diff --git a/core/src/main/java/org/kiwix/kiwixmobile/core/main/CoreMainActivity.java b/core/src/main/java/org/kiwix/kiwixmobile/core/main/CoreMainActivity.java
deleted file mode 100644
index f49e3f3c7..000000000
--- a/core/src/main/java/org/kiwix/kiwixmobile/core/main/CoreMainActivity.java
+++ /dev/null
@@ -1,51 +0,0 @@
-/*
- * Kiwix Android
- * Copyright (c) 2019 Kiwix <android.kiwix.org>
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program. If not, see <http://www.gnu.org/licenses/>.
- *
- */
-
-package org.kiwix.kiwixmobile.core.main;
-
-import android.content.Intent;
-import android.os.Bundle;
-import androidx.fragment.app.Fragment;
-import org.jetbrains.annotations.Nullable;
-import org.kiwix.kiwixmobile.core.R;
-import org.kiwix.kiwixmobile.core.base.BaseActivity;
-
-public abstract class CoreMainActivity extends BaseActivity implements WebViewProvider {
-  @Override protected void onCreate(@Nullable Bundle savedInstanceState) {
-    super.onCreate(savedInstanceState);
-    setContentView(R.layout.activity_new_navigation);
-  }
-
-  @Override protected void onActivityResult(int requestCode, int resultCode,
-    @androidx.annotation.Nullable Intent data) {
-    super.onActivityResult(requestCode, resultCode, data);
-
-    for (Fragment it : getSupportFragmentManager().getFragments()) {
-      it.onActivityResult(requestCode, resultCode, data);
-    }
-  }
-
-  @androidx.annotation.Nullable @Override public KiwixWebView getCurrentWebView() {
-    for (Fragment frag : getSupportFragmentManager().getFragments()) {
-      if (frag instanceof WebViewProvider) {
-        return ((WebViewProvider) frag).getCurrentWebView();
-      }
-    }
-    return null;
-  }
-}
diff --git a/core/src/main/java/org/kiwix/kiwixmobile/core/main/CoreMainActivity.kt b/core/src/main/java/org/kiwix/kiwixmobile/core/main/CoreMainActivity.kt
new file mode 100644
index 000000000..cb742d60e
--- /dev/null
+++ b/core/src/main/java/org/kiwix/kiwixmobile/core/main/CoreMainActivity.kt
@@ -0,0 +1,51 @@
+/*
+ * Kiwix Android
+ * Copyright (c) 2019 Kiwix <android.kiwix.org>
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+package org.kiwix.kiwixmobile.core.main
+
+import android.content.Intent
+import android.os.Bundle
+import org.kiwix.kiwixmobile.core.R
+import org.kiwix.kiwixmobile.core.base.BaseActivity
+
+abstract class CoreMainActivity : BaseActivity(), WebViewProvider {
+  override fun onCreate(savedInstanceState: Bundle?) {
+    super.onCreate(savedInstanceState)
+    setContentView(R.layout.activity_new_navigation)
+  }
+
+  override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) {
+    super.onActivityResult(requestCode, resultCode, data)
+    supportFragmentManager.fragments.forEach { it.onActivityResult(requestCode, resultCode, data) }
+  }
+
+  override fun onRequestPermissionsResult(
+    requestCode: Int,
+    permissions: Array<out String>,
+    grantResults: IntArray
+  ) {
+    super.onRequestPermissionsResult(requestCode, permissions, grantResults)
+    supportFragmentManager.fragments.forEach {
+      it.onRequestPermissionsResult(requestCode, permissions, grantResults)
+    }
+  }
+
+  override fun getCurrentWebView(): KiwixWebView? {
+    return supportFragmentManager.fragments.filterIsInstance<WebViewProvider>().first()
+      .getCurrentWebView()
+  }
+}