KCD/ImageView.swift

   1 //
   2 //  ImageView.swift
   3 //  KCD
   4 //
   5 //  Created by Hori,Masaki on 2017/01/02.
   6 //  Copyright © 2017年 Hori,Masaki. All rights reserved.
   7 //
   8
   9 import Cocoa
  10
  11 final class ImageView: NSView {
  12
  13     var images: [NSImage] = [] {
  14
  15         didSet { needsDisplay = true }
  16     }
  17
  18     var imageRect: NSRect {
  19
  20         if images.isEmpty { return .zero }
  21
  22         let bounds = self.bounds
  23         let offset = bounds.width * 0.1 / 2 / 3
  24         let border = offset * 3
  25         let rect = bounds.insetBy(dx: border, dy: border)
  26         let size = images[0].size
  27         let ratioX = rect.height / size.height
  28         let ratioY = rect.width / size.width
  29         let ratio = ratioX > ratioY ? ratioY : ratioX
  30         let drawSize = NSSize(width: size.width * ratio, height: size.height * ratio)
  31
  32         return NSRect(
  33             x: rect.minX + (rect.width - drawSize.width) / 2,
  34             y: rect.minY + (rect.height - drawSize.height) / 2,
  35             width: drawSize.width,
  36             height: drawSize.height)
  37     }
  38
  39     private var internalImageShadow: NSShadow?
  40
  41     private var imageShadow: NSShadow {
  42
  43         if let s = internalImageShadow { return s }
  44
  45         let s = NSShadow()
  46         s.shadowOffset = NSSize(width: 2, height: -2)
  47         s.shadowBlurRadius = 4
  48         s.shadowColor = NSColor.darkGray
  49         internalImageShadow = s
  50
  51         return s
  52     }
  53
  54     override func draw(_ dirtyRect: NSRect) {
  55
  56         NSColor.controlBackgroundColor.set()
  57         NSBezierPath.stroke(bounds)
  58
  59         NSColor.black.set()
  60         NSBezierPath.defaultLineWidth = 1.0
  61         NSBezierPath.stroke(bounds)
  62
  63         NSBezierPath.clip(bounds.insetBy(dx: 1, dy: 1))
  64
  65         imageShadow.set()
  66
  67         let count = images.count
  68
  69         let alphaFactor = 0.7
  70         var alpha = pow(alphaFactor, Double(count - 1))
  71
  72         let offset = bounds.width * 0.1 / 2 / 3
  73         let border = offset * 3
  74         let rect = bounds.insetBy(dx: border, dy: border)
  75
  76         images
  77             .enumerated()
  78             .reversed()
  79             .forEach {
  80                 let offsetRect = rect.offsetBy(dx: offset * CGFloat($0.offset), dy: offset * CGFloat($0.offset))
  81                 let drawRect = imageRect(with: offsetRect, imageSize: $0.element.size)
  82                 $0.element.draw(in: drawRect, from: .zero, operation: .sourceOver, fraction: CGFloat(alpha))
  83                 alpha /= alphaFactor
  84         }
  85     }
  86
  87     private func imageRect(with rect: NSRect, imageSize: NSSize) -> NSRect {
  88
  89         let ratioX = rect.height / imageSize.height
  90         let ratioY = rect.width / imageSize.width
  91         let ratio = ratioX > ratioY ? ratioY : ratioX
  92         let drawSize = NSSize(width: imageSize.width * ratio,
  93                               height: imageSize.height * ratio)
  94
  95         return NSRect(
  96             x: rect.minX + (rect.width - drawSize.width) / 2,
  97             y: rect.minY + (rect.height - drawSize.height) / 2,
  98             width: drawSize.width,
  99             height: drawSize.height)
 100     }
 101 }