[ACS-10304] KN: personal files: Column resizing available via mouse but not accessible via keyboard (#11616)

lib/core/src/lib/datatable/directives/resizable/resize-handle.directive.spec.ts

@@ -161,5 +161,17 @@ describe('ResizeHandleDirective', () => {
             expect(resizableContainer.resizeByKeyboard).not.toHaveBeenCalled();
             expect(event.preventDefault).not.toHaveBeenCalled();
         });
+
+        it('should not prevent default on Shift+Tab to allow reverse focus navigation', () => {
+            const event = new KeyboardEvent('keydown', { key: 'Tab', shiftKey: true });
+            spyOn(event, 'preventDefault');
+            spyOn(event, 'stopPropagation');
+
+            directive.onKeydown(event);
+
+            expect(resizableContainer.resizeByKeyboard).not.toHaveBeenCalled();
+            expect(event.preventDefault).not.toHaveBeenCalled();
+            expect(event.stopPropagation).not.toHaveBeenCalled();
+        });
     });
 });

lib/core/src/lib/datatable/directives/resizable/resize-handle.directive.ts

@@ -34,32 +34,29 @@ export class ResizeHandleDirective implements OnInit, OnDestroy {
 
     @HostListener('keydown', ['$event'])
     onKeydown(event: KeyboardEvent): void {
-        let delta: number | null = null;
         const shiftDelta = 40;
-        if (event.shiftKey) {
-            delta += shiftDelta;
-        }
         const rightStepBaseValue = 20;
+        const shiftModifier = event.shiftKey ? shiftDelta : 0;
+
+        let delta: number | null = null;
+
         switch (event.key) {
             case 'ArrowRight':
             case 'ArrowUp':
-                delta += rightStepBaseValue;
+                delta = shiftModifier + rightStepBaseValue;
                 break;
             case 'ArrowLeft':
             case 'ArrowDown':
-                delta = -delta;
+                delta = -shiftModifier;
                 break;
             default:
-                break;
+                return;
         }
 
-        if (delta !== null) {
         event.preventDefault();
         event.stopPropagation();
-
         this.resizableContainer.resizeByKeyboard(delta);
     }
-    }
 
     ngOnInit(): void {
         this.zone.runOutsideAngular(() => {