From 823b993b74f29eddace8e2beb0a34d3f4ce7079c Mon Sep 17 00:00:00 2001
From: Tomi Virkki <virkki@vaadin.com>
Date: Thu, 26 Sep 2024 13:54:00 +0300
Subject: [PATCH] feat: scroll focused dashboard widget into view

---
 packages/dashboard/src/vaadin-dashboard.js | 30 +++++++++++---
 packages/dashboard/test/dashboard.test.ts  | 46 ++++++++++++++++++++++
 2 files changed, 70 insertions(+), 6 deletions(-)

diff --git a/packages/dashboard/src/vaadin-dashboard.js b/packages/dashboard/src/vaadin-dashboard.js
index 4eb70f6e5e..1ebe4f0c82 100644
--- a/packages/dashboard/src/vaadin-dashboard.js
+++ b/packages/dashboard/src/vaadin-dashboard.js
@@ -244,12 +244,30 @@ class Dashboard extends ControllerMixin(DashboardLayoutMixin(ElementMixin(Themab
     // Remove the unused wrappers
     wrappers.forEach((wrapper) => wrapper.remove());
 
-    if (focusedWrapperWillBeRemoved) {
-      // The wrapper containing the focused element was removed. Try to focus the element in the closest wrapper.
-      requestAnimationFrame(() =>
-        this.__focusWrapperContent(wrapperClosestToRemovedFocused || this.querySelector(WRAPPER_LOCAL_NAME)),
-      );
-    }
+    requestAnimationFrame(() => {
+      if (focusedWrapperWillBeRemoved) {
+        // The wrapper containing the focused element was removed. Try to focus the element in the closest wrapper.
+        this.__focusWrapperContent(wrapperClosestToRemovedFocused || this.querySelector(WRAPPER_LOCAL_NAME));
+      }
+
+      const focusedItem = this.querySelector('[focused]');
+      if (focusedItem && !this.__insideViewport(focusedItem)) {
+        // If the focused wrapper is not in the viewport, scroll it into view
+        focusedItem.scrollIntoView();
+      }
+    });
+  }
+
+  /** @private */
+  __insideViewport(element) {
+    const rect = element.getBoundingClientRect();
+    const dashboardRect = this.getBoundingClientRect();
+    return (
+      rect.bottom >= dashboardRect.top &&
+      rect.right >= dashboardRect.left &&
+      rect.top <= dashboardRect.bottom &&
+      rect.left <= dashboardRect.right
+    );
   }
 
   /** @private */
diff --git a/packages/dashboard/test/dashboard.test.ts b/packages/dashboard/test/dashboard.test.ts
index 8dc6fe340e..d4da2a9073 100644
--- a/packages/dashboard/test/dashboard.test.ts
+++ b/packages/dashboard/test/dashboard.test.ts
@@ -13,6 +13,7 @@ import {
   getParentSection,
   getRemoveButton,
   getResizeHandle,
+  getScrollingContainer,
   onceResized,
   setGap,
   setMaximumColumnWidth,
@@ -569,6 +570,51 @@ describe('dashboard', () => {
       expect(removeButton.getBoundingClientRect().height).to.be.above(0);
     });
 
+    it('should scroll the focused item into view on render', async () => {
+      // Limit the dashboard height to force scrolling
+      dashboard.style.height = '300px';
+      await onceResized(dashboard);
+      // Focus the first item
+      getElementFromCell(dashboard, 0, 0)!.focus();
+
+      // Add enough items to push the focused item out of view
+      dashboard.items = Array.from({ length: 10 }, (_, i) => ({ id: i.toString() })).reverse();
+      await nextFrame();
+      await nextFrame();
+
+      // Expect the focused item to have been scrolled back into view
+      const widgetRect = document.activeElement!.getBoundingClientRect();
+      const dashboardRect = dashboard.getBoundingClientRect();
+      expect(widgetRect.bottom).to.be.above(dashboardRect.top);
+      expect(widgetRect.top).to.be.below(dashboardRect.bottom);
+    });
+
+    it('should not scroll the focused item into view if it is partially visible', async () => {
+      // Limit the dashboard height to force scrolling
+      dashboard.style.height = '300px';
+      await onceResized(dashboard);
+      // Focus the first item
+      getElementFromCell(dashboard, 0, 0)!.focus();
+
+      // Add enough items to make the dashboard scrollable
+      dashboard.items = Array.from({ length: 10 }, (_, i) => ({ id: i.toString() }));
+      await nextFrame();
+      await nextFrame();
+
+      // Scroll the dashboard to make the focused item partially visible
+      const scrollingContainer = getScrollingContainer(dashboard);
+      const scrollTop = Math.round(document.activeElement!.getBoundingClientRect().height / 2);
+      scrollingContainer.scrollTop = scrollTop;
+
+      // Change the items to trigger a render
+      dashboard.items = dashboard.items.slice(0, -1);
+      await nextFrame();
+      await nextFrame();
+
+      // Expect no scrolling to have occurred
+      expect(scrollingContainer.scrollTop).to.equal(scrollTop);
+    });
+
     describe('focus restore on focused item removal', () => {
       beforeEach(async () => {
         dashboard.editable = true;