yoonseopshin

import android.os.Build
import android.security.KeyPairGeneratorSpec
import android.security.keystore.KeyGenParameterSpec
import android.security.keystore.KeyProperties
import android.util.Base64
import timber.log.Timber
import java.math.BigInteger
import java.security.GeneralSecurityException
import java.security.KeyPairGenerator
import java.security.KeyStore

yoonseopshin

Hexadecimal color code for transparency

How to set transparency with hex value ?

For example, you want to set 40% alpha transparence to #000000 (black color), you need to add 66 like this #66000000.

Download This sample on Google Play Store

yoonseopshin

data class RGBA(var red: Long = 0, var green: Long = 0, var blue: Long = 0, var alpha: Double = 0.0)

fun main() {
	// rgba-order
	val base = RGBA(124, 77, 255, 0.06)
	val added = RGBA(255, 255, 255, 0.06)
    
	val mix = RGBA()
	// alpha
	mix.alpha = 1 - (1 - added.alpha) * (1 - base.alpha)

yoonseopshin

class CustomSpeedLinearLayoutManager(
        context: Context,
        private val offsetProvider: (position: Int) -> Int
    ) : LinearLayoutManager(context) {

        override fun smoothScrollToPosition(recyclerView: RecyclerView, state: RecyclerView.State, position: Int) {
            val viewHolder = recyclerView.findViewHolderForAdapterPosition(position)?.itemView
            val itemHeight = viewHolder?.height ?: 0
            
            // just sample value, speed up if viewholder's height is long enough.