[AI review experiment] upstream PR #9612

[sissbruecker]

Throwaway PR for AI code-review experiment.

Reconstructs the pre-review state of vaadin#9612 at commit 084d19abcb892744ae56ca4f069f1a078cc25381.

Do not merge.

[sissbruecker]

PR Reviewer Guide 🔍

Here are some key observations to aid the review process:

⏱️ Estimated effort to review: 3 🔵🔵🔵⚪⚪

🧪 PR contains tests

🔒 No security concerns identified

⚡ Recommended focus areas for review Logic Bug In single-selection mode, activating an already-selected item while __deselectDisallowed is true returns from the handler before row-details handling runs. This means clicking an open details row in that state never calls setDetailsVisible(null), so details can get stuck open. Skip only the deselection path and continue to the details toggle. if (item && item.selected && grid.__deselectDisallowed) { return; Nested Events The new activation listeners handle any cell-activate or row-activate event that reaches the grid. If another grid is rendered inside this grid's details, activation events from the nested grid can bubble to the parent and cause parent-side selection or details updates using the child item key. Guard the handler so it only processes events whose target is this grid. function onItemActivate(event) { const item = event.detail.model?.item; if (selectionMode === 'SINGLE') { if (item && item.selected && grid.__deselectDisallowed) { return; } if (item && !item.selected) { grid.$connector.doSelection([item], true); } else { grid.$connector.doDeselection([...grid.selectedItems], true); } } if (!grid.__disallowDetailsOnClick) { if (item && !item.detailsOpened) { grid.$server.setDetailsVisible(item.key); } else { grid.$server.setDetailsVisible(null); } } } grid.addEventListener('cell-activate', onItemActivate); grid.addEventListener('row-activate', onItemActivate);