Feature request: Add rainbow for new empty line with auto indents

[Move2win]

Automatically add rainbow for new empty line who inherits an auto-indent param from the previous line.

[marcelwgn]

This is definitely a good idea. If you wish to contribute this feature, feel free to do so, I'm not sure when I will get to this.

[marcelwgn]

Could you share a document/example where this is the case? I found that Visual Studio inserts virtual indentation that is only render but does not exist in the actual text. If the line contains actual whitespaces or tabs, they should be colored correctly.

[Move2win]

Could you share a document/example where this is the case?

In this case, the visual studio cursor gives an auto-indent after pressing enter, but IndentRainbow does not react to this.

I found that Visual Studio inserts virtual indentation that is only render but does not exist in the actual text.

This should be why IndentRaimbow does not react to auto-indent creation by pressing enter.
I found out that if I add a space at one of the ends of the auto-indent lines, the rainbow will appear even if I delete that space later, the rainbow will keep anyway.

Even that's the case. I found it very inconvenient to add and then delete space for every empty line to get them to show the rainbow.
It would be great if it could be improved.

[szalapski]

I'd like to propose a "one step farther" variation: I'd like to see lines that are blank (only whitespace) should always show the same rainbow indent as the last previous non-whitespace line. For example, in move2win's screenshot above, lines 76-83 would all have the same rainbow colors as line 75, regardless of whether they are empty or have tabs or spaces.

I think it is okay to show these even though there are no space/tab characters "underneath" the proposed rainbow colors there because the goal of the extension is to show the structure of code, not to visualize space/tab characters.

[marcelwgn]

This is definitely a good idea, however implementation is probably not that easy since we would now need to store the indentation of the last line. Doable but not as easy as other features that have been added throughout the years 😅

[marcelwgn]

After trying to implement this and getting a running version of this in this feature branch, unfortunately this is not something this extension can provide right now.

There are several issues which are caused on how the extension (and the Visual Studio extensibility API for that matter) work. In short, the APIs I am using operate on a single line so a feature that relies on other lines is not easy (or maybe even possible) to implement.

While in theory the basic coloring works, this breaks when the text span that dictates the color for empty lines changes its indentation, the empty lines do not get recalculated by VS leaving the lines with a wrong coloring. There is a way to fix this but requires more development work and also would have a performance impact. Another issue, though not of technical nature would be how empty lines should be treated if there is no content after them, i.e. near the end of file; should they be colored or left empty?

None the less, here is the VSIX where a preliminary version of this is implemented, I would love your feedback on whether this is what you expected (ignoring the invalidation issue).
IndentRainbow with empty line coloring.zip