A collection of TexView extension functions (justify fun for now)

TextViewExt.kt

import android.text.Spanned
import android.text.style.ImageSpan
import android.graphics.drawable.ColorDrawable
import android.text.SpannableString
import android.text.SpannableStringBuilder
import android.widget.TextView
import java.util.concurrent.atomic.AtomicBoolean

fun TextView.justify() {

    val isJustify = AtomicBoolean(false)

    val textString = this.text.toString()

    val textPaint = this.paint

    val builder = SpannableStringBuilder()

    this.post {
        if (!isJustify.get()) {

            val lineCount = this.lineCount
            val thisWidth = this.width

            for (i in 0 until lineCount) {

                val lineStart = this.layout.getLineStart(i)
                val lineEnd = this.layout.getLineEnd(i)

                val lineString = textString.substring(lineStart, lineEnd)

                if (i == lineCount - 1) {
                    builder.append(SpannableString(lineString))
                    break
                }

                val trimSpaceText = lineString.trim { it <= ' ' }
                val removeSpaceText = lineString.replace(" ".toRegex(), "")

                val removeSpaceWidth = textPaint.measureText(removeSpaceText)
                val spaceCount = (trimSpaceText.length - removeSpaceText.length).toFloat()

                val eachSpaceWidth = (thisWidth - removeSpaceWidth) / spaceCount

                val spannableString = SpannableString(lineString)
                for (j in 0 until trimSpaceText.length) {
                    val c = trimSpaceText[j]
                    if (c == ' ') {
                        val drawable = ColorDrawable(0x00ffffff)
                        drawable.setBounds(0, 0, eachSpaceWidth.toInt(), 0)
                        val span = ImageSpan(drawable)
                        spannableString.setSpan(span, j, j + 1, Spanned.SPAN_EXCLUSIVE_EXCLUSIVE)
                    }
                }

                builder.append(spannableString)
            }

            this.text = builder
            isJustify.set(true)
        }
    }
}