Use new complete_theme() function to get the complete set of theme elements

Author: cpsievert

R/ggplotly.R

@@ -463,12 +463,19 @@ gg2list <- function(p, width = NULL, height = NULL,
     assign(var, built_env[[var]], envir = envir)
   }
 
-  # initiate plotly.js layout with some plot-wide theming stuff
-  theme <- ggfun("plot_theme")(plot)
-  elements <- names(which(sapply(theme, inherits, "element")))
+  # Get the "complete" set of theme elements and calculate their values
+  if (is.function(asNamespace("ggplot2")$complete_theme)) {
+    theme <- ggplot2::complete_theme(plot$theme)
+    elements <- names(theme)
+  } else {
+    theme <- ggfun("plot_theme")(plot)
+    elements <- names(which(sapply(theme, inherits, "element")))
+  }
+  
   for (i in elements) {
     theme[[i]] <- ggplot2::calc_element(i, theme)
   }
+  
   # Translate plot wide theme elements to plotly.js layout
   pm <- unitConvert(theme$plot.margin, "pixels")
   gglayout <- list(