transitions

DetailsActivity.kt

override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_detailed)

        var url = intent.getStringExtra("link")
  // set same transition name
        detailImg.transitionName = url
        detailImg.setOnClickListener {
            finishAfterTransition()
        }

        postponeEnterTransition()
        Glide.with(this)
                .load(url)
                .listener(object : RequestListener<Drawable> {
                    override fun onLoadFailed(e: GlideException?,
                                              model: Any?,
                                              target: Target<Drawable>?,
                                              isFirstResource: Boolean): Boolean {
                        return false
                    }

                    override fun onResourceReady(resource: Drawable?,
                                                 model: Any?,
                                                 target: Target<Drawable>?,
                                                 dataSource: DataSource?,
                                                 isFirstResource: Boolean): Boolean {
                        val bmp = (resource as BitmapDrawable).bitmap
                        Palette.from(bmp).generate{p->
                            var color = p.getMutedColor(Color.parseColor("#fafafa"))
                            detailedRoot.setBackgroundColor(color)
                            startPostponedEnterTransition()
                        }
                        return false
                    }

                })
                .into(detailImg)
    }

FirstActivity.kt

override fun openRssDetails(dataHolder: DataHolder,
                                holder: ViewHolder) {
    val intent = Intent(this, DetailsActivity::class.java)
    val sharedElement = holder.icon
    intent.putExtra("dataHolder", dataHolder)
    val options = ActivityOptionsCompat.makeSceneTransitionAnimation(this,
                                                                     sharedElement,
                                                                     sharedElement.transitionName)
    startActivity(intent, options.toBundle())
}

styles.xml

<!-- Base application theme. -->
<style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
    <!-- Customize your theme here. -->
    <item name="android:windowContentTransitions">true</item>
    ...
</style>