I have a lot of acronyms in my thesis and I am using the acro package. I would like to know if there is an option to make it possible for the acronyms within the thesis to display a mouse over definition, this is obviously only a function useful for the PDF output file, is there a possibility to make them display the long name if the mouse is hovered over the acronym term?
(FIXED) Edit: problem using the \tooltip macro (FIXED)
To AlexG I encountered a problem with using the \tooltip macro whereby you get the following overlapping of acronyms:

I can't work out why or how to fix it, but its an essential flaw of the \tooltip macro as, when I remove it it disappears: please feel free to play around with this MWE:
\documentclass[a4paper,11pt]{scrreprt}
\usepackage{acro}
\usepackage{tensor}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% The re-defining of the acronym entering commands \ac for the normal form, \acp for the plural form of the acronym, \acl, \aclp
\let\acorig\ac
\let\acporig\acp
\def\ac#1{\acifused{#1}{\tooltip*[black]{\acs{#1}}{\acl{#1}}}{\acorig{#1}}}
\def\acp#1{\acifused{#1}{\tooltip*[black]{\acsp{#1}}{\aclp{#1}}}{\acporig{#1}}}
%%%%%%%%%% THE LONG ASS MACRO
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% usage: \tooltip[<link colour>]{<link text>}[<tip box colour>]{<tip text>}
% \tooltip*[<link colour>]{<link text>}[<tip box colour>]{<tip text>}
% (starred variant is not draggable)
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\usepackage{media9}[2014/02/06]
\usepackage{xcolor}
\usepackage{calc}
\usepackage{tikzpagenodes}
\usetikzlibrary{calc}
\newlength{\whatsleft}
\newlength{\tipshift}
\ExplSyntaxOn
\let\tpPdfLink\mix_pdflink:nn
\let\tpPdfAnnot\mix_pdfannot:nnnn\def\tpPdfLastAnn{\g_mix_pdflastann_tl}
\let\tpPdfXform\mix_pdfxform:n\def\tpPdfLastXform{\g_mix_pdflastxform_tl}
\let\tpInsertAcroForm\mix_insert_acroform:
\ExplSyntaxOff
\makeatletter
\NewDocumentCommand{\tooltip}{sO{blue}mO{yellow!20}m}{{%
\leavevmode%
\tpPdfLink{%
/Subtype/Screen%
/AA<<%
/E<</S/JavaScript/JS(%
var fd=this.getField('tip.\thetcnt');%
\IfBooleanTF{#1}{fd.display=display.visible;}{%
if(typeof(click\thetcnt)=='undefined'){%
var click\thetcnt=false;%
var fdor\thetcnt=fd.rect;var dragging\thetcnt=false;%
}%
if(fd.display==display.hidden){%
fd.delay=true;fd.display=display.visible;fd.delay=false;%
}%
}%
this.dirty=false;%
)>>%
/X<</S/JavaScript/JS(%
\IfBooleanTF{#1}{fd.display=display.hidden;}{%
if(!click\thetcnt&&!dragging\thetcnt){fd.display=display.hidden;}%
if(!dragging\thetcnt){click\thetcnt=false;}this.dirty=false;%
}%
)>>%
\IfBooleanF{#1}{%
/U<</S/JavaScript/JS(click\thetcnt=true;this.dirty=false;)>>%
/PC<</S/JavaScript/JS (%
var fd=this.getField('tip.\thetcnt');%
try{fd.rect=fdor\thetcnt;}catch(e){}%
fd.display=display.hidden;this.dirty=false;%
)>>%
}%
>>%
}{{\color{#2}#3}}%
\sbox\tiptext{\fcolorbox{black}{#4}{#5}}%
\edef\twd{\the\wd\tiptext}%
\edef\tht{\the\ht\tiptext}%
\edef\tdp{\the\dp\tiptext}%
\measureremainder{\whatsleft}%
\tipshift=0pt%
\ifdim\whatsleft<\twd\setlength\tipshift{\whatsleft-\twd}\fi%
\hspace{\tipshift}\tpPdfXform{\tiptext}%
\raisebox{\heightof{#3}}[0pt][0pt]{\makebox[0pt][l]{%
\tpPdfAnnot{\twd}{\tht}{\tdp}{%
/Subtype/Widget/FT/Btn/Ff 65536/T (tip.\thetcnt)/F 3%
/MK<</TP 1/I \tpPdfLastXform/IF<</S/A/FB true/A [0.0 0.0]>>>>%
\IfBooleanF{#1}{%
/AA <<%
/U <<%
/S/JavaScript/JS(%
var fd=event.target;%
var mX=this.mouseX;var mY=this.mouseY;%
var drag=function(){%
var nX=this.mouseX;var nY=this.mouseY;%
var dX=nX-mX;var dY=nY-mY;%
var fdr=fd.rect;%
fdr[0]+=dX;fdr[1]+=dY;fdr[2]+=dX;fdr[3]+=dY;%
fd.rect=fdr;mX=nX;mY=nY;%
};%
if(!dragging\thetcnt){%
dragging\thetcnt=true;Int=app.setInterval("drag()",1);%
}%
else{app.clearInterval(Int);dragging\thetcnt=false;}%
this.dirty=false;%
)%
>>%
>>%
}%
}%
\xdef\@anim@fields{\@anim@fields\space\tpPdfLastAnn}
\tpInsertAcroForm
}}%
\stepcounter{tcnt}%
}}
\makeatother
\newsavebox\tiptext\newcounter{tcnt}
\newcommand{\measureremainder}[1]{%
\begin{tikzpicture}[overlay,remember picture]
\path let \p0 = (0,0), \p1 = (current page text area.east) in
[/utils/exec={\pgfmathsetlength#1{\x1-\x0}\global#1=#1}];
\end{tikzpicture}%
}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% DEFINED ACRONYMS
\DeclareAcronym{pwr}{
short = PWR ,
short-plural = s ,
long = Pressurised Water Reactor ,
long-plural = s ,
class = reactor ,
}
\DeclareAcronym{ebr}{
short = EBR-I ,
short-plural = ,
long = Experimental Breeder Reactor I ,
long-plural = ,
class = reac.exist ,
}
\DeclareAcronym{vhtr}{
short = VHTR ,
short-plural = s ,
long = Very High Temperature Reactor ,
long-plural = s ,
class = reactor ,
}
\DeclareAcronym{sfr}{
short = SFR ,
short-plural = s ,
long = Sodium Fast Reactor ,
long-plural = s ,
class = reactor ,
}
\DeclareAcronym{heu}{
short = HEU ,
short-plural = ,
long = High Enriched Uranium ,
long-plural = ,
class = reac.term ,
}
\DeclareAcronym{leu}{
short = LEU ,
short-plural = ,
long = Low Enriched Uranium ,
long-plural = ,
class = reac.term ,
}
\DeclareAcronym{htgr}{
short = HTGR ,
short-plural = s ,
long = High Temperature Gas cooled Reactor ,
long-plural = s ,
alt = HTR ,
class = reactor ,
}
\begin{document}
The flexibility of fuel cycle use is one of the attractive features presented by \acp{htgr}. Initially \acp{htgr} took advantage of the efficient uranium-thorium fuel cycle which combined \ac{heu} as fissile fuel with fertile thorium that would breed fissile \nuclide[233][92]{U} during operation. With the non-proliferation treaty in force by 1970 a \ac{leu} fuel cycle was designed and adopted to avoid diversion of fissile material.
\end{document}



fancytooltips,cooltooltipsandpdfcommentcan create pop-ups I think. – Torbjørn T. Feb 20 '14 at 12:17\tooltipmacro for draggable tooltips which supports all known output drivers. – AlexG Feb 20 '14 at 12:54supports all known output driversmean that the\tooltipmacro can be integrated with theacropackage? – Fiztban Feb 20 '14 at 13:36latex+dvips+ps2pdf,pdflatex,lualatex,latex+dvipdfmx,xelatex. I tried to integrate it with theacropackage. See below. – AlexG Feb 20 '14 at 13:50\tooltipcode has been fixed. – AlexG Feb 21 '14 at 09:27