Precondition Failure: Invalid Input Index When Using Geometryreader in Swiftui Starting with iOS 13.4

iOS 13.4 Crashes app with vague message: precondition failure: type check failed: 101, expected Text, got _HiddenModifier

Found the issue:

This line of code, which i added to avoid screen glitches in swiftUI caused it:

Text("").hidden()

commented it out and it all works fine..

weird!

precondition failure: type check failed: 104, expected Image, got _ColorInvertEffect with .colorInvert() in SwiftUI on iOS 13.4

I ended up working around this by changing my loadWitnessSignatureImage function to invert the colors of the UIImage using an extension of UIImage

The revised loadImage function:

    func loadWitnessSignatureImage() {
        guard let witnessSignatureData = release.witnessSignature?.storedData() else {
            return
        }

        let img = UIImage(data: witnessSignatureData)
        if colorScheme == .dark {
            witnessSignatureImage = Image(uiImage: img!.invertedColors()!)
        } else {
            witnessSignatureImage = Image(uiImage: img!)

        }
    }

The .invertedColors() extension:

extension UIImage {
    func invertedColors() -> UIImage? {
        guard let cgImage = self.cgImage else { return nil }
        let ciImage = CoreImage.CIImage(cgImage: cgImage)
        guard let filter = CIFilter(name: "CIColorInvert") else { return nil }
        filter.setDefaults()
        filter.setValue(ciImage, forKey: kCIInputImageKey)
        let context = CIContext(options: nil)
        guard let outputImage = filter.outputImage else { return nil }
        guard let outputImageCopy = context.createCGImage(outputImage, from: outputImage.extent) else { return nil }
        return UIImage(cgImage: outputImageCopy, scale: self.scale, orientation: .up)
    }
}

iOS 13.4: didSet() not called anymore for a @Published Bool when using toggle()

It has been solved with today's Xcode 11.5 Swift 5.2.4. Good!

encrypting assets (video files) in Adobe AIR

I solved this for a DVD application encrypting all the assets in the DVD and executing a HTTP Server inside the AIR application that decrypts it.

It works in this way:

1 - The images, videos, or assets are encrypted and saved anywhere, in our case the DVD assets folder with a master key.

2 - The Air application contains inside a very simple HTTP server who reads the file decrypts it and send it only to the same Air application using a simple Flash Video Player or using a tag like <img src="localhost:5050/assetcode.jpg">

The code used inside the air application to serve the file is like:

import com.hurlant.crypto.prng.ARC4;
            import com.hurlant.util.Hex;
            import com.hurlant.crypto.Crypto;
            import com.hurlant.crypto.symmetric.ICipher;
            
            var key:ByteArray = Hex.toArray(Hex.fromString("masterkey"));
            var rc4:ARC4 = new ARC4(key);
            
            var fs:FileStream = new FileStream();
            fs.open( content, FileMode.READ );
            var ba:ByteArray = new ByteArray();
            
            
            fs.readBytes( ba, 0, fs.bytesAvailable );
            ba.position = 0;
            fs.close();
            
            
            
            rc4.decrypt(ba);
            //cipher.decrypt(ba);
            
            innerSendHTML(s, ext2mime[content.extension], ba );
            
            ba.length = 0;

We use the RC4 algorithm because it's the faster in our tests.

For the HTTP Server we used a sample http application from the Flash Camp 2010, you could find it in google.

Regards

--

www.imaginacolombia.com

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