Android orientation reverts back after back button is pressed

Question

I have 2 activities with a default orientation specified in the AndroidManifest.xml

<activity android:name="com.package.name.Activities.BrowseBooksActivity"
        android:screenOrientation="portrait"/>
<activity android:name="com.package.name.Activities.ReadBooksActivity"
        android:screenOrientation="landscape"/>

The user clicks an item in BrowseBooksActivity (in portrait) and the ReadBooksActivity (in landscape) is launched. But when the back button is pressed, BrowseBooksActivity initially starts as portrait for about a second and then reverts to landscape mode. How to fix this?

BrowseBooksActivity:

class BrowseBooksActivity : AppCompatActivity() {

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

    fetchBooks ()

    recyclerview_main.layoutManager = LinearLayoutManager(this)
}


fun fetchBooks () {

              // some processing

                runOnUiThread {
                    recyclerview_main.adapter = BrowseBooksAdapter(bookList)
                }}

BrowseBooksAdapter:

class BrowseBooksAdapter (val bookFeed: List<ResourcesList>): RecyclerView.Adapter<CustomViewHolder>()  {

    override fun getItemCount(): Int {
        return bookFeed.count()
    }

    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): CustomViewHolder {
        val layoutInflater = LayoutInflater.from(parent.context)
        val cellForRow = layoutInflater.inflate(R.layout.browsebooks_layout, parent, false)
        return CustomViewHolder(cellForRow)
    }

    override fun onBindViewHolder(holder: CustomViewHolder, position: Int) {
        holder.v.textview_booktitle?.text = bookFeed[position].name
        Picasso.get().load(bookFeed[position].coverURI).into(holder.v.ImageView_bookcover)
        holder.bookFeed = bookFeed[position]
    }
}

class CustomViewHolder(val v: View, var bookFeed : ResourcesList? = null): RecyclerView.ViewHolder(v) {

    init {
        v.setOnClickListener {
            val intent = Intent (v.context, ReadBooksActivity::class.java)

            intent.putExtra("ID", bookFeed?.id)

            v.context.startActivity(intent)
        }

    }
    }

ReadBooksActivity:

class ReadBooksActivity : Activity() {

private var mCurlView: CurlView? = null
private var newbookList : ResourcesList? = null

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

    var index = 0
    if (lastNonConfigurationInstance != null) {
        index = lastNonConfigurationInstance as Int
    }

    mCurlView = findViewById(R.id.curl)
    mCurlView!!.setSizeChangedObserver(SizeChangedObserver())
    mCurlView!!.setCurrentIndex(index)
    mCurlView!!.setBackgroundColor(-0xdfd7d0)

    var bookId = intent.getIntExtra("ID", 0)

    Thread (Runnable {

            //some processing to load data to mBitmaps
        mCurlView!!.setBitmapProvider(BitmapProvider(mBitmaps))

        }).start()


    mCurlView!!.setEnableTouchPressure(true)
    mCurlView!!.set2PagesLandscape(true)


}

score 1 · Answer 1 · answered Apr 23 '18 at 05:41

1

Seems to be bug when we have single activity as portrait in app. Below link might help : Android 8.1 screen orientation issue: flipping to landscape a portrait screen

answered Apr 23 '18 at 05:41

Sahil

952
1
7
14

score 0 · Accepted Answer · answered Apr 24 '18 at 01:14

For anyone still having problems with this bug, here is a workaround provided in the link shared by Sahil.

On the "second" activity, add the following:

    onCreate(){
       setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_SENSOR_LANDSCAPE);
}

onPause(){ 
      if (android.os.Build.VERSION.SDK_INT >= 27) {
             setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_SENSOR_PORTRAIT);
      }
}

onResume(){
      if (android.os.Build.VERSION.SDK_INT >= 27) {
             setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_SENSOR_LANDSCAPE);
      }
}

Android orientation reverts back after back button is pressed

2 Answers2