fix(dockview-core): use visibility:hidden instead of display:none for always renderer

Prevents resize-to-0x0 events when panels with renderer='always' are hidden,
which disrupted virtualized components (e.g. data grids) that manage their
own scrollbars. Adds pointer-events:none to preserve drag-and-drop behaviour
on hidden overlays. Closes #1063.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: mathuo

packages/dockview-core/src/__tests__/overlay/overlayRenderContainer.spec.ts

@@ -169,7 +169,8 @@ describe('overlayRenderContainer', () => {
         expect(panelContentEl.parentElement).toBe(container);
         expect(container.parentElement).toBe(parentContainer);
 
-        expect(container.style.display).toBe('');
+        expect(container.style.visibility).toBe('');
+        expect(container.style.pointerEvents).toBe('');
 
         expect(container.style.left).toBe('50px');
         expect(container.style.top).toBe('100px');
@@ -181,7 +182,8 @@ describe('overlayRenderContainer', () => {
 
         onDidDimensionsChange.fire({});
         await exhaustAnimationFrame();
-        expect(container.style.display).toBe('');
+        expect(container.style.visibility).toBe('');
+        expect(container.style.pointerEvents).toBe('');
 
         expect(container.style.left).toBe('49px');
         expect(container.style.top).toBe('99px');
@@ -193,22 +195,25 @@ describe('overlayRenderContainer', () => {
 
         (panel as Writable<IDockviewPanel>).api.isVisible = false;
         onDidVisibilityChange.fire({});
-        expect(container.style.display).toBe('none');
+        expect(container.style.visibility).toBe('hidden');
+        expect(container.style.pointerEvents).toBe('none');
         expect(
             referenceContainer.element.getBoundingClientRect
         ).toHaveBeenCalledTimes(2);
 
         (panel as Writable<IDockviewPanel>).api.isVisible = true;
         onDidVisibilityChange.fire({});
-        expect(container.style.display).toBe('');
+        expect(container.style.pointerEvents).toBe('');
+        await exhaustAnimationFrame();
+        expect(container.style.visibility).toBe('');
 
-        expect(container.style.left).toBe('49px');
-        expect(container.style.top).toBe('99px');
-        expect(container.style.width).toBe('101px');
-        expect(container.style.height).toBe('201px');
+        expect(container.style.left).toBe('50px');
+        expect(container.style.top).toBe('100px');
+        expect(container.style.width).toBe('100px');
+        expect(container.style.height).toBe('200px');
         expect(
             referenceContainer.element.getBoundingClientRect
-        ).toHaveBeenCalledTimes(2);
+        ).toHaveBeenCalledTimes(3);
     });
 
     test('related z-index from `aria-level` set on floating panels', async () => {

packages/dockview-core/src/overlay/overlayRenderContainer.ts

@@ -205,9 +205,11 @@ export class OverlayRenderContainer extends CompositeDisposable {
             if (panel.api.isVisible) {
                 this.positionCache.invalidate();
                 resize();
+                focusContainer.style.pointerEvents = '';
+            } else {
+                focusContainer.style.visibility = 'hidden';
+                focusContainer.style.pointerEvents = 'none';
             }
-
-            focusContainer.style.display = panel.api.isVisible ? '' : 'none';
         };
 
         const observerDisposable = new MutableDisposable();
@@ -261,7 +263,7 @@ export class OverlayRenderContainer extends CompositeDisposable {
              * the dnd events for the expect behaviours to continue to occur in terms of dnd
              *
              * the dnd observer does not need to be conditional on whether the panel is visible since
-             * non-visible panels are 'display: none' and in such case the dnd observer will not fire.
+             * non-visible panels have 'pointer-events: none' and in such case the dnd observer will not fire.
              */
             new DragAndDropObserver(focusContainer, {
                 onDragEnd: (e) => {