%%% Testing: switching between absolute and relative mode

\documentclass{article}

\usepackage[absolute,showboxes]{textpos}
\setlength{\parindent}{0pt}
\TPHorizModule=1cm
\TPVertModule=1cm

\usepackage{color}

\begin{document}

Here is some text, which appears in the body of the page.
\begin{textblock}{5}(0,0)
This text is at (0,0), and should appear at the very top-left corner.
\end{textblock}

Here is more text, which also appears in the body.
\begin{textblock}{5}(1,1)
This text is at (1,1), and should appear near the top-left corner, 1cm
in and down.
\end{textblock}

\newpage
\TPoptions{ absolute=false,
        showboxes = false}

Here is some text, which appears in the body of page two.
\begin{textblock}{5}(0,0)
This text is at (0,0), and appears at the top-left of the text block,
just under `Here is some text'.
It should not have a box around it.
\end{textblock}

\vskip4cm
Here is more text, which also appears in the body of p.2.
\begin{textblock}{5}(1,1)
This text is at (1,1), and also appears in the text block 1cm along
and down from the `Here is more text', and without a surrounding box.
\end{textblock}

\TPoptions{absolute=true, showboxes=true, showtext=false}

\vskip4cm
Text.  The corresponding text block should appear only as a box, with
no text inside it.  It appears in the top-left corner of the page.
\begin{textblock}{5}(0,0)
This text should not appear (just the box, positioned 2cm along and
down from `Text.'
\end{textblock}

\TPoptions{absolute=false, showboxes=true, showtext=true}

\vskip4cm
Text 2.
\begin{textblock}{5}(6,0)
This text should appear surrounded by a box, level with, but along from, `Text 2'.
\end{textblock}

\newpage
\TPoptions{absolute=true,overlay=true} % the overlay option is ignored

Page 3.  Page 3.  Page 3.  Page 3.  Page 3.  Page 3.  Page 3.  Page 3.
Page 3.  Page 3.  Page 3.  Page 3.  Page 3.  Page 3.  Page 3.  Page 3.

\begin{textblock}{5}(0,0)
This text appears at the extreme top-left of page three.
\end{textblock}

\textblockcolour{yellow}
\begin{textblock}{5}(4,4.5)
  This text appears at (4,5).  It appears \emph{below} the text: that
  is, the \texttt{overlay=true} option is currently ignored (this
  might potentially change in future, but I've no current plans to
  implement that).
\end{textblock}

\end{document}