CODEWITHSUNDEEP
iosobjective-cswift
Gagan_iOS
Gagan_iOS

Reputation: 4060

Set Color Intensity of UIView

I am working on the background colour of Views. Each view has different intensity level from 0 to 1. Now I have to set background colour as red based on Views intensity. I have written below code for red colour based on intensity 

view.backgroundColor = UIColor(colorLiteralRed: Float(1.0 - cellAlpha), green: 255.0, blue: 255.0, alpha: 1)  //UIColor.red intensity based on views

But I am unable to set red colour intensity using above?

Can anyone suggest how to set the intensity of a colour based on the float to vary from 0 to 1.? Please let me know If I have to explain my question.

Upvotes: 0

Views: 588

Answers (2)

meaning-matters
meaning-matters

Reputation: 22946

Assuming cellAlpha is between 0 and 1:

UIColor(colorLiteralRed: CGFloat(255.0 - cellAlpha * 255.0), green: 255.0, blue: 255.0, alpha: 1)

Note that it's CGFloat, not Float. But better to save you all these 255.0's:

UIColor(red: CGFloat(1.0 - cellAlpha), green: 1.0, blue: 1.0, alpha: 1.0)

However, it sounds as if you want to change the redness only. For this you'd need to use:

UIColor(hue: 0.0, saturation: CGFloat(1.0 - cellAlpha), brightness: 1.0 , alpha: 1.0)

I just put your CGFloat(1.0 - cellAlpha) as saturation; you probably need to adjust/correct that.

Upvotes: 1

Software2
Software2

Reputation: 2738

Notice how the other values go up to 255. You need to scale your value up to that as well.

let redScale = 255.0 * (1.0 - Float(cellAlpha))
view.backgroundColor = UIColor(colorLiteralRed: redScale, green: 255.0, blue: 255.0, alpha: 1)

Upvotes: 0

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