0, width: 1000, height: 500))
holderView.backgroundColor = UIColor.lightGrayColor()
holderView.addSubview(label)
holderView.addSubview(label2)
holderView.addSubview(label3)
XCPlaygroundPage.currentPage.liveView = holderView
With the result looking like this:
You can see the spaces at the end of each of the lines.
This is actually the definition of how kerning works; it adjusts the space between the kerned character and where the next character will be. Whether a next character proceeds to be drawn or not is irrelevant.
Standard Attributes
The kerning attribute indicates how much the following character should be shifted from its default offset as defined by the current character’s font; a positive kern indicates a shift farther along and a negative kern indicates a shift closer to the current character.
If it helps, think about doing this in a word processor. If kerning is on, and you type a character, where would you expect the insertion point to be then? The expected answer would be "offset from the just typed character by the amount of kern" as that's what happens in the default case of kern being 0, correct? Well, that's exactly what's happening here: if you kern the last character of a string, the string therefore includes the last kern.
So the correct thing to do here is to wrap up your dropLast() logic in an extension and call it a day.
Create an extension
import UIKit
extension UILabel {
#IBInspectable var kerning: Float {
get {
var range = NSMakeRange(0, (text ?? "").characters.count)
guard let kern = attributedText?.attribute(NSKernAttributeName, atIndex: 0, effectiveRange: &range),
value = kern as? NSNumber
else {
return 0
}
return value.floatValue
}
set {
var attText:NSMutableAttributedString?
if let attributedText = attributedText {
attText = NSMutableAttributedString(attributedString: attributedText)
} else if let text = text {
attText = NSMutableAttributedString(string: text)
} else {
attText = NSMutableAttributedString(string: "")
}
let range = NSMakeRange(0, attText!.length)
attText!.addAttribute(NSKernAttributeName, value: NSNumber(float: newValue), range: range)
self.attributedText = attText
}
}
}
This was answered here

How to adjust a UILabel line spacing programmatically in Swift?

I have a multiline UILabel as shown here:
I achieved this using the following code:
label.lineBreakMode = .ByWordWrapping
label.numberOfLines = 2
I'm trying to "decrease" the line spacing between the 1st line and 2nd line, and I tried to use the following code:
let text = label.attributedText
let mas = NSMutableAttributedString(attributedString:text!)
mas.replaceCharactersInRange(NSMakeRange(0, mas.string.utf16.count),
withString: label.text!)
label.attributedText = mas
However, it does not seem to work.
Thanks
Programmatically with Swift 4
Using label extension
extension UILabel {
// Pass value for any one of both parameters and see result
func setLineSpacing(lineSpacing: CGFloat = 0.0, lineHeightMultiple: CGFloat = 0.0) {
guard let labelText = self.text else { return }
let paragraphStyle = NSMutableParagraphStyle()
paragraphStyle.lineSpacing = lineSpacing
paragraphStyle.lineHeightMultiple = lineHeightMultiple
let attributedString:NSMutableAttributedString
if let labelattributedText = self.attributedText {
attributedString = NSMutableAttributedString(attributedString: labelattributedText)
} else {
attributedString = NSMutableAttributedString(string: labelText)
}
// Line spacing attribute
attributedString.addAttribute(NSAttributedStringKey.paragraphStyle, value:paragraphStyle, range:NSMakeRange(0, attributedString.length))
self.attributedText = attributedString
}
}
Now call extension function
let label = UILabel()
let stringValue = "How\nto\nadjust\na\nUILabel\nline\nspacing\nprogrammatically\nin\nSwift"
// Pass value for any one argument - lineSpacing or lineHeightMultiple
label.setLineSpacing(lineSpacing: 2.0) . // try values 1.0 to 5.0
// or try lineHeightMultiple
//label.setLineSpacing(lineHeightMultiple = 2.0) // try values 0.5 to 2.0
Or using label instance (Just copy & execute this code to see result)
let label = UILabel()
let stringValue = "How\nto\nadjust\na\nUILabel\nline\nspacing\nprogrammatically\nin\nSwift"
let attrString = NSMutableAttributedString(string: stringValue)
var style = NSMutableParagraphStyle()
style.lineSpacing = 24 // change line spacing between paragraph like 36 or 48
style.minimumLineHeight = 20 // change line spacing between each line like 30 or 40
// Line spacing attribute
attrString.addAttribute(NSAttributedStringKey.paragraphStyle, value: style, range: NSRange(location: 0, length: stringValue.characters.count))
// Character spacing attribute
attrString.addAttribute(NSAttributedStringKey.kern, value: 2, range: NSMakeRange(0, attrString.length))
label.attributedText = attrString
Swift 3
let label = UILabel()
let stringValue = "How to\ncontrol\nthe\nline spacing\nin UILabel"
let attrString = NSMutableAttributedString(string: stringValue)
var style = NSMutableParagraphStyle()
style.lineSpacing = 24 // change line spacing between paragraph like 36 or 48
style.minimumLineHeight = 20 // change line spacing between each line like 30 or 40
attrString.addAttribute(NSParagraphStyleAttributeName, value: style, range: NSRange(location: 0, length: stringValue.characters.count))
label.attributedText = attrString
From Interface Builder:
You're on the right track with NSAttributedString. You need to set the line spacing of the paragraph style:
let paragraphStyle = NSMutableParagraphStyle()
paragraphStyle.lineSpacing = 30 // Whatever line spacing you want in points
attributedString.addAttribute(NSParagraphStyleAttributeName, value:paragraphStyle, range:NSMakeRange(0, attributedString.length))
label.attributedText = attributedString;
Do this in the storyboard.....
func updateLabel(with title: String) {
let paragraphStyle = NSMutableParagraphStyle()
paragraphStyle.lineHeightMultiple = 0.8
paragraphStyle.alignment = .center
let string = NSAttributedString(string: title, attributes: [.paragraphStyle: paragraphStyle])
label.attributedText = string
}

centering text in a UILabel with an NSAttributedString

Going through some basic improvements to a application I am working on. Still new to the iOS swift development scene. I figured that the lines of text in my code would automatically be centered because I set the label to center. After a little bit of research I discovered this is not the case. How would I align code like this to center:
let atrString = try NSAttributedString(
data: assetDetails!.cardDescription.dataUsingEncoding(NSUTF8StringEncoding)!,
options: [NSDocumentTypeDocumentAttribute:NSHTMLTextDocumentType],
documentAttributes: nil)
assetDescription.attributedText = atrString
You need to create a paragraph style specifying center alignment, and set that paragraph style as an attribute on your text. Example playground:
import UIKit
import PlaygroundSupport
let style = NSMutableParagraphStyle()
style.alignment = NSTextAlignment.center
let richText = NSMutableAttributedString(string: "Going through some basic improvements to a application I am working on. Still new to the iOS swift development scene. I figured that the lines of text in my code would automatically be centered because I set the label to center.",
attributes: [ NSParagraphStyleAttributeName: style ])
// In Swift 4, use `.paragraphStyle` instead of `NSParagraphStyleAttributeName`.
let label = UILabel(frame: CGRect(x: 0, y: 0, width: 200, height: 400))
label.backgroundColor = UIColor.white
label.attributedText = richText
label.numberOfLines = 0
PlaygroundPage.current.liveView = label
Result:
Since you're parsing an HTML document to create your attributed string, you'll need to add the attribute after creation, like this:
let style = NSMutableParagraphStyle()
style.alignment = NSTextAlignment.center
let richText = try NSMutableAttributedString(
data: assetDetails!.cardDescription.data(using: String.Encoding.utf8)!,
options: [NSDocumentTypeDocumentAttribute:NSHTMLTextDocumentType],
documentAttributes: nil)
richText.addAttributes([ NSParagraphStyleAttributeName: style ],
range: NSMakeRange(0, richText.length))
// In Swift 4, use `.paragraphStyle` instead of `NSParagraphStyleAttributeName`.
assetDescription.attributedText = richText
Update for Swift 4
In Swift 4, attribute names are now of type NSAttributeStringKey and the standard attribute names are static members of that type. So you can add the attribute like this:
richText.addAttribute(.paragraphStyle, value: style, range: NSMakeRange(0, richText.length))
In Swift 4.1 :
let style = NSMutableParagraphStyle()
style.alignment = NSTextAlignment.center
lbl.centerAttributedText = NSAttributedString(string: "Total Balance",attributes: [.paragraphStyle: style])
(edited for code block)
You can use this utility function to do all common configuration for label
#discardableResult
public func DULabel(text: String, frame: CGRect = .zero, parent:UIView? = nil , font:UIFont, textColor:UIColor = .black, numOfLines:Int = 0 ,textAlignment: NSTextAlignment = .center,lineSpaceing:CGFloat = 0, cb: ((UILabel)->Void)? = nil )-> UILabel! {
let label = UILabel()
label.frame = frame
label.font = font
label.textColor = textColor
label.textAlignment = textAlignment
label.numberOfLines = numOfLines
if( lineSpaceing == 0 ){
label.text = text
}
else {
let paragraphStyle = NSMutableParagraphStyle()
paragraphStyle.lineSpacing = lineSpaceing
paragraphStyle.alignment = textAlignment
let attrString = NSMutableAttributedString(string: text)
attrString.addAttribute(.paragraphStyle, value:paragraphStyle, range:NSMakeRange(0, attrString.length))
label.attributedText = attrString
}
if let parent = parent {
parent.addSubview(label)
}
cb?(label)
return label
}

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