how to set the location and font size of the graph?

Question

Now I write some code to draw the graph. However, the graph is too large, I just want to put it in the left half of the document. So how to set the font size and location of the graph?

Also, I want to change the and-or-gate to diamond or bigoplus in the graph like

I don't known how to draw it,would someone help me? The code below is taken from TeXample fault tree example:

\documentclass{minimal}
\usepackage{tikz}
\usetikzlibrary{shapes.gates.logic.US,trees,positioning,arrows}
\begin{document}
\begin{tikzpicture}[
% Gates and symbols style
    and/.style={and gate US,thick,draw,rotate=90,
        anchor=east,xshift=-1mm},
    or/.style={or gate US,thick,draw,rotate=90,
        anchor=east,xshift=-1mm},
    be/.style={circle,thick,draw,anchor=north,
        minimum width=0.7cm},
    tr/.style={buffer gate US,thick,draw,rotate=90,
        anchor=east,minimum width=0.8cm},
% Label style
    label distance=3mm,
    every label/.style={blue},
% Event style
    event/.style={rectangle,thick,draw,text width=2cm,
        text centered,font=\sffamily,anchor=north},
% Children and edges style
    edge from parent/.style={->,very thick,draw=black!70},
    edge from parent path={(\tikzparentnode.south) -- ++(0,-1.05cm)
            -| (\tikzchildnode.north)},
    level 1/.style={sibling distance=5cm,level distance=1.4cm,
            growth parent anchor=south,nodes=event},
    level 2/.style={sibling distance=5cm},
    level 3/.style={sibling distance=3cm},
    level 4/.style={sibling distance=2cm}
%%  For compatability with PGF CVS add the absolute option:
%   absolute
    ]

  \begin{scope}[xshift=-15cm,yshift=-5cm,very thick]
%% Draw events and edges
    \node (g1) [event] {No flow to receiver}
         child{node (g2) {No flow from Component B}
            child {node (g3) {No flow into Component B}
               child {node (g4) {No flow from Component A1}
                  child {node (t1) {No flow from source1}}
                  child {node (b2) {Component A1 blocks flow}}
            }
               child {node (g5) {No flow from Component A2}
                  child {node (t2) {No flow from source2}}
                  child {node (b3) {Component A2 blocks flow}}
            }
           }
            child {node (b1) {Component B blocks flow}}
        };
%% Place gates and other symbols
%% In the CVS version of PGF labels are placed differently than in PGF 2.0
%% To render them correctly replace '-20' with 'right' and add the 'absolute'
%% option to the tikzpicture environment. The absolute option makes the
%% node labels ignore the rotation of the parent node.
   \node [or]   at (g2.south)   [label=-20:G02] {};
   \node [and]  at (g3.south)   [label=-20:G03] {};
   \node [or]   at (g4.south)   [label=-20:G04] {};
   \node [or]   at (g5.south)   [label=-20:G05] {};
   \node [be]   at (b1.south)   [label=below:B01]   {};
   \node [be]   at (b2.south)   [label=below:B02]   {};
   \node [be]   at (b3.south)   [label=below:B03]   {};
   \node [tr]   at (t1.south)   [label=below:T01]   {};
   \node [tr]   at (t2.south)   [label=below:T02]   {};
\end{scope}
\end{tikzpicture}
\end{document}

Answer 1

Below there's one possibility. The main points:

1. First the tikzpicture code was written (modify the code according to your needs).
2. Then, the \resizebox command (from the graphicx package) was used to scale down the tikzpicture width to 0.5\textwidth (use the desired width and/or height).

3. Then the scaled figure was place inside a wrapfigure environment from the wrapfig package to allow text wrapping.

   \documentclass{article}
   \usepackage{graphicx}
   \usepackage{tikz}
   \usetikzlibrary{shapes,arrows,positioning}
   \usepackage{wrapfig}
   \usepackage{lipsum}% just to generate text for the example
   
   \begin{document}
   
   \lipsum[2]
   \begin{wrapfigure}{l}{.5\textwidth}
   \resizebox{.5\textwidth}{!}{\begin{tikzpicture}[
   oplus/.style={draw,circle, text width=2.5em,fill=blue!20,
     postaction={path picture={% 
       \draw[black]
         (path picture bounding box.south west) -- (path picture bounding box.north east) 
         (path picture bounding box.north west) -- (path picture bounding box.south east);}}},
   block/.style = {rectangle, draw, fill=blue!20, 
       text width=5em,align=center, minimum height=3em},
   decision/.style = {diamond, draw, fill=blue!20, 
       text width=4.5em,inner sep=0pt},
   line/.style = {draw,thick, -latex'},
   node distance=1.8cm and 1cm
   ]
   
   % Place nodes
   \node [block] (a) {text};
   \node [block, below of=a] (b) {text};
   \node [decision, below of=b] (c) {};
   \node [block, below left of=c,xshift=-1cm, yshift=-0.3cm] (cl) {text};
   \node [block, below right of=c,xshift=1cm, yshift=-0.3cm] (cr) {text};
   \node [oplus, below of=cl] (cla) {};
   \node [block, below of=cla] (clb) {text};
   
   % Draw edges
   \path [line] (a) -- (b);
   \path [line] (b) -- (c);
   \path [line] (c) -| (cl) node [near start,anchor=south] {if};
   \path [line] (c) -| (cr) node [near start,anchor=south] {else};
   \path [line] (cl) -- (cla);
   \path [line] (cla) -- (clb);
   
   \end{tikzpicture}}
   \end{wrapfigure}
   \lipsum[1-2]
   \end{document}