Hi there, Is there any kotlin native function or w...

# android

[Umar Ata]

Hi there,
Is there any kotlin native function or workaround I can use to count number of emojis in text
And also check if text has only emoji

I am using Unicode range to check if text contains surrogate but this feels not good

I also written code to use Character class but not confident if it is good to do loops for every text in list

[ephemient]

checking for surrogates is definitely the wrong thing to do, as it'll catch all non-BMP unicode characters, of which only a tiny fraction are emoji

[ephemient]

the only way to do this is to reference the Unicode standard, which changes approximately yearly; see https://unicode.org/reports/tr51/#Emoji_Properties_and_Data_Files for example

[ephemient]

you almost certainly will want to use a library like ICU to handle that for you

[Umar Ata]

What about this answer
https://stackoverflow.com/a/49849459/5794116

[ephemient]

if you're on Android, then 1. the platform has ICU built-in and 2. that answer uses an unbundled emoji library which gets updated, https://developer.android.com/jetpack/androidx/releases/emoji

[ephemient]

but that's not usable from Kotlin Native

[Umar Ata]

Ok
That means I can't make library that can be shared to both iOS and Android
Swift has built in support to give Boolean if it is emoji
https://developer.apple.com/documentation/swift/unicode/scalar/properties/3081577-isemoji

[Umar Ata]

I am looking for same in kotlin

[ephemient]

Swift does it by depending on ICU in its runtime, which is a significant pain to distribute for non-Apple targets. Kotlin doesn't, so…

[Umar Ata]

I am not able to find emoji sample for icu, I can see the docs, can you help me find one
My requirement is simple
I will get text that may have emoji or text or both
I need to know if text contains only emoji or both text and emoji, and if only emoji then I need the count

[Umar Ata]

this function returns true if text contains emoji

private fun containsEmoji(displayName: String): Boolean {
    val nameLength = displayName.length
    for (i in 0 until nameLength) {
        val hs = displayName[i]
        if (hs.code in 0xd800..0xdbff) {
            val ls = displayName[i + 1]
            val uc = (hs.code - 0xd800) * 0x400 + (ls.code - 0xdc00) + 0x10000
            if (uc in 0x1d000..0x1f77f) {
                return true
            }
        } else if (Character.isHighSurrogate(hs)) {
            val ls = displayName[i + 1]
            if (ls.code == 0x20e3) {
                return true
            }
        } else {
            // non surrogate
            if (hs.code in 0x2100..0x27ff) {
                return true
            } else if (hs.code in 0x2B05..0x2b07) {
                return true
            } else if (hs.code in 0x2934..0x2935) {
                return true
            } else if (hs.code in 0x3297..0x3299) {
                return true
            } else if (hs.code == 0xa9 || hs.code == 0xae || hs.code == 0x303d || hs.code == 0x3030 ||
                hs.code == 0x2b55 || hs.code == 0x2b1c || hs.code == 0x2b1b || hs.code == 0x2b50
            ) {
                return true
            }
        }
    }
    return false
}

[ephemient]

no, because it's missing emoji modifiers which can make other characters either become emoji or not