New table lexer does not allow for selection of code

[jneen]

I have suddenly remembered the reason we used the single-row table approach. While the new table lexer does allow for wrapping of lines, when a user attempts to select code, the line numbers become included in the selection. I'm not sure if there is a way around this, but I would like to look into it sometime in the near future.

[jneen]

cc @ashmaroli

[ashmaroli]

I believe this can be easily overcome by CSS:

.rouge-line-table .rouge-gutter {
  -moz-user-select: none;
  -webkit-user-select: none;
  user-select: none;
}

[jneen]

Is there a way to include this in the default configuration? I would honestly be okay inlining this sort of thing.

[pyrmont]

Perhaps somewhere around here?

rouge/lib/rouge/theme.rb

Lines 171 to 173 in 73662c9

	# shared styles for tableized line numbers
	yield "#{@scope} table td { padding: 5px; }"
	yield "#{@scope} table pre { margin: 0; }"

[ashmaroli]

@pyrmont I think the styles above should be inlined only for the HTMLLineTable formatter and not for all formatters / themes..

[pyrmont]

@ashmaroli If the above rules are inserted regardless of whether the formatter is inserting a table or not, why not also insert rules about line selection?

[ashmaroli]

@pyrmont There are couple of reasons:

• The above code (the lines you've linked to) will probably be removed in Rouge 4.0 (even though there hasn't been an official decision yet).
• We're aiming to disable selection of line-number cell only and since the cells' classname is configurable, we'd have to select the cell(s) by the element tags (i.e. table td:first-of-type)
• By having the above hardcoded for all formatters, there's a chance we may affect a custom formatter downstream, especially if that formatter outputs the table with the first column for some other purpose other than housing preformatted line-number cells.
• By having the styles hardcoded only for html-line-table, the effects of (those syles) are contained within a single formatter (that is not even activated by default via the Legacy Formatter).

[pyrmont]

@ashmaroli These are good counterarguments. My objection is grounded in the fact that this feels like a breaking change.

That said, while I think that's technically true I do acknowledge:

1. this formatter is unlikely to be in widespread use given when it was added;
2. the proposed rules are very narrow and unlikely to cause unintended behaviour;
3. you can always create a custom formatter if, for some reason, you wanted the original behaviour.

After considering this further, I'd say that I'm OK with the approach proposed.

[ashmaroli]

Thanks Michael. And I wouldn't consider it a breaking-change. Just enhancing / fixing a very recently released feature. ( It is subjective to how the situation is perceived 😉 ).

[pyrmont]

Again, it's somewhat academic given the scope of the changes but I strongly disagree. Using this formatter previously allowed content in the gutter to be selected. Now that functionality is both gone and cannot be enabled as the CSS rules are to be inserted inline and so cannot be overridden.

[ashmaroli]

Ah! That's true, indeed!