# xaringanthemer
Easily style your [xaringan](https://github.com/yihui/xaringan) slides
with **xaringanthemer**.

- [Installation](#installation)
- [Quick Intro](#quick-intro)
- [Themes](#themes)
- [Monotone](#monotone)
- [Duotone](#duotone)
- [Solarized](#solarized)
- [Theme Settings](#theme-settings)
- [Adding Custom CSS](#adding-custom-css)
- [Fonts](#fonts)
## Installation
**xaringanthemer** lives here on GitHub.
``` r
# install.packages("devtools")
devtools::install_github("gadenbuie/xaringanthemer")
```
## Quick Intro
First, add `css: xaringan-themer.css` to your xaringan slides YAML
header under `xaringan::moonreader:`.
``` yaml
output:
xaringan::moon_reader:
lib_dir: libs
css: xaringan-themer.css
```
Then, in the knitr setup chunk, load **xaringanthemer** and try one of
the [theme functions](#themes).
```` markdown
```{r setup, include = FALSE}
options(htmltools.dir.version = FALSE)
library(xaringanthemer)
mono_light(
base_color = "#1c5253",
header_font_google = google_font("Josefin Sans"),
text_font_google = google_font("Montserrat", "300", "300i"),
code_font_google = google_font("Droid Mono")
)
```
````

**xaringanthemer** is Tab friendly – [use autocomplete to
explore](#fully-customized) the themes\!
## Themes
### Monotone
Use these functions to automatically create a consistent color palette
for your slides, based around a single color.
#### `mono_light()`
A light theme based around a single color.

#### `mono_dark()`
A dark theme based around a single color.

#### `mono_accent()`
The default xaringan theme with a single color used for color accents on
select elements (headers, bold text, etc.).

#### `mono_accent_inverse()`
An “inverted” default xaringan theme with a single color used for color
accents on select elements (headers, bold text, etc.).

### Duotone
These themes build from two (ideally) complementary colors.
#### `duo()`
A two-colored theme based on a primary and secondary color.

#### `duo_accent()`
The default Xaringan theme with two accent colors.

#### `duo_accent_inverse()`
An “inverted” default Xaringan theme with two accent colors.

### Solarized
There are also two themes based around the [solarized color
palette](http://ethanschoonover.com/solarized), `solarized_light()` and
`solarized_dark()`. For both themes, it is advisted to change the syntax
highlighting theme to `solarized-light` or `solarized-dark` (looks great
paired or constrasted).
#### `solarized_light()`

#### `solarized_dark()`

To do this, your YAML header should look more-or-less like this:
``` yaml
output:
xaringan::moon_reader:
lib_dir: libs
css: ["xaringan-themer.css"]
nature:
highlightStyle: solarized-dark
highlightLines: true
countIncrementalSlides: false
```
## Theme Settings
The theme functions listed above are just wrappers around the central
function of this package, `write_xaringan_theme()`. If you want to start
from the default **xaringan** theme and make a few modifications, start
there.
All of the theme template variables are repeated in each of the theme
functions (instead of relying on `...`) so that you can use
autocompletion to find and change the defaults for any theme function.
To override the default value of any theme functions, set the
appropriate argument in the theme function.
As an example, try loading `xaringanthemer`, type out `duo_theme(` and
then press Tab to see all of the theme options.
All of the theme options are named so that you first think of the
element you want to change, then the property of that element.
Here are some of the `text_` theme options:
- `text_color`
- `text_bold_color`
- `text_slide_number_color`
- `text_size`
- `text_size_h1`
- *and more …*
And here are the title slide theme options:
- `title_slide_text_color`
- `title_slide_background_color`
- `title_slide_background_image`
## Adding Custom CSS
You can also add custom CSS classes using the `extra_css` argument in
the theme functions. This argument takes a named list of CSS definitions
each containing a named list of CSS property-value pairs.
``` r
extra_css <- list(
".red" = list(color = "red"),
".small" = list("font-size" = "90%"),
".full-width" = list(
display = "flex",
width = "100%",
flex = "1 1 auto"
)
)
```
If you would rather keep your additional css definitions in a separate
file, you can call `write_extra_css()` separately. Just be sure to
include your new CSS file in the list of applied files in your YAML
header.
``` r
write_extra_css(css = extra_css, outfile = "custom.css")
```
``` css
/* Extra CSS */
.red {
color: red;
}
.small {
font-size: 90%;
}
.full-width {
display: flex;
width: 100%;
flex: 1 1 auto;
}
```
This is most helpful when wanting to define helper classes to work with
the [remark.js](https://github.com/gnab/remark) `.class[]` syntax. Using
the above example, we could color text red `.red[like this]` or write
`.small[in smaller font size]`.
## Fonts
Yihui picked out great fonts for the default **xaringan** theme, but
sometimes you want something new and interesting.
**xaringanthemer** makes it easy to use [Google
Fonts](https://fonts.google.com) in your presentations (well, as long as
you have an internet connection) or to fully specify your font files.
To use [Google Fonts](https://fonts.google.com), set the `_font_google`
theme arguments – `text_font_google`, `header_font_google`,
`code_font_google` — using the `google_font()` helper. See
`?google_font` for more info.
``` r
mono_light(
header_font_google = google_font("Josefin Slab", "600"),
text_font_google = google_font("Work Sans", "300", "300i"),
code_font_google = google_font("IBM Plex Mono")
)
```
If you set an `xxx_font_google` theme arguments, then `xxx_font_family`,
`xxx_font_weight` and `xxx_font_url` are overwritten – where `xxx` in
`{header, text, code}`. Of course, you can manually set
`header_font_url`, etc., and ignore the `header_font_google` argument.
For example, suppose you want to use a ligature font for the code font,
such as [Fira Code](https://github.com/yihui/xaringan/issues/83). Just
set `code_font_family` and `code_font_url`\!
``` r
solarized_dark(
code_font_family = "Fira Code",
code_font_url = "https://cdn.rawgit.com/tonsky/FiraCode/1.204/distr/fira_code.css"
)
```
-----
**xaringanthemer** was built by [Garrick
Aden-Buie](https://www.garrickadenbuie.com)
([@grrrck](https://twitter.com/grrrck)).
Big thank you to [Yihui Xie](https://yihui.name), especially for
[xaringan](https://github.com/yihui/xaringan). Also thanks to [Ole
Petter Bang](http://gnab.org) for
[remark.js](https://github.com/gnab/remark).
Feel free to [file an
issue](https://github.com/gadenbuie/xaringanthemer/issues) if you find a
bug or have a theme suggestion – or better yet, submit a pull request\!