An example for itemized list

By default, ConTeXt uses $\bullet$ as the marker for top level itemization. The
font that I am using, Neo Euler, does not have a `\bullet` glyph, so the item
marker is not shown.

In the next few steps, I will show how to change them item marker.
Setup itemize head style

The itemize environment in ConTeXt provides two types of items: normal items
that are created using `\item` or `\startitem ... \stopitem` and items with
heads, created using `\head` or `\starthead ... \stophead`.

I like to use the second alternative in presentations. The advantage is that the
item head can be typeset in a different style than the regular items; so it adds
some emphasis to the main points.

See:

- http://wiki.contextgarden.net/Command/head

for more details.
Use metapost to create a item marker

I like to use filled square as the top-level item marker. Rather than using math
symbols for the item marker, I use Metapost to draw the square.

For more details on using MetaPost, read:

- http://wiki.contextgarden.net/MetaPost_in_ConTeXt
- http://www.pragma-ade.com/general/manuals/metafun-s.pdf

For details on symbols, read:

- http://wiki.contextgarden.net/Symbols
Set spacing for itemize

Tweak the spacing around bullet according to your preference.
Example for nested bullet list

Sometimes I use nested levels of itemization in presentations. The default
settings for 2nd level of itemization does not look nice. I will change these
defaults in the next few edits.
Tight itemized list for level 2

By default, lists in ConTeXt are `unpacked`. I prefer to use second level lists
without any additional spacing around the items; hence the `nowhite` option.

This setup is not perfect because of the extra space before the 2nd level
items. This will be fixed in the next commit
Remove unwanted spacing before 2nd level list

ConTeXt provides different alternatives for determining the spacing around
itemized lists, but there is no high level interface around these alternatives.

With the default alternative, I could not set the spacing around itemized lists
according to my liking; so I change an internal macro to choose a different
alternative for determining spacing around itemize lists.

There might be a better, higher-level way to get the same visual output, but I
am not aware of it.
Set 2nd level itemize marker

I like to use a small triangle as a marker for 2nd level itemized lists. Rather
than using a math symbol for the triangle, I use Metapost as before.
Set document metadata

Simply set the metadata. The next few commits will show how to use this
metadata.
Add metadata to footer

Again, this is a matter of personal choice. I like to include the presentation
title and the author in the footer of each slide. Read:

- http://wiki.contextgarden.net/Headers_and_Footers

for details on setting the footer and

- http://wiki.contextgarden.net/Inside_ConTeXt#Using_variables

for information on variables.
Simple title page

This shows how to create a titlepage. The main idea is to use the `set` key for
variables to call a setup that uses a `makeup` page to create the titlepage.
Notice that the page numbers of the subsequent pages are correct. This is
because we used `\userpage` and `\lastuserpage` to show page numbers, and a
makeup page does not increment the userpage number.

The title page is has no style setup. The next few commits will show how to add
different style elements to the titlepage.
Added styling to titlepage

There are different ways to add style to the titlepage. I create different
style commands: `titlestyle`, `authorstyle`, etc for each metadata element and
then use them to style the corresponding element.
Sample text for display math

Notice that by default, ConTeXt uses `\blank[big]` around displaymath. In the
next commit, In the next commit, I will correct the spacing.
Set spacing around display math

Setting spacing around display math is a bit tricky. The obvious

    \setupformulas[spacebefore=small, spaceafter=small]

does not work. I think that this is because I use

    \setupwhitespace[big]

and ConTeXt vertical spacing model is such that the largest vspace value (big
in this case) wins.

After a bit of trial and error, I settled on this:

    \setupformula
        [spacebefore={nowhite,quarterline}, spaceafter={back,nowhite,quarterline}]

For `spacebefore`, the parameter `nowhite` kills all the whitespace and
then `quarterline` sets the space before the formula to be 0.25\lineheight.

Surprisingly, the same setting `{nowhite,quarterline}` does not work when used
for `spaceafter`. We need an addition `back` parameter to kill the previous
vpsace.
Example text for images

The simpleslides module provides two ways of including images: a horizontal
mode and a vertical mode. I like that, and want to provide similar alternatives
in this case.

A horizontal image should occupy as must horizontal space as possible without
overflowing the page height.

A vertical image should not be wider than 0.5\textwidth and should occupy as
much vertical space as possible.

For now, we use dummy settings `horizontal` and `vertical` for these two types
of images. The actual settings will be defined in the the next commits.
Remove figure numbers

I don't prefer the figures in presentations to be numbered so I remove them.
Define settings for horizontal images

Read:

- http://wiki.contextgarden.net/Command/defineexternalfigure

for details on defining settings for figures.

To determine the amount of vertical space left on the page, we define a measure
`page`. The exact value of this measure is taken from a solution by Wolfgang
Schuster on the ConTeXt mailing list.
Add setting for vertical images

The idea for the settings for vertical images is the same as that of horizontal
images. We add a little bit more vertical space around vertical images.
Tweak space around figures

By default, ConTeXt includes a big space before and after a float. I find that
to be excessive; so I reduced the space.

See:

- http://wiki.contextgarden.net/Command/setupfloat

for details.