随着beamer
-班级可以使用 轻松重复帧\againframe
。这样做时,帧号会增加一。这通常很有意义。但是,我想给人一种印象,即我真的再次显示了完全相同的帧。因此,帧号也应该跳回。
以下 MWE 可能使我的问题更容易理解:
\documentclass{beamer}
\useoutertheme{infolines}
\begin{document}
\newcounter{thisframenumber}
\setcounter{thisframenumber}{\value{framenumber}}
\begin{frame}[label=A]
Frame A
\end{frame}
\begin{frame}
Frame B
\end{frame}
% steps frame counter
\againframe{A}
% frame number from previous frame
\againframe[noframenumbering]{A}
% desired behavior
\newcounter{tmpframenumber}
\setcounter{tmpframenumber}{\value{framenumber}}
\setcounter{framenumber}{\value{thisframenumber}}
\againframe{A}
\setcounter{framenumber}{\value{tmpframenumber}}
\begin{frame}
Frame C
\end{frame}
\end{document}
如您所见,我找到了一种实现所需行为的解决方案。然而,这个解决方案包括两个\newcounter
和四个\setcounter
命令。有没有更简单的解决方案?
附言:我的梦想是,有一个选择\againframe
,比如\againframe[originalframenumbering]{A}
。
答案1
忘记我的评论。
Beamer 为此提供了四个宏
\beamer@savecounter
:保存特定的计数器;\beamer@restorecounter
:恢复保存的计数器;\beamer@labelsavecounter
:保存该标签下特定的计数器;\beamer@labelrestorecounter
:恢复保存的计数器。
所以剩下的问题是:
我应该在哪里以及如何插入它们\beamer@xxxxcounter{c@framenumber}
?
首先,您需要一个密钥oldframenumbering
以及noframenumbering
用来指示\againframe
应该使用什么数字。
其次,您需要一种continueframenumbering
机制,以防c@framenumber
万一oldframenumbering
发生更改。(我只在必要时才恢复号码。但是您随时都可以恢复它。)
\beamer@@@@frame<#1>[#2]
第三,由于 beamer 处理的是 中定义的帧号beamerbaseframe.sty
,所以我需要复制并修改它的定义。
所以我最终得到:
\documentclass[handout,20pt]{beamer}
\useoutertheme{infolines}
\makeatletter
% replacing `noframenumbering' by oldframenumbering
\newif\ifbeamer@oldframenumbering
\beamer@oldframenumberingfalse
\define@key{beamerframe}{oldframenumbering}[true]{\beamer@oldframenumberingtrue}
% replacing `noframenumbering' by continueframenumbering
\newif\ifbeamer@continueframenumbering
\beamer@continueframenumberingfalse
% save framenumber w.r.t. labels
\define@key{beamerframe}{label}{
\def\beamer@againname{#1}
{\let\@elt\beamer@labelsavecounter\beamer@overlaycounterresets}
%%% old definition ↑↑↑
%%%new code ↓↓↓
{
\ifbeamer@continueframenumbering
\beamer@restorecounter{c@framenumber}
\fi
\stepcounter{framenumber}\beamer@labelsavecounter{c@framenumber}\addtocounter{framenumber}{-1}
}
}
% handling frame number
\def\beamer@@@@frame<#1>[#2]{%
\framewidth\textwidth
\beamer@savemode%
\def\beamer@mode{\mode<all>}%
\def\beamer@frametemplate{}%
\def\beamer@againname{}%
\def\beamer@undolabels{}%
\def\beamer@cramped{}%
\def\beamer@displaybreak{}%
\setbox\beamer@footins=\box\voidb@x%
\beamer@autobreakcount=0\relax%
\beamer@autobreaklastheight=16000pt%
\beamer@zoomcount=0\relax%
\beamer@containsverbatimfalse%
\beamer@isfragilefalse%
\beamer@autobreakfalse%
\beamer@shrinkfalse%
\beamer@plainframefalse%
\global\advance\beamer@zoomframecount by1\relax%
\csname beamer@dosecondmode\beamer@defaultdosecondmode\endcsname%
\ifbeamer@centered\setkeys{beamerframe}{c}\else\setkeys{beamerframe}{t}\fi%
\setkeys{beamerframe}{environment=frame}%
\setkeys{beamerframe}{#2}%
\beamer@frametemplate%
%%% old definition ↑↑↑
%%% modified `oldframenumbering' code ↓↓↓
\ifbeamer@noframenumbering
\beamer@noframenumberingfalse
\else
\ifbeamer@continueframenumbering
\beamer@continueframenumberingfalse
\beamer@restorecounter{c@framenumber}
\fi
\ifbeamer@oldframenumbering
\beamer@oldframenumberingfalse
\beamer@continueframenumberingtrue
\beamer@savecounter{c@framenumber}
\beamer@labelrestorecounter{c@framenumber}
\else
\stepcounter{framenumber}
\fi
\fi%
%%% old definition ↓↓↓
{\let\@elt\beamer@savecounter\beamer@overlaycounterresets}
\gdef\beamer@framestartpage{}%
\gdef\beamer@whichframes{#1}%
\ifx\beamer@framerestriction\@undefined\else% restriction stuff
\expandafter\beamer@checkifinlist\beamer@framerestriction\relax%
\fi%
\ifbeamer@inlecture%
\else%
\gdef\beamer@whichframes{all:0}%
\fi%
\ifx\beamer@againname\@empty%
\beamer@slideinframe=0\relax%
\beamer@anotherslidefalse%
{\beamer@masterdecode{\beamer@whichframes}}%
\ifbeamer@anotherslide%
\let\beamer@howtotreatframe\beamer@doseveralframes%
\ifbeamer@containsverbatim%
\let\beamer@howtotreatframe\beamer@dosingleframe%
\fi%
\ifbeamer@autobreak%
\let\beamer@howtotreatframe\beamer@autobreakframe%
\fi%
\ifbeamer@isfragile%
\let\beamer@howtotreatframe\beamer@doexternalframe%
\fi%
\else% no slides in frame
\let\beamer@howtotreatframe\beamer@donoframe%
\fi%
\else% again mode
\let\beamer@howtotreatframe\beamer@doseveralframes%
\ifbeamer@isfragile%
\let\beamer@howtotreatframe\beamer@doexternalframe%
\fi%
\ifbeamer@containsverbatim
\let\beamer@howtotreatframe\beamer@dosingleframe
\fi
\fi%
\beamer@howtotreatframe}
\begin{document}
\makeatletter
\def\insertshortdate{\Huge\hspace*{-5cm}}\Huge
\frame[label=A]{Alfa}
\frame[label=B]{Bravo}
\againframe[oldframenumbering]{A}
\frame[label=C]{Charlie}
\againframe[oldframenumbering]{B}
\againframe[oldframenumbering]{A}
\frame[label=D]{Delta}
\againframe[oldframenumbering]{C}
\againframe[oldframenumbering]{B}
\againframe[oldframenumbering]{A}
\frame[label=E]{Echo}
\frame{Echo}
\againframe[oldframenumbering]{E}
\frame{Echo}
\saved@A@c@framenumber
\saved@B@c@framenumber
\saved@C@c@framenumber
\saved@D@c@framenumber
\saved@E@c@framenumber
\end{document}