Notes on Sentences

Question

I have a sentence like this "पठ् + अ + ति" and I want to add some notes like shown in the attached image. Is there a package for such things or I need to work with Tikz.

Any reference material or help would be appreciated.

============Edited question based on Solution given by Gonzolo =========== Here is MWE and the output I am getting.

\documentclass{article}
\usepackage{fontspec,xltxtra,xunicode}
\usepackage{tikz}
\usetikzlibrary{shapes.callouts}
\setmainfont[Script=Devanagari,AutoFakeBold=3.5]{Sanskrit 2003}
\definecolor{myblue}{RGB}{122,175,234}

\newcommand\tikzmark[1]{%
  \tikz[remember picture,overlay]\node (#1) {};}
\newcommand\MyNote[3][]{%
\begin{tikzpicture}[remember picture,overlay]
\node[rectangle callout, fill=myblue,text width=2cm,align=center,font=\sffamily\bfseries\color{white},#1] at #2 {#3}; 
\end{tikzpicture}%
}

\begin{document}

पठ् \tikzmark{a}\qquad + अ + \tikzmark{b} ति ।

\MyNote[callout relative pointer={(0,1)}]{([yshift=-1.5cm]a)}{क्रिया को धारण करता है वह धातु है ।}
\MyNote[callout relative pointer={(0,1)}]{([yshift=-1.5cm]b)}{"अ \& ति" का कर्ता अर्थ को कह रहा है}

\end{document}

Answer 1

You can use the shapes.callouts library from TikZ:

\documentclass{article}
\usepackage{tikz}
\usetikzlibrary{shapes.callouts}

\definecolor{myblue}{RGB}{122,175,234}

\newcommand\tikzmark[1]{%
  \tikz[remember picture,overlay]\node (#1) {};}
\newcommand\MyNote[3][]{%
\begin{tikzpicture}[remember picture,overlay]
\node[rectangle callout, fill=myblue,text width=2cm,align=center,font=\sffamily\bfseries\color{white},#1] at #2 {#3}; 
\end{tikzpicture}%
}

\begin{document}

Some \tikzmark{a}text\qquad Some other\tikzmark{b} text

\MyNote[callout relative pointer={(0,1)}]{([yshift=-1.5cm]a)}{some note for the first text}
\MyNote[callout relative pointer={(0,1)}]{([yshift=-1.5cm]b)}{some note for the second text}

\end{document}

For details, please see Section 48.7 Callout Shapesin the PGF manual.

With the Sanskrit 2003 font used, \sffamily must be removed from the font attributes:

\documentclass{article}
\usepackage{fontspec,xunicode}
\usepackage{tikz}
\usetikzlibrary{shapes.callouts}
\setmainfont[Script=Devanagari,AutoFakeBold=3.5]{Sanskrit 2003}
\definecolor{myblue}{RGB}{122,175,234}

\newcommand\tikzmark[1]{%
  \tikz[remember picture,overlay]\node (#1) {};}
\newcommand\MyNote[3][]{%
\begin{tikzpicture}[remember picture,overlay]
\node[rectangle callout, fill=myblue,text width=2cm,align=center,font=\color{white},#1] at #2 {#3}; 
\end{tikzpicture}%
}

\begin{document}

पठ् \tikzmark{a}\qquad + अ + \tikzmark{b} ति ।

\MyNote[callout relative pointer={(0.6,1)}]{([yshift=-1.65cm,xshift=-1cm]a)}{क्रिया को धारण करता है वह धातु है ।}
\MyNote[callout relative pointer={(-0.5,1)}]{([yshift=-1.65cm,xshift=0.65cm]b)}{"अ \& ति" का कर्ता अर्थ को कह रहा है}

\end{document}

Answer 2

You can do this very well with TikZ with the callout shapes from the shapes.callouts library.

The notes are set as a label with the option overlay, so that they do not affect the size of the TikZ picture (we don’t want it to be bigger than the labeled text). For correction of the vertical dimensions the line

\path[draw=none] (tikz@callout.north) -- (tikz@callout.south);

is added, otherwise it will protrude in the next or the previous line.

I wouldn’t use this in running text but put it in a float or at least the center environment.

The base of the callout pointer is as wide as the labeled text (here is and sentence).

The pointer points to the nearest point on the border of the labeled text, this is achieved with the tricky line

tikz@label@post/.append style={/pgf/callout absolute pointer=\tikz@node@at},

that makes sure that \tikz@node@at is evaluated after it is actually computed.

Code

\documentclass{article}
\usepackage{tikz}
\usetikzlibrary{shapes.callouts}
\makeatletter
\tikzset{
  Text/.style={
    shape=rectangle,
    anchor=base,
    inner xsep=+0pt,
    outer xsep=+0pt,
    outer ysep=+0pt,
    label={[%
      shape=rectangle callout,
      /utils/exec={%
        \pgfpointdiff
          {\pgfpointanchor{\tikzlastnode}{west}}
          {\pgfpointanchor{\tikzlastnode}{east}}},
      callout pointer width/.expanded=\the\pgf@x,
      tikz@label@post/.append style={/pgf/callout absolute pointer=\tikz@node@at},
      alias=tikz@callout]#1}
  },
  label position=below,
  label distance=2ex,
  every label/.style={draw,overlay},
  labels/.style={every label/.append style={#1}}
}
\makeatother
\newcommand*{\myNote}[3][]{%
  \tikz[baseline,#1]{
    \node[Text={#3}] {#2};
    \path[draw=none] (tikz@callout.north) -- (tikz@callout.south);
  }%
}
\begin{document}
  This \myNote{is}{This is a verb.} a \myNote[label position=above]{sentence}{This is another word.}.
\end{document}

Output