# [NTG-context] Hiding the content (drawing empty boxes?)

Hans Hagen pragma at wxs.nl
Thu Jul 7 23:57:23 CEST 2005

```Mojca Miklavec wrote:
> Hello,
>
> Some TeX challenge (probably not solvable?): for gurus only.
>
> Is there a way to somehow
>
> \starthidden
> ...
> \stophidden,
>
> which would leave exactly the same amount of blank space as if the
> content would be typeset?
>
> Adam suggested to use transparent font colour, but this doesn't solve
> the problem as this won't stop the images, frames and nested
> \color[red]{font color changing commands} being displayed.
>
> I tried to adapt the macro \demobox from the TeXBOOK which processes
> token by token and draws an empty box instead of that token. It works
> perfectly as long as there is only plain text between the braces, but as
> soon there is something more complex, it breaks. This behaviour is
> probably to be expected, but I have no idea how to let all the commands
> do what they are expected to do and only prohibit placing any boxes with
> some content.

\defineproperty[mojcas-secrets][layer][state=top]

\starttext

\input tufte

\startproperty[mojcas-secrets]\input knuth \stopproperty

\input tufte

\stoptext

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