From fbe2d639811d61e1588026f3c6f407b678262895 Mon Sep 17 00:00:00 2001
From: Alan Tai <alan.tai@zuhlke.com>
Date: Fri, 16 Nov 2018 12:53:51 +0800
Subject: [PATCH] Fix Core Animation implementation due to changes in Mojave
 layer-backing

---
 DevExcuses/Sources/DevExcusesView.swift |  2 +-
 DevExcuses/Sources/KenBurnsView.swift   | 21 +++++++++++++--------
 2 files changed, 14 insertions(+), 9 deletions(-)

diff --git a/DevExcuses/Sources/DevExcusesView.swift b/DevExcuses/Sources/DevExcusesView.swift
index 498f3a7..c1523f7 100644
--- a/DevExcuses/Sources/DevExcusesView.swift
+++ b/DevExcuses/Sources/DevExcusesView.swift
@@ -318,7 +318,6 @@ class DevExcusesView: ScreenSaverView {
 
     private func updateImageView(data: Data) {
         let imageView = KenBurnsView(frame: self.frame)
-        self.addSubview(imageView)
 
         imageView.animate(
             image   : NSImage(data: data),
@@ -329,6 +328,7 @@ class DevExcusesView: ScreenSaverView {
             oldImageView.removeFromSuperview()
         }
 
+        self.addSubview(imageView)
         self.imageView = imageView
     }
 
diff --git a/DevExcuses/Sources/KenBurnsView.swift b/DevExcuses/Sources/KenBurnsView.swift
index 101699b..52b9ee6 100644
--- a/DevExcuses/Sources/KenBurnsView.swift
+++ b/DevExcuses/Sources/KenBurnsView.swift
@@ -3,15 +3,21 @@ import Cocoa
 final class KenBurnsView: NSImageView {
     private let configs = Configs()
 
+    private var duration: TimeInterval = 15
+
     func animate(image: NSImage?, alpha: CGFloat, duration: TimeInterval) {
-        self.image = image
+        self.image         = image
+        self.alphaValue    = alpha
+        self.duration      = duration
+    }
 
-        guard let image = self.image else {
-            return
-        }
+    override var wantsUpdateLayer: Bool {
+        return true
+    }
 
-        let width          = Double(image.size.width)
-        let height         = Double(image.size.height)
+    override func makeBackingLayer() -> CALayer {
+        let width          = Double(self.frame.size.width)
+        let height         = Double(self.frame.size.height)
         let maxScale       = Double(self.configs.maxZoom) / 100
         let fromScale      = Double.random(min: 1, max: maxScale)
         let toScale        = Double.random(min: 1, max: maxScale)
@@ -40,8 +46,7 @@ final class KenBurnsView: NSImageView {
         layer.add(xAnimation, forKey: xAnimation.keyPath)
         layer.add(yAnimation, forKey: yAnimation.keyPath)
 
-        self.layer      = layer
-        self.alphaValue = alpha
+        return layer
     }
 
     private static func randomTranslation(min: Double, max: Double, scale: Double) -> Double {