Generate UIImage for ColorPicker (CGDataProvider and CGImageSource) - ios

Question

Guys I am new in swift and programming, I want to generate a Image to be shown for a ColorPicker I'm using SwiftColorPicker for that and have the following code for image creating:
private func createImageFromData(_ width:Int, height:Int) {
let colorSpace = CGColorSpaceCreateDeviceRGB()
let bitmapInfo = CGBitmapInfo(rawValue: CGImageAlphaInfo.premultipliedFirst.rawValue)
provider = CGDataProvider(data: mutableData)
imageSource = CGImageSourceCreateWithDataProvider(provider, nil)
let cgImage = CGImage.init(width: width, height: height, bitsPerComponent: 8, bitsPerPixel: 32, bytesPerRow: width * 4, space: colorSpace, bitmapInfo: bitmapInfo, provider: provider, decode: nil, shouldInterpolate: true, intent: .defaultIntent)
if let cgimg = cgImage {
image = UIImage(cgImage: cgimg)
PHPhotoLibrary.shared().performChanges({
PHAssetChangeRequest.creationRequestForAsset(from: self.image!)
}, completionHandler: { success, error in
if success {
print("succes")
}
else if let error = error {
print("error")
debugPrint(error as Any)
}
else {
print("woooot?")
}
})
} else { print("Where the hell is the image?") }
}
func changeSize(_ width:Int, height:Int) {
self.width = width
self.height = height
let size:Int = width * height * 4
CFDataSetLength(mutableData, size)
createImageFromData(width, height: height)
}
init(width:Int, height:Int) {
self.width = width
self.height = height
let size:Int = width * height * 4
mutableData = CFDataCreateMutable(kCFAllocatorDefault, size)
createImageFromData(width, height: height)
}
public func writeColorData(_ h:CGFloat, a:CGFloat) {
let d = CFDataGetMutableBytePtr(self.mutableData)
if width == 0 || height == 0 {
return
}
var i:Int = 0
let h360:CGFloat = ((h == 1 ? 0 : h) * 360) / 60.0
let sector:Int = Int(floor(h360))
let f:CGFloat = h360 - CGFloat(sector)
let f1:CGFloat = 1.0 - f
var p:CGFloat = 0.0
var q:CGFloat = 0.0
var t:CGFloat = 0.0
let sd:CGFloat = 1.0 / CGFloat(width)
let vd:CGFloat = 1 / CGFloat(height)
var double_s:CGFloat = 0
var pf:CGFloat = 0
let v_range = 0..<height
let s_range = 0..<width
for v in v_range {
pf = 255 * CGFloat(v) * vd
for s in s_range {
i = (v * width + s) * 4
d?[i] = UInt8(255)
if s == 0 {
q = pf
d?[i+1] = UInt8(q)
d?[i+2] = UInt8(q)
d?[i+3] = UInt8(q)
continue
}
double_s = CGFloat(s) * sd
p = pf * (1.0 - double_s)
q = pf * (1.0 - double_s * f)
t = pf * ( 1.0 - double_s * f1)
switch(sector) {
case 0:
d?[i+1] = UInt8(pf)
d?[i+2] = UInt8(t)
d?[i+3] = UInt8(p)
case 1:
d?[i+1] = UInt8(q)
d?[i+2] = UInt8(pf)
d?[i+3] = UInt8(p)
case 2:
d?[i+1] = UInt8(p)
d?[i+2] = UInt8(pf)
d?[i+3] = UInt8(t)
case 3:
d?[i+1] = UInt8(p)
d?[i+2] = UInt8(q)
d?[i+3] = UInt8(pf)
case 4:
d?[i+1] = UInt8(t)
d?[i+2] = UInt8(p)
d?[i+3] = UInt8(pf)
default:
d?[i+1] = UInt8(pf)
d?[i+2] = UInt8(p)
d?[i+3] = UInt8(q)
}
}
}
}
and:
// Write colors to data array
if self.data1Shown { self.pickerImage2!.writeColorData(self.h, a:self.a) }
else { self.pickerImage1!.writeColorData(self.h, a:self.a)}
with:
public var a:CGFloat = 1 {
didSet {
if a < 0 || a > 1 {
a = max(0, min(1, a))
}
}
}
public var h:CGFloat = 0 { // // [0,1]
didSet {
if h > 1 || h < 0 {
h = max(0, min(1, h))
}
renderBitmap()
setNeedsDisplay()
}
}
It fails when i try to save it to photo albums (i've done that cause I was not able to set the image so I tried to save it to understand if it's ok or it's a error), and voila! An graceful error appears:
Error Domain=NSCocoaErrorDomain Code=-1 "(null)"
So I wanna know maybe someone knows what to do, how I can fix this, here is the link on gitHub for the Source (maybe it will help):
https://github.com/MrMatthias/SwiftColorPicker
Thanks!

Answer 1

I've made a helpful swift extension to create a UIImage of a solid color.
Feel free to use it:
extension UIImage {
static func image(of color: UIColor, size: CGSize) -> UIImage {
UIGraphicsBeginImageContextWithOptions(size, false, 0.0)
color.set()
UIRectFill(CGRect(origin: CGPoint.zero, size: size))
let image = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
return image!
}
}
Then you can use it by:
let redImage = UIImage.image(of: .red, size: CGSize(width: 200, height: 200))
Hope that helps!