---
title: "Text boxes and decorations"
author: "SPDS, uni.kn"
date: "2019 06 15"
output: 
  rmarkdown::html_vignette: 
    fig_caption: yes
vignette: > 
  %\VignetteIndexEntry{Text}
  %\VignetteEngine{knitr::rmarkdown}
  %\VignetteEncoding{UTF-8}
---

```{r setup, include = FALSE}
options(max.print = "75")
knitr::opts_chunk$set(echo = TRUE,
	             cache = FALSE,
               prompt = FALSE,
               tidy = FALSE,
               collapse = TRUE, 
               comment = "#>",
               message = FALSE,
               warning = FALSE,
               # ## Default figure options:
               # fig.width = 7.2, 
               # fig.asp = .618, # golden ratio
               # out.width = "75%",
               fig.align = "center"
               )
```

<!-- unikn pkg logo and link: -->
<a href = "https://github.com/hneth/unikn/">
<img src = "../inst/pix/unikn.png" alt = "unikn::" align = "right" width = "140px" style = "width: 140px; float: right; border:0;"/>
</a>

This vignette explains the **unikn** functions for plotting graphical elements and text decorations. 
(See the vignette on [color](colors.html) for information on colors, color palettes, and corresponding functions.) 

Please install and/or load the **unikn** package to get started: 

```{r load_pkg_text, message = FALSE, warning = FALSE}
# install.packages('unikn')  # install unikn from CRAN client
library('unikn')             # load the package
```

## Overview 

Beyond providing support for [colors](colors.html), **unikn** provides functions for plotting graphical elements (like boxes) and text decorations (with colored backgrounds or underlining). 
Before illustrating these functions, please note some caveats: 

- Plotting text (i.e., graphically rendering characters) is rarely a good idea. In contrast to the vector fonts used by DTP programs, plotted text typically does not scale (when changing the size of images) and cannot be recognized automatically (e.g., copied, indexed, or scraped). 
Hence, the following functions should only be used when no better solutions are available (e.g., for adding text to graphs, or for obstructing automatic text recognition). 

- Like all other templates, our renderings are subject to constraints and limitations. For instance, as any standard installation of [R](https://www.r-project.org/) lacks the prescribed "Theinhardt" fonts, we only mimic the official design specifications (in Arial, sans serif). 

That said, digital decorations can be useful to emphasize or structure information, provided that they can be produced easily and flexibly. The **unikn** package helps preventing common mistakes by novices (e.g., boxes or lines extending beyond text, or step-functions in multi-line headings) and can be customized and improved by expert users. Hence, we hope that the following functions are useful for plotting graphical elements (e.g., boxes, logos, etc.) and help you achieve a uniform look when styling presentations or visualizations. 

Please load the **unikn** package to get started: 

```{r load_pkg, message = FALSE, warning = FALSE}
library(unikn)  # load unikn package
```

## Plotting empty slides and boxes

As the text functions of **unikn** add styled text to an existing plot, we must first create a plot to which we can add text. 
**unikn** provides 2 basic functions for creating new plots:

1. `slide` plots an empty canvass (or rectangular frame); 
2. `xbox` plots a colored box with an X in its top right corner.

Here are both commands with their default settings: 

```{r slide_def, fig.align = 'center', fig.width = 4, fig.height = 3}
slide()  # plot default slide
```

```{r xbox_def, fig.align = 'center', fig.width = 2, fig.height = 2}
xbox()  # plot default xbox
```

Both functions accept additional arguments to customize their appearance. 

### Colors

The background and border colors of slides can be changed by setting their `col`, `border`, and `lwd` arguments:

```{r slide_col, fig.align = 'center', fig.width = 4, fig.height = 3}
slide(col = pal_seeblau[[1]], border = Petrol, lwd = 5)  # set colors of slide background and border
slide(col = pal_peach[[2]], border = NA)  # colored slide without a border
```

Similarly, the background color of xboxes can be changed by the `col` argument:

```{r xbox_col, fig.align = 'center', fig.width = 2, fig.height = 2}
xbox(col = Pinky)  # set background color of xbox
```

### Dimensions

By default, both `slide` and `xbox` fill the entire plotting region (i.e., all margins are set to 0).

The width of a slide is set to 4/3 of its height (of 1). 
To change this default, use the `dim` argument for specifying the slide's x- and y-dimensions, respectively:

```{r slide_dim, fig.align = 'center', fig.width = 6, fig.height = 2}
slide(dim = c(3, 1))  # a slide 3 times wider than high
```

Similarly, an xbox has the default dimensions of a unit square (i.e., `dim = c(1, 1)`). 
To change this default, use the `dim` argument for specifying the xbox's `x`- and `y`-dimensions, respectively:

```{r xbox_dim, fig.align = 'center', fig.width = 2, fig.height = 4}
xbox(col = Petrol, dim  = c(1, 2))  # an xbox 2 times higher than wide
```

The 2 strokes of the X (in the top right corner) are orthogonal when viewing the `xbox` at the aspect ratio indicated by `dim` (i.e., here: at a ratio of width x = 1 to height y = 2). When viewing the box at any different aspect ratio, the X seems distorted. Hence, viewing and printing plots at the desired aspect ratio is crucial for designing an xbox.

## Plotting styled text

There are 3 main functions for plotting text with decorations: 

- `mark` allows highlighting text with colored background boxes; 
- `uline` allows underlining text with colored lines; 
- `post` allows posting text in rectangular `xbox` elements.

In addition, there are 2 auxiliary functions: 

- `headline` allows plotting headlines with colored background boxes; 
- `url_unikn` allows formatting URLs the uni.kn way. 

The following sections illustrate the functions and their main options in turn. 

### Mark text

The `mark` function allows highlighting text by plotting it with colored background boxes (to provide the functionality of "Markieren"): 

```{r mark_demo, echo = FALSE, fig.width = 3, fig.height = 3}
lbl_blank <- c("                                                ",
              "                                      ",
              "                                                      ",
              "                                                ",
              "                              ")

# (a) Create a new plot (of type "slide"):
mark(labels = lbl_blank,
     x = 0, y = .85, y_layout = .03,
     col_bg = Seeblau,
     cex = 1.0,
     new_plot = "slide")
```

By default, `mark` assumes that we want to add highlighted text to an already existing plot. 
The text labels to be added are provided (as a character vector) by the `labels` argument, their coordinates as the corresponding `x` and `y` arguments. 
Various text decorations (i.e., text and background colors, text sizes, and font types) can be set by specifying additional arguments (i.e., `col`, `col_bg`, `cex`, and `font`, respectively): 

```{r set_par, echo = FALSE}
# Set par:
opar <- par(no.readonly = TRUE)  # all par settings that can be changed.
par(mar = c(1, 1, 1, 1))
```


```{r mark_messy_plot, echo = TRUE, fig.width = 6, fig.height = 4}
# Some pre-existing plot: 
n <- 20
set.seed(1)
par(mar = c(0, 0, 0, 0))
plot(x = runif(n), y = runif(n), type = "p", pch = 16, cex = 20, col = grey(0, .2),
     axes = FALSE, xlab = "", ylab = "")

# Add 1 marked label:
mark(labels = "Some messy plot", x = .02, y = .9)

# Add 2 more marked labels:
mark(labels = c("Note something here", "More highlighting here"), 
     x = c(.1, .6), y = c(.2, .4),
     col_bg = c(pal_seeblau[[2]], pal_peach[[3]]), cex = 1.2)
```

```{r reset_opar, echo = FALSE}
# Restore plot settings:
par(opar)
```

If no pre-existing plot is available, setting the `new_plot` argument to either `"blank"` or `"slide"` will generate a new default plot (by using the `slide` function described above):

```{r mark_new_plot, echo = TRUE, fig.width = 4, fig.height = 4}
# A sentence to plot: 
s <- c("Markieren",
       "ist ein Bestandteil",
       "von Studieren.")

# Create a new plot (of type "slide"):
mark(labels = s,
     x = 0, y = .85, y_layout = .03,
     col_bg = Seeblau,
     cex = 1.5,
     new_plot = "slide")

# Add text to the same plot:
mark(labels = s,
     x = 0, y = .40, y_layout = .03,
     col_bg = pal_pinky[[2]],
     cex = 1.5, 
     new_plot = "none")
```

Instead of providing explicit `x` and `y` coordinates for all text elements in `labels`, the calls above defined an initial coordinate and used a numeric `y_layout` argument to fix the distance between consecutive text labels (to a value of `.03`). Special values for `y_layout` are: 

- `y_layout = "even"` for an even distribution of labels across the available y-space, and 
- `y_layout = "flush"` to omit space between adjacent labels (as in `y_layout = 0`).  

See `?mark` for details. 

### Underline text

The `uline` function allows emphasizing text by plotting it with colored underlining (to provide the functionality of "Unterstreichen"): 

```{r uline_demo, echo = FALSE, fig.width = 3, fig.height = 3}
slogan <- c("Geradlinig", "Authentisch", "Beweglich", "Offen", "Paradiesisch")
uline(labels = slogan,
      x = 0, y = .9, y_layout = "even",
      cex = 1.1, font = 2,
      new_plot = "blank")
```

As with `mark` above, the `uline` command distinguishes between creating a new plot (by setting `new_plot` to either `"blank"` or "`slide`") or 
adding to a pre-existing plot (by using the default `new_plot = "none"`): 

```{r uline_ex1, echo = TRUE, fig.width = 4.5, fig.height = 3}
lbl_uline <- c("This is neat, true, and terribly important")
uline(labels = lbl_uline, new_plot = "blank", y = .6, cex = 1.1)  # create a new plot
uline(labels = "(which is why we underline it).", y = .45, cex = 1)  # add to plot
```

The arguments for text elements (`labels`), text positions (`x`, `y`, `y_layout`), and text properties and decorations (`col`, `col_bg`, `cex`, and `font`) work as they do for `mark`. For instance, shorter vectors are recycled to match the length of `labels`: 

```{r uline_ex2, echo = TRUE, fig.width = 3, fig.height = 3}
slogan <- c("Geradlinig", "Farbenfroh", "Beweglich", "Bunt", "Paradiesisch")
uline(labels = slogan,
      x = c(0, .5), y = .9, y_layout = "even",
      col = c("black", Bordeaux), col_bg = c(Seeblau, Seegruen), 
      cex = 1.1, font = 2, new_plot = "blank")
```

### Post text

The `post` function allows adding text to a rectangular `xbox` (to provide the functionality of "Merken"): 

```{r post_demo, echo = FALSE, fig.width = 4, fig.height = 2}
xbox(col = Seegruen, dim = c(4, 2))
post(labels = "Please note", x = .1, y = 1.2, cex = 1.2, font = 2, new_plot = FALSE)
post(labels = c("For good results, always design and view", "boxes and text at the size at which they", "will be saved and displayed later."), 
     x = .1, y = .8, y_layout = .1, cex = 1, font = 1, new_plot = FALSE)
```

By default, `post` assumes a pre-existing `xbox` to which the text elements of `labels` are to be added.  
For square boxes, setting `new_plot` to `"xbox"` creates a new `xbox` with its default dimensions of `dim = c(1, 1)`.  
By adjusting its color and text arguments, `post` allows creating simple badges or logos: 

```{r post_logo, echo = TRUE, fig.width = 2, fig.height = 2, fig.show = "hold"}
# Badge (to view as 250 x 250 pixel):
post(labels = "ToDo", y = .35, 
     col = "white", col_bg = pal_signal[[1]],
     cex = 3, font = 2, new_plot = "xbox")  

# Badge (to view as 250 x 250 pixel):
post(labels = "R", y = .35, 
     col = "white", col_bg = pal_seeblau[[5]],
     cex = 8, font = 2, new_plot = "xbox")
```

Another use of `post` is to create an image that provides contact details: 

```{r post_address, echo = TRUE, fig.width = 3, fig.height = 3}
address <- c("Dr. B. F. Skinner", " ",
             "Department of Psychology",
             "Office F101",
             "Tel.: +49 7531 88-0815",
             "Fax: +49 7531 88-0810",
             "b.f.skin@uni-konstanz.de")

post(labels = "Contact",
     y = .7,
     cex = 1.2, font = 2,
     col_bg = Petrol,
     new_plot = "xbox")  # create new plot 

post(labels = address,
     y = .5, y_layout = .03,
     new_plot = "none")  # add to plot
```

### Headings

The `heading` function makes it easy to create recognizable headings: 

```{r heading_demo, echo = FALSE, fig.width = 4, fig.height = 3}
heading(labels = c("Ich bin", "eine", "Headline."))
```

By default, the function creates a new slide (i.e., `new_plot = "slide"`) and positions the text elements of `labels` on its left edge (i.e., `x = 0`, `y = .8` and `y_layout = "flush"`). Headings violating the recommendations (see p. 25 of the CD manual) will generate a message, for instance: 

```{r heading_warn, echo = TRUE, message = TRUE, fig.width = 4, fig.height = 3}
# Beware of step-wise arrangements:
heading(labels = c("Ich", "bin keine", "gute Headline."))

# To avoid warning:
heading(labels = c("Ich bin", "eine alternative", "Headline."))
```

When colors are left unspecified, `heading` selects colors that are appropriate 
for the number of elements in `labels` (i.e., shades of `Seeblau` for `col_bg = "default"`). 
However, default colors can be overwritten by setting the `col` and `col_bg` arguments:

```{r heading_col, echo = TRUE, fig.width = 4, fig.height = 3}
heading(labels = c("Ene,", "mene, miste,", "es rappelt", "in der Kiste."), 
        col = "white", col_bg = c(Pinky, Seegruen, Bordeaux, Karpfenblau))
```

### URLs

One of the more obscure rules (on p. 31 of the CD manual) concerns the rendering of URLs, in which typical web patterns (like "http" or "www") are to be omitted and replaced by a typographical dash (which is longer than a hyphen). The `url_unikn` utility function allows formatting URLs the uni.kn way:

```{r url_post, fig.align = 'center', fig.width = 2, fig.height = 2}
my_url <- url_unikn("https://www.uni-konstanz.de/")  # input URL as copied from web browser
my_url  # formatted URL

# Put URL at bottom of an xbox:
post(labels = my_url, x = .05, y = .1, font = 4, 
     col_bg = pal_seeblau[[5]], new_plot = "xbox")
```


## Resources

The following versions of **unikn** and corresponding resources are currently available: 

Type:                    | Version:           | URL:                           |         
:------------------------|:-------------------|:-------------------------------| 
A. **unikn** (R package): | [Release version](https://CRAN.R-project.org/package=unikn) | <https://CRAN.R-project.org/package=unikn> |
    &nbsp;                | [Development version](https://github.com/hneth/unikn)       | <https://github.com/hneth/unikn> | 
B. Online documentation:  | [Release version](https://hneth.github.io/unikn)            | <https://hneth.github.io/unikn> | 
    &nbsp;                | [Development version](https://hneth.github.io/unikn/dev)    | <https://hneth.github.io/unikn/dev> | 

## Vignettes

<!-- unikn pkg logo and link: -->
<a href = "https://github.com/hneth/unikn/">
<img src = "../inst/pix/unikn.png" alt = "unikn::" align = "right" width = "140px" style = "width: 140px; float: right; border:0;"/>
</a>

The following vignettes provide instructions and examples for using the **unikn** objects and functions: 

<!-- Table of vignettes: --> 

| Nr.  | Vignette | Content    |        
| ---: |:---------|:-----------|
| 1. | [Colors](colors.html) | Colors and color palettes | 
| 2. | [Text](text.html)     | Text boxes and decorations | 

<!-- eof. -->
