I have a NSAttributedString that was loaded from a RTF file, so it already holds several font-attributes for different ranges.
Now I want to adapt the font size to the screensize of the device, but when I add a whole new font attribute with a new size, the other fonts disappear.
Is there a way to change only the font size for the whole string?
If you only want to change the size of any given font found in the attributed string then you can do:
let newStr = someAttributedString.mutableCopy() as! NSMutableAttributedString
newStr.beginEditing()
newStr.enumerateAttribute(.font, in: NSRange(location: 0, length: newStr.string.utf16.count)) { (value, range, stop) in
if let oldFont = value as? UIFont {
let newFont = oldFont.withSize(20) // whatever size you need
newStr.addAttribute(.font, value: newFont, range: range)
}
}
newStr.endEditing()
print(newStr)
This will keep all other attributes in place.
If you want to replace all fonts in a given attributed string with a single font of a given size but keep all other attributes such as bold and italic, see:
NSAttributedString, change the font overall BUT keep all other attributes?
Related
I'm reading an existing PDF using PDFKit. I get an attributedString for a page, but the fonts in the string don't match the fonts actually in the PDF:
The fonts in the PDF (according to several different apps) are:
CourierFinalDraft (TypeType Roman) Embedded Subset
CourierFinalDraft-Bold (TrueType Roman) Embedded Subset
CourierFinalDraft-Italic (TrueType Roman) Embedded Subset
My Swift code to get the font is:
guard let page = pdf.page(at: pageNo) else { return }
guard let content = page.attributedString else { return }
content.enumerateAttributes(in: range, options:[]) {(dict: [String:Any], range: NSRange, stop: UnsafeMutablePointer<ObjCBool>) -> Void in
let font = dict[NSFontAttributeName] as! UIFont
}
All of the text is returned in a single range. The font returned has the following:
font-family: "Times New Roman"
font-name: "TimesNewRomanPSMT"
So the Bold and Italic text are returned in the same range as the normal text, and I can't distinguish among them, which is what I'm trying to do. As well as the font name I also look at:
font.fontDescriptor.symbolicTraits.contains(.traitItalic)
but of course this is always False as all text is returned in the same range as if it is normal.
This is using the XCode simulator, in case that's relevant. The PDF does render correctly (including bold and italics) on Safari in the Simulator. Unfortunately I can't try it out on a real iPhone.
This question is a few years old, but I found that I had to make a mutable copy of the data in order to interact with it and then use the information available to modify the underlying font and re-display it.
let str = content.mutableCopy() as! NSMutableAttributedString
str.beginEditing()
str.enumerateAttribute(.font,
in: NSRange(location: 0, length: str.length),
options: []) { value, range, _ in
guard let value = value as? UIFont else {
return
}
let isBold = value.fontDescriptor.symbolicTraits.contains(.traitBold)
let font = // Your font logic here based on traits
str.removeAttribute(.font, range: range)
str.addAttribute(.font, value: font, range: range)
str.addAttribute(.paragraphStyle, value: style, range: range)
}
str.endEditing()
I have not gone over performance issues on this yet for larger pdfs, but it does not seem to take up too many resources for pdfs between 10-20 pages. For a higher number of pages, I would most likely create an actual paging mechanism and then adjust for each page on the fly rather than loop the entire pdf file.
I have a UITextView, and I want to change its font size.
however, I want it to change relatively since it pulls from a file that has multiple font sizes in it and I want it to change accordingly.
for example, I have a word in font size 36 and one in font size 12 and I want to scale them by 0.75% to 27 and 9 respectively.
If I try:
textview.font = UIFont(name: textview.font.fontName, size: 20)
it will only change the entire UITextView font size.
thanks!
You can use this extension:
extension NSAttributedString {
#warn_unused_result
func scaleBy(scale: CGFloat) -> NSAttributedString {
let scaledAttributedString = NSMutableAttributedString(attributedString: self)
scaledAttributedString.enumerateAttribute(NSFontAttributeName, inRange: NSRange(location: 0, length: scaledAttributedString.length), options: NSAttributedStringEnumerationOptions(rawValue: 0)) { (value, range, _) in
if let oldFont = value as? UIFont {
let newFont = oldFont.fontWithSize(oldFont.pointSize * scale)
scaledAttributedString.removeAttribute(NSFontAttributeName, range: range)
scaledAttributedString.addAttribute(NSFontAttributeName, value: newFont, range: range)
}
}
return scaledAttributedString
}
}
Then just call something like:
textField.attributedText = textField.attributedText!.scaleBy(0.5)
Example:
You would have to write (or find) a parser for the rich text format file that could extract the font size data for each text element (I think this would be the \fsN tags in most cases) and then use that number (multiplied by 0.75) to set the size of each word or phrase individually. You could use an attributed string if the differently sized words need to be recombined into a single string, but that wouldn't be necessary if each word or phrase was in a separate label.
Personally, I would disregard the font sizes of the source data and impose a layout within the app that looks nice, if that's an option.
I have a UILabel in my storyboard, and I have an #IBOutlet to it in my controller. In my viewDidLoad, I am setting its attributed text with two different font sizes.
let str1 = NSMutableAttributedString(string: "first", attributes: [NSFontAttributeName: UIFont.systemFontOfSize(15.0)])
let str2 = NSMutableAttributedString(string: "second", attributes: [NSFontAttributeName: UIFont.systemFontOfSize(10.0)])
str1.appendAttributedString(str2)
myLabel.attributedText = str1
Unfortunately, when I run the app, I can see the "firstsecond" string, but all in the same size (str1's 15-point font). Why is str2's 10-point font not being set?
Thanks in advance.
You have to use addAttribute(...) to apply multiple attributes to the same string.
let first = "first"
let second = "second"
let string = NSMutableAttributedString(string: first + second)
string.addAttribute(NSFontAttributeName, value: UIFont.systemFontOfSize(15), range: NSMakeRange(0, first.characters.count))
string.addAttribute(NSFontAttributeName, value: UIFont.systemFontOfSize(10), range: NSMakeRange(first.characters.count, second.characters.count))
myLabel.attributedText = string
The documentation for UILabel's attributedText property states:
assigning a new value updates the values in the font, textColor, and
other style-related properties so that they reflect the style
information starting at location 0 in the attributed string.
So whatever the style information is at location 0, that's what the label's going to be. That's why you're only seeing str1's 15 point font.
I'm trying to apply two attributes to a string, one for kerning (NSKernAttributeName) and one for the font (NSFontAttributeName). Although I've checked and rechecked 1000 times, I can only get the kerning attribute to be applied to the string. Here's my setup:
let runAtTitle = "RUN AT"
var attRunAt = NSMutableAttributedString(string: runAtTitle)
let font = UIFont(name: "HelveticaNeue-Bold", size: 76.0)!
let attrs = [NSFontAttributeName: font, NSKernAttributeName: -3.0]
attRunAt.addAttributes(attrs, range: NSMakeRange(0, attRunAt.length))
runAtLabel.attributedText = attRunAt
When I build the app, the kerning is applied to my string, but the font is not. It uses the default 12pt Helvetica. Please tell me I'm doing something wrong.
I just tried your code in Playground and it works fine. Most likely you are setting the text attribute of the label after setting the attributedText. That will revert the string to the normal label string with its attributes, or perhaps for some strange reason keep the kern attribute.
Here is what I get with your code:
and after adding
label.text = "RUN AT"
I have a label where there is text which should be bold and with another font size. Is there any possibility to do it like the line break ("Hello \n World!") with a command or do I have to make another label for this?
Thanks!
Look at the API for NSAttributedString -- it allows you to create a string that specifies portions of the string that should be styled with specific text styles and/or fonts. The resulting object can be used instead of a plain string with UILabel (and other UI elements) by setting the label's attributedText property instead of the usual text property.
To make just the word "bold" appear in 18 point bold, try something like the following:
var label = UILabel()
let bigBoldFont = UIFont.boldSystemFontOfSize(18.0)
var attrString = NSMutableAttributedString(string: "This text is bold.")
attrString.addAttribute(kCTFontAttributeName, value: bigBoldFont, range: NSMakeRange(13, 4))
label.attributedText = attrString
The range specified determines the portion of the string to which the named attributed (in this case, the font) should be applied. And note that the parameters to NSMakeRange are the starting character position and the length of the range.