Creating CGColor from RGB Value - swift

I use the following code to set the background of a viewcontroller
view.wantsLayer = true
let myColor = NSColor(calibratedRed: 50, green: 50, blue: 50, alpha: 1.0)
view.layer?.backgroundColor = myColor.cgColor
But on debugging myColor i get the following color instead of the intended color

Here is the documentation. Anything above 1 is considered as 1. You need to divide each value by 255.
view.wantsLayer = true
let myColor = NSColor(calibratedRed: 50/255, green: 50/255, blue: 50/255, alpha: 1.0)
view.layer?.backgroundColor = myColor.cgColor
Also, check this out -> Link

Range of color components (RGBA) vary between [0,1]
init(red:green:blue:alpha:)
Creates a color object with the specified red, green, blue, and alpha
channel values. This method accepts extended color component values.
If the red, green, blue, or alpha values are outside of the 0-1.0
range,
So you can get cgColor
view.layer?.backgroundColor = NSColor(calibratedRed: 50.0/255.0, green: 50.0/255.0, blue: 50.0/255.0, alpha: 1.0).cgColor

Related

Why does only the built-in UIColors work here? [duplicate]

This question already has answers here:
UIColor not working with RGBA values
(6 answers)
Closed 3 years ago.
Having failed miserably at further attempts to solve this question on my own, I'm trying something I thought would work for certain:
func switchColor(data:UInt32){
switch data {
case 1..<200:
backgroundGeometry.firstMaterial?.diffuse.contents =
UIColor(red: CGFloat(242), green: CGFloat(90), blue: CGFloat(90), alpha: 1.0)
case 200..<400:
backgroundGeometry.firstMaterial?.diffuse.contents =
UIColor(red: CGFloat(252), green: CGFloat(162), blue: CGFloat(115), alpha: 1.0)
case 400..<600:
backgroundGeometry.firstMaterial?.diffuse.contents =
UIColor(red: CGFloat(244), green: CGFloat(235), blue: CGFloat(99), alpha: 1.0)
case 600..<800:
backgroundGeometry.firstMaterial?.diffuse.contents =
UIColor(red: CGFloat(110), green: CGFloat(195), blue: CGFloat(175), alpha: 1.0)
case 800..<1000:
backgroundGeometry.firstMaterial?.diffuse.contents =
UIColor(red: CGFloat(91), green: CGFloat(118), blue: CGFloat(211), alpha: 1.0)
default:
backgroundGeometry.firstMaterial?.diffuse.contents = UIColor.green
}
}
All the non-default cases turns the node white.
The default case does turn it green - and within each case, statements like UIColor.red, UIColor.blue work fine as well.
So why the heck doesn't the above statements work?
Hope you can help, I'm completely at a loss here :(
Edit: Thanks for the swift and not least correct answers! All accepted and upvoted, but I'm too much of a newbie for it to display. Thanks! :)
This should work for you:
func switchColor(data: UInt32) {
guard let contents = backgroundGeometry.firstMaterial?.diffuse.contents else {
fatalError("First material is nil") // If this really can be empty, just replace this with return
}
switch data {
case 1..<200:
contents = UIColor(red: 242/255, green: 90/255, blue: 90/255, alpha: 1)
case 200..<400:
contents = UIColor(red: 252/255, green: 162/255, blue: 115/255, alpha: 1)
case 400..<600:
contents = UIColor(red: 244/255, green: 235/255, blue: 99/255, alpha: 1)
case 600..<800:
contents = UIColor(red: 110/255, green: 195/255, blue: 175/255, alpha: 1)
case 800..<1000:
contents = UIColor(red: 91/255, green: 118/255, blue: 211/255, alpha: 1)
default:
contents = .green
}
}
The maximum value of a color is 1.0, not 255. Therefore you need to divide the values.
According to the documentation, the red, green, blue and alfa values are Float between 0.0 to 1.0 respectively. Also, a value below 0.0 is treated as 0.0 and value above 1.0 is treated as 1.0.
So you must construct the UIColor as this
UIColor(red: 91/255, green: 118/255, blue: 211/255, alpha: 1)
You need to construct them like
UIColor(red:242.0/255.0, green:90.0/255.0, blue:90.0/255.0, alpha: 1.0)
you can find the init in Docs
red/blue/green values below 0.0 are interpreted as 0.0, and values above 1.0 are interpreted as 1.0.
Another note also there is a difference between
90/255 // wrong
and
90.0/255.0 // right
the latter is the correct one as the former will truncate the floating part as it's an integer division

Is it possible to make a comparison between several colors and then change it to its closest coounter part?

For eg.
I have 3 colors.
color1 = UIColor(red: 142/255, green: 165/255, blue: 94/255, alpha: 1)
color2 = UIColor(red: 141/255, green: 114/255, blue: 96/255, alpha: 1)
color3 = UIColor(red: 214/255, green: 194/255, blue: 149/255, alpha: 1)
Is it possible to identify that color1 is closest to color2 and not color3 in swift and then make the necessary adjustments to color1 such that color1 == color2?
If you compare color1 and color2, you can see that they are of slightly different shades but are very very similar.
can I compare merely based on RGB values or do I have to use hex values?
Thanks

Setting tintColor for Apple Watch complication

I am trying to set the header text color for a Modular Large complication.
I have already customized the watch face to use Multicolor.
However, when I build and run this code, the header text color is still white (which is the default).
Why isn't the color updating?
private func templateForClassModularLarge(className: Schedule) -> CLKComplicationTemplateModularLargeStandardBody {
let template = CLKComplicationTemplateModularLargeStandardBody()
let headerTextProvider = CLKSimpleTextProvider(text: "My Schedule", shortText: "Schedule")
headerTextProvider.tintColor = UIColor(red: 101, green: 153, blue: 255, alpha: 1)
template.headerTextProvider = headerTextProvider
template.body1TextProvider = CLKTimeIntervalTextProvider(startDate: className.start, endDate: className.end)
template.body2TextProvider = CLKSimpleTextProvider(text: className.description, shortText: className.shortDescription)
return template
}
UIColor parameter types are CGFloat, specified as a value from 0.0 to 1.0.
Because your RGB parameters are greater than 1, the color ends up being white, which would be:
UIColor(red: 1, green: 1, blue: 1, alpha: 1)
To fix this issue, simply change your tintColor to
headerTextProvider.tintColor = UIColor(red: 101/255, green: 153/255, blue: 255/255, alpha: 1)

Swift - why NSColor becomes lighter when rendered

I've created NSWindow and made it's background colour absolutely blue (#0000FF). But when the window is rendered, the colour is "lighter" than it should be (#0F3FFB).
class LilWindow: NSViewController {
override func viewDidLoad() {
self.view.window?.backgroundColor =
NSColor.init(red: 0, green: 0, blue: 1, alpha: 1)
}
Does anyone know why it is happening and how to fix this? (screenshot attached)
Okay, so after a couple of hours fiddling with code and #KenThomases help, I figured out that if you want your RGB colours to looks correctly on NSImages and NSWindows, you must convert it into NSDeviceRGBColorSpace colorspace. To do this I've written a simple function:
func toScreenColor(color:NSColor) -> NSColor {
var red: CGFloat = 0, green: CGFloat = 0, blue: CGFloat = 0, alpha: CGFloat = 0
color
.colorUsingColorSpaceName(NSCalibratedRGBColorSpace)!
.getRed(&red, green: &green, blue: &blue, alpha: &alpha)
return NSColor(deviceRed: red, green: green, blue: blue, alpha: alpha)
}

Extra argument in call when using var

I'm trying to use this code:
var alpha : Float
alpha = 0.5
self.view.backgroundColor = UIColor(red: 1, green:0, blue: 0, alpha:alpha)
However, I get the error:
Extra argument 'green' in call
What is wrong with this code? Moreover, why is
self.view.backgroundColor = UIColor(red: 1, green:0, blue: 0, alpha: 0)
working just fine?
Answer was: Swift UIColor initializer - compiler error only when targeting iPhone5s
Use float instead of integers.
UIColor(red: 1.0, green:0.0, blue: 0.0, alpha:alpha)
This also happens when you unwrap the a UIColor instance that wasn't declared as optional.
Instead of:
let brokenColor = UIColor(red: 1.0, green: 1.0, blue: 1.0, alpha: 1.0)!
Use this:
let color: UIColor! = UIColor(red: 1.0, green: 1.0, blue: 1.0, alpha: 1.0)
If you are using variables use following -
var color: UIColor = UIColor(red: CGFloat(red), green: CGFloat(green), blue: CGFloat(blue), alpha: CGFloat(alpha))
My particular iteration of this error happened when I was trying to set the border color of a button, and was getting the "extra argument 'green' in call" error, but once I stored it in a constant the true error arose, which was the constant not being CGColor. So this fixed it.
let borderColor:UIColor = UIColor(red: 23/255, green: 247/255, blue: 252/255, alpha: 1)
loginButton.layer.borderColor = borderColor.CGColor
Put a space after the semicolons in the call
green: 0, alpha: alpha