Making a wallpaper app in Kotlin. Can't seem to get the wallpaper to fit the user screen

I am making a wallpaper app. I am taking images from my firebase database. But when i tap on set as wallpaper button in my app the wallpaper leaves some empty black space at the top as well as at the bottom. Can't seem to get it to work even after trying out different similar answers on stackoverflow.

My wallpaper set activity :

import android.app.WallpaperManager
import android.content.Context
import android.graphics.Bitmap
import android.graphics.Canvas
import android.graphics.Point
import android.graphics.Rect
import android.os.Build
import android.os.Bundle
import android.view.WindowManager
import android.widget.Toast
import androidx.annotation.RequiresApi
import androidx.appcompat.app.AppCompatActivity
import androidx.core.view.drawToBitmap
import com.squareup.picasso.Picasso
import kotlinx.android.synthetic.main.activity_set_wallpaper.*
import java.io.IOException


class SetWallpaperActivity : AppCompatActivity() {
        var image: String?=null
    @RequiresApi(Build.VERSION_CODES.N)
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_set_wallpaper)

        val intent=intent
        image=intent.getStringExtra("image")
        Picasso.get().load(intent.getStringExtra("image")).into(image_set_wallpaper)
        val wm = this.getSystemService(Context.WINDOW_SERVICE) as WindowManager
        val display = wm.defaultDisplay
        val size = Point()
        display.getSize(size)

        val height: Int = size.y
        val width: Int = size.x

        set_wallpaper.setOnClickListener {
            val result:Bitmap=rl_iv.drawToBitmap()

            val wallpaperManager = WallpaperManager.getInstance(this)

            try {
                wallpaperManager.setBitmap(result)
                }
            catch (ex: IOException) {
                ex.printStackTrace()

            }

        }
        set_lock_wallpaper.setOnClickListener {
            val wpManager = WallpaperManager.getInstance(this)
            val myBitmap: Bitmap = rl_iv.drawToBitmap()
            try {
                wpManager.setBitmap(myBitmap, null, true, WallpaperManager.FLAG_LOCK)
            }
            catch (ex: IOException) {
                ex.printStackTrace()

            }
        }

    }
}

Its xml code is

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".SetWallpaperActivity">

    <RelativeLayout
        android:id="@+id/rl_iv"
        android:layout_width="match_parent"
        android:layout_height="match_parent">

    <ImageView
        android:id="@+id/image_set_wallpaper"
        android:layout_width="match_parent"
        android:scaleType="fitXY"
        android:layout_height="match_parent"
        android:layout_marginBottom="20dp"
        android:layout_marginTop="20dp"/>

    </RelativeLayout>

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:layout_marginBottom="20dp"
        android:orientation="horizontal">

    <Button
        android:id="@+id/set_wallpaper"
        android:layout_width="0dp"
        android:layout_weight="1"
        android:layout_height="wrap_content"
        android:text="SET as HOME SCREEN WALLPAPER"
        android:layout_alignParentBottom="true"
        android:layout_marginBottom="20dp"
        android:background="@drawable/shape_button_rounded"
        android:focusableInTouchMode="true"
        android:gravity="center"/>

    <Button
        android:id="@+id/set_lock_wallpaper"
        android:layout_width="0dp"
        android:layout_weight="1"
        android:layout_height="wrap_content"
        android:text="SET as LOCK SCREEN WALLPAPER"
        android:layout_alignParentBottom="true"
        android:layout_toRightOf="@id/set_wallpaper"
        android:background="@drawable/shape_button_rounded"
        android:focusableInTouchMode="true"
        android:layout_marginBottom="20dp"
        android:gravity="center"/>

    </LinearLayout>

</RelativeLayout>

Please suggest what i should edit in my code to get it work. I am new to this. Please use Kotlin to explain

You are getting the black space because of the margins in the XML file.

 <ImageView
        android:id="@+id/image_set_wallpaper"
        android:layout_width="match_parent"
        android:scaleType="fitXY"
        android:layout_height="match_parent"
        android:layout_marginBottom="20dp"
        android:layout_marginTop="20dp"/>

Remove the layout_margin-xx- in the ImageView attribute to get your desired output.

Your ImageView in the XML file should be like this:

 <ImageView
        android:id="@+id/image_set_wallpaper"
        android:layout_width="match_parent"
        android:scaleType="fitXY"
        android:layout_height="match_parent"/>

This should solve your problem.