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// Add recognisers for back and forward |
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let swipeLeftRecognizer = UISwipeGestureRecognizer(target: self, action: #selector(handleSwipe(recognizer:))) |
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let swipeRightRecognizer = UISwipeGestureRecognizer(target: self, action: #selector(handleSwipe(recognizer:))) |
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swipeLeftRecognizer.direction = .left |
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swipeRightRecognizer.direction = .right |
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webView.addGestureRecognizer(swipeLeftRecognizer) |
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webView.addGestureRecognizer(swipeRightRecognizer) |
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|
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@objc private func handleSwipe(recognizer: UISwipeGestureRecognizer) { |
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if (recognizer.direction == .left) { |
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if webView.canGoForward { |
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// snapshot current page |
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guard let webViewSnapshot = webView.snapshotView(afterScreenUpdates: true) else { webView.goForward(); return } |
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webViewSnapshot.frame = view.frame |
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view.insertSubview(webViewSnapshot, belowSubview: webView) |
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// go back in the browser |
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webView.goForward() |
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// get snapshot of previous page |
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let image = CIImage(ioSurface: webView._snapshotLayerContents(forBackForwardListItem: webView.backForwardList.forwardItem) as! IOSurfaceRef) |
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let imageView = UIImageView(image: UIImage(ciImage: image)) |
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imageView.frame = view.frame |
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imageView.isUserInteractionEnabled = false |
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view.insertSubview(imageView, aboveSubview: webView) |
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// animate the current page snapshot away |
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imageView.frame.origin.x += imageView.frame.size.width |
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self.webView.frame.origin.x += self.webView.frame.size.width |
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Timer.scheduledTimer(withTimeInterval: 0.2, repeats: false) { _ in |
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UIView.animate(withDuration: 0.2, delay: 0, options: .curveEaseOut, animations: { |
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imageView.frame.origin.x -= imageView.frame.size.width |
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self.webView.frame.origin.x -= self.webView.frame.size.width |
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}, completion: { _ in |
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webViewSnapshot.removeFromSuperview() |
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UIView.animate(withDuration: 0.2, delay: 0, options: .curveEaseIn, animations: { |
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imageView.alpha = 0 |
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}, completion: {_ in |
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imageView.removeFromSuperview() |
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}) |
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}) |
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} |
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} |
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} |
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|
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if (recognizer.direction == .right) { |
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if webView.canGoBack { |
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// snapshot current page |
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guard let webViewSnapshot = webView.snapshotView(afterScreenUpdates: true) else { webView.goBack(); return } |
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webViewSnapshot.frame = view.frame |
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view.insertSubview(webViewSnapshot, aboveSubview: webView) |
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// go back in the browser |
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webView.goBack() |
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// get snapshot of previous page |
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let image = CIImage(ioSurface: webView._snapshotLayerContents(forBackForwardListItem: webView.backForwardList.backItem) as! IOSurfaceRef) |
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let imageView = UIImageView(image: UIImage(ciImage: image)) |
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imageView.frame = view.frame |
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imageView.isUserInteractionEnabled = false |
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view.insertSubview(imageView, belowSubview: webViewSnapshot) |
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// animate the current page snapshot away |
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UIView.animate(withDuration: 0.2, delay: 0, options: .curveEaseIn, animations: { |
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webViewSnapshot.frame.origin.x += webViewSnapshot.frame.size.width |
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}, completion: { _ in |
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webViewSnapshot.removeFromSuperview() |
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UIView.animate(withDuration: 0.2, delay: 0, options: .curveEaseIn, animations: { |
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imageView.alpha = 0 |
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}, completion: {_ in |
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imageView.removeFromSuperview() |
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}) |
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}) |
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} |
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} |
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} |
