From 0c084510ea8f25ef9801a9615cdf0f15c43c53e0 Mon Sep 17 00:00:00 2001
From: Abdul Wadood <abdulwd97@gmail.com>
Date: Mon, 25 Nov 2019 19:18:26 +0530
Subject: [PATCH] Use filterIsInstance & mapNotNull to filter book titles

---
 .../kiwix/kiwixmobile/core/webserver/ZimHostActivity.kt   | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/core/src/main/java/org/kiwix/kiwixmobile/core/webserver/ZimHostActivity.kt b/core/src/main/java/org/kiwix/kiwixmobile/core/webserver/ZimHostActivity.kt
index 8b1f7926c..05c2c2e00 100644
--- a/core/src/main/java/org/kiwix/kiwixmobile/core/webserver/ZimHostActivity.kt
+++ b/core/src/main/java/org/kiwix/kiwixmobile/core/webserver/ZimHostActivity.kt
@@ -175,9 +175,11 @@ class ZimHostActivity : BaseActivity(), ZimHostCallbacks, ZimHostContract.View {
   }
 
   private fun saveHostedBooks(booksList: ArrayList<BooksOnDiskListItem>) {
-    sharedPreferenceUtil.hostedBooks =
-      booksList.filter { book -> book.isSelected && book is BookOnDisk && book.book.title != null }
-        .map { book -> (book as BookOnDisk).book.title }.toSet()
+    sharedPreferenceUtil.hostedBooks = booksList.asSequence()
+      .filter(BooksOnDiskListItem::isSelected)
+      .filterIsInstance<BookOnDisk>()
+      .mapNotNull { it.book.title }
+      .toSet()
   }
 
   private fun layoutServerStarted() {