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