Focusable Linear Smooth Scrolling for use with Android TV and Recycler View

FocusableLinearLayoutManager.kt

/**
 * The MIT License (MIT)
 * Copyright (c) 2018 David Carver
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 * <p>
 * The above copyright notice and this permission notice shall be included
 * in all copies or substantial portions of the Software.
 * <p>
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS
 * OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF
 * OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

import android.content.Context
import android.support.v7.widget.LinearLayoutManager
import android.support.v7.widget.RecyclerView

class FocusableLinearLayoutManager(val context: Context) : LinearLayoutManager(context) {

   override fun smoothScrollToPosition(recyclerView: RecyclerView?, state: RecyclerView.State?, position: Int) {
     val smoothScroller = FocusableLinearSmoothScroller(context)
     smoothScroller.targetPosition = position
     startSmoothScroll(smoothScroller)
  }
}

FocusableLinearSmoothScroller.kt

/**
 * The MIT License (MIT)
 * Copyright (c) 2018 David Carver
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 * <p>
 * The above copyright notice and this permission notice shall be included
 * in all copies or substantial portions of the Software.
 * <p>
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS
 * OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF
 * OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

import android.content.Context
import android.support.v7.widget.LinearSmoothScroller
import android.support.v7.widget.RecyclerView
import android.view.View

class FocusableLinearSmoothScroller(context: Context) : LinearSmoothScroller(context) {

  var targetView : View? = null

  override fun onTargetFound(targetView: View?, state: RecyclerView.State?, action: Action?) {
    super.onTargetFound(targetView, state, action)
    this.targetView = targetView
  }

  override fun onStop() {
    super.onStop()

    if (targetView != null && !targetView!!.hasFocus()) {
      targetView!!.requestFocusFromTouch()
    }
  }
}