swift - 使用 Cocoa for OS X、Xcode 9.3、Swift 4.1 复制 View 问题

Question

我是编程新手，正在尝试使用 Xcode 9.3 和 Swift 4.1 学习 Mac OS 的 Cocoa。我读过有关 C++ 和 Objective-C 的书籍。现在我正在阅读 Big Nerd Ranch 的书《Mac OS 的 Cocoa 编程》第 5 版，该书使用 Swift 2.0(我自己)。试图解决 Swift 2.0 到 4.1 之间的差异时遇到了一些挑战，我不知道这个问题是否是其中的一部分。

为了总结练习，我创建了一个骰子。练习的一部分是通过双击骰子来改变骰子的编号。我这样做了，而且成功了。现在我需要将骰子复制两次，总共三个骰子。

我按照步骤复制了骰子(突出显示 dieView 和 command-D)，现在我有了三个骰子。每个 View 都接受第一响应者，并且每个 View 随后接受键盘输入以更改骰子上显示的数字。我可以用鼠标选择关键窗口，并且突出显示哪个窗口处于事件状态。然而，双击“掷”骰子仅适用于原始骰子，不适用于其他两个。当它们完全重复时怎么可能呢？既然它们被复制了，我怎样才能让双击在其他两个骰子中工作，因为它们应该具有相同的代码？

我还尝试将原始骰子移动到第三个位置，将两个新骰子移过来，现在双击时仍然是第一个位置的骰子，而不是最后两个骰子。当我将骰子移动到堆叠位置时，一个在另一个之上，一个在另一个之上，一开始我将它们放在窗口的左侧，并且双击对其中任何一个都不起作用。我调整了窗口大小，使它们全部堆叠在左侧，并且双击仅适用于底部芯片。

我知道这与骰子所在的自定义 View 窗口有关，但鼠标单击不应该在该窗口中的任何位置注册吗？显然，点击次数已被记录，因为我可以将关键窗口更改为每个骰子。只是双击功能无法正常工作。

这是我的 dieView 代码:

import Cocoa

@IBDesignable class DieView: NSView {

    var intValue: Int? = 1 {
        didSet {
            needsDisplay = true
        }
    }

    var pressed: Bool = false {
        didSet {
            needsDisplay = true
        }
    }

    var dieShape = NSBezierPath()

    override var intrinsicContentSize: NSSize {
        return NSSize(width: 20, height: 20)
    }

    override func draw(_ dirtyRect: NSRect) {
        let backgroundColor = NSColor.lightGray
        backgroundColor.set()
        NSBezierPath.fill(bounds)
        drawDieWithSize(size: bounds.size)
    }

    func metricsForSize(size: CGSize) -> (edgeLength: CGFloat, dieFrame: CGRect) {
        let edgeLength = min(size.width, size.height)
        let padding = edgeLength/10.0
        let drawingBounds = CGRect(x: 0, y: 0, width: edgeLength, height: edgeLength)
        var dieFrame = drawingBounds.insetBy(dx: padding, dy: padding)
        if pressed {
            dieFrame = dieFrame.offsetBy(dx: 0, dy: -edgeLength/40)
        }
        return (edgeLength, dieFrame)
    }

    func drawDieWithSize(size: CGSize) {
        if let intValue = intValue {
            let (edgeLength, dieFrame) = metricsForSize(size: size)
            let cornerRadius:  CGFloat = edgeLength/5.0
            let dotRadius = edgeLength/12.0
            let dotFrame = dieFrame.insetBy(dx: dotRadius * 2.5, dy: dotRadius * 2.5)

            // The glint must be within the dot.
            let glintFrame = dotFrame

            NSGraphicsContext.saveGraphicsState()

            let shadow = NSShadow()
            shadow.shadowOffset = NSSize(width: 0, height: -1)
            //shadow.shadowBlurRadius = edgeLength/20
            shadow.shadowBlurRadius = (pressed ? edgeLength/100 : edgeLength/20)
            shadow.set()

            // Draw the rounded shape of the die profile:
            // Challenge use color Gradient - commented portions are used to make white die and were removed to make code more readable in this post
            let gradient = NSGradient(starting: NSColor.red, ending: NSColor.blue)
            dieShape =
                NSBezierPath(roundedRect: dieFrame, xRadius: cornerRadius, yRadius: cornerRadius)
            gradient?.draw(in: dieShape, angle: 1.0)

            // Challlenge - use stroke() to add a border the die
            NSColor.black.set()
            dieShape.lineWidth = 4
            dieShape.stroke()

            NSGraphicsContext.restoreGraphicsState()
            // Shadow will not apply to subequent drawing commands

            // ready to draw the dots.
            // Nested Function to make drawing dots cleaner:
            func drawDot(u: CGFloat, v: CGFloat) {
                let dotOrigin = CGPoint(x: dotFrame.minX + dotFrame.width * u,
                                        y: dotFrame.minY + dotFrame.height * v)
                let dotRect =
                    CGRect(origin: dotOrigin, size: CGSize.zero).insetBy(dx: -dotRadius, dy: -dotRadius)
                // The dots will be black:
                NSColor.black.set()
                NSBezierPath(ovalIn: dotRect).fill()
                }


            // nested function to draw a glint in each dot
            func drawGlint(u: CGFloat, v: CGFloat) {
                let glintOrigin = CGPoint(x: glintFrame.minX + glintFrame.width * u,
                                          y: glintFrame.minY + glintFrame.height * v)
                let glintRect =
                    CGRect(origin: glintOrigin,
                           size: CGSize(width: 3.5, height: 3.5)).insetBy(dx: -0.5, dy: -0.5)

                // Glints will be white
                NSColor.white.set()
                NSBezierPath(rect: glintRect).fill()
            }

            // If intVlaue is in range...
            if intValue >= 1 && intValue <= 6 {
                // Draw the dots:
                if intValue == 1 || intValue == 3 || intValue == 5 {
                    drawDot(u: 0.5, v: 0.5)     // Center dot
                    drawGlint(u: 0.55, v: 0.55)
                }
                if intValue >= 2 && intValue <= 6 {
                    drawDot(u: 0, v: 1)     // upper left
                    drawGlint(u: 0.05, v: 1.05)
                    drawDot(u: 1, v: 0)     // Lower right
                    drawGlint(u: 1.05, v: 0.05)
                }
                if intValue >= 4 && intValue <= 6 {
                    drawDot(u: 1, v: 1)     // Upper right
                    drawGlint(u: 1.05, v: 1.05)
                    drawDot(u: 0, v: 0)     // lower left
                    drawGlint(u: 0.05, v: 0.05)
                }
                if intValue == 6 {
                    drawDot(u: 0, v: 0.5)   // Mid left/right
                    drawGlint(u: 0.05, v: 0.55)
                    drawDot(u: 1, v: 0.5)
                    drawGlint(u: 1.05, v: 0.55)
                }
            } else {
                let paraStyle = NSParagraphStyle.default.mutableCopy() as! NSMutableParagraphStyle
                paraStyle.alignment = .center
                let font = NSFont.systemFont(ofSize: edgeLength * 0.5)
                let attrs = [NSAttributedStringKey.foregroundColor: NSColor.black,
                    NSAttributedStringKey.font : font,
                    NSAttributedStringKey.paragraphStyle: paraStyle ]
                let string = "\(intValue)" as NSString
                string.drawCentered(in: dieFrame, attributes: attrs)

            }
        }
    }

    func randomize() {
        intValue = Int(arc4random_uniform(5)) + 1
    }

    // MARK: - Mouse Events

    override func mouseDown(with event: NSEvent) {
        if dieShape.contains(event.locationInWindow) {
            Swift.print("mouseDown CLICKCOUNT: \(event.clickCount)")
            let dieFrame = metricsForSize(size: bounds.size).dieFrame
            let pointInView = convert(event.locationInWindow, from: nil)
            pressed = dieFrame.contains(pointInView)
        }
    }

    override func mouseDragged(with event: NSEvent) {
        Swift.print("mouseDragged")
    }

    override func mouseUp(with event: NSEvent) {
        if dieShape.contains(event.locationInWindow) {
            Swift.print("mouseUp clickCount: \(event.clickCount)")
            if event.clickCount == 2 {
                randomize()
            }
            pressed = false
        }
    }

    // MARK: - First Responder

    override func drawFocusRingMask() {
        NSBezierPath.fill(bounds)
    }

    override var focusRingMaskBounds: NSRect {
        return bounds
    }

    override var acceptsFirstResponder: Bool { return true }

    override func becomeFirstResponder() -> Bool {
        return true
    }

    override func resignFirstResponder() -> Bool {
        return true
    }

    // MARK: Ketboard Events

    override func keyDown(with event: NSEvent) {
        interpretKeyEvents([event])
    }

    override func insertText(_ insertString: Any) {
        let text = insertString as! String
        if let number = Int(text) {
            intValue = number
        }
    }

    override func insertTab(_ sender: Any?) {
        window?.selectNextKeyView(sender)
    }

    override func insertBacktab(_ sender: Any?) {
        window?.selectPreviousKeyView(sender)
    }
}

Answer 1

快速浏览一下后，我猜测问题出在 if dieShape.contains(event.locationInWindow) 中。

diaShape 位于局部( View )坐标中。但 event.locationInWindow 位于窗口坐标中。您需要先将窗口坐标转换为本地坐标，然后才能测试命中点。

请参阅 locationInWindow 的文档:

let eventLocation = event.locationInWindow
let localPoint = self.convert(eventLocation, from: nil)
if dieShape.contains(localPoint)
   ...

如果您的 View 靠近窗口的原点，则窗口和 View 坐标之间的差异足够小，它可能会起作用，但距离较远的 View 则不会。