---
title: "Styling numbered markers"
vignette: >
  %\VignetteIndexEntry{Styling numbered markers}
  %\VignetteEngine{quarto::html}
  %\VignetteEncoding{UTF-8}
knitr:
  opts_chunk:
    collapse: true
    comment: "#>"
    fig-width: 7
    fig-height: 4
---

This article changes how the markers and their numbers look, and shows how
they follow themes and facets. For the basics, see
[Get started](ggindex.html).

```{r}
#| label: setup
library(ggplot2)
library(ggindex)

cars <- mtcars
cars$model <- rownames(cars)
cars$rank <- rank(-cars$mpg, ties.method = "first")
```

## Styling the markers

The markers use the standard `colour`, `fill`, `shape`, `size`, `stroke` and
`alpha` aesthetics, so they work with the usual ggplot2 scales. Here the most
efficient car of each cylinder class is filled by class.

```{r}
#| label: scales
cars$best <- cars$mpg == ave(cars$mpg, cars$cyl, FUN = max)

ggplot(cars, aes(wt, mpg)) +
  geom_point(colour = "grey60") +
  geom_focus(
    aes(label = rank, focus = best, info = model, fill = factor(cyl)),
    shape = 22,
    size = 7
  ) +
  scale_fill_brewer("Cylinders", palette = "Set2") +
  scale_info_discrete("Best in class") +
  theme_minimal()
```

## Styling the numbers

The numbers take the `family` and `fontface` aesthetics and the `text.colour`
and `text.size` parameters. By default they use the marker's `colour`. The
legend keys show the same style.

```{r}
#| label: text
ggplot(cars, aes(wt, mpg)) +
  geom_point(colour = "grey60") +
  geom_focus(
    aes(label = rank, focus = rank <= 5, info = model),
    fill = "grey20",
    text.colour = "white",
    fontface = "bold"
  ) +
  theme_minimal()
```

## Themes

Without other settings, markers are filled with the theme's `paper` colour
and drawn with its `ink` colour, so they follow the theme.

```{r}
#| label: theme
ggplot(cars, aes(wt, mpg)) +
  geom_point(colour = "grey50") +
  geom_focus(aes(label = rank, focus = rank <= 5, info = model)) +
  theme_minimal(ink = "white", paper = "grey15")
```

## Facets

Focus points are drawn in the panel they fall in, and a panel without focus
points shows only the other layers. The three most efficient cars all have
four cylinders.

```{r}
#| label: facets
ggplot(cars, aes(wt, mpg)) +
  geom_point(colour = "grey60") +
  geom_focus(aes(label = rank, focus = rank <= 3, info = model)) +
  facet_wrap(vars(cyl), labeller = label_both) +
  theme_minimal()
```