Lit is the umbrella term for the next major
lit-html (v2) and lit-element (v3) versions.
Therefore we will refer to these components as
*Lit* in TYPO3 from now on as well.

These two libraries also have been migrated into
a single entry point module named `lit`.
It is officially described as:
> The main module exports the core pieces needed for component
> development: LitElement, html, css, and the most

lit-html v2 and lit-element v3 are mostly compatible
to the previous major versions. Main changes are

 * Deprecation of the `lit-element` entry point in
   favor of the new `lit` module
 * @internalProperty changed to @state
 * shadow css declaration via static property
   instead of static getter method
 * The CSSResult type declaration is gone
 * Directive (currently unused in TYPO3) API has changed

Related testing framework change is:
https://github.com/TYPO3/testing-framework/pull/229

Commands used:

  rm -rf typo3/sysext/core/Resources/Public/JavaScript/Contrib/{@lit,lit-element,lit-html,lit}/
  yarn add lit@^2.0.0-rc.1 lit-html@^2.0.0-rc.2 lit-element@^3.0.0-rc.1
  yarn add --dev rollup@^2.32.0 @rollup/plugin-replace
  grunt build
  git add typo3/sysext/core/Resources/Public/JavaScript/Contrib/{@lit,lit-element,lit-html,lit}/

  composer require --dev typo3/testing-framework:^6.8.1
  composer require --dev typo3/testing-framework:^6.8.1 \
    --no-update --working-dir=typo3/sysext/core

Resolves: #93965
Releases: master
Change-Id: I9b659d851e6ad9dc3cc649bd40aab886b86fb0f8
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/68104

Tested-by: Oliver Hader <oliver.hader@typo3.org>
Tested-by: TYPO3com <noreply@typo3.com>
Tested-by: core-ci <typo3@b13.com>
Tested-by: Benni Mack <benni@typo3.org>
Tested-by: Benjamin Franzke <bfr@qbus.de>
Reviewed-by: Oliver Hader <oliver.hader@typo3.org>
Reviewed-by: Benni Mack <benni@typo3.org>
Reviewed-by: Benjamin Franzke <bfr@qbus.de>

Benni Mack authored Apr 03, 2021 and Richard Haeser committed Apr 08, 2021

This change adds a new Lit-based custom HTML component
called "<typo3-backend-navigation-switcher>" which moves
the current navigation frame resizable feature in a more flexible
re-usable way.

All RecordLinkHandlers and ElementBrowsers now have a
resizable and collapsible navigation area.

In addition, all logic is now decoupled from Viewport.ts

All ElementBrowser / RecordHandlers now also define
an inline style width to avoid jumping of the navigation area
within the modal box.

Further optimizations in this area:
* Remove the media queries for the CSS classes in the element browser?
* The newly introduced LIT element could be built as shadow DOM

Resolves: #93857
Releases: master
Change-Id: I66724086942e0778e05b9c26dd956bb8417af6d0
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/68692

Tested-by: Benjamin Franzke <bfr@qbus.de>
Tested-by: TYPO3com <noreply@typo3.com>
Tested-by: core-ci <typo3@b13.com>
Tested-by: Richard Haeser <richard@richardhaeser.com>
Reviewed-by: Benjamin Franzke <bfr@qbus.de>
Reviewed-by: Richard Haeser <richard@richardhaeser.com>