Minor refactoring

data/src/main/java/tachiyomi/data/source/SourcePagingSource.kt

@@ -0,0 +1,66 @@
+package tachiyomi.data.source
+
+import androidx.paging.PagingSource
+import androidx.paging.PagingState
+import eu.kanade.tachiyomi.source.CatalogueSource
+import eu.kanade.tachiyomi.source.model.FilterList
+import eu.kanade.tachiyomi.source.model.MangasPage
+import eu.kanade.tachiyomi.source.model.SManga
+import tachiyomi.core.util.lang.awaitSingle
+import tachiyomi.core.util.lang.withIOContext
+
+typealias SourcePagingSourceType = PagingSource<Long, SManga>
+
+abstract class SourcePagingSource(
+    protected val source: CatalogueSource,
+) : SourcePagingSourceType() {
+
+    abstract suspend fun requestNextPage(currentPage: Int): MangasPage
+
+    override suspend fun load(params: LoadParams<Long>): LoadResult<Long, SManga> {
+        val page = params.key ?: 1
+
+        val mangasPage = try {
+            withIOContext {
+                requestNextPage(page.toInt())
+                    .takeIf { it.mangas.isNotEmpty() }
+                    ?: throw NoResultsException()
+            }
+        } catch (e: Exception) {
+            return LoadResult.Error(e)
+        }
+
+        return LoadResult.Page(
+            data = mangasPage.mangas,
+            prevKey = null,
+            nextKey = if (mangasPage.hasNextPage) page + 1 else null,
+        )
+    }
+
+    override fun getRefreshKey(state: PagingState<Long, SManga>): Long? {
+        return state.anchorPosition?.let { anchorPosition ->
+            val anchorPage = state.closestPageToPosition(anchorPosition)
+            anchorPage?.prevKey ?: anchorPage?.nextKey
+        }
+    }
+}
+
+class SourceSearchPagingSource(source: CatalogueSource, val query: String, val filters: FilterList) : SourcePagingSource(source) {
+    override suspend fun requestNextPage(currentPage: Int): MangasPage {
+        return source.fetchSearchManga(currentPage, query, filters).awaitSingle()
+    }
+}
+
+class SourcePopularPagingSource(source: CatalogueSource) : SourcePagingSource(source) {
+    override suspend fun requestNextPage(currentPage: Int): MangasPage {
+        return source.fetchPopularManga(currentPage).awaitSingle()
+    }
+}
+
+class SourceLatestPagingSource(source: CatalogueSource) : SourcePagingSource(source) {
+    override suspend fun requestNextPage(currentPage: Int): MangasPage {
+        return source.fetchLatestUpdates(currentPage).awaitSingle()
+    }
+}
+
+class NoResultsException : Exception()