library(SJava)
.JavaInit(list(classPath=paste(Sys.getenv("OMEGA_HOME"), "..", "..", sep = .Platform$file.sep)))


setJavaFunctionConverter(function(x, className) {
           print("This is a silly converter for a JButton")
           val <- .Java(x, "getText")
           val <- c(text = val, action = .Java(x, "getActionCommand"))
           print(val)
           return(val)
    }, function(obj, className){
     ok <- className == "javax.swing.JButton"
     cat("In JButton match:", ok, "\n")
     return(ok)
})

setJavaConvertible("JButton")

testJButton =
  #
  # Note that we will see several converters being called 
  # in this example.
# > testJButton()
# In match: TRUE 
# [1] "This is a silly converter for a JButton"
# In match: FALSE 
# Looking for RealVariable java.lang.String 
# In match: FALSE 
# Looking for RealVariable java.lang.String 
# [1] "testing" "testing"
# [1] "testing" "testing"
  #
  # The reason for this is that the .Java() calls within the converter
  # attempt to convert the String elements from the getText
function() {
  .JavaConstructor("JButton", "testing", .convert = TRUE)
}

# Now we use a closure to handle both the conversion and matching
# and this gives us mutable state.
#
# We just count the number of times the converter is called.
 
realVariableConverterHandler <-
 function() {
   n <- 0
   cvt <- function(obj, className) {
      n <<- n + 1
      .Java(obj, "getValues")
   }
   matcher <- function(obj, className) {
     cat("Looking for RealVariable", className, "\n")
     return(className == "org.omegahat.DataStructures.Data.RealVariable")
   }
   return(list(converter=cvt, matcher=matcher, count = function(){ n } ))
 }


rvCvt <- realVariableConverterHandler()
setJavaFunctionConverter(rvCvt$converter, rvCvt$matcher)

setJavaConvertible("org.omegahat.DataStructures.Data.RealVariable")

testRealVariable =
function() {  
  .JavaConstructor("org.omegahat.DataStructures.Data.RealVariable", rnorm(10), .convert = TRUE)
}