Custom View Styling
class ProgressButton @JvmOverloads constructor(
context: Context,
attrs: AttributeSet? = null,
defStyleAttr: Int = R.attr.progressButtonStyle,
defStyleRes: Int = R.style.ProgressButtonStyle
) : View(context, attrs, defStyleAttr, defStyleRes) {
val typedArray = context.obtainStyledAttributes(attrs, R.styleable.ProgressButton, defStyleAttr, defStyleRes)