Make a text box legend for factors in ggplot2 bar chart? (R)

Question

install.packages("ggplot2")
library(ggplot2)

vector1 <- c(1, 4, 5, 6, 2, 4, 5, 8)
vector2 <- c(1, 2, 3, 4, 5, 6, 7, 8)
dataframe <- data.frame(vector1, vector2)
dataframe$vector2 <- as.factor(dataframe$vector2)


plot <- ggplot(dataframe, aes(vector2, vector1))
plot +geom_bar(stat = "identity")

I would like to make a text box somewhere in the bar chart window that shows values of 1-8 corresponding to levels of a factor. If I give the levels character-based names, it clutters the x-axis, and I don't want that. So I figured a legend that corresponds numbers to the levels would be great alternative. eg Ideally, each level of a factor is descending as a row, like a legend.

1 - slippery roads 2 - dry roads 3 - something creative

etc.

Answer 1

Ok here is another approach. There might be easier ones.

We use the guide for fill, remove the legend keys and overlay a second set of bars.

ggplot() + geom_col(data = dataframe, aes(vector2, vector1, fill = vector2)) + 
           geom_col(data = dataframe, mapping = aes(vector2, vector1))  + 

           scale_fill_discrete(name = "", labels = paste0(1:8, " roads")) + 
           theme(legend.position = c(.3, .8), 
                 legend.key = element_blank(),
                 legend.background = element_blank()) + 

           guides(fill=guide_legend(override.aes=list(fill = NA), 
                  keywidth = 0, keyheight = 0, nrow = 2))