DataGrid - Fix the issue with the focus method not setting the focus to the grid (T1308919) (DevExpress#33088)

(cherry picked from commit 4f47ff9)

Author: markallenramirez

e2e/testcafe-devextreme/tests/dataGrid/common/keyboardNavigation/keyboardNavigation.functional.ts

@@ -1,5 +1,6 @@
 import { Selector, ClientFunction } from 'testcafe';
 import { createScreenshotsComparer } from 'devextreme-screenshot-comparer';
+import Button from 'devextreme-testcafe-models/button';
 import DataGrid from 'devextreme-testcafe-models/dataGrid';
 import CommandCell from 'devextreme-testcafe-models/dataGrid/commandCell';
 import { ClassNames } from 'devextreme-testcafe-models/dataGrid/classNames';
@@ -6576,3 +6577,66 @@ test('The last cell should be focused after changing the page size (T1063530)',
     })();
   });
 });
+
+test('Focus should be set to the grid to allow keyboard navigation when the focus method is called (T1308919)', async (t) => {
+  // arrange
+  const button = new Button('#otherContainer');
+  const dataGrid = new DataGrid('#container');
+  const firstDataCell = dataGrid.getDataCell(0, 0);
+  const firstRow = dataGrid.getDataRow(0);
+  const secondRow = dataGrid.getDataRow(1);
+
+  // assert
+  await t.expect(dataGrid.isReady()).ok();
+
+  // act
+  await dataGrid.apiFocus(firstDataCell.element);
+
+  // assert
+  await t
+    .expect(firstDataCell.isFocused).ok()
+    .expect(firstRow.isFocusedRow).ok();
+
+  // act
+  await button.focus();
+
+  // assert
+  await t
+    .expect(button.isFocused)
+    .ok()
+    .expect(firstDataCell.isFocused)
+    .notOk('focus should be on the button')
+    .expect(firstRow.isFocusedRow)
+    .ok('row should still have the focused-row style');
+
+  // act
+  await t.pressKey('down');
+
+  // assert
+  await t
+    .expect(secondRow.isFocusedRow)
+    .notOk('grid kbn should not work');
+
+  // act
+  await t
+    .pressKey('enter') // trigger button click
+    .pressKey('down');
+
+  // assert
+  await t
+    .expect(secondRow.isFocusedRow)
+    .ok('grid is focused, so kbn should work');
+}).before(async () => {
+  await createWidget('dxDataGrid', {
+    dataSource: [{ id: 1, name: 'test1' }, { id: 2, name: 'test2' }],
+    keyExpr: 'id',
+    focusedRowEnabled: true,
+  });
+  await createWidget('dxButton', {
+    text: 'Focus Grid',
+    onClick() {
+      const grid = ($ as any)('#container').dxDataGrid('instance');
+      grid.focus();
+    },
+  }, '#otherContainer');
+});

packages/devextreme/js/__internal/grids/grid_core/keyboard_navigation/m_keyboard_navigation.ts

@@ -1674,6 +1674,12 @@ export class KeyboardNavigationController extends KeyboardNavigationControllerCo
           $focusElement
             .removeClass(CELL_FOCUS_DISABLED_CLASS)
             .removeClass(FOCUSED_CLASS);
+
+          const isTargetInGrid = gridCoreUtils.isElementInCurrentGrid(this, $(e.relatedTarget));
+          if (!isTargetInGrid) {
+            this._resetFocusedCell(true);
+            this._resetFocusedView();
+          }
         }
       });
       if (!skipFocusEvent) {

packages/testcafe-models/dataGrid/index.ts

@@ -742,16 +742,12 @@ export default class DataGrid extends GridCore {
     )();
   }
 
-  apiFocus(): Promise<void> {
+  apiFocus(cellElement?: Selector): Promise<void> {
     const { getInstance } = this;
 
     return ClientFunction(
-      () => (getInstance() as any).focus(),
-      {
-        dependencies: {
-          getInstance,
-        },
-      },
+      () => (getInstance() as any).focus(cellElement?.()),
+      { dependencies: { getInstance, cellElement } },
     )();
   }