Mouseover coordinates in plot area are wrong when coord_fixed of ggplot is set

[patrickroocks]

The hoverOpts options of a plot area seems to provides wrong mouse coordinates, if a ggplot object is contained in the plot area using the option coord_fixed.

Here is a minimal example:

library(shiny)
library(ggplot2)

ui <- fluidPage(
  plotOutput("plot1", height = "300px", width = "100%",
             hover = hoverOpts(id = "plot_hover")),
  verbatimTextOutput("hover_info")
)

server <- function(input, output) {

  output$plot1 <- renderPlot({
    ggplot(mtcars, aes(x=mpg,y=qsec)) + geom_point() + 
      coord_fixed(xlim=c(0,30),ylim=c(0,30))
  })

  output$hover_info <- renderPrint({
    if(!is.null(input$plot_hover))
      paste0(input$plot_hover$x, " ", input$plot_hover$y)
    })
}

shinyApp(ui, server)`

When having a wide browser window (such that coord_fixed causes space in the left and in the right of the plot object) and positioning the mouse pointer near to the origin we get too high values for the x-value. It seems that coord_fixed is ignored by hoverOpts.

I already posted this on SO, where you also see a screenshot illustrating the problem:

http://stackoverflow.com/questions/35659823/mouseover-coordinates-in-ggplot-shiny-are-wrong-when-coord-fixed-is-set