Question

我正在尝试为NSBezierPath添加撤消功能。

此函数使用半径为45.的NSBezierPath绘制圆，其中mouseLocation为圆的中心

然后它在CAShapeLayer上绘制NSBezierPath并添加到NSViewController的视图中。

我应该如何为此方法添加撤消功能。提前谢谢。

func bezierPathMouseUndoTest(mouseLocation: CGPoint, color: NSColor) {

    let frame = CGRect(x: CGFloat(0), y: CGFloat(0), width: CGFloat(100), height: CGFloat(100))

    // The path should be the entire circle.
    let circlePath = NSBezierPath.init()
    circlePath.appendArc(withCenter: CGPoint(x: mouseLocation.x, y: mouseLocation.y), radius: (frame.size.width - 10)/2, startAngle: CGFloat(90.0), endAngle: CGFloat(-270.0), clockwise: true) // start from up

    // Setup the CAShapeLayer with the path, colors, and line width
    circleLayer = CAShapeLayer()

    circleLayer.path = circlePath.CGPath

    circleLayer.fillColor = NSColor.clear.cgColor
    circleLayer.strokeColor = color.cgColor
    circleLayer.lineWidth = 5.0;

    circleLayer.strokeEnd = 1.0
    circleLayer.frame = frame

    // Add the circleLayer to the view's layer's sublayers
    self.view.layer?.addSublayer(circleLayer)
    self.undoManager?.setActionName("Draw Bezier Path")

}

Answer 1

谢谢Willeke。

我添加了使用附加的两个函数将bezierPath添加到新图层的撤消操作。并且稍微更改了上面的代码。

将“self.view.layer？.addSublayer（circleLayer）”替换为 “self.addSublayer（layer：circleLayer）”

删除“self.undoManager？.setActionName（”绘制Bezier路径“）”

在

下添加两个功能

func addSublayer(layer: CALayer) {
    undoManager?.registerUndo(withTarget: self, selector: #selector(removeSublayer), object: layer)
    self.undoManager?.setActionName("Draw Bezier Path")
    self.view.layer?.addSublayer(layer)

}

func removeSublayer(layer: CALayer) {
    undoManager?.registerUndo(withTarget: self, selector: #selector(addSublayer), object: layer)
    layer.removeFromSuperlayer()
}

如何在Swift 4上的Mac OS X上使用NSUndoManager为NSBezierPath添加撤消？

1 个答案: