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 ///  複数の画像をカスケードして表示する
  12 final class ImageView: NSView {
  13
  14     var images: [NSImage] = [] {
  15
  16         didSet { needsDisplay = true }
  17     }
  18
  19     var imageRect: NSRect {
  20
  21         if images.isEmpty {
  22
  23             return .zero
  24         }
  25
  26         let bounds = self.bounds
  27         let offset = bounds.width * 0.1 / 2 / 3
  28         let border = offset * 3
  29         let rect = bounds.insetBy(dx: border, dy: border)
  30         let size = images[0].size
  31         let ratio = min(rect.width / size.width, rect.height / size.height)
  32         let drawSize = NSSize(width: size.width * ratio, height: size.height * ratio)
  33
  34         return NSRect(
  35             x: rect.minX + (rect.width - drawSize.width) / 2,
  36             y: rect.minY + (rect.height - drawSize.height) / 2,
  37             width: drawSize.width,
  38             height: drawSize.height)
  39     }
  40
  41     private var internalImageShadow: NSShadow?
  42
  43     private var imageShadow: NSShadow {
  44
  45         if let s = internalImageShadow {
  46
  47             return s
  48         }
  49
  50         let s = NSShadow()
  51         s.shadowOffset = NSSize(width: 2, height: -2)
  52         s.shadowBlurRadius = 4
  53         s.shadowColor = NSColor.darkGray
  54         internalImageShadow = s
  55
  56         return s
  57     }
  58
  59     override func draw(_ dirtyRect: NSRect) {
  60
  61         NSColor.controlBackgroundColor.set()
  62         NSBezierPath.stroke(bounds)
  63
  64         NSColor.black.set()
  65         NSBezierPath.defaultLineWidth = 1.0
  66         NSBezierPath.stroke(bounds)
  67
  68         NSBezierPath.clip(bounds.insetBy(dx: 1, dy: 1))
  69
  70         imageShadow.set()
  71
  72         let count = images.count
  73
  74         let alphaFactor = 0.7
  75         var alpha = pow(alphaFactor, Double(count - 1))
  76
  77         let offset = bounds.width * 0.1 / 2 / 3
  78         let border = offset * 3
  79         let rect = bounds.insetBy(dx: border, dy: border)
  80
  81         images
  82             .enumerated()
  83             .reversed()
  84             .forEach {
  85
  86                 let offsetRect = rect.offsetBy(dx: offset * CGFloat($0.offset), dy: offset * CGFloat($0.offset))
  87                 let drawRect = imageRect(with: offsetRect, imageSize: $0.element.size)
  88                 $0.element.draw(in: drawRect, from: .zero, operation: .sourceOver, fraction: CGFloat(alpha))
  89                 alpha /= alphaFactor
  90         }
  91     }
  92
  93     private func imageRect(with rect: NSRect, imageSize: NSSize) -> NSRect {
  94
  95         let ratio = min(rect.width / imageSize.width, rect.height / imageSize.height)
  96         let drawSize = NSSize(width: imageSize.width * ratio,
  97                               height: imageSize.height * ratio)
  98
  99         return NSRect(
 100             x: rect.minX + (rect.width - drawSize.width) / 2,
 101             y: rect.minY + (rect.height - drawSize.height) / 2,
 102             width: drawSize.width,
 103             height: drawSize.height)
 104     }
 105 }