部分角丸カスタムView

自分用のメモなので解説はないです。

RoundedCornersView.kt

import android.content.Context
import android.content.res.Resources
import android.graphics.Canvas
import android.graphics.Path
import android.graphics.RectF
import android.util.AttributeSet
import android.widget.FrameLayout

/**
 * 角丸View.
 */
class RoundedCornersView(context: Context, attrs: AttributeSet?) : FrameLayout(context, attrs) {

    private val round = 5.toPx.toFloat()
    private val path = Path()

    init {
        setWillNotDraw(false)
    }

    override fun onDraw(canvas: Canvas) {
        path.addRoundRect(getRectF(canvas), round, round, Path.Direction.CW)
        // StartTop, EndTopだけ角丸にする.
        path.addRoundRect(getRectF(canvas), floatArrayOf(10f, 10f, 10f, 10f, 0f, 0f, 0f, 0f), Path.Direction.CW)
        canvas.clipPath(path)
        super.onDraw(canvas)
    }

    private fun getRectF(canvas: Canvas): RectF = RectF(canvas.clipBounds)


    private val Int.toPx: Int
        get() = (this * Resources.getSystem().displayMetrics.density).toInt()
}