Android - How can I change the color of a part of a String located in string.xml?

Question

In my application (in Kotlin), I have a string like this in my string.xml : <string name="buy_price">Buy %1$s %2$s for %3$s %4$s</string>

Where, for example %1$s is the amount, %2$s the item name, %3$s the amount and %4$s the fiat's name.

I want to set some colors for %1$s, %2$s, %3$s, ... . But I dont know how. I have been thinking to concatenate like 5 textView which store one part of the string but it's not very clean ...

Can you help me please

Answer 1

Spannable implementation:

val category = "Monitor"
val item = "LG - 2562"
val currency = "Rs"
val amount = "1234"

val text = getString(R.string.buy_price, category, item, currency, amount)

val categoryColor = Color.BLUE
val categoryStart = text.indexOf(category)
val categoryEnd = categoryStart + category.length

val itemColor = Color.GREEN
val itemStart = text.indexOf(item)
val itemEnd = itemStart + item.length

val currencyColor = Color.RED
val currencyStart = text.indexOf(currency)
val currencyEnd = currencyStart + currency.length

val amountColor = Color.MAGENTA
val amountStart = text.indexOf(amount)
val amountEnd = amountStart + amount.length

textView.text = SpannableStringBuilder(text).apply {
    setSpan(
        ForegroundColorSpan(categoryColor),
        categoryStart,
        categoryEnd,
        Spannable.SPAN_EXCLUSIVE_EXCLUSIVE
    )
    setSpan(
        ForegroundColorSpan(itemColor),
        itemStart,
        itemEnd,
        Spannable.SPAN_EXCLUSIVE_EXCLUSIVE
    )
    setSpan(
        ForegroundColorSpan(currencyColor),
        currencyStart,
        currencyEnd,
        Spannable.SPAN_EXCLUSIVE_EXCLUSIVE
    )
    setSpan(
        ForegroundColorSpan(amountColor),
        amountStart,
        amountEnd,
        Spannable.SPAN_EXCLUSIVE_EXCLUSIVE
    )
}

Result: