Hi all! Is there a (out of the box) way to obtain the Hex value (as #aaxxyyzz) from a given `Color`?

# compose

[alorma]

Hi all! Is there a (out of the box) way to obtain the Hex value (as #aaxxyyzz) from a given Color?

[Kirill Grouchnikov]

Color.toArgb will give you an "encoded" integer, and then you can do "#%08X".format(argbInt) on it

[Kirill Grouchnikov]

Note that String.format is not in common, but rather only available for jvm at the moment - https://kotlinlang.org/api/latest/jvm/stdlib/kotlin.text/format.html

[ephemient]

in this case you could do something like

"#" + argbInt.toUInt().toString(radix = 16).padStart(8, '0')

in common, although ideally we'd have a common function for this https://youtrack.jetbrains.com/issue/KT-50309

[alorma]

hey, the first optioon worked perfect1

[alorma]

Just.. is ther a way to obtain it withut alpha?

[Colton Idle]

heres some code iw rote to do this

val textColor =
    Integer.toHexString(colorValue.toArgb())
        .padStart(8, '0')
        .toUpperCase(Locale.ROOT)
        .removeRange(0, 2)
val transparencyValue =
    if (shouldShowTransparencyValue)
        Integer.toHexString(colorValue.toArgb())
            .padStart(8, '0')
            .toUpperCase(Locale.ROOT)
            .take(2)
            .getTransparencyValue()
    else ""

[Colton Idle]

/** Helper to get a human readable alpha percentage from a 2 char hex code */
private fun String.getTransparencyValue(): String {
  return (this.toInt(16) / 255F * 100).roundToInt().toString() + "%"
}

[ephemient]

Integer is JVM-only. if you need common, you can do something like

argbInt.and(0xffffff).toString(radix = 16).padStart(6, '0')

to mask off the alpha

[Albert Chang]

I think you can just use "#%06X".format(color.toArgb() and 0xFFFFFF).

[Colton Idle]

@alorma let me know what you end up using. This code in my codebase looks super hacky and so if you write some ext function that you wanna share here, that works for me. 😄

[alorma]

I've end up using @Albert Chang version... but feeling like

[Colton Idle]

@alorma you should file a bug/FR for provide an extension from color to string hex value. I'd star it. Worth a shot. 😅

[ephemient]

the .format() functions are all JVM-only, I was providing non-JVM variants since that was brought up by Kirill

[ephemient]

I agree that (regardless of non-JVM-specific formatting) colors should have both parsing and stringification in Compose

[Kirill Grouchnikov]

It gets tricky. Or maybe not tricky, but there's an implicit assumption in here that sRGB color space is the one and only way to "represent" a color. So yes, it is a rather traditional default way of specifying color, but it's just one of more than a dozen color spaces supported by Compose.

[ephemient]

that's fair, but Color(Int) and Color.toArgb() are sRGB so it is special