Creating the Presentation


Adding Slides
Changing defaults

In the previous chapter, we designed our presentation. We know now with some accuracy the general contents of the talk. We know were we will talk about. Slides should contain a kind of guideline for your talk.

Filling your Slides

As general rule, each slide should contain:
  • a title, to show what the subject of the slide is;
  • figures, pictures, and code-examples which are used in your talk;
  • very little text.
Text should be used as sparsely as possible. If you need to use some text, then stick to simple sentences, preferably single words. The sentences (or words) have the importance as section-headers in a written paper. Your talk fills the text in the section shown on the slide.

Although the quality of displaying devices did improve considerably over the last years (a good quality beamer with 1024x768 is readily available), they cannot compete with plastic foil. But even with the perfect sharpeness of foils, you shall not put much information on it.

In general:

  • Do not put more than 7 items on a slide.
  • Use huge letters: everyone, even in the back-seats of the room must be able to read it without problem.
  • Do not use more than 30 words on a slide.
  • Preferrable, do not put any words (except the title) on the slide.
  • Use your slides horizontally.

Good slides are sparsely filled.

Getting Started with PPresenter

At last: now we can start with composing our slides with PPresenter. The more you know about the programming language Perl, the more use you can profit from the features of PPresenter. If you never used the language, then you should start reading on the notation of strings in Perl (might also be useful for more experienced Perl programmers).

A presentation in PPresenter is a Perl program. You write a program using objects (Perl can be used as an object oriented language, and PPresenter is doing so). Each slide is an object. But the main object (the only one you create explicitly) is the PPresenter object.

An presentation, without any slides defined, looks as follows:

  1:  #!/usr/local/bin/perl -w
  2:  use strict;

  3:  use PPresenter;
  4:  my $show = PPresenter->new;

  5:  $show->run;
If you want to copy this example into a file, click this link: "Template for the Presentation".

On UNIX systems:
The first line is used to start Perl on the moment this script is run. The Perl interpreter may be in a different directory, so change the path accordingly. Then, set execute permission on the file (chmod +x file).

The -w option used in the first line is to tell Perl to complain on everything what might be a mistake in your program. As the perl manual page justifyably remarks as a bug: it is just an option, it should have been made obligatory.

On Windows systems:
Your script should be named with extention .pl, and you have to inform Windows to start Perl when the .pl extention is found.

Whether warnings are produced (and they should, to help you) depends on your windows configuration. If -w is not the default, then you can add "$^W = 1;" to your program, which has the same effects.

Also the second line is used to improve our code. By adding "use strict" to our program, Perl will complain about all variables used without previous declaration with my. This will safe you from typing errors in variable names.

The third line orders Perl to compile the software of PPresenter. On its turn, the PPresenter software will enforce compilation of Tk (the graphical system) and ImageMagick (for image manipulation, if installed). Compilation consumes quite some time (a few seconds) because we are talking about many thousands lines of Perl-script.

At line 4, we create the presentation (-object). In one program, you can define more than one presentation, but it is usually easier to make one presentation on more than one screen in such case.
There are quite a number of options to new, but you can add them later, in the final stages of the presentation-development.

The last line (line 5) starts the show. Between lines 4 and 5, the actual work has to be done. Inbetween those lines, you change the defaults, possibly add extra displays, and add the slides to your presentation.

Next: Styles.

Portable Presenter is written and maintained by Mark Overmeer. Copyright (C) 2000-2002, Free Software Foundation FSF.