我正在尝试将 Apple Pencil 与 WKWebView 集成。
期望的行为:
所以在花了更多时间之后,我得出了一个非常 hacky 的解决方案,我实际上并不喜欢这个解决方案:
WKWebView
和一个透明的PKCanvasView
。hitTest
以始终返回 nil。drawingGestureRecognizer
添加到WKWebView
drawingGestureRecognizer.allowedTouchTypes = [NSNumber(value: UITouch.TouchType.pencil.rawValue)]
设置为 PKCanvasView
这种方法有效,但它消除了实施的大量灵活性。
到目前为止,我已经尝试了两种方法:
当我检测到它来自手指时,有选择地取消画布上的用户输入。这没有用,因为在事件被视图消耗之前我无法检测到这一点。
创建一个透明的超级视图,并在我进行检测时为 PKCanvasView 和 WKWebView 手动调用 touchesBegan/touchesMoved/touchesEnded。不幸的是,这也不起作用,因为调用这些方法没有做任何事情。
这是我到目前为止的一些基本代码:
struct SUICanvasView: UIViewControllerRepresentable {
let url: URL?
func makeUIViewController(context: Context) -> ZRCanvasReader {
let canvasReader = ZRCanvasReader()
canvasReader.openUrl(url: url)
return canvasReader
}
func updateUIViewController(_ uiViewController: ZRCanvasReader, context: Context) {
}
typealias UIViewControllerType = ZRCanvasReader
}
class ZRCanvasReader: UIViewController {
lazy var canvas: PKCanvasView = {
let v = PKCanvasView()
v.isOpaque = false
v.backgroundColor = .clear
return v
}()
lazy var toolPicker: PKToolPicker = {
let toolPicker = PKToolPicker()
return toolPicker
}()
lazy var webView: WKWebView = {
let prefs = WKWebpagePreferences()
prefs.allowsContentJavaScript = true
let config = WKWebViewConfiguration()
config.defaultWebpagePreferences = prefs
let webview = WKWebView(frame: .zero, configuration: config)
return webview
}()
override func viewDidLoad() {
super.viewDidLoad()
view.addSubview(webView)
view.addSubview(canvas)
webView.frame = view.frame
canvas.frame = view.frame
toolPicker.addObserver(canvas)
toolPicker.setVisible(true, forFirstResponder: canvas)
}
func openUrl(url: URL?) {
guard let loadingUrl = url else {
return
}
let request = URLRequest(url: loadingUrl)
webView.load(request)
}
}
// Set PKCanvasView to same size as UIScrollView's content size
canvasView = PKCanvasView(frame: CGRect(origin: .zero, size: scrollView.contentSize))
scrollView.addSubview(canvasView)
// Disable UIScrollView scroll with one finger
scrollView.panGestureRecognizer.minimumNumberOfTouches = 2