Working Example of Unicode Issue with ggplot2 and shiny

server.R

library(shiny)
library(ggplot2)
# library(Cairo)
# options(shiny.usecairo=T)

# Define colors and shapes
colors <-  c("#1f77b4", "#ff7f0e", "#2ca02c", "#d62728", "#9467bd", 
             "#8c564b", "#e377c2", "#7f7f7f", "#bcbd22", "#17becf")
shapes1 <- c(1,0,3,4,8,5,2,6,-0x25C1, -0x25B7)
shapes2 <- 1:10

shinyServer(function(input, output, session){

  output$plot <- renderPlot({
    dd <- data.frame(x=1:10, y=0, grp = 1:10, color=colors, shape=ifelse(input$unicode=="unicode", shapes1, shapes2))
    
    
    ggplot(data=dd, aes(x=x, y=y, shape=factor(grp))) + 
      geom_point(size=6) + coord_fixed(ratio=1) +
      scale_shape_manual(values=list(shapes2, shapes1)[[(input$unicode=="unicode")+1]], guide="none") + 
      theme(axis.text=element_blank(), axis.ticks=element_blank(), axis.title=element_blank())
  })
  
})

ui.R

library(shiny)
seed <- runif(1, 1000, 1000000)
shinyUI(fluidPage(
  titlePanel("Demonstration - Unicode Characters"),
  fluidRow(
    column(
      2,
      wellPanel(
        radioButtons("unicode", "CharacterType", choices=c("Unicode"="unicode", "R Default"="normal"))
      )        
    ),
    column(10,
           div(align="center", plotOutput("plot"))
    )
  )
))