Convert java threads to kotlin coroutines

app/src/main/java/exh/util/SearchOverride.kt

@@ -5,6 +5,7 @@ import eu.kanade.tachiyomi.source.model.MangasPage
 import eu.kanade.tachiyomi.source.online.UrlImportableSource
 import exh.GalleryAddEvent
 import exh.GalleryAdder
+import kotlinx.coroutines.flow.flow
 import rx.Observable
 
 private val galleryAdder by lazy {
@@ -17,19 +18,24 @@ private val galleryAdder by lazy {
 fun UrlImportableSource.urlImportFetchSearchManga(context: Context, query: String, fail: () -> Observable<MangasPage>): Observable<MangasPage> =
     when {
         query.startsWith("http://") || query.startsWith("https://") -> {
-            Observable.fromCallable {
-                val res = galleryAdder.addGallery(context, query, false, this)
-                MangasPage(
-                    (
-                        if (res is GalleryAddEvent.Success) {
-                            listOf(res.manga)
-                        } else {
-                            emptyList()
-                        }
-                        ),
-                    false
+            flow {
+                emit(
+                    galleryAdder.addGallery(context, query, false, this@urlImportFetchSearchManga)
                 )
             }
+                .asObservable()
+                .map { res ->
+                    MangasPage(
+                        (
+                            if (res is GalleryAddEvent.Success) {
+                                listOf(res.manga)
+                            } else {
+                                emptyList()
+                            }
+                            ),
+                        false
+                    )
+                }
         }
         else -> fail()
     }