"Increase list level" action inserts keyboard key if the list indent is invalid

- foo
<press-shortcut>- bar

- foo
  - bar

- foo
  <press-shortcut-again>- bar

// E.g. if we bind the shortcut to `alt + .` it will insert a special character `≥`.
- foo
  ≥-bar

First of all, I would expect it to do nothing rather than inserting the default shortcut.

Secondly, I think that it should allow you to make invalid indentations, otherwise it feels like Visual Basic popping up a modal dialog when you make a syntax error 😵 . All other editors don’t prevent me from writing invalid code - as sometimes you need to as part of refactoring, etc.

I also think that when there is an empty list, the tab key should behave like this action (see https://github.com/vsch/idea-multimarkdown/issues/469).

[vsch]

Addressed by #469 to use tab/backtab for indent/unindent

[vsch]

@vjpr, the indent action is context sensitive and not just “insert spaces”. It will “indent” the item and its sub-items, if it has any, indent action on item 2:

1. item 1
2. item 2
   * sub item
     * sub-sub item

Will result in:

1. item 1
   1. item 2
      * sub item
        * sub-sub item

If you want plain text editing behaviour then you should use tab or spaces. I will add config option for number of spaces for a tab then you can set it to 2 and get what you want. However, setting smart tabs, which will use context sensitive behaviour will result in the “indent list item action” when appropriate or simple tab when not. So you will get the above indentation behaviour when the caret is after the list item marker.

Markdown has complex context, especially when it is being edited getting the AST and text can be out of sync. Trying to do the right thing as far as being intuitive is very difficult with lots of unexpected gotchas.

This is the reason why I have been hesitant to put in “smart” tab behaviour. There is a lot of trial and error with tons of special conditions leading to very long stabilization periods that the users hate.