I have a textfield that has a sum attached to the output
just wondering how do I write a line that has the effect of:
If the final figure is less then zero the text colour is red
and if the output is positive figure text is another colour.
txtsum.textColor = UIColor (red: 255.0, green: 0.0, blue: 0.0, alpha: 1.0)
This works to set the colour as red.
Just don’t know how to write a statement( if thats what I need) guessing its if and else statement
This my output line
txtsum!.text = NSString(format: "%.2f", sum1)
It is indeed a simple if statement. Run this every time you change the text of the text field:
if sum1 < 0 {
txtsum.textColor = UIColor(red: 255.0, green: 0.0, blue: 0.0, alpha: 1.0)
}
else {
txtsum.textColor = UIColor(red: 0.0, green: 0.0, blue: 0.0, alpha: 1.0)
}
Related
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
I am trying to change the text colour in a UITextField using the following code (RGBA value) however it just appears white, or clear, I'm not too sure as the background is white itself.
passwordTextField.textColor = UIColor(red: CGFloat(202.0), green: CGFloat(228.0), blue: CGFloat(230.0), alpha: CGFloat(100.0))
passwordTextField.returnKeyType = UIReturnKeyType.Done
passwordTextField.placeholder = "Password"
passwordTextField.backgroundColor = UIColor.clearColor()
passwordTextField.borderStyle = UITextBorderStyle.RoundedRect
passwordTextField.font = UIFont(name: "Avenir Next", size: 14)
passwordTextField.textAlignment = NSTextAlignment.Center
passwordTextField.secureTextEntry = true
RGB values for UIColor are between 0 and 1 (see the documentation "specified as a value from 0.0 to 1.0")
You need to divide your numbers by 255:
passwordTextField.textColor = UIColor(red: CGFloat(202.0/255.0), green: CGFloat(228.0/255.0), blue: CGFloat(230.0/255.0), alpha: CGFloat(1.0))
Another thing, you don't need to create CGFloats:
passwordTextField.textColor = UIColor(red:202.0/255.0, green:228.0/255.0, blue:230.0/255.0, alpha:1.0)
Using convenience init ( code like a pro )
Step 1
extension UIColor {
convenience init(r: CGFloat, g: CGFloat, b: CGFloat) {
self.init(red: r/255, green: g/255, blue: b/255, alpha: 1)
}
}
Usage
//let color = UIColor(red: 202/255, green: 228/255, blue: 230/255, alpha: 1) ☠️
let color = UIColor(r: 202, g: 228, b: 230) // 😍
try this instead :
passwordTextField.textColor = UIColor(red: 0.792, green: 0.894, blue: 0.901, alpha: 1.0
Always put substituted values. 202/255 = 0.792
red, green, blue and alpha are supposed to be between 0.0 and 1.0.
As others mentioned, UIColor components are normalized in the range 0.0 ~ 1.0 (I think wide color gamuts are the exception, but haven't researched that yet).
A conveninet extension to the UIColor class will let you use values in the 0~255 range (like those obtained from various inspectors and image editing tools):
import UIKit
extension UIColor {
convenience init(
redByte red:UInt8,
greenByte green:UInt8,
blueByte blue:UInt8,
alphaByte alpha:UInt8
) {
self.init(
red: CGFloat(red )/255.0,
green: CGFloat(green)/255.0,
blue: CGFloat(blue )/255.0,
alpha: CGFloat(alpha)/255.0
)
}
}
UIColor convenient methods, from Integers, or from Hex.
extension UIColor {
convenience init(red: Int, green: Int, blue: Int, alpha: CGFloat) {
assert(red >= 0 && red <= 255, "Invalid red component")
assert(green >= 0 && green <= 255, "Invalid green component")
assert(blue >= 0 && blue <= 255, "Invalid blue component")
self.init(red: CGFloat(red) / 255.0, green: CGFloat(green) / 255.0, blue: CGFloat(blue) / 255.0, alpha: alpha)
}
convenience init(rgb: Int, alpha: CGFloat = 1) {
self.init(
red: (rgb >> 16) & 0xFF,
green: (rgb >> 8) & 0xFF,
blue: rgb & 0xFF,
alpha: alpha
)
}
}
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
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
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