Two animated display components: TTBaseSkeletonMarkView — a simple shimmer placeholder for loading states, and TTBaseBorderTrailView — an animated gradient arc that races around a view's border (Motion-Primitives inspired).

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💀 TTBaseSkeletonMarkView

A TTBaseUIView subclass that sets its background to viewBgSkeleton with default corner radius. Drop it anywhere to indicate loading content.

// Over any view
let skeleton = TTBaseSkeletonMarkView()
imageView.addSubview(skeleton)
skeleton.setFullContraints(constant: 0)

// Remove when data loads
URLSession.shared.dataTask(with: url) { data, _, _ in
    DispatchQueue.main.async {
        UIView.animate(withDuration: 0.2) { skeleton.alpha = 0 }
        skeleton.removeFromSuperview()
        imageView.image = UIImage(data: data!)
    }
}.resume()

// Array of skeleton rows (list shimmer)
let skeletonViews: [TTBaseSkeletonMarkView] = (0..<5).map { _ in
    let v = TTBaseSkeletonMarkView()
    v.setHeightAnchor(constant: 60)
    return v
}
stackView.addArrangedSubviews(skeletonViews)

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✨ TTBaseBorderTrailView

An animated gradient border arc that loops endlessly around the view. Powered by CAGradientLayer (conic) + CAShapeLayer mask animations. Non-interactive — layer on top of any view.

// Default config: purple→blue→teal trail
let trail = TTBaseBorderTrailView()
containerView.addSubview(trail)
trail.setFullContraints(constant: 0)
trail.start()

// Custom config
let config = TTBaseBorderTrailView.Config(
    lineWidth: 3,
    cornerRadius: 20,
    trailLength: 0.15,  // 15% of perimeter
    duration: 1.8,
    colors: [.systemOrange, .systemPink, .systemPurple],
    glowOpacity: 0.5
)
let trail = TTBaseBorderTrailView(config: config)
buttonView.addSubview(trail)
trail.setFullContraints(constant: 0)
trail.start()

// Stop animation
trail.stop()

// Update config at runtime (auto restarts)
trail.config.colors = [.systemGreen, .systemTeal]

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📖 TTBaseBorderTrailView.Config

Property	Default	Description
lineWidth	2	Trail stroke width in points
cornerRadius	16	Must match container's corner radius
trailLength	0.12	Fraction of perimeter (0.01–0.95)
duration	2.4s	Time for one full revolution
colors	purple/blue/teal	Gradient color stops
glowOpacity	0.35	Layer shadow intensity (0 = off)