The “View - HTML Source” menu item is presented as a radio button when it actually toggles like a checkbox, while still exclusive. When selected it greys alternative radio buttons and but can be toggled to re-enable them. Toggling swaps function between editing and WYSIWIG.
I believe this implementation is needlessly confusing and the concept should be handled as three radio buttons, pick one, options always present even if disabled.
It isn't intuitive to toggle a radio button like a checkbox, and if modality is the goal all buttons should all be active while exclusive options. The view toggling effect behaves like a radio button with other radio buttons actually still in play, but only after toggling, the current means to the same end.
The help file below should be considered part of a repair. Specifically, “or opening an existing one” doesn’t appear possible where “one” is referring to an HTML file. When opened, an existing file of any extension hides the “View - HTML Source” radio button. I believe any menu item should be present while disabled if not selectable, not hidden modality:
To compare, note that the style menu works, while not how I wish it was handled, because radio buttons remain evident and give the user a visual affordance to understand what's happening, combining inputs with annunciators.
Steps to Reproduce:
1. Select menu "File>New>HTML Document"
2. Select menu "View>HTML Source"; option missing without step #1
3. Save dialogue appears, new document returns to editing with !DOCTYPE boilerplate
Selecting menu "View>HTML Source" will now toggle between code and HTML code and WYSIWIG views.
Actual results notwithstanding, this maneuver should be implemented as three radio buttons for HTML/Web/Normal where HTML should remain but disabled if not available. I would never expect to toggle a radio button as the very nature of that control is to be mutually exclusive amongst alternative buttons.
User Profile Reset: No
OpenGL enabled: Yes
Explanation condensed from my exasperated version, with more background, at:
I took a very long time to figure out what was actually happening, combining the given interface with the the incorrect help file, before I accidentally toggled the radio button and all became clear. Also noted were the large percentage of help requests from users struggling to understand HTML formats within Writer.
Absolutely true, and reported a few times.
But I wonder why anyone would edit HTML with LibreOffice. Isn't it better to remove all this functionality? But better discuss this at the duplicate.
*** This bug has been marked as a duplicate of bug 101179 ***
Going to the 2016 report, although I can only agree with you in general.