ggplot2 multiple plots, with shared legend, one background colour, 1 main and 3 sub-titles and non-standards layout

Question

I am trying to create a plot that will be combination of 6 plots made in ggplot2. The conditions are

1. One main title
2. Three subtitles
3. Common background color
4. Diffrent sizes of plots
5. One legend at the bottom

And it should look something like it:

I have found bits and pices, but I dont know how to put it togheter.

To add main title I used Place title of multiplot panel with ggplot2

layout <- matrix(c(1, 1, 2, 3, 3, 4), nrow = 2, byrow = TRUE)
grid.arrange(A, B, C, D, top = "Title",
             layout_matrix = layout)

I have found function multiplot (http://www.cookbook-r.com/Graphs/Multiple_graphs_on_one_page_(ggplot2)/) and it dose allow to plot several charts with diffrent sizes, but the other reqirements are not met

plot_list <- list(A, B, C, D)
layout <- matrix(c(1, 1, 2, 3, 3, 4), nrow = 2, byrow = TRUE)
multiplot(plotlist = plot_list, layout = layout) 

I have also found how to create common legend, but the charts sizes are the same (Add a common Legend for combined ggplots)

grid_arrange_shared_legend <- function(...) {
  plots <- list(...)
  g <- ggplotGrob(plots[[1]] + theme(legend.position="bottom"))$grobs
  legend <- g[[which(sapply(g, function(x) x$name) == "guide-box")]]
  lheight <- sum(legend$height)
  grid.arrange(
    do.call(arrangeGrob, lapply(plots, function(x)
      x + theme(legend.position="none"))),
    legend,
    ncol = 1,
    heights = unit.c(unit(1, "npc") - lheight, lheight))
}

grid_arrange_shared_legend(A, B, C, D)

sample data

DF <- data.frame(ID = 1:10, Pop = (1:10)^2, gr = c("A", rep("B", 8), "A"))
DF_Pie <- DF %>%
  group_by(gr) %>%
  summarise(Years = n(),
            Pop_Years = sum(Pop))

A <-  ggplot(DF, aes(x = ID, col = gr, fill = gr)) +
  geom_bar()+ 
  theme(legend.position="none")

B <- ggplot(DF_Pie, aes(x = factor(1), y = Years, fill = gr))+
  geom_bar(width = 1, stat = "identity") +
  coord_polar("y", start=0)+ 
  theme(legend.position="none")

C <- ggplot(DF, aes(x = ID, y = Pop, col = gr, fill = gr)) +
  geom_bar(stat="identity") +
  theme(legend.position="bottom")

D <- ggplot(DF_Pie, aes(x = factor(1), y = Pop_Years, fill = gr))+
  geom_bar(width = 1, stat = "identity") +
  coord_polar("y", start=0) + 
  theme(legend.position="none")

EDIT

Thanks to @hpesoj626 I know how to make everything, but the condition 3 still applys - the common background color

EDIT 2

I have created following chart but the space between plots and titles are huge

Answer 1

From the linked post, there is a ggpubr solution. I looked at the package and saw ggpubr::anotate_figure, which seems able to do what you want. I did some tweaks with the plots A, B, C, D.

A <-  ggplot(DF, aes(x = ID, col = gr, fill = gr)) +
  geom_bar() + 
  xlab(NULL) + theme(legend.position = "none")

B <- ggplot(DF_Pie, aes(x = factor(1), y = Years, fill = gr))+
  geom_bar(width = 1, stat = "identity") +
  coord_polar("y", start=0) +  labs(x = NULL, y = NULL) + theme(legend.position = "none")

C <- ggplot(DF, aes(x = ID, y = Pop, col = gr, fill = gr)) +
  geom_bar(stat="identity")  

D <- ggplot(DF_Pie, aes(x = factor(1), y = Pop_Years, fill = gr))+
  geom_bar(width = 1, stat = "identity") +
  coord_polar("y", start=0) +  labs(x = NULL, y = NULL)


p1 <- ggarrange(A, B, ncol=2) 
p2 <- ggarrange(C, D, ncol=2, common.legend = TRUE, legend = "bottom") 

p1 <- annotate_figure(p1, top = text_grob("According to years"))
p2 <- annotate_figure(p2, top = text_grob("According to population"))

p <- ggarrange(p1, p2, nrow=2, common.legend = TRUE, legend="bottom", heights = c(3,3.75)) 
annotate_figure(p, top = text_grob("Main title", face = "bold", size = 16))