AspectRatioCardView Android - Kotlin

AspectRatioCardView.kt

class AspectRatioCardView @JvmOverloads constructor(
  context: Context,
  attrs: AttributeSet? = null,
  defStyleAttr: Int = 0
) : CardView(context, attrs, defStyleAttr) {

  private var ratio = 1.0f

  init {
    attrs?.let {
      val typedArray = context.obtainStyledAttributes(attrs, R.styleable.AspectRatioCardView)
      ratio = typedArray.getFloat(R.styleable.AspectRatioCardView_arcv_ratio, 1.0f)
      typedArray.recycle()
    }
  }

  override fun onMeasure(
    widthMeasureSpec: Int,
    heightMeasureSpec: Int
  ) {
    super.onMeasure(widthMeasureSpec, heightMeasureSpec)

    val widthWithoutPadding = measuredWidth - paddingLeft - paddingRight
    val maxHeight = (widthWithoutPadding * ratio).toInt()

    val width = widthWithoutPadding + paddingLeft + paddingRight
    val height = maxHeight + paddingTop + paddingBottom

    super.onMeasure(
        View.MeasureSpec.makeMeasureSpec(width, View.MeasureSpec.EXACTLY),
        View.MeasureSpec.makeMeasureSpec(height, View.MeasureSpec.EXACTLY)
    )
  }
}

attrs_aspect_ratio_card_view.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>
  <declare-styleable name="AspectRatioCardView">
    <attr format="float" name="arcv_ratio"/>
  </declare-styleable>
</resources>