beamer
Can somebody explain what the difference between \defbeamertemplate* and \setbeamertemplate is?
Specifically:
\defbeamertemplate*{title page}{default}[1][]
This code is from the default beamer theme.
What I do not understand:
default do? Sometimes it can be named something different.1 part mean?\setbeamertemplate not used instead for everything?Here's half an answer.
The reason that it is half an answer is because of the way that beamer builds a frame. In essence, the stuff on a frame can be divided in to "frame" and "content". The "frame" component is actually typeset by hooking in to the headers and footers bit of TeX's output routine. This ensures that it goes behind the actual content. The "content" is then rendered afterwards. The "frame" component consists of all the stuff like backgrounds, sidebars, and so forth. Interestingly, the frame title is part of the "content".
What I've worked out so far is the order in which the "frame" stuff is laid out, and (mostly) what it consists of. To follow the trail, you need to look at the definition of \ps@navigation in beamerbaseframecomponents.sty and search for everywhere it has a \usebeamertemplate (though you have to be on the lookout for calls to other functions that also call templates).
Exactly what each piece is and how it is to be used is covered in the manual (section 8.2) as Matthew says, but that doesn't tell you the order (well, not obviously) and on the basis that a picture is worth a thousand words anyway, I thought that the following pictures might help.
First, a frame itself:
And now the exploded diagram, at least as far as the "frame" part goes.
It's not quite the same as I didn't take apart the templates and reuse them, but hopefully each bit is unique enough to show what it is.
With regard to the content, then there's less need to do the "explosion" because stuff tends not to get put on top of other stuff, so then it's just a question of knowing what can go in to a frame. The exception is, perhaps, the frame title which one could consider as part of the "frame" part but which, by reason of implementation, is in the "content" part. So for that, reading the beamer user guide is probably as good as you're going to get.
I shan't put the code for doing the above. It isn't pleasant! Nor is it readily adaptable to other situations.
Beamer Theme Matrix can help you to understand how it works. It shows how different color themes change every main theme. If the whole theme (inner, outer, font, color) was defined inside a unique file, you should modify this file. Being everything divided in independent fragments, just selecting a combination of them provides a new aspect for your presentation.
Section 15.1 Five Flavour Themes in beameruserguide clearly explain differences between them. It's easy to imagin what color and font themes do. inner themes define how elements inside a slide (items, enumerate, blocks, ...) look
while outer themes define headlines, footlines, sidebar, ...
In fact, all main themes are defined as a combination of inner, outer, font and color themes. Just two examples, AnnArbor theme is defined with
\useinnertheme[shadow=true]{rounded}
\useoutertheme{infolines}
\usecolortheme{wolverine}
\setbeamerfont{block title}{size={}}
\setbeamercolor{titlelike}{parent=structure,bg=yellow!85!orange}
while Copenhagen is
\useoutertheme{split}
\useinnertheme{rounded}
\usecolortheme{whale}
\usecolortheme{orchid}
\setbeamerfont{block title}{size={}}
Although beamer works this way, you don't have to follow it. If you want a constant theme, with very few options, everything can be defined inside a main theme file. If your theme is called "mytheme", define everything inside a file called beamerthememytheme.sty file and store it into your working folder while you are testing it. As soon as your theme is ready, move it to your local tree.
Best Answer
From the user manual, page 169: