在 Canvas 的左右两侧添加文本

Question

我正在创建一个自定义画布，如下图所示，左侧是文本，右侧还需要文本，如下图所示。我在左侧有部分文本，但是如何让文本在画布的左右显示？

这是我想要展示的内容：

当前代码：

private val textSize: Float = 70.toFloat()
private val groupSpacing = 100
private val paint = Paint()
init {
    paint.textSize = textSize
}
override fun onDrawOver(c: Canvas, parent: RecyclerView, state: RecyclerView.State) {
    for (i in 0 until parent.childCount) {
        val view = parent.getChildAt(i)
        val position = parent.getChildAdapterPosition(view)
        if (position == 0) {
            c.drawText("  Default", view.left.toFloat(),
                    view.top - groupSpacing / 2 + textSize / 3, paint)
        } else if (position == 1) {
            c.drawText("  Other", view.left.toFloat(),
                    view.top - groupSpacing / 2 + textSize / 3, paint)
        }
    }
}

上面的代码只显示默认

Answer 1

我能够通过以下方式实现这一目标：

class CustomItemDecorator(context: Context) : RecyclerView.ItemDecoration() {
    private var textSize: Float
    private val groupSpacing = 100
    private val paint = Paint()
    private val dragPaint = Paint()

    init {
        val dpSize: Int = context.resources.getDimensionPixelSize(R.dimen.decorator_font_size)
        textSize = dpSize * context.resources.displayMetrics.scaledDensity
        paint.textSize = textSize


        paint.color = context.resources.getColor(R.color.venue_grey)
        paint.typeface = Typeface.create(Typeface.DEFAULT, Typeface.BOLD)

        dragPaint.textSize = textSize
        dragPaint.color = context.resources.getColor(R.color.venue_grey)
    }

    override fun onDrawOver(c: Canvas, parent: RecyclerView, state: RecyclerView.State) {
        super.onDrawOver(c, parent, state)
        for (i in 0 until parent.childCount) {
            val view = parent.getChildAt(i)
            val position = parent.getChildAdapterPosition(view)
            if (position == 0) {
                paint.textAlign = Paint.Align.LEFT
                c.drawText("DEFAULT", 35f,
                        view.top - groupSpacing / 2 + textSize / 3, paint)
                dragPaint.textAlign = Paint.Align.RIGHT
                c.drawText("Some Text that is off to the right", view.right.toFloat() - 30,
                        view.top - groupSpacing / 2 + textSize / 3, dragPaint)
            } else if (position == 1) {
                val x = view.x + 30
                view.width
                //the alignment below may need to be adjusted to 80 or 90?
                paint.textAlign = Paint.Align.LEFT
                c.drawText("OTHER", 35f,
                        view.top - groupSpacing / 2 + textSize / 3, paint)
            }
        }
    }

    override fun getItemOffsets(outRect: Rect, view: View, parent: RecyclerView, state: RecyclerView.State) {
        if (parent.getChildAdapterPosition(view) == 0 || parent.getChildAdapterPosition(view) == 1) {
            outRect.set(0, groupSpacing, 0, 0)
        }
    }
}