What?

Closes #78869

Prevents clicking or tapping the expanded image from closing the lightbox when navigation controls are present in a gallery lightbox.

Why?

When a gallery lightbox is open, clicking anywhere on the overlay — including directly on the expanded image — closes it. For a standalone image lightbox this is a reasonable affordance, but in a gallery with navigation controls it causes unexpected dismissals.

On touch devices the impact is significant: the only visible controls are the navigation buttons, so a user tapping the image to inspect detail, or slightly mis-tapping while reaching for a nav button, loses their place in the gallery with no recovery other than reopening and navigating back.

The behavior was inherited from the single-image lightbox implementation when gallery navigation was introduced in #62906, without being re-evaluated in the context of a navigable gallery.

How?

Added a handleImageContainerClick action in view.js that calls event.stopPropagation() when state.hasNavigation is true. This follows the same pattern the Previous/Next navigation buttons already use to prevent accidental closes.

The handler is attached to both .lightbox-image-container elements in the PHP template. A has-navigation CSS class is also toggled on the overlay to reset cursor: zoom-out to cursor: default on the image container, so the cursor no longer implies the image is clickable-to-close.

• Single-image lightboxes (no navigation) are unaffected — clicking
  the image still closes the dialog.
• The Close button, Escape key, and clicking the background (scrim)
  continue to close the gallery lightbox.

Testing Instructions

1. Create a new post or page.
2. Insert a Gallery block with two or more images.
3. In the block settings, enable Lightbox.
4. Save/preview the post.
5. Click an image to open the lightbox.
6. Click or tap directly on the expanded image.
   → Expected: Nothing happens. The lightbox stays open.
7. Click the × Close button.
   → Expected: Lightbox closes.
8. Reopen the lightbox, then press Escape.
   → Expected: Lightbox closes.
9. Reopen the lightbox, then click the dark background area outside
   the image.
   → Expected: Lightbox closes.
10. Repeat steps 5–9 on a touch device or with browser DevTools in
    mobile emulation

Single-image regression check:
11. Insert a standalone Image block (not in a Gallery) and enable
Lightbox.
12. Open the lightbox and click the image.
→ Expected: Lightbox still closes (existing behavior unchanged).

Testing Instructions for Keyboard

1. Open the gallery lightbox using Enter or Space on a focused
   image thumbnail.
2. Press Arrow Left / Arrow Right to navigate between images.
3. Press Escape → lightbox should close.
4. Use Tab to cycle focus between the Close button and navigation
   buttons; confirm focus is trapped inside the overlay.

Screenshots or screencast

Before

After

Use of AI Tools

This PR was developed with the assistance of GitHub Copilot. Each change was reviewed and validated by me.