Navigation block: Make nested menus fully customizable (Megamenus)

[adamziel]

This is how the current dropdown/nested menu looks like:

The way it works is that the navigation link block supports nested navigation link blocks. This is fine for simple dropdowns like the one above, but does not support more advanced use cases like the ones below:

A good start would be supporting an arbitrary wrapper block such as columns, or even some kind of a "box" block that would be like columns with just one column. Supporting a drawer menu at some point would be nice too.

[adamziel]

cc @noisysocks @draganescu @tellthemachines @talldan @shaunandrews

[shaunandrews]

I've been toying with the idea of a Submenu block, which would offer customization options like width and color, along with acting like a specialized Group block that could contain blocks like Columns and Image. Here's a rough GIF to (hopefully) show how it could work:

There's also a clickable Figma prototype you can try.

[draganescu]

This has been discussed in Slack in the weekly navigation sync.

It's a bit unclear how does a submenu block differ from a group or columns block.

[tellthemachines]

I wonder if the Submenu block couldn't instead be a generic Dropdown block, that could also be used elsewhere outside Navigation? And perhaps we could also have a Slideout block, that could contain a Navigation block (or not, it could just contain a bunch of Buttons, or anything else really). The Slideout could just be a wrapper with a close button and <InnerBlocks>.