theme improvements that include not relying on dev versions ggplot2

DESCRIPTION

@@ -7,7 +7,11 @@ Authors@R: c(
     person("Bob", "Rudis", email = "bob@rud.is", role = c("aut", "cre"), 
            comment = c(ORCID = "0000-0001-5670-2640")),
     person("Harold", "Gil", email = "hgil@marionhealth.org", role = "ctb",
-           comment = "fix for show.guide")
+           comment = "fix for show.guide"),
+    person("Brian", "Adams", email = "btadams478@gmail.com", role = "ctb",
+           comment = "theme testing & feedback"),
+    person("Thomas", "Wood", role = "ctb",
+           comment = "Significant suggestions & testing that made new features possible")
   )
 Maintainer: Bob Rudis <bob@rud.is>
 Description: Cartogram heatmaps are an alternative to choropleth maps for 'USA' States
@@ -28,7 +32,7 @@ Suggests:
 Depends:
     R (>= 3.2.0),
 Imports:
-    ggplot2 (>= 2.2.1.9000),
+    ggplot2 (>= 2.2.1),
     scales (>= 0.5.0),
     grid
 RoxygenNote: 6.0.1

R/theme-statebin.R

@@ -11,8 +11,16 @@ theme_statebins <- function(legend_position="bottom",
                             base_line_size = base_size/22,
                             base_rect_size = base_size/22) {
 
-  gg <- theme_bw(base_family = base_family, base_size = base_size,
+  if ("base_line_size" %in% names(formals(ggplot2::theme_bw))) {
+    gg <- theme_bw(base_family = base_family, base_size = base_size,
                  base_line_size = base_line_size, base_rect_size = base_rect_size)
+  } else {
+    gg <- theme_bw(base_family = base_family, base_size = base_size)
+    gg <- gg + theme(size = base_line_size)
+    gg <- gg + theme(rect = element_rect(fill = "white", colour = "black",
+                                         size = base_rect_size, linetype = 1))
+  }
+
   gg <- gg + theme(panel.border=element_blank())
   gg <- gg + theme(strip.background = element_rect(color="#2b2b2b", fill="white"))
   gg <- gg + theme(panel.grid=element_blank())
@@ -22,6 +30,8 @@ theme_statebins <- function(legend_position="bottom",
   gg <- gg + theme(plot.title=element_text(hjust=0.5))
   gg <- gg + theme(axis.title.x=element_text(hjust=0.5))
   gg <- gg + theme(legend.position=legend_position)
+  gg <- gg + theme(plot.title=element_text(size=16, hjust=0))
+  gg <- gg + theme(plot.margin = margin(30,30,30,30))
   gg
 
 }