Administration: Add box reordering toggle to Screen Options.

[j111q]

Trac ticket: https://core.trac.wordpress.org/ticket/50699

This continues #12180, originally authored by @poligilad-auto. Poli’s original feature commit is preserved in this branch; I’m carrying the existing work and review feedback forward while Poli is away.

Summary

• Adds a Screen Options setting for enabling or disabling box reordering.
• Stores the setting as one per-user preference shared across screens on the current site and keeps reordering enabled by default.
• Disables drag-and-drop sorting and hides the keyboard move controls and drop zones when reordering is disabled.
• Places the “Allow boxes to be rearranged” checkbox under “Additional settings” on screens that support meta boxes.

Screenshot

Review follow-up

• Uses the absence of the disabled body class to represent the enabled state.
• Leaves hidden move controls to CSS instead of changing their accessibility attributes in JavaScript.
• Preserves the existing Screen Options guidance and adds a separate sentence explaining the new setting.
• Uses the user option API consistently when saving and reading the per-user, per-site preference.
• Avoids duplicate sortable updates when the checkbox changes.
• Preserves the legacy hidden editor-expand fieldset when a post screen has no meta boxes.
• Replaces the unused rendering helper test with coverage through the real Screen Options rendering path.

Compatibility

• Reordering remains enabled by default.
• Existing meta box markup and keyboard controls remain unchanged while reordering is enabled.
• The preference applies across screens on the current site for each user, matching the direction confirmed on the Trac ticket.

AI assistance

Codex was used to inspect the existing feedback, implement revisions, add tests, and draft this description. I manually verified the user-facing behavior, and the automated checks listed below were run. I do not independently have the technical expertise to validate every code change, so this draft is seeking human developer review before it is considered ready.

Testing

• npm run test:php -- --filter Tests_Admin_IncludesScreen tests/phpunit/tests/admin/includesScreen.php
• npm run test:php -- --group ajax --filter Tests_Ajax_wpAjaxMetaBoxReordering
• npx grunt jshint:core --file=src/js/_enqueues/admin/postbox.js
• npx grunt jshint:core --file=src/js/_enqueues/admin/common.js
• PHPCS on all eight touched PHP and PHPUnit files.
• npm run build:dev
• git diff --check

Manually verified on the Dashboard that disabling the setting disables drag-and-drop, hides both keyboard move controls, and that re-enabling it restores both interaction methods.

[github-actions]

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[Copilot]

Pull request overview

This PR introduces a new Screen Options setting that lets users enable/disable meta box (postbox) reordering across wp-admin screens that support meta boxes. It wires the preference through wp-admin rendering, JS behaviors (drag-and-drop and keyboard move controls), and an authenticated Ajax endpoint, with PHPUnit coverage for both the Ajax persistence and Screen Options rendering.

Changes:

• Add a “Enable box reordering” checkbox under “Additional settings” in Screen Options when a screen has meta boxes, and display supporting guidance text.
• Persist the preference as a per-user setting via a new meta-box-reordering Ajax action and apply it via an admin body class.
• Update admin JS/CSS to disable sortable behavior and hide keyboard move controls/drop zones when reordering is disabled, plus add tests for the new behavior.

Reviewed changes

Copilot reviewed 12 out of 12 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
tests/phpunit/tests/ajax/wpAjaxMetaBoxReordering.php	Adds Ajax test coverage to verify the user option is saved correctly.
tests/phpunit/tests/admin/includesScreen.php	Adds tests for default enabled behavior and Screen Options rendering logic.
tests/phpunit/includes/testcase-ajax.php	Whitelists the new Ajax action for the Ajax test harness.
src/wp-admin/includes/screen.php	Introduces wp_is_meta_box_reordering_enabled() helper for reading the preference.
src/wp-admin/includes/class-wp-screen.php	Renders the new Screen Options toggle and related guidance; adjusts “Additional settings” markup handling.
src/wp-admin/includes/ajax-actions.php	Adds wp_ajax_meta_box_reordering() endpoint to store the preference.
src/wp-admin/css/dashboard.css	Hides dashboard empty drop containers when reordering is disabled.
src/wp-admin/css/common.css	Adds styling for additional settings fieldset and hides move controls when reordering is disabled.
src/wp-admin/admin-header.php	Applies meta-box-reordering-disabled body class based on the preference.
src/wp-admin/admin-ajax.php	Registers meta-box-reordering as a core POST Ajax action.
src/js/_enqueues/admin/postbox.js	Adds UI logic to enable/disable reordering, persist state, and gate keyboard move behavior.
src/js/_enqueues/admin/common.js	Prevents responsive sortable toggling from being triggered by the new checkbox; disables sortables when reordering is disabled.

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[Copilot]

Pull request overview

Copilot reviewed 12 out of 12 changed files in this pull request and generated 2 comments.

[github-actions]

The following accounts have interacted with this PR and/or linked issues. I will continue to update these lists as activity occurs. You can also manually ask me to refresh this list by adding the props-bot label.

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Props poligilad, jillq.

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