swift - 使用平移手势缩放 UITextView

Question

我正在开发一项功能，用户可以通过拖动右下角来使用平移手势添加文本贴纸、缩放和旋转它。

我创建了一个继承自 UIView 的自定义类，在其上放置了 UITextView，在角落上放置了 3 个用于按钮的 View (关闭、编辑和缩放/旋转)，并在顶部放置了用于手势的透明 UIView。

抱歉，我没有足够的声誉来添加图片

文本贴纸 View 结构 - https://imgur.com/lDz47fV

我的尝试是在平移手势上使用 CGAffineTransform。平移手势位于旋转按钮 View (左下角)

@IBAction func resizeGestureRecognizer(_ sender: UIPanGestureRecognizer) {
        let touchLocation = sender.location(in: self.superview)
        let center = self.center

        switch sender.state {
        case .began:
            self.deltaAngle = CGFloat(atan2f(Float(touchLocation.y - center.y), Float(touchLocation.x - center.x))) - CGAffineTransformGetAngle(self.transform)
            self.initialDistance = CGPointGetDistance(point1: center, point2: touchLocation)
            //self.initialBounds = self.bounds
        case .changed:
            let angle = atan2f(Float(touchLocation.y - center.y), Float(touchLocation.x - center.x))
            let angleDiff = Float(self.deltaAngle) - angle
            let scale = CGPointGetDistance(point1: center, point2: touchLocation) / self.initialDistance

            // downscale buttons to ramain same size and rotation
            for button in buttonViews {
                var t = CGAffineTransform.identity
                t = t.rotated(by: CGFloat(angleDiff))
                t = t.scaledBy(x: 1/scale, y: 1/scale)
                button.transform = t
            }

            var t = CGAffineTransform.identity
            t = t.rotated(by: CGFloat(-angleDiff))
            t = t.scaledBy(x: scale, y: scale)
            self.transform = t

//            textView.layer.shouldRasterize = true
//            textView.layer.rasterizationScale = 20
        case .ended, .cancelled:
            print("ended")
        default:
            break
        }
    }

此代码有效，但每次我尝试调整大小或旋转贴纸时，它都会缩小到原始比例。我错过了什么？

结果 - https://imgur.com/QHPlI93

此外，作为缩放字体质量的解决方法，我使用巨大的字体大小(100)和 0.5 的贴纸比例:

override func awakeFromNib() {
        textView.textContainerInset = UIEdgeInsets(top: 10, left: 20, bottom: 10, right: 20)
        frameView.layer.cornerRadius = 13
        showEditingHandlers = true
        textView.becomeFirstResponder()

        let scale: CGFloat = 0.5

        for button in buttonViews {
            var t = CGAffineTransform.identity
            t = t.scaledBy(x: 1/scale, y: 1/scale)
            button.transform = t
        }


        var t = CGAffineTransform.identity
        t = t.scaledBy(x: scale, y: scale)
        self.transform = t

        textView.delegate = self
        update()
    }

Answer 1

好的，如果其他人会搜索类似的问题，我会发布我的解决方案

我在类(class)顶部添加了比例变量:

var scale: CGFloat = 0
var savedScale: CGFloat = 0.5 // 0.5 becuase I use double font size and scaled my sticker by 0.5 to handle font blur

接下来，在我的手势处理函数中，我只保存最后一个比例，如下所示:

@IBAction func resizeGestureRecognizer(_ sender: UIPanGestureRecognizer) {
        let touchLocation = sender.location(in: self.superview)
        let center = self.center



        switch sender.state {
        case .began:

            print("saved scale = \(savedScale)")
            self.deltaAngle = CGFloat(atan2f(Float(touchLocation.y - center.y), Float(touchLocation.x - center.x))) - CGAffineTransformGetAngle(self.transform)
            self.initialDistance = CGPointGetDistance(point1: center, point2: touchLocation)
        case .changed:
            let angle = atan2f(Float(touchLocation.y - center.y), Float(touchLocation.x - center.x))
            let angleDiff = Float(self.deltaAngle) - angle
            scale = CGPointGetDistance(point1: center, point2: touchLocation) / self.initialDistance

            print("scale: \(scale)")
            scale = scale * savedScale // <- added this

            // downscale buttons to ramain same size and rotation
            for button in buttonViews {
                var t = CGAffineTransform.identity
                //t = t.rotated(by: CGFloat(angleDiff))
                t = t.scaledBy(x: 1/scale, y: 1/scale)
                button.transform = t
            }

            var t = CGAffineTransform.identity
            t = t.rotated(by: CGFloat(-angleDiff))
            t = t.scaledBy(x: scale, y: scale)
            self.transform = t
        case .ended, .cancelled:
            print("ended")
            savedScale = 1 * scale // <- and this
        default:
            break
        }
    }