I am running LibreOffice 188.8.131.52 on Linux Mint 20 Cinnamon. I am a big fan of the new option to hide the menu bar in the Writer app via `View > [ ] Menubar`. I would like to use it with the Single Toolbar UI but unfortunately my preference resets every time I re-launch Writer. I understand that this is done by design as, by default, the toolbar does not have a show/hide menubar icon (I have added one to mine).
Most software that have an option for hiding the menu bar implements a standard shortcut to show it at any time when hidden; all you have to do is hit the `Alt` key and the menu bar will show up momentarily when hidden. Hitting `ESC`, `Alt` again, or clicking outside the menubar will hide it once more. This is how the hidden menubar is implemented in Firefox, Thunderbird, Nemo, Atom, Typora, among many others.
Steps to Reproduce:
1. Customise Single or Standard Toolbars by adding a Menubar icon to them
2. Click on the icon to hide the menubar
3. Restart the application
Menubar is back being shown at the next startup
User preference for hidden menubar would be kept between sessions. This might require implementing the standard `Alt` shortcut as described in this report's description.
User Profile Reset: No
From the discussion: https://ask.libreoffice.org/en/question/281406/hiding-menu-bar-permanently/
(In reply to gilbertohasnofb from comment #0)
> I am running LibreOffice 184.108.40.206 on Linux Mint 20 Cinnamon. I am a big fan
> of the new option to hide the menu bar in the Writer app via `View > [ ]
There is no such menu "View > [ ] Menubar" option by default. You must have done a customization to get this available in your menu.
Sorry, you are right. I customised both the toolbar and the View menu. But the steps I described to reproduce it are still correct. Regardless of this customisation, implementing the Alt shortcut would allow the menubar to be hidden in any UI mode as there would not be any danger of an user not being able to access it.
For GSOC 2016 work on the Notebook Bar an UNO toggle control was provided  and is integral to the MUFFIN modes, but as noted for bug 90195 it was not assigned a short-cut.
When I customize the Writer View menu and add the .uno:MenuBar toggle it will persist for the 'Contextual Single' mode. But not for Standard or Single as noted. So try with Contextual Single (IMHO its hybrid handling of context sensitive elements makes it the best of the MUFFIN assemblages).
IMHO the better customization than a View menu assignment is to assign a keyboard shortcut to the toggle control. I find <Atl>+<Ctrl>+F10 easy to work with, and the shortcut is essential for UI mode where you are unable to exit without the main menu.
There is still some question as to a11y support, that the <F10> alone should expose the main menu to position the UI to a consistent place -- bug 90195, bug 107343
But this is => NAB
Otherwise there is no benefit cross platform to overloading <Esc>/<Alt> for main menu handling, and as enhancement would be a clear => WF
(In reply to V Stuart Foote from comment #3)
> But this is => NAB
We want to keep the user choice and I don't see a workflow where hiding the menubar would be desired only temporary. Also for classic UIs. Even with the bug 107343 we would need to make it persistent.