Write group labels in first bar or above instead of legend - r

Question

I have a stacked barplot with the following data
df <- expand.grid(name = c("oak","birch","cedar"),
sample = c("one","two"),
type = c("sapling","adult","dead"))
df$count <- sample(5:200, size = nrow(df), replace = T)
I generate a barplot and try to add the group lables to it:
ggplot(df, aes(x = name, y = count, fill = type)) +
geom_bar(stat = "identity") +
coord_flip() +
theme(legend.position="none") +
geom_text(aes(label = type, position = "stack"))
It produces:
Two to three questions arise:
How can I make the labels appear in the top bar only?
How can I make the labels appear in the center of the bar section?
Optionally: How can I make the labels appear on top of the top bar being connected to their sections by arrows?

Answer 1

There is a link suggested above. That will help you. Here, I have another suggestion.
set.seed(123)
df <- expand.grid(name = c("oak","birch","cedar"),
sample = c("one","two"),
type = c("sapling","adult","dead"))
df$count <- sample(5:200, size = nrow(df), replace = T)
### Arrange a data frame (summing up sample one and two)
library(dplyr)
ana <- df %>%
group_by(name, type) %>%
summarise(total = sum(count))
# Draw a figure once
bob <- ggplot(ana, aes(x = name, y = total, fill = type)) +
geom_bar(stat = "identity", position = "stack")
# Get a data frame for ggplot
cathy <- ggplot_build(bob)$data[[1]]
# calculate text position & add text labels
cathy$y_pos <- (cathy$ymin + cathy$ymax) / 2
cathy$label <- rep(c("sampling", "adult", "dead"), times = 3)
# Subset the data for labeling for the top bar
dan <- cathy[c(7:9), ]
# Draw a figure again
bob +
annotate(x = dan$x, y = dan$y_pos, label = dan$label, geom="text", size=3) +
coord_flip()