metatext/Views/UIKit/AnimatingLayoutManager.swift
2021-02-22 18:51:31 -08:00

46 lines
1.5 KiB
Swift

// Copyright © 2021 Metabolist. All rights reserved.
import SDWebImage
import UIKit
final class AnimatingLayoutManager: NSLayoutManager {
weak var view: UIView?
override func drawGlyphs(forGlyphRange glyphsToShow: NSRange, at origin: CGPoint) {
guard let textStorage = textStorage else {
super.drawGlyphs(forGlyphRange: glyphsToShow, at: origin)
return
}
var attachmentImageViews = Set<SDAnimatedImageView>()
textStorage.enumerateAttribute(
.attachment,
in: NSRange(location: 0, length: textStorage.length)) { attachment, _, _ in
guard let animatedAttachment = attachment as? AnimatedTextAttachment,
let imageBounds = animatedAttachment.imageBounds
else { return }
animatedAttachment.imageView.frame = imageBounds
animatedAttachment.imageView.contentMode = .scaleAspectFit
if animatedAttachment.imageView.superview != view {
view?.addSubview(animatedAttachment.imageView)
}
attachmentImageViews.insert(animatedAttachment.imageView)
}
for subview in view?.subviews ?? [] {
guard let attachmentImageView = subview as? SDAnimatedImageView else { continue }
if !attachmentImageViews.contains(attachmentImageView) {
attachmentImageView.removeFromSuperview()
}
}
super.drawGlyphs(forGlyphRange: glyphsToShow, at: origin)
}
}