How to add bulleted list to android application?

Question

I have googled my question but there is not working answer provided. How do add a bulleted list to my textview.

Answer 1

Ready-to-use Kotlin extension

fun List.toBulletedList(): CharSequence {
    return SpannableString(this.joinToString("\n")).apply {
        this@toBulletedList.foldIndexed(0) { index, acc, span ->
            val end = acc + span.length + if (index != this@toBulletedList.size - 1) 1 else 0
            this.setSpan(BulletSpan(16), acc, end, 0)
            end
        }
    }
}

Usage:

val bulletedList = listOf("One", "Two", "Three").toBulletedList()
label.text = bulletedList

Colors and size:

To change bullet color or size use CustomBulletSpan instead of BulletSpan

package com.fbs.archBase.ui.spans

import android.graphics.Canvas
import android.graphics.Color
import android.graphics.Paint
import android.text.Layout
import android.text.Spanned
import android.text.style.LeadingMarginSpan
import androidx.annotation.ColorInt

class CustomBulletSpan(
        private val bulletRadius: Int = STANDARD_BULLET_RADIUS,
        private val gapWidth: Int = STANDARD_GAP_WIDTH,
        @ColorInt private val circleColor: Int = STANDARD_COLOR
) : LeadingMarginSpan {

    private companion object {
        val STANDARD_BULLET_RADIUS = Screen.dp(2)
        val STANDARD_GAP_WIDTH = Screen.dp(8)
        const val STANDARD_COLOR = Color.BLACK
    }

    private val circlePaint = Paint().apply {
    color = circleColor
        style = Paint.Style.FILL
        isAntiAlias = true
    }

    override fun getLeadingMargin(first: Boolean): Int {
        return 2 * bulletRadius + gapWidth
    }

    override fun drawLeadingMargin(
            canvas: Canvas, paint: Paint, x: Int, dir: Int,
            top: Int, baseline: Int, bottom: Int,
            text: CharSequence, start: Int, end: Int,
            first: Boolean,
            layout: Layout?
    ) {
        if ((text as Spanned).getSpanStart(this) == start) {
            val yPosition = (top + bottom) / 2f
            val xPosition = (x + dir * bulletRadius).toFloat()

            canvas.drawCircle(xPosition, yPosition, bulletRadius.toFloat(), circlePaint)
        }
    }
}