# Provides an example of listening to a Reporter, and
# putting the changes to a Memory in a nicer format
#
# Author: Bob Jacobsen, copyright 2006
# Part of the JMRI distribution
#
# The Reporter and Memory names are hardcoded in the example
# near the bottom.  Change those to something that makes
# sense for your layout

import jmri
import java
import java.beans

# First, define the listener class.  This gets messages
# from the reporter, uses them to keep track of the decoders
# in a block, and writes that list to a memory for display.
#
class ReporterFormatter(java.beans.PropertyChangeListener):
  def propertyChange(self, event):
    if (event.propertyName == "currentReport") :
      # new report, format and store
      self.report = event.newValue
      if (isinstance(self.report,jmri.Reportable)) :
         # use the IdTag information from 4.15.3+
         self.value = self.format(self.report.toReportString())
      elif (self.report != None ) :
         # use the text format from pre 4.15.3
         self.value = self.format(self.report)
      else :
         self.value = ""
      self.memory.setValue(self.value)
    return 

  def start(self, reporterName, memoryName) :
    # connect the object to the reporter, and start to work
    self.memory = memories.provideMemory(memoryName)
    reporters.provideReporter(reporterName).addPropertyChangeListener(self)
    self.content = []
    self.memory.setValue("")
    self.reporterName = reporterName
    return

  def stop(self) :
    # Cease operation.  
    # You can call start() again if desired.
    reporters.getReporter(self.reporterName).removePropertyChangeListener(self)
    return
    
  def format(self, inputString) :
    # Return a formated version of the input string.
    # This is where the real work of the class takes place.
    #
    # In this simple version, we just keep a list that contains
    # all the names, and return that
    #
    # First check if this is an arrival
    if (self.isEnter(inputString)) :
        # yes, if name not there, append
        if (not (self.number(inputString) in self.content)) :
          self.content.append(self.number(inputString))  
    # Then check if this is a departure
    if (self.isExit(inputString)) :
        # yes, if name there, remove
        if (self.number(inputString) in self.content) :
          del self.content[self.content.index(self.number(inputString))]
    # and return updated value
    result = ""
    for item in self.content :
      result = result+item+" "
    return (result)

  def number(self, message) :
    # return the number of the locomotive from a message
    return message[:-6]

  def isEnter(self, message) :
    # return True if the message is an "entry"
    return (message[-5:]=="enter")
    
  def isExit(self, message) :
    # return True if the message is an "exits"
    return (message[-5:]=="exits")
    
# End of the definition of the FormattedReporter class
    
#########################################################

# Below here is an example of the use of this class.
# Modify if to use names appropriate for your layout and
# execute it from your own scripts after doing execfile("jython/ReporterFormatter.py")
#
# m = ReporterFormatter()
# m.start("LR145", "IM145")
#
# At this point, messages from LocoNet reporter LR145 are being sent to memory IM145
# To stop this, you can later say
# m.stop()


#########################################################

# See jython/test/ReporterFormatterTest.py for test code and sample LocoNet sequences