自动“放大” PDF 中的超文本框；无需 JavaScript

Question

这是点击缩放框的 JavaScript 免费版本。（适用于 pdfLaTeX、LuaLaTeX、XeLaTeX、LaTeX+Dvips。）

\zoombox[dotted box line width in px, default: 1]{<contents>}

它利用“鼠标按钮按下”和“鼠标按钮弹起”事件来放大和缩小。在演讲情况下，这非常可靠，并且足以对幻灯片上的细节进行简短解释。

已使用 Acrobat Reader 和 PDF-XChange 成功测试。Foxit Reader 无法正确放大，应向开发人员报告，在 Evince 中它根本不起作用。

第一个代码示例目标beamer类文档，并应在全屏/演示模式。缩放目标位于屏幕中央按下鼠标按钮时。释放按钮时，它会缩小到整个页面视图。（这比返回第二个代码示例中使用的上一个视图更可靠。）为了获得最佳性能，文档的纵横比（beamer选项aspectratio）应与目标视频投影仪或显示器相匹配。

为了beamer课程文件：

\documentclass[
  aspectratio=169,% must match the target video projector/monitor, default: 43
  hyperref={pdfpagemode=FullScreen}
]{beamer}
\usepackage{graphicx}

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  usage: \zoombox[<dotted border width in pix, default: 1>]{<content>}
%
%  * optimized version for BEAMER class:
%     - zoom target centred on screen upon zoom-in   (mouse btn press)
%     - whole-page-view upon zoom-out                (mouse btn release)
%                                       
%  * !! to be used in FULL-SCREEN mode !!
%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\usepackage{pdfbase,calc}

\ExplSyntaxOn
\let\pbsPdfDest\pbs_pdfdest:nnnn
\let\pbsPdfAnnot\pbs_pdfannot:nnnn
\ExplSyntaxOff
\newsavebox\zbox
\newcounter{zoom}
\newdimen\zAr\newdimen\pAr %aspect ratios of zoom target and document page
\newdimen\zwd\newdimen\zht\newdimen\zdp %intermediate and final zoom target dims

\newcommand{\zoombox}[2][1]{% [#1] (optional) sets border line width, default: 1 pixel
                            % {#2} box context
  \sbox\zbox{#2}%
  \setlength\zAr{1pt*\ratio{\wd\zbox}{\ht\zbox+\dp\zbox}}%
  \setlength\pAr{1pt*\ratio{\paperwidth}{\paperheight}}%
  \ifdim\zAr>\pAr\relax%
    \setlength\zwd{\wd\zbox}\setlength\zht{\zwd*\ratio{\paperheight}{\paperwidth}}%
    \setlength\zdp{(\zht-\ht\zbox-\dp\zbox)*\real{0.5}+\dp\zbox}%
    \setlength\zht{\zht-\zdp}%
  \else%
    \setlength\zht{\ht\zbox+\dp\zbox}%
    \setlength\zwd{\zht*\ratio{\paperwidth}{\paperheight}}%
    \setlength\zht{\ht\zbox}\setlength\zdp{\dp\zbox}%
  \fi%
  \pbsPdfDest{zb\thezoom.out}{fit}{1}{}% full-slide view for zoom-out
  \makebox[0pt][l]{\makebox[\wd\zbox][c]{% zoom-in target
    \pbsPdfDest{zb\thezoom.in}{fitr}{1}{\phantom{\vrule
      width \zwd\space height\space \zht\space depth \zdp
  }}}}%
  \makebox[0pt][l]{{\fboxsep=0.5\fboxsep\hskip-\fboxsep%
    \pbsPdfAnnot{\dimexpr\wd\zbox+2\fboxsep\relax}{%
      \dimexpr\ht\zbox+\fboxsep\relax}{%
      \dimexpr\dp\zbox+\fboxsep\relax}{%
      /Subtype/Link/Border [0 0 #1[#1]]%
      }%
    \pbsPdfAnnot{\dimexpr\wd\zbox+2\fboxsep\relax}{%
      \dimexpr\ht\zbox+\fboxsep\relax}{%
      \dimexpr\dp\zbox+\fboxsep\relax}{%
      /Subtype/Widget/FT/Btn/Ff 65536/H/N
      /T (zb\thezoom)
      /AA <<
        /D <</S/GoTo /D (zb\thezoom.in)>>
        /U <</S/GoTo /D (zb\thezoom.out)>>
        /X <</S/GoTo /D (zb\thezoom.out)>>
      >>
      }%
  }}%
  \usebox{\zbox}%
  \stepcounter{zoom}%
}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

\begin{document}

\begin{frame}
  1-px-border (default): \zoombox{\includegraphics[width=1cm]{example-image-a}}\quad
                         \zoombox{Hello World!}\\[2ex]
  2-px-border: \zoombox[2]{\includegraphics[width=1cm]{example-image-b}}\\[2ex]
  zero-width-border: \zoombox[0]{\includegraphics[width=1cm]{example-image-golden-upright}}\quad
  \zoombox[0]{\includegraphics[width=1cm]{example-image-golden}}
\end{frame}

\end{document}

第二个代码示例GoBack在释放鼠标按钮时执行操作（返回上一个视图）。

请注意，GoBack缩小操作在 A-Readers X 和 XI 中已损坏且无法使用，但在 AR-DC 中又恢复了。

适用于任何文档类，但稳定性较差。（PDF 查看器中保存的视图堆栈有时可能会变得混乱。）

\documentclass{article}
\usepackage{graphicx}

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% usage: \zoombox[<dotted border width in pix, default: 1>]{<content>}
%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\usepackage{pdfbase,calc}

\ExplSyntaxOn
\let\pbsPdfDest\pbs_pdfdest:nnnn
\let\pbsPdfAnnot\pbs_pdfannot:nnnn
\ExplSyntaxOff
\newsavebox\zbox
\newcounter{zoom}

\newcommand{\zoombox}[2][1]{% [#1] (optional) sets border line width, default: 1 pixel
  \leavevmode%                {#2} box context
  \sbox\zbox{#2}%
  \makebox[0pt][l]{{\fboxsep=0.5\fboxsep\hskip-\fboxsep%
    \pbsPdfAnnot{\dimexpr\wd\zbox+2\fboxsep\relax}{%
      \dimexpr\ht\zbox+\fboxsep\relax}{%
      \dimexpr\dp\zbox+\fboxsep\relax}{%
      /Subtype/Link/A <</S/GoTo /D (zb\thezoom)>>/Border [0 0 #1[#1]]%
      }%
    \pbsPdfAnnot{\dimexpr\wd\zbox+2\fboxsep\relax}{%
      \dimexpr\ht\zbox+\fboxsep\relax}{%
      \dimexpr\dp\zbox+\fboxsep\relax}{%
      /Subtype/Widget/FT/Btn/Ff 65536/H/N
      /T (zb\thezoom)/TU (Press mouse button to zoom in.)
      /AA <<
        /D <</S/GoTo /D (zb\thezoom)>>
        /U <</S/Named /N/GoBack>>
        /X <</S/Named /N/GoBack>>
      >>
      }%
  }}%
  \pbsPdfDest{zb\thezoom}{fitr}{1}{\usebox{\zbox}}%
  \stepcounter{zoom}%
}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

\begin{document}\parindent=0pt

1-px-border (default): \zoombox{\includegraphics[width=1cm]{example-image-a}}\quad
2-px-border: \zoombox[2]{\includegraphics[width=1cm]{example-image-b}}\\[2ex]
zero-width-border: \zoombox[0]{\includegraphics[width=1cm]{example-image-golden-upright}}
\zoombox[0]{\strut Hello World!}

\end{document}

Answer 1