UITextView exclusionPaths bottom right - ios

Question

I am trying to do something whatsapp like for messages for having a cell that resizes based on contentsize and in the bottom right corner to have the date... the problem is that I don't know the rectangle position for the excluded path because the text is dynamic and I have something like this but works only for multiple lines, but not for a single line:
NSString *txt=#"I'm writing ";//a text renderer using Core Text, and I discovered I’ll need to wrap text around objects (such as is done in any DTP program). I couldn’t find any easy answers as to how to do this in the documentation, so having finally got it working I’ll share what I did. To lay out text in a custom shape in Core Text, you can pass a CGPath in when you create your CTFramesetterRef. Originally this only supported rectangular paths, but now it supports fully custom paths. My first thought was to see if I could subtract the region to wrap around from the path for my frame’s border, and pass the result in to Core Text as a path. It turns out firstly that subtracting one path from another in Core Graphics is not trivial. However, if you simply add two shapes to the same path, Core Graphics can use a winding rule to work out which areas to draw. Core Text, at least as of iOS 4.2, can also use this kind of algorithm. This will work for many cases: if you can guarantee that your object to be wrapped will be fully inside the frame (and not overlapping the edge), just go ahead and add its border to the same path as your frame, and Core"; // Text will do the rest.";
txtText.text=txt;
CGSize textFrame = [txtText sizeThatFits:CGSizeMake(235, MAXFLOAT)];
UIBezierPath * imgRect = [UIBezierPath bezierPathWithRect:CGRectMake(textFrame.width-35, textFrame.height-20, 35, 20)];
txtText.textContainer.exclusionPaths = #[imgRect];
textFrame = [txtText sizeThatFits:CGSizeMake(235, MAXFLOAT)];
//int frameWidth=375;
txtText.frame=CGRectIntegral(CGRectMake(10, 10, textFrame.width, textFrame.height));
lblHour.frame=CGRectIntegral(CGRectMake(textFrame.width-35, textFrame.height-15, 35, 20));
viewCanvasAround.frame=CGRectIntegral(CGRectMake(50, 100, textFrame.width+20, textFrame.height+20));

Answer 1

I had the same problem too. I added attributedString with textAttachment which it has a size. You will set an estimated maximum size. There's no problem with a single line either.
(Sorry, I am not good at English.)
This is the sample code.
var text: String! {
didSet {
let font = UIFont.systemFont(ofSize: 13);
let att = NSMutableAttributedString.init(string: text, attributes: [NSAttributedString.Key.foregroundColor : UIColor.black,
NSAttributedString.Key.font : font]);
let attachment = NSTextAttachment.init(data: nil, ofType: nil);
var size = extraSize;
size.height = font.lineHeight;
attachment.bounds = CGRect.init(origin: CGPoint.init(), size: size);
att.append(NSAttributedString.init(attachment: attachment));
textView.attributedText = att;
}
}

Answer 2

There is a nice solution my colleague found in actor.im. https://github.com/actorapp/actor-platform/blob/master/actor-sdk/sdk-core-ios/ActorSDK/Sources/Controllers/Content/Conversation/Cell/AABubbleTextCell.swift#L312
let container = YYTextContainer(size: CGSizeMake(maxTextWidth, CGFloat.max))
textLayout = YYTextLayout(container: container, text: attributedText)!
// print("Text Layouted")
// Measuring text and padded text heights
let textSize = textLayout.textBoundingSize
if textLayout.lines.count == 1 {
if textLayout.textBoundingSize.width < maxTextWidth - timeWidth {
//
// <line_0> <date>
//
bubbleSize = CGSize(width: textSize.width + timeWidth, height: textSize.height)
} else {
//
// <line_________0>
// <date>
//
bubbleSize = CGSize(width: textSize.width, height: textSize.height + 16)
}
} else {
let maxWidth = textSize.width
let lastLine = textLayout.lines.last!.width
if lastLine + timeWidth < maxWidth {
//
// <line_________0>
// <line_________1>
// ..
// <line_n> <date>
//
bubbleSize = textSize
} else if lastLine + timeWidth < maxTextWidth {
//
// |------------------|
// <line______0>
// <line______1>
// ..
// <line______n> <date>
//
bubbleSize = CGSize(width: max(lastLine + timeWidth, maxWidth), height: textSize.height)
} else {
//
// <line_________0>
// <line_________1>
// ..
// <line_________n>
// <date>
//
bubbleSize = CGSize(width: max(timeWidth, maxWidth), height: textSize.height + 16)
}
}

Answer 3

I had the same problem (for me it was a button in right corner) and there is the way how I resolved it:
- (void)viewWillLayoutSubviews {
[super viewWillLayoutSubviews];
[self updateTextExclusionPaths];
}
- (void)updateTextExclusionPaths {
// Remove old exclusionPaths to calculate right rects of new
textView.textContainer.exclusionPaths = #[];
// Force textView to layout the text without exclusionPaths
[textView.layoutManager glyphRangeForTextContainer:textView.textContainer];
/// Because of some specifics of my implementation I had a problem with wrong frame of my button. So I calculated it manually
// Calculate new exclusionPaths
CGRect buttonFrameInTextView = [superViewOfTextView convertRect:button.frame toView:textView];
// Calculate textView.text size without any exclusionPaths to calculate right button frame
CGSize textViewSize = [textView sizeThatFits:CGSizeMake(textView.frame.size.width, CGFLOAT_MAX)];
// Update Y position of button
buttonFrameInTextView.origin.y = size.height - buttonFrameInTextView.size.height;
// Add new exclusionPaths
UIBezierPath *buttonRectBezierPath = [UIBezierPath bezierPathWithRect:buttonFrameInTextView];
textView.textContainer.exclusionPaths = #[ buttonRectBezierPath ];
}