mjhjmtu

I want to implement a macro that takes exactly one parameter and will create a line above and below the content and ignores the text indentation.

This is meant to place some event information in protocols no matter what context I am in right now (e.g. within an enumerate or itemize).

It should interrupt the current block and always use the complete column width and then continue the block afterwards.

However, I am having problems with the vertical centering:

newcommandbartext[1]
 kern4pt % space above the rules
 hrule height 0.5pt
 vspace0.1cm
 noindent #1
 vspace0.1cm
 hrule height 0.5pt
 kern4pt % space below the rules


% Example Usage:

beginitemize
 item First Point
 item Second Point
 bartextCharlie enters the meeting
 item third point
 fouth point
enditemize

The text "Charlie enters the meeting" should begin at the left, like the "Some text before".

also the lines are placed pretty odd an the text within the lines isnt vertically centered.

Any clues/ suggestions?

You can use a (non-floating) float:

documentclassarticle
usepackagearray,float
newcommandbartext[1]%
parmedskip
begingroup
intextsep=smallskipamount
extrarowheight =3pt %or perhaps a bit less ...
arrayrulewidth=.5pt
 beginfigure[H]%
 begintabular@ptextwidth@
 hline
 #1
 \hline
 endtabular%
 endfigure%
parendgroup

begindocument
a
 bartextCharlie enters the meeting
b
beginitemize
 item First Point
 item Second Point
 bartextCharlie enters the meeting
 item third point
 item fouth point
enditemize
enddocument

Assuming that you do not want to use something like

enditemize
bartext...
beginitemize[resume*]

you could use the following code that is inspired by How can I check if the current code is inside a certain environment?

documentclassarticle
usepackageenumitem
usepackagelipsum


makeatletter
defitemizenameitemize
defenumeratenameenumerate
newcommandbartext[1]%
 ifx@currenviritemizename
 enditemize
 kern4pt % space above the rules
 hrule height 0.5pt
 vspace0.1cm
 noindent #1
 vspace0.1cm
 hrule height 0.5pt
 kern4pt
 beginitemize[resume*]
 else
 ifx@currenvirenumeratename
 endenumerate
 kern4pt % space above the rules
 hrule height 0.5pt
 vspace0.1cm
 noindent #1
 vspace0.1cm
 hrule height 0.5pt
 kern4pt
 beginenumerate[resume*]
 else
 kern4pt % space above the rules
 hrule height 0.5pt
 vspace0.1cm
 noindent #1
 vspace0.1cm
 hrule height 0.5pt
 kern4pt
 fi
 fi
newcommand@myenvnamemyenv
makeatother

begindocument

lipsum[5]

beginitemize
 item First Point
 item Second Point
 bartextCharlie enters the meeting 
 item third point
 item fouth point
enditemize

lipsum[5]

beginenumerate
 item First Point
 item Second Point
 bartextCharlie enters the meeting 
 item third point
 item fouth point
endenumerate

lipsum[5]

bartextCharlie enters the meeting 

enddocument

You can use the functionalities of enumitem:

documentclassreport%memoir
usepackageenumitem
usepackagelipsum

newcommandbartext[1]
kern4pt % space above the rules
hrule height 0.5pt
vspace0.1cm
noindent #1
vspace0.1cm
hrule height 0.5pt
kern4pt % space below the rules


begindocument

Some text. Some more text. Some more text. Some more text. Some more text. Some more text. Some more text. Some more text. Some more text.

beginitemize[after=vspace*-topsep]
 item First Point
 item Second Point
enditemize
 bartextCharlie enters the meeting
beginitemize[resume*, before=vspace*-topsep]
 item third point
 item fourth point
enditemize

enddocument