Detect if a user has typed an emoji character in UITextView

Question

I have a UITextView and I need to detect if a user enters an emoji character.

I would think that just checking the unicode value of the newest character would suffic

Answer 1

Here is the emoji detection method in Swift. It works fine. Hope it will help others.

 func isEmoji(_ character: String?) -> Bool {

        if character == "" || character == "\n" {
            return false
        }
        let characterRender = UILabel(frame: CGRect(x: 0, y: 0, width: 1, height: 1))
        characterRender.text = character
        characterRender.backgroundColor = UIColor.black  
        characterRender.sizeToFit()
        let rect: CGRect = characterRender.bounds
        UIGraphicsBeginImageContextWithOptions(rect.size, true, 0.0)

        if let contextSnap:CGContext = UIGraphicsGetCurrentContext() {
            characterRender.layer.render(in: contextSnap)
        }

        let capturedImage: UIImage? = (UIGraphicsGetImageFromCurrentImageContext())
        UIGraphicsEndImageContext()
        var colorPixelFound:Bool = false

        let imageRef = capturedImage?.cgImage
        let width:Int = imageRef!.width
        let height:Int = imageRef!.height

        let colorSpace = CGColorSpaceCreateDeviceRGB()

        let rawData = calloc(width * height * 4, MemoryLayout.stride).assumingMemoryBound(to: CUnsignedChar.self)

            let bytesPerPixel:Int = 4
            let bytesPerRow:Int = bytesPerPixel * width
            let bitsPerComponent:Int = 8

            let context = CGContext(data: rawData, width: Int(width), height: Int(height), bitsPerComponent: Int(bitsPerComponent), bytesPerRow: Int(bytesPerRow), space: colorSpace, bitmapInfo: CGImageAlphaInfo.premultipliedLast.rawValue | CGBitmapInfo.byteOrder32Big.rawValue)



        context?.draw(imageRef!, in: CGRect(x: 0, y: 0, width: width, height: height))

            var x:Int = 0
            var y:Int = 0
            while (y < height && !colorPixelFound) {

                while (x < width && !colorPixelFound) {

                    let byteIndex: UInt  = UInt((bytesPerRow * y) + x * bytesPerPixel)
                    let red = CGFloat(rawData[Int(byteIndex)])
                    let green = CGFloat(rawData[Int(byteIndex+1)])
                    let blue = CGFloat(rawData[Int(byteIndex + 2)])

                    var h: CGFloat = 0.0
                    var s: CGFloat = 0.0
                    var b: CGFloat = 0.0
                    var a: CGFloat = 0.0

                    var c = UIColor(red:red, green:green, blue:blue, alpha:1.0)
                    c.getHue(&h, saturation: &s, brightness: &b, alpha: &a)

                    b = b/255.0

                    if Double(b) > 0.0 {
                        colorPixelFound = true
                    }
                    x+=1
                }
                x=0
                y+=1
            }

        return colorPixelFound
}