[WIP] Quotes and link previews

submodules/TelegramUI/Components/TextLoadingEffect/Sources/TextLoadingEffect.swift

@@ -0,0 +1,149 @@
+import Foundation
+import UIKit
+import Display
+import AppBundle
+import HierarchyTrackingLayer
+
+private let shadowImage: UIImage? = {
+    UIImage(named: "Stories/PanelGradient")
+}()
+
+public final class TextLoadingEffectView: UIView {
+    let hierarchyTrackingLayer: HierarchyTrackingLayer
+    
+    private let maskContentsView: UIView
+    private let maskHighlightNode: LinkHighlightingNode
+    
+    private let maskBorderContentsView: UIView
+    private let maskBorderHighlightNode: LinkHighlightingNode
+    
+    private let backgroundView: UIImageView
+    private let borderBackgroundView: UIImageView
+    
+    private let duration: Double
+    private let gradientWidth: CGFloat
+    
+    private var size: CGSize?
+    
+    override public init(frame: CGRect) {
+        self.hierarchyTrackingLayer = HierarchyTrackingLayer()
+        
+        self.maskContentsView = UIView()
+        self.maskHighlightNode = LinkHighlightingNode(color: .black)
+        self.maskHighlightNode.useModernPathCalculation = true
+        
+        self.maskBorderContentsView = UIView()
+        self.maskBorderHighlightNode = LinkHighlightingNode(color: .black)
+        self.maskBorderHighlightNode.borderOnly = true
+        self.maskBorderHighlightNode.useModernPathCalculation = true
+        self.maskBorderContentsView.addSubview(self.maskBorderHighlightNode.view)
+        
+        self.backgroundView = UIImageView()
+        self.borderBackgroundView = UIImageView()
+        
+        self.gradientWidth = 120.0
+        self.duration = 1.0
+        
+        super.init(frame: frame)
+        
+        self.isUserInteractionEnabled = false
+        
+        self.maskContentsView.mask = self.maskHighlightNode.view
+        self.maskContentsView.addSubview(self.backgroundView)
+        self.addSubview(self.maskContentsView)
+        
+        self.maskBorderContentsView.mask = self.maskBorderHighlightNode.view
+        self.maskBorderContentsView.addSubview(self.borderBackgroundView)
+        self.addSubview(self.maskBorderContentsView)
+        
+        let generateGradient: (CGFloat) -> UIImage? = { baseAlpha in
+            return generateImage(CGSize(width: self.gradientWidth, height: 16.0), opaque: false, scale: 1.0, rotatedContext: { size, context in
+                context.clear(CGRect(origin: CGPoint(), size: size))
+                
+                let foregroundColor = UIColor(white: 1.0, alpha: min(1.0, baseAlpha * 4.0))
+                
+                if let shadowImage {
+                    UIGraphicsPushContext(context)
+                    
+                    for i in 0 ..< 2 {
+                        let shadowFrame = CGRect(origin: CGPoint(x: CGFloat(i) * (size.width * 0.5), y: 0.0), size: CGSize(width: size.width * 0.5, height: size.height))
+                        
+                        context.saveGState()
+                        context.translateBy(x: shadowFrame.midX, y: shadowFrame.midY)
+                        context.rotate(by: CGFloat(i == 0 ? 1.0 : -1.0) * CGFloat.pi * 0.5)
+                        let adjustedRect = CGRect(origin: CGPoint(x: -shadowFrame.height * 0.5, y: -shadowFrame.width * 0.5), size: CGSize(width: shadowFrame.height, height: shadowFrame.width))
+                        
+                        context.clip(to: adjustedRect, mask: shadowImage.cgImage!)
+                        context.setFillColor(foregroundColor.cgColor)
+                        context.fill(adjustedRect)
+                        
+                        context.restoreGState()
+                    }
+                    
+                    UIGraphicsPopContext()
+                }
+            })?.withRenderingMode(.alwaysTemplate)
+        }
+        
+        self.backgroundView.image = generateGradient(0.5)
+        self.borderBackgroundView.image = generateGradient(1.0)
+        
+        self.layer.addSublayer(self.hierarchyTrackingLayer)
+        self.hierarchyTrackingLayer.didEnterHierarchy = { [weak self] in
+            guard let self, let size = self.size else {
+                return
+            }
+            self.updateAnimations(size: size)
+        }
+    }
+    
+    required init?(coder: NSCoder) {
+        fatalError("init(coder:) has not been implemented")
+    }
+    
+    private func updateAnimations(size: CGSize) {
+        if self.backgroundView.layer.animation(forKey: "shimmer") != nil {
+            return
+        }
+
+        let animation = self.backgroundView.layer.makeAnimation(from: 0.0 as NSNumber, to: (size.width + self.gradientWidth + size.width * 0.0) as NSNumber, keyPath: "position.x", timingFunction: CAMediaTimingFunctionName.easeOut.rawValue, duration: self.duration, delay: 0.0, mediaTimingFunction: nil, removeOnCompletion: true, additive: true)
+        animation.repeatCount = Float.infinity
+        self.backgroundView.layer.add(animation, forKey: "shimmer")
+        self.borderBackgroundView.layer.add(animation, forKey: "shimmer")
+    }
+    
+    public func update(color: UIColor, textNode: TextNode, range: NSRange) {
+        var rectsSet: [CGRect] = []
+        if let cachedLayout = textNode.cachedLayout {
+            if let rects = cachedLayout.rangeRects(in: range)?.rects, !rects.isEmpty {
+                rectsSet = rects
+            }
+        }
+        
+        let maskFrame = CGRect(origin: CGPoint(), size: textNode.bounds.size).insetBy(dx: -4.0, dy: -4.0)
+        
+        self.maskContentsView.backgroundColor = color.withAlphaComponent(0.1)
+        self.maskBorderContentsView.backgroundColor = color.withAlphaComponent(0.12)
+        
+        self.backgroundView.tintColor = color
+        self.borderBackgroundView.tintColor = color
+        
+        self.maskContentsView.frame = maskFrame
+        self.maskBorderContentsView.frame = maskFrame
+        
+        self.maskHighlightNode.updateRects(rectsSet)
+        self.maskHighlightNode.frame = CGRect(origin: CGPoint(x: -maskFrame.minX, y: -maskFrame.minY), size: CGSize())
+        
+        self.maskBorderHighlightNode.updateRects(rectsSet)
+        self.maskBorderHighlightNode.frame = CGRect(origin: CGPoint(x: -maskFrame.minX, y: -maskFrame.minY), size: CGSize())
+        
+        if self.size != maskFrame.size {
+            self.size = maskFrame.size
+            
+            self.backgroundView.frame = CGRect(origin: CGPoint(x: -self.gradientWidth, y: 0.0), size: CGSize(width: self.gradientWidth, height: maskFrame.height))
+            self.borderBackgroundView.frame = CGRect(origin: CGPoint(x: -self.gradientWidth, y: 0.0), size: CGSize(width: self.gradientWidth, height: maskFrame.height))
+            
+            self.updateAnimations(size: maskFrame.size)
+        }
+    }
+}