refix

Author: Tucchhaa

packages/devextreme/js/__internal/grids/grid_core/pager/m_pager.ts

@@ -9,9 +9,9 @@ const PAGER_CLASS = 'pager';
 export const MAX_PAGES_COUNT = 10;
 
 const getPageIndex = function (dataController) {
-  if (dataController.pageSize() === 0) {
-    return dataController.pageCount();
-  }
+  // if (dataController.pageSize() === 0) {
+  //   return dataController.pageCount();
+  // }
 
   // eslint-disable-next-line radix
   return 1 + (parseInt(dataController.pageIndex()) || 0);

packages/devextreme/js/__internal/grids/grid_core/virtual_scrolling/m_virtual_scrolling.ts

@@ -1026,18 +1026,17 @@ export const data = (Base: ModuleType<DataController>) => class VirtualScrolling
   }
 
   private _getChangedLoadParams() {
-    const loadedPageParams = this.getLoadPageParams(true);
-    const { pageIndex, loadPageCount } = this.getLoadPageParams();
-    const pageIndexIsValid = this._pageIndexIsValid(pageIndex);
-    let result: any = null;
-
-    if (!this._isLoading && pageIndexIsValid && (pageIndex !== loadedPageParams.pageIndex || loadPageCount !== loadedPageParams.loadPageCount)) {
-      result = {
-        pageIndex,
-        loadPageCount,
-      };
+    const lastLoadPageParams = this.getLoadPageParams(true);
+    const loadPageParams = this.getLoadPageParams();
+    const pageIndexIsValid = this._pageIndexIsValid(loadPageParams.pageIndex);
+    const isParamsChanged = loadPageParams.pageIndex !== lastLoadPageParams.pageIndex
+      || loadPageParams.loadPageCount !== lastLoadPageParams.loadPageCount;
+
+    if (!this._isLoading && pageIndexIsValid && isParamsChanged) {
+      return loadPageParams;
     }
-    return result;
+
+    return null;
   }
 
   private _pageIndexIsValid(pageIndex) {
@@ -1061,18 +1060,16 @@ export const data = (Base: ModuleType<DataController>) => class VirtualScrolling
     const allLoadedInAppendMode = isAppendMode(this) && this.totalItemsCount() < lastRequiredItemCount;
     const isRepaintMode = this.option('editing.refreshMode') === 'repaint';
     const pageIndexIncreased = changedParams?.pageIndex > currentPageIndex;
-    let result = false;
 
     if (!dataSourceAdapter || (virtualPaging && checkLoading && ((isRepaintMode && viewportIsFilled) || (pageIndexIncreased || pageIndexNotChanged && allLoadedInAppendMode)))) {
-      return result;
+      return false;
     }
 
     if (virtualPaging && this._isLoading) {
       this._needUpdateViewportAfterLoading = true;
     }
 
     if (virtualPaging && changedParams) {
-      result = true;
       dataSourceAdapter.pageIndex(changedParams.pageIndex);
       dataSourceAdapter.loadPageCount(changedParams.loadPageCount);
       this._repaintChangesOnly = true;
@@ -1083,15 +1080,17 @@ export const data = (Base: ModuleType<DataController>) => class VirtualScrolling
         this._needUpdateDimensions = undefined;
       }).done(() => {
         const isLastPage = this.pageCount() > 0 && this.pageIndex() === this.pageCount() - 1;
-        (viewportChanging || isLastPage) && this._updateVisiblePageIndex();
+        // (viewportChanging || isLastPage) && this._updateVisiblePageIndex();
         if (this._needUpdateViewportAfterLoading) {
           this._needUpdateViewportAfterLoading = false;
           this.loadViewport({ checkLoadedParamsOnly: true });
         }
       });
+
+      return true;
     }
 
-    return result;
+    return false;
   }
 
   private loadViewport(params?) {
@@ -1116,6 +1115,8 @@ export const data = (Base: ModuleType<DataController>) => class VirtualScrolling
           useProcessedItemsCache: noPendingChangesInEditing,
           cancelEmptyChanges: true,
         });
+
+        this._updateVisiblePageIndex();
       }
     }
   }