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I am trying to allow the user to rotate text they place on a view inside UITextViews. The problem is when I rotate them using the transform property, the text gets cutoff. However, when I do this with UILabels, it works fine, so why not UITextViews? The bounds of UITextView (shown in green) never changes, so I am not sure why this is happening. The amount of cutoff seems related to the height of the text view.
The only work around I've found is to do the transform asynchronously. I don't know why it works, but I don't think it's a good solution. You can see this in action with the following code.
import UIKit
class ViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
for xPos in stride(from: 80, to: view.bounds.width, by: 80) {
let point = CGPoint(x: xPos, y: 100)
let textView = makeTextView(at: point)
//DispatchQueue.main.async {
let angle = xPos / 400.0
textView.transform = CGAffineTransform(rotationAngle: angle)
//}
view.addSubview(textView)
}
}
private func makeTextView(at point: CGPoint) -> UITextView {
let textView = UITextView()
textView.text = "1234567890"
textView.isScrollEnabled = false
textView.backgroundColor = .green
textView.center = CGPoint(x: point.x, y: point.y)
textView.bounds.size = CGSize(width: 80, height: 24)
return textView
}
}
What is the correct way to rotate them?
I have a question regarding rounded corners and text background color for a custom UIView.
Basically, I need to achieve an effect like this (image attached - notice the rounded corners on one side) in a custom UIView:
I'm thinking the approach to use is:
Use Core Text to get glyph runs.
Check highlight range.
If the current run is within the highlight range, draw a background rectangle with rounded corners and desired fill color before drawing the glyph run.
Draw the glyph run.
However, I'm not sure whether this is the only solution (or for that matter, whether this is the most efficient solution).
Using a UIWebView is not an option, so I have to do it in a custom UIView.
My question being, is this the best approach to use, and am I on the right track? Or am I missing out something important or going about it the wrong way?
TL;DR; Create a custom-view, which renders same old NSAttributedString, but with rounded-corners.
Unlike Android's SpannableString, iOS does not support "custom-render for custom-string-attributes", at least not without an entire custom-view (at time of writing, 2022).
I managed to achieve the above effect, so thought I'd post an answer for the same.
If anyone has any suggestions about making this more effective, please feel free to contribute. I'll be sure to mark your answer as the correct one. :)
For doing this, you'll need to add a "custom attribute" to NSAttributedString.
Basically, what that means is that you can add any key-value pair, as long as it is something that you can add to an NSDictionary instance. If the system does not recognize that attribute, it does nothing. It is up to you, as the developer, to provide a custom implementation and behavior for that attribute.
For the purposes of this answer, let us assume I've added a custom attribute called: #"MyRoundedBackgroundColor" with a value of [UIColor greenColor].
For the steps that follow, you'll need to have a basic understanding of how CoreText gets stuff done. Check out Apple's Core Text Programming Guide for understanding what's a frame/line/glyph run/glyph, etc.
So, here are the steps:
Create a custom UIView subclass.
Have a property for accepting an NSAttributedString.
Create a CTFramesetter using that NSAttributedString instance.
Override the drawRect: method
Create a CTFrame instance from the CTFramesetter.
You will need to give a CGPathRef to create the CTFrame. Make that CGPath to be the same as the frame in which you wish to draw the text.
Get the current graphics context and flip the text coordinate system.
Using CTFrameGetLines(...), get all the lines in the CTFrame you just created.
Using CTFrameGetLineOrigins(...), get all the line origins for the CTFrame.
Start a for loop - for each line in the array of CTLine...
Set the text position to the start of the CTLine using CGContextSetTextPosition(...).
Using CTLineGetGlyphRuns(...) get all the Glyph Runs (CTRunRef) from the CTLine.
Start another for loop - for each glyphRun in the array of CTRun...
Get the range of the run using CTRunGetStringRange(...).
Get typographic bounds using CTRunGetTypographicBounds(...).
Get the x offset for the run using CTLineGetOffsetForStringIndex(...).
Calculate the bounding rect (let's call it runBounds) using the values returned from the aforementioned functions.
Remember - CTRunGetTypographicBounds(...) requires pointers to variables to store the "ascent" and "descent" of the text. You need to add those to get the run height.
Get the attributes for the run using CTRunGetAttributes(...).
Check if the attribute dictionary contains your attribute.
If your attribute exists, calculate the bounds of the rectangle that needs to be painted.
Core text has the line origins at the baseline. We need to draw from the lowermost point of the text to the topmost point. Thus, we need to adjust for descent.
So, subtract the descent from the bounding rect that we calculated in step 16 (runBounds).
Now that we have the runBounds, we know what area we want to paint - now we can use any of the CoreGraphis/UIBezierPath methods to draw and fill a rect with specific rounded corners.
UIBezierPath has a convenience class method called bezierPathWithRoundedRect:byRoundingCorners:cornerRadii: that let's you round specific corners. You specify the corners using bit masks in the 2nd parameter.
Now that you've filled the rect, simply draw the glyph run using CTRunDraw(...).
Celebrate victory for having created your custom attribute - drink a beer or something! :D
Regarding detecting that the attribute range extends over multiple runs, you can get the entire effective range of your custom attribute when the 1st run encounters the attribute. If you find that the length of the maximum effective range of your attribute is greater than the length of your run, you need to paint sharp corners on the right side (for a left to right script). More math will let you detect the highlight corner style for the next line as well. :)
Attached is a screenshot of the effect. The box on the top is a standard UITextView, for which I've set the attributedText. The box on the bottom is the one that has been implemented using the above steps. The same attributed string has been set for both the textViews.
Again, if there is a better approach than the one that I've used, please do let me know! :D
Hope this helps the community. :)
Cheers!
Just customize NSLayoutManager and override drawUnderline(forGlyphRange:underlineType:baselineOffset:lineFragmentRect:lineFragmentGlyphRange:containerOrigin:) Apple API Document
In this method, you can draw underline by yourself, Swift code,
override func drawUnderline(forGlyphRange glyphRange: NSRange,
underlineType underlineVal: NSUnderlineStyle,
baselineOffset: CGFloat,
lineFragmentRect lineRect: CGRect,
lineFragmentGlyphRange lineGlyphRange: NSRange,
containerOrigin: CGPoint
) {
let firstPosition = location(forGlyphAt: glyphRange.location).x
let lastPosition: CGFloat
if NSMaxRange(glyphRange) < NSMaxRange(lineGlyphRange) {
lastPosition = location(forGlyphAt: NSMaxRange(glyphRange)).x
} else {
lastPosition = lineFragmentUsedRect(
forGlyphAt: NSMaxRange(glyphRange) - 1,
effectiveRange: nil).size.width
}
var lineRect = lineRect
let height = lineRect.size.height * 3.5 / 4.0 // replace your under line height
lineRect.origin.x += firstPosition
lineRect.size.width = lastPosition - firstPosition
lineRect.size.height = height
lineRect.origin.x += containerOrigin.x
lineRect.origin.y += containerOrigin.y
lineRect = lineRect.integral.insetBy(dx: 0.5, dy: 0.5)
let path = UIBezierPath(rect: lineRect)
// let path = UIBezierPath(roundedRect: lineRect, cornerRadius: 3)
// set your cornerRadius
path.fill()
}
Then construct your NSAttributedString and add attributes .underlineStyle and .underlineColor.
addAttributes(
[
.foregroundColor: UIColor.white,
.underlineStyle: NSUnderlineStyle.single.rawValue,
.underlineColor: UIColor(red: 51 / 255.0, green: 154 / 255.0, blue: 1.0, alpha: 1.0)
],
range: range
)
That's it!
I did it by checking frames of text fragments. In my project I needed to highlight hashtags while a user is typing text.
class HashtagTextView: UITextView {
let hashtagRegex = "#[-_0-9A-Za-z]+"
private var cachedFrames: [CGRect] = []
private var backgrounds: [UIView] = []
override init(frame: CGRect, textContainer: NSTextContainer?) {
super.init(frame: frame, textContainer: textContainer)
configureView()
}
required init?(coder: NSCoder) {
super.init(coder: coder)
configureView()
}
override func layoutSubviews() {
super.layoutSubviews()
// Redraw highlighted parts if frame is changed
textUpdated()
}
deinit {
NotificationCenter.default.removeObserver(self)
}
#objc private func textUpdated() {
// You can provide whatever ranges needed to be highlighted
let ranges = resolveHighlightedRanges()
let frames = ranges.compactMap { frame(ofRange: $0) }.reduce([], +)
if cachedFrames != frames {
cachedFrames = frames
backgrounds.forEach { $0.removeFromSuperview() }
backgrounds = cachedFrames.map { frame in
let background = UIView()
background.backgroundColor = UIColor.hashtagBackground
background.frame = frame
background.layer.cornerRadius = 5
insertSubview(background, at: 0)
return background
}
}
}
/// General setup
private func configureView() {
NotificationCenter.default.addObserver(self, selector: #selector(textUpdated), name: UITextView.textDidChangeNotification, object: self)
}
/// Looks for locations of the string to be highlighted.
/// The current case - ranges of hashtags.
private func resolveHighlightedRanges() -> [NSRange] {
guard text != nil, let regex = try? NSRegularExpression(pattern: hashtagRegex, options: []) else { return [] }
let matches = regex.matches(in: text, options: [], range: NSRange(text.startIndex..<text.endIndex, in: text))
let ranges = matches.map { $0.range }
return ranges
}
}
There is also a helper extension to determine frames of ranges:
extension UITextView {
func convertRange(_ range: NSRange) -> UITextRange? {
let beginning = beginningOfDocument
if let start = position(from: beginning, offset: range.location), let end = position(from: start, offset: range.length) {
let resultRange = textRange(from: start, to: end)
return resultRange
} else {
return nil
}
}
func frame(ofRange range: NSRange) -> [CGRect]? {
if let textRange = convertRange(range) {
let rects = selectionRects(for: textRange)
return rects.map { $0.rect }
} else {
return nil
}
}
}
Result text view:
I wrote the below code following the #codeBearer answer.
import UIKit
class CustomAttributedTextView: UITextView {
override func layoutSubviews() {
super.layoutSubviews()
}
func clearForReuse() {
setNeedsDisplay()
}
var lineCountUpdate: ((Bool) -> Void)?
override func draw(_ rect: CGRect) {
super.draw(rect)
UIColor.clear.setFill()
UIColor.clear.setFill()
guard let context = UIGraphicsGetCurrentContext() else { return }
context.textMatrix = .identity
context.translateBy(x: 0, y: bounds.size.height)
context.scaleBy(x: 1.0, y: -1.0)
let path = CGMutablePath()
let size = sizeThatFits(CGSize(width: self.frame.width, height: .greatestFiniteMagnitude))
path.addRect(CGRect(x: 0, y: 0, width: size.width, height: size.height), transform: .identity)
let framesetter = CTFramesetterCreateWithAttributedString(attributedText as CFAttributedString)
let frame: CTFrame = CTFramesetterCreateFrame(framesetter, CFRangeMake(0, attributedText.length), path, nil)
let lines: [CTLine] = frame.lines
var origins = [CGPoint](repeating: .zero, count: lines.count)
CTFrameGetLineOrigins(frame, CFRangeMake(0, 0), &origins)
for lineIndex in 0..<lines.count {
let line = lines[lineIndex]
let runs: [CTRun] = line.ctruns
var tagCountInOneLine = 0
for run in runs {
var cornerRadius: CGFloat = 3
let attributes: NSDictionary = CTRunGetAttributes(run)
var imgBounds: CGRect = .zero
if let value: UIColor = attributes.value(forKey: NSAttributedString.Key.customBackgroundColor.rawValue) as? UIColor {
var ascent: CGFloat = 0
imgBounds.size.width = CGFloat(CTRunGetTypographicBounds(run, CFRangeMake(0, 0), &ascent, nil, nil) + 4)
imgBounds.size.height = ascent + 6
let xOffset = CTLineGetOffsetForStringIndex(line, CTRunGetStringRange(run).location, nil)
imgBounds.origin.x = origins[lineIndex].x + xOffset + 3
imgBounds.origin.y = origins[lineIndex].y - 13
if lineIndex != 0 {
imgBounds.origin.y = imgBounds.origin.y - 1
}
let path = UIBezierPath(roundedRect: imgBounds, cornerRadius: cornerRadius)
value.setFill()
path.fill()
value.setStroke()
}
}
}
}
}
extension CTFrame {
var lines: [CTLine] {
let linesAO: [AnyObject] = CTFrameGetLines(self) as [AnyObject]
guard let lines = linesAO as? [CTLine] else {
return []
}
return lines
}
}
extension CTLine {
var ctruns: [CTRun] {
let linesAO: [AnyObject] = CTLineGetGlyphRuns(self) as [AnyObject]
guard let lines = linesAO as? [CTRun] else {
return []
}
return lines
}
}
I want cursor at specific position.
I show my requirement in image.
let arbitraryValue: Int = 5
if let newPosition = txtroutine.position(from: txtroutine.beginningOfDocument, offset: arbitraryValue) {
txtroutine.selectedTextRange = txtroutine.textRange(from: newPosition, to: newPosition)
}
I have something like this but my code is in obj-c hope you can make it in swift,
Get the current position of cursor
- (NSInteger)cursorPosition
{
UITextRange *selectedRange = self.selectedTextRange;
UITextPosition *textPosition = selectedRange.start;
return [self offsetFromPosition:self.beginningOfDocument toPosition:textPosition];
}
// set cursor at your specfic location
- (void)setCursorPosition:(NSInteger)position
{
UITextPosition *textPosition = [self positionFromPosition:self.beginningOfDocument offset:position];
[self setSelectedTextRange:[self textRangeFromPosition:textPosition toPosition:textPosition]];
}
You can achieve this by overriding -textRectForBounds:. It will only change the inset of text i.e in your case it's cursor.
You need to subclass UITextField for that.
class PaddedTextfield: UITextField {
var horizontalInsetValue: CGFloat = 0
var verticalInsetValue: CGFloat = 0
override func textRect(forBounds bounds: CGRect) -> CGRect {
return bounds.insetBy(dx: horizontalInsetValue, dy: verticalInsetValue)
}
override func editingRect(forBounds bounds: CGRect) -> CGRect {
return bounds.insetBy(dx: horizontalInsetValue , dy: verticalInsetValue)
}
override func placeholderRect(forBounds bounds: CGRect) -> CGRect {
return bounds.insetBy(dx: horizontalInsetValue, dy: verticalInsetValue)
}
}
You can use this textfield wherever you want.
you can use leftView property of UITextField to set position as per your requirement :
//add a 12pt padding to the textField
Swift 3.0 :
textField.leftView = UIView(frame: CGRect(x: 0, y: 0, width: 12, height: 0))
textField.leftViewMode = .always
Try this , feel free to comment .
my problem is solved by adding this simple line in viewdidload()
self.txtroutine.layer.sublayerTransform = CATransform3DMakeTranslation(15, 0, 0);
Below is an image of some UITextFields. Regarding the large one on the bottom, how do I get it to start text at the top left (not the middle), and how do I get them all to start a bit to the right. As you can see, they are awkwardly close to the left edge.
For textField, override following methods:
class InsetTextField: UITextField {
var inset: CGFloat = 10
override func textRect(forBounds bounds: CGRect) -> CGRect {
return bounds.insetBy(dx: inset, dy: 0)
}
override func editingRect(forBounds bounds: CGRect) -> CGRect {
return bounds.insetBy(dx: inset, dy: 0)
}
override func placeholderRect(forBounds bounds: CGRect) -> CGRect {
return bounds.insetBy(dx: inset, dy: 0)
}
}
For textView:
textView.contentInset = UIEdgeInsetsMake(inset, inset, inset, inset);
And you can be involved when the textView is done editing, check out this question.
You can sublcass to a custom TextField:
import UIKit
class CustomTextField: UITextField {
var inset:CGFloat = 12 // You can set the inset you want
override func textRect(forBounds bounds: CGRect) -> CGRect {
return bounds.insetBy(dx: inset, dy: 0)
}
override func editingRect(forBounds bounds: CGRect) -> CGRect {
return bounds.insetBy(dx: inset, dy: 0)
}
}
The result, you can see the inset of the CustomTextField:
Edit
By default, UITextFields only have one line. Based off your image, I'd assume you want the user to have space to type a paragraph. For paragraphs, it is better to use UITextViews. It'd be a simpler solution for your problem.
I always use TextViews for biographies because it just makes my life much easier.
add left padding of your textfield
let paddingVie = UIView(frame: CGRect(x: 0, y:0, width: 10, height: 10))
yourtextField.leftView = paddingVie
yourtextField.leftViewMode = .always
for textview add
yourTextVieName.textContainerInset =
UIEdgeInsetsMake(8,5,8,5); // top, left, bottom, right
I have a question regarding rounded corners and text background color for a custom UIView.
Basically, I need to achieve an effect like this (image attached - notice the rounded corners on one side) in a custom UIView:
I'm thinking the approach to use is:
Use Core Text to get glyph runs.
Check highlight range.
If the current run is within the highlight range, draw a background rectangle with rounded corners and desired fill color before drawing the glyph run.
Draw the glyph run.
However, I'm not sure whether this is the only solution (or for that matter, whether this is the most efficient solution).
Using a UIWebView is not an option, so I have to do it in a custom UIView.
My question being, is this the best approach to use, and am I on the right track? Or am I missing out something important or going about it the wrong way?
TL;DR; Create a custom-view, which renders same old NSAttributedString, but with rounded-corners.
Unlike Android's SpannableString, iOS does not support "custom-render for custom-string-attributes", at least not without an entire custom-view (at time of writing, 2022).
I managed to achieve the above effect, so thought I'd post an answer for the same.
If anyone has any suggestions about making this more effective, please feel free to contribute. I'll be sure to mark your answer as the correct one. :)
For doing this, you'll need to add a "custom attribute" to NSAttributedString.
Basically, what that means is that you can add any key-value pair, as long as it is something that you can add to an NSDictionary instance. If the system does not recognize that attribute, it does nothing. It is up to you, as the developer, to provide a custom implementation and behavior for that attribute.
For the purposes of this answer, let us assume I've added a custom attribute called: #"MyRoundedBackgroundColor" with a value of [UIColor greenColor].
For the steps that follow, you'll need to have a basic understanding of how CoreText gets stuff done. Check out Apple's Core Text Programming Guide for understanding what's a frame/line/glyph run/glyph, etc.
So, here are the steps:
Create a custom UIView subclass.
Have a property for accepting an NSAttributedString.
Create a CTFramesetter using that NSAttributedString instance.
Override the drawRect: method
Create a CTFrame instance from the CTFramesetter.
You will need to give a CGPathRef to create the CTFrame. Make that CGPath to be the same as the frame in which you wish to draw the text.
Get the current graphics context and flip the text coordinate system.
Using CTFrameGetLines(...), get all the lines in the CTFrame you just created.
Using CTFrameGetLineOrigins(...), get all the line origins for the CTFrame.
Start a for loop - for each line in the array of CTLine...
Set the text position to the start of the CTLine using CGContextSetTextPosition(...).
Using CTLineGetGlyphRuns(...) get all the Glyph Runs (CTRunRef) from the CTLine.
Start another for loop - for each glyphRun in the array of CTRun...
Get the range of the run using CTRunGetStringRange(...).
Get typographic bounds using CTRunGetTypographicBounds(...).
Get the x offset for the run using CTLineGetOffsetForStringIndex(...).
Calculate the bounding rect (let's call it runBounds) using the values returned from the aforementioned functions.
Remember - CTRunGetTypographicBounds(...) requires pointers to variables to store the "ascent" and "descent" of the text. You need to add those to get the run height.
Get the attributes for the run using CTRunGetAttributes(...).
Check if the attribute dictionary contains your attribute.
If your attribute exists, calculate the bounds of the rectangle that needs to be painted.
Core text has the line origins at the baseline. We need to draw from the lowermost point of the text to the topmost point. Thus, we need to adjust for descent.
So, subtract the descent from the bounding rect that we calculated in step 16 (runBounds).
Now that we have the runBounds, we know what area we want to paint - now we can use any of the CoreGraphis/UIBezierPath methods to draw and fill a rect with specific rounded corners.
UIBezierPath has a convenience class method called bezierPathWithRoundedRect:byRoundingCorners:cornerRadii: that let's you round specific corners. You specify the corners using bit masks in the 2nd parameter.
Now that you've filled the rect, simply draw the glyph run using CTRunDraw(...).
Celebrate victory for having created your custom attribute - drink a beer or something! :D
Regarding detecting that the attribute range extends over multiple runs, you can get the entire effective range of your custom attribute when the 1st run encounters the attribute. If you find that the length of the maximum effective range of your attribute is greater than the length of your run, you need to paint sharp corners on the right side (for a left to right script). More math will let you detect the highlight corner style for the next line as well. :)
Attached is a screenshot of the effect. The box on the top is a standard UITextView, for which I've set the attributedText. The box on the bottom is the one that has been implemented using the above steps. The same attributed string has been set for both the textViews.
Again, if there is a better approach than the one that I've used, please do let me know! :D
Hope this helps the community. :)
Cheers!
Just customize NSLayoutManager and override drawUnderline(forGlyphRange:underlineType:baselineOffset:lineFragmentRect:lineFragmentGlyphRange:containerOrigin:) Apple API Document
In this method, you can draw underline by yourself, Swift code,
override func drawUnderline(forGlyphRange glyphRange: NSRange,
underlineType underlineVal: NSUnderlineStyle,
baselineOffset: CGFloat,
lineFragmentRect lineRect: CGRect,
lineFragmentGlyphRange lineGlyphRange: NSRange,
containerOrigin: CGPoint
) {
let firstPosition = location(forGlyphAt: glyphRange.location).x
let lastPosition: CGFloat
if NSMaxRange(glyphRange) < NSMaxRange(lineGlyphRange) {
lastPosition = location(forGlyphAt: NSMaxRange(glyphRange)).x
} else {
lastPosition = lineFragmentUsedRect(
forGlyphAt: NSMaxRange(glyphRange) - 1,
effectiveRange: nil).size.width
}
var lineRect = lineRect
let height = lineRect.size.height * 3.5 / 4.0 // replace your under line height
lineRect.origin.x += firstPosition
lineRect.size.width = lastPosition - firstPosition
lineRect.size.height = height
lineRect.origin.x += containerOrigin.x
lineRect.origin.y += containerOrigin.y
lineRect = lineRect.integral.insetBy(dx: 0.5, dy: 0.5)
let path = UIBezierPath(rect: lineRect)
// let path = UIBezierPath(roundedRect: lineRect, cornerRadius: 3)
// set your cornerRadius
path.fill()
}
Then construct your NSAttributedString and add attributes .underlineStyle and .underlineColor.
addAttributes(
[
.foregroundColor: UIColor.white,
.underlineStyle: NSUnderlineStyle.single.rawValue,
.underlineColor: UIColor(red: 51 / 255.0, green: 154 / 255.0, blue: 1.0, alpha: 1.0)
],
range: range
)
That's it!
I did it by checking frames of text fragments. In my project I needed to highlight hashtags while a user is typing text.
class HashtagTextView: UITextView {
let hashtagRegex = "#[-_0-9A-Za-z]+"
private var cachedFrames: [CGRect] = []
private var backgrounds: [UIView] = []
override init(frame: CGRect, textContainer: NSTextContainer?) {
super.init(frame: frame, textContainer: textContainer)
configureView()
}
required init?(coder: NSCoder) {
super.init(coder: coder)
configureView()
}
override func layoutSubviews() {
super.layoutSubviews()
// Redraw highlighted parts if frame is changed
textUpdated()
}
deinit {
NotificationCenter.default.removeObserver(self)
}
#objc private func textUpdated() {
// You can provide whatever ranges needed to be highlighted
let ranges = resolveHighlightedRanges()
let frames = ranges.compactMap { frame(ofRange: $0) }.reduce([], +)
if cachedFrames != frames {
cachedFrames = frames
backgrounds.forEach { $0.removeFromSuperview() }
backgrounds = cachedFrames.map { frame in
let background = UIView()
background.backgroundColor = UIColor.hashtagBackground
background.frame = frame
background.layer.cornerRadius = 5
insertSubview(background, at: 0)
return background
}
}
}
/// General setup
private func configureView() {
NotificationCenter.default.addObserver(self, selector: #selector(textUpdated), name: UITextView.textDidChangeNotification, object: self)
}
/// Looks for locations of the string to be highlighted.
/// The current case - ranges of hashtags.
private func resolveHighlightedRanges() -> [NSRange] {
guard text != nil, let regex = try? NSRegularExpression(pattern: hashtagRegex, options: []) else { return [] }
let matches = regex.matches(in: text, options: [], range: NSRange(text.startIndex..<text.endIndex, in: text))
let ranges = matches.map { $0.range }
return ranges
}
}
There is also a helper extension to determine frames of ranges:
extension UITextView {
func convertRange(_ range: NSRange) -> UITextRange? {
let beginning = beginningOfDocument
if let start = position(from: beginning, offset: range.location), let end = position(from: start, offset: range.length) {
let resultRange = textRange(from: start, to: end)
return resultRange
} else {
return nil
}
}
func frame(ofRange range: NSRange) -> [CGRect]? {
if let textRange = convertRange(range) {
let rects = selectionRects(for: textRange)
return rects.map { $0.rect }
} else {
return nil
}
}
}
Result text view:
I wrote the below code following the #codeBearer answer.
import UIKit
class CustomAttributedTextView: UITextView {
override func layoutSubviews() {
super.layoutSubviews()
}
func clearForReuse() {
setNeedsDisplay()
}
var lineCountUpdate: ((Bool) -> Void)?
override func draw(_ rect: CGRect) {
super.draw(rect)
UIColor.clear.setFill()
UIColor.clear.setFill()
guard let context = UIGraphicsGetCurrentContext() else { return }
context.textMatrix = .identity
context.translateBy(x: 0, y: bounds.size.height)
context.scaleBy(x: 1.0, y: -1.0)
let path = CGMutablePath()
let size = sizeThatFits(CGSize(width: self.frame.width, height: .greatestFiniteMagnitude))
path.addRect(CGRect(x: 0, y: 0, width: size.width, height: size.height), transform: .identity)
let framesetter = CTFramesetterCreateWithAttributedString(attributedText as CFAttributedString)
let frame: CTFrame = CTFramesetterCreateFrame(framesetter, CFRangeMake(0, attributedText.length), path, nil)
let lines: [CTLine] = frame.lines
var origins = [CGPoint](repeating: .zero, count: lines.count)
CTFrameGetLineOrigins(frame, CFRangeMake(0, 0), &origins)
for lineIndex in 0..<lines.count {
let line = lines[lineIndex]
let runs: [CTRun] = line.ctruns
var tagCountInOneLine = 0
for run in runs {
var cornerRadius: CGFloat = 3
let attributes: NSDictionary = CTRunGetAttributes(run)
var imgBounds: CGRect = .zero
if let value: UIColor = attributes.value(forKey: NSAttributedString.Key.customBackgroundColor.rawValue) as? UIColor {
var ascent: CGFloat = 0
imgBounds.size.width = CGFloat(CTRunGetTypographicBounds(run, CFRangeMake(0, 0), &ascent, nil, nil) + 4)
imgBounds.size.height = ascent + 6
let xOffset = CTLineGetOffsetForStringIndex(line, CTRunGetStringRange(run).location, nil)
imgBounds.origin.x = origins[lineIndex].x + xOffset + 3
imgBounds.origin.y = origins[lineIndex].y - 13
if lineIndex != 0 {
imgBounds.origin.y = imgBounds.origin.y - 1
}
let path = UIBezierPath(roundedRect: imgBounds, cornerRadius: cornerRadius)
value.setFill()
path.fill()
value.setStroke()
}
}
}
}
}
extension CTFrame {
var lines: [CTLine] {
let linesAO: [AnyObject] = CTFrameGetLines(self) as [AnyObject]
guard let lines = linesAO as? [CTLine] else {
return []
}
return lines
}
}
extension CTLine {
var ctruns: [CTRun] {
let linesAO: [AnyObject] = CTLineGetGlyphRuns(self) as [AnyObject]
guard let lines = linesAO as? [CTRun] else {
return []
}
return lines
}
}