Merge pull request #225 from tunjid/fix-paging-source

Fix unresolved use of ITEMS_PER_PAGE

Author: tunjid

basic/end/app/src/main/java/com/example/android/codelabs/paging/data/ArticlePagingSource.kt

@@ -68,10 +68,10 @@ class ArticlePagingSource : PagingSource<Int, Article>() {
     // The refresh key is used for the initial load of the next PagingSource, after invalidation
     override fun getRefreshKey(state: PagingState<Int, Article>): Int? {
         // In our case we grab the item closest to the anchor position
-        // then return its id - ITEMS_PER_PAGE as a buffer
+        // then return its id - (state.config.pageSize / 2) as a buffer
         val anchorPosition = state.anchorPosition ?: return null
         val article = state.closestItemToPosition(anchorPosition) ?: return null
-        return ensureValidKey(key = article.id - ITEMS_PER_PAGE)
+        return ensureValidKey(key = article.id - (state.config.pageSize / 2))
     }
 
     /**

basic/end/app/src/main/java/com/example/android/codelabs/paging/ui/ArticleViewModel.kt

@@ -24,7 +24,6 @@ import androidx.paging.PagingData
 import androidx.paging.cachedIn
 import com.example.android.codelabs.paging.data.Article
 import com.example.android.codelabs.paging.data.ArticleRepository
-import com.example.android.codelabs.paging.data.ITEMS_PER_PAGE
 import kotlinx.coroutines.flow.Flow
 
 private const val ITEMS_PER_PAGE = 50