How can you tell when a layout has been drawn?

Question

I have a custom view that draws a scrollable bitmap to the screen. In order to initialize it, i need to pass in the size in pixels of the parent layout object. But during th

Answer 1

Better with kotlin extension functions

inline fun View.waitForLayout(crossinline yourAction: () -> Unit) {
    val vto = viewTreeObserver
    vto.addOnGlobalLayoutListener(object : ViewTreeObserver.OnGlobalLayoutListener {
        override fun onGlobalLayout() {
            when {
                vto.isAlive -> {
                    vto.removeOnGlobalLayoutListener(this)
                    yourAction()
                }
                else -> viewTreeObserver.removeOnGlobalLayoutListener(this)
            }
        }
    })
}