Вторая часть по кэшу

2026-05-08 22:48:56 +03:00
parent d4c41b333a
commit a0b50b57b0
21 changed files with 237 additions and 377 deletions
@@ -0,0 +1,43 @@
+package chats.data.local.paging
+
+import androidx.paging.PagingSource
+import androidx.paging.PagingState
+import chats.data.local.dao.MessageDao
+import chats.data.local.database.MessageEntity
+
+/**
+ * PagingSource для загрузки сообщений из Room Database
+ */
+class MessagePagingSource(
+    private val chatId: String,
+    private val messageDao: MessageDao
+) : PagingSource<Int, MessageEntity>() {
+
+    companion object {
+        private const val PAGE_SIZE = 30
+    }
+
+    override suspend fun load(params: LoadParams<Int>): LoadResult<Int, MessageEntity> {
+        return try {
+            val position = params.key ?: 0 // Начинаем с 0
+            
+            val messages = messageDao.getMessagesPaged(
+                chatId = chatId,
+                offset = position,
+                limit = PAGE_SIZE
+            )
+
+            LoadResult.Page(
+                data = messages,
+                prevKey = if (position > 0) position - PAGE_SIZE else null,
+                nextKey = if (messages.isEmpty()) null else position + PAGE_SIZE
+            )
+        } catch (e: Exception) {
+            LoadResult.Error(e)
+        }
+    }
+
+    override fun getRefreshKey(state: PagingState<Int, MessageEntity>): Int? {
+        return state.anchorPosition
+    }
+}