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