如何使用SpannableString更改行间距？

Question

对于一个项目，我必须在EditText中编辑带有一些属性的文本，例如粗体，斜体，大小等。因此，我制作了一个CustomSpan，它实现StyleSpan，并具有我需要的所有属性。在我的代码下面：

class CustomSpan(
    val bold: Boolean = false,
    val italic: Boolean = false,
    val size: Int = 14,
    val color: Int = Color.BLACK,
    val letterSpacing: Float = 0f
): StyleSpan(when {
        bold && italic -> Typeface.BOLD_ITALIC
        bold -> Typeface.BOLD
        italic -> Typeface.ITALIC
        else -> Typeface.NORMAL
    }) {

    override fun updateDrawState(ds: TextPaint) {
        super.updateDrawState(ds)

        ds.color = color
        ds.textSize = size.toFloat()
        ds.letterSpacing = letterSpacing
    }

    override fun updateMeasureState(paint: TextPaint) {
        super.updateMeasureState(paint)

        paint.color = color
        paint.textSize = size.toFloat()
        paint.letterSpacing = letterSpacing
    }

    fun copy() : CustomSpan = CustomSpan(bold, italic, size, color, font, letterSpacing)

    fun copyWith(bold: Boolean? = null,
                 italic: Boolean? = null,
                 size: Int? = null,
                 color: Int? = null,
                 letterSpacing: Float? = null) : CustomSpan {

        return CustomSpan(
            bold = bold ?: this.bold,
            italic = italic ?: this.italic,
            size = size ?: this.size,
            color = color ?: this.color,
            letterSpacing = letterSpacing ?: this.letterSpacing
        )
    }
}

但是，我还需要更改EditText中各行之间的行距。为此，我想更改底部或填充，但是我不知道该怎么做。你有什么想法吗？

谢谢您的帮助，祝您愉快！

Answer 1

可能您可以通过baselineShift实现，您可以尝试这样的事情：

override fun updateDrawState(ds: TextPaint) {
    super.updateDrawState(ds)

    ds.color = color
    ds.textSize = size.toFloat()
    ds.letterSpacing = letterSpacing

    // here you might want to play with a specific value or ds.ascent/ds.descent..
    ds.baselineShift += 12
}