79

Sometimes I want an element on a frame to change in steps. I do this by

\only<2>{  
...  
}  
\only<3>{  
...  
}  

etc.

But this causes the frame to jump due to different sizes of the included content. How can this be avoided?

6 Answers6

65

This issue is addressed in the beamer manual in section 9.5 Dynamically Changing Text or Images, p.85 for v.3.10.

You need to use either the overlayarea environment which is "more flexible but less user friendly" or the overprint environment.

\begin{overlayarea}{⟨area width⟩}{⟨area height⟩}
  ⟨environment contents⟩
\end{overlayarea}

\begin{overprint}[⟨area width⟩]
  ⟨environment contents⟩
\end{overprint}

You then need to use \onslide<⟨num⟩> instead of \only<⟨num⟩>{...}. The numbers must be disjoint.

Example:

\begin{overprint}
  % on every slide (not sure if it is officially supported)
  \onslide<1>
  % on first slide
  \onslide<2>
  % on slide two
  \onslide<3>
  % on slide three
  % etc.
\end{overprint}
Martin Scharrer
  • 262,582
  • 3
    Using \only within either an overprint or overlayarea environment seems to work fine. Also, \onslide doesn't behave the same as \only, so sometimes \only may be preferred. – Mark Aug 31 '16 at 00:45
  • 3
    No, \only does not work as intended. Also, very important is to not use braces around onlide's "arguments" (even if they are necessary for the same construct in overlayarea). Using braces makes the elements not overlap at all as they should. – stefanct Aug 07 '18 at 14:36
  • 4
    I am using overlayarea with only. Is it possible to make overlayarea choose its own area height, which should be equal to the height of the longest only<> entry? – kksagar Jan 24 '19 at 14:21
44

Wrap your code fragment inside the overlayarea environment.

Jukka Suomela
  • 20,795
  • 13
  • 74
  • 91
23

The jumping occurs because beamer normally vertically centres the content on the frame.

One way to achieve a constant starting point for content of all heights(*) is to tell beamer to top align the frame. This can either be done on a frame-by-frame basis with

\begin{frame}[t]

or globally for the whole presentation:

\documentclass[t]{beamer}

MWE:

\documentclass{beamer}

\begin{document}

\begin{frame}[t]
    \only<1>{abc}

    \only<2>{abc abc abc abc abc abc abc abc abc abc abc abc abc abc abc abc abc abc }
\end{frame} 

\end{document}

enter image description here

(*) at least for all heights which don't overflow the available text height.

4

When dealing with figures, it can be sufficient to use \tikz[overlay] inside \only:

\only<.>{
  \tikz[overlay,xshift=0em,yshift=0ex]{\draw node {
      % content goes here
   };}
}
Timm
  • 899
2

Use a command phantom to build a same size of the elements.

\only<2>{
...
}
\only<2>{
\phantom{xxxx}
}
\only<3>{
xxxx
}
Martin Scharrer
  • 262,582
S. Boonto
  • 1,074
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    This can result in movement of common items. Using overprint as suggested in other answers avoids this problem. – Liam Feb 01 '13 at 22:45
  • For many cases, this will probably suffice. This is exactly what i needed :) – bmurauer Jan 07 '17 at 20:31
1

It seems that encapsulating the content of each step in textblocks often solves the problem of jumping frames. This is an example for a frame:

\begin{frame}
\only<1->
{ 
\begin{textblock*}{100mm}(10mm,0.2\textheight)
% first content
\end{textblock*}
}
\only<2->
{
\begin{textblock*}{100mm}(10mm,0.5\textheight)
% second content
\end{textblock*}
}
\end{frame}
MartinB
  • 11
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    Welcome to TeX.SX. Please provide a full example, instead some fragments. Another reason of jumping frames could be omitted % characters ;-) –  May 08 '15 at 15:45