Convert the LeaderboardFragment to kotlin

Author: psh

app/src/main/java/fr/free/nrw/commons/profile/leaderboard/DataSourceClass.kt

@@ -5,8 +5,8 @@ import androidx.lifecycle.MutableLiveData
 import androidx.paging.PageKeyedDataSource
 import fr.free.nrw.commons.auth.SessionManager
 import fr.free.nrw.commons.mwapi.OkHttpJsonApiClient
-import fr.free.nrw.commons.profile.leaderboard.LeaderboardConstants.LOADED
-import fr.free.nrw.commons.profile.leaderboard.LeaderboardConstants.LOADING
+import fr.free.nrw.commons.profile.leaderboard.LeaderboardConstants.LoadingStatus.LOADING
+import fr.free.nrw.commons.profile.leaderboard.LeaderboardConstants.LoadingStatus.LOADED
 import io.reactivex.disposables.CompositeDisposable
 import io.reactivex.disposables.Disposable
 import timber.log.Timber
@@ -23,7 +23,7 @@ class DataSourceClass(
     private val limit: Int,
     private val offset: Int
 ) : PageKeyedDataSource<Int, LeaderboardList>() {
-    val progressLiveStatus: MutableLiveData<String> = MutableLiveData()
+    val progressLiveStatus: MutableLiveData<LeaderboardConstants.LoadingStatus> = MutableLiveData()
     private val compositeDisposable = CompositeDisposable()
 
 

app/src/main/java/fr/free/nrw/commons/profile/leaderboard/LeaderboardConstants.kt

@@ -19,17 +19,18 @@ object LeaderboardConstants {
      */
     const val USER_LINK_PREFIX: String = "https://commons.wikimedia.org/wiki/User:"
 
-    /**
-     * This is the a constant string for the state loading, when the pages are getting loaded we can
-     * use this constant to identify if we need to show the progress bar or not
-     */
-    const val LOADING: String = "Loading"
-
-    /**
-     * This is the a constant string for the state loaded, when the pages are loaded we can
-     * use this constant to identify if we need to show the progress bar or not
-     */
-    const val LOADED: String = "Loaded"
+    sealed class LoadingStatus {
+        /**
+         * This is the state loading, when the pages are getting loaded we can
+         * use this constant to identify if we need to show the progress bar or not
+         */
+        data object LOADING: LoadingStatus()
+        /**
+         * This is the state loaded, when the pages are loaded we can
+         * use this constant to identify if we need to show the progress bar or not
+         */
+        data object LOADED: LoadingStatus()
+    }
 
     /**
      * This API endpoint is to update the leaderboard avatar