android - 具有换行符的 BulletSpan 在 Android 中不起作用

Question

我正在使用定制的 BulletSpan。我想显示带有'\n'的长文本。除了带有'\n'的文本行之外，每一行都很好。Bulleetspan 不能将缩进应用于换行文本。这就是结果。

最后一个文本是一个文本。并且文本里面有'\n'。

代码是..

class MainActivity : AppCompatActivity() {
private lateinit var binding: ActivityMainBinding

override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    binding = ActivityMainBinding.inflate(layoutInflater)
    setContentView(binding.root)

    val source = listOf("Spans are powerful markup objects that you can use to style text at a character or paragraph level.",
    "By attaching spans to text objects, you can change text in a variety of ways, ",
    "including adding color, making the text clickable,\scaling the text size,\nand drawing text in a customized way.")

    val sb = SpannableStringBuilder()

    for (i in source.indices) {
        val length = sb.length
        sb.append(source[i])
        sb.append("\n")
        sb.setSpan(CustomBulletSpan(
            bulletRadius = dip(8),
            gapWidth = dip(14),
            mColor = color(),
            mWantColor = true
        ), length, length + 1, Spanned.SPAN_INCLUSIVE_EXCLUSIVE)
    }

    binding.tvResult.text = sb

}

private fun dip(dp: Int): Int {
    return TypedValue.applyDimension(
        TypedValue.COMPLEX_UNIT_DIP,
        dp.toFloat(),
        resources.displayMetrics
    ).toInt()
}

private fun color(): Int {
    return ContextCompat.getColor(applicationContext, R.color.gray);
} 
}

和 customBullentSpan 代码是..

class CustomBulletSpan(
val bulletRadius: Int = STANDARD_BULLET_RADIUS,
val gapWidth: Int = STANDARD_GAP_WIDTH,
val mColor: Int = STANDARD_COLOR,
val mWantColor: Boolean = false
) : LeadingMarginSpan {

companion object {
    // Bullet is slightly bigger to avoid aliasing artifacts on mdpi devices.
    private const val STANDARD_BULLET_RADIUS = 4
    private const val STANDARD_GAP_WIDTH = 2
    private const val STANDARD_COLOR = 0
}

private var mBulletPath: Path? = null


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

override fun drawLeadingMargin(
    c: Canvas,
    p: 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 style = p.style
        p.style = Paint.Style.FILL
        var oldColor = 0
        if (mWantColor) {
            oldColor = p.color
            p.color = mColor
        }

        val yPosition = if (layout != null) {
            val line = layout.getLineForOffset(start)
            layout.getLineBaseline(line).toFloat() - bulletRadius * 1.3f
        } else {
            (top + bottom) / 1.3f
        }

        val xPosition = (x + dir * bulletRadius).toFloat()

        if (c.isHardwareAccelerated) {
            if (mBulletPath == null) {
                mBulletPath = Path()
                mBulletPath!!.addCircle(0.0f, 0.0f, bulletRadius.toFloat(), Path.Direction.CW)
            }
            c.save()
            c.translate(xPosition, yPosition)
            c.drawPath(mBulletPath!!, p)
            c.restore()
        } else {
            c.drawCircle(xPosition, yPosition, bulletRadius.toFloat(), p)
        }

        if (mWantColor) {
            p.color = oldColor
        }

        p.style = style
    }
 }
}

我怎么解决这个问题？？

Answer 1

您可以只获取字符串并按 \n 拆分并应用 span

    var len = 0

    for (i in source.indices) {

        if (source[i].contains("\n")) {
            val splitted = source[i].split("\n")
            for (k in splitted.indices) {
                len = sb.length
                sb.append(splitted[k])
                sb.append("\n")
                sb.setSpan(
                        CustomBulletSpan(
                                bulletRadius = dip(8),
                                gapWidth = dip(14),
                                mColor = color(),
                                mWantColor = true
                        ), len, len + 1, Spanned.SPAN_INCLUSIVE_EXCLUSIVE
                )
            }
        } else {
            len = sb.length
            sb.append(source[i])
            sb.append("\n")
            sb.setSpan(
                    CustomBulletSpan(
                            bulletRadius = dip(8),
                            gapWidth = dip(14),
                            mColor = color(),
                            mWantColor = true
                    ), len, len + 1, Spanned.SPAN_INCLUSIVE_EXCLUSIVE
            )

        }
    }

另一种方法是拆分并将其添加到新列表并迭代相同并应用跨度

  val newList = mutableListOf<String>()
    for (item in source) {
       if(item.contains("\n")) {
           val split = item.split("\n")
           for (splitItem in split){
               newList.add(splitItem)
           }
       } else{
           newList.add(item)
       }
    }