A port of the Google Wave FedOne Echoey.java agent to Ruby

rechoey.rb

# Copyright 2009 Google Inc. (original Java code)
# Copyright 2009 Eric Kidd (Ruby translation)
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#      http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

# Usage: jruby rechoey.rb rechoey@domain server port

require 'java'
require 'dist/fedone-agent-api-0.2.jar'

import 'com.google.common.collect.ImmutableMap'

import 'org.waveprotocol.wave.examples.fedone.agents.agent.AbstractAgent'
import 'org.waveprotocol.wave.examples.fedone.agents.agent.AgentConnection'
import 'org.waveprotocol.wave.examples.fedone.waveclient.common.ClientUtils'
import 'org.waveprotocol.wave.examples.fedone.waveclient.console.ConsoleUtils'
import 'org.waveprotocol.wave.model.document.operation.DocOpCursor'
import 'org.waveprotocol.wave.model.document.operation.impl.AttributesImpl'
import 'org.waveprotocol.wave.model.document.operation.impl.BufferedDocOpImpl'
import 'org.waveprotocol.wave.model.operation.wave.WaveletDocumentOperation'

# This is a simple translation of the Java Echoey code.
class REchoey < AbstractAgent
  def initialize(username, hostname, port=9876)
    super(AgentConnection.new_connection(username, hostname, port))
  end

  def doc_size wavelet, doc_name
    doc = wavelet.documents.get(doc_name)
    doc ? ClientUtils.find_document_size(doc) : 0
  end

  def append_lines(wavelet, lines)
    # Build the operation we want to perform on the document.
    builder = BufferedDocOpImpl::DocOpBuilder.new
    size = doc_size(wavelet, "main")
    builder.retain(size) if size > 0
    line_attrs = ImmutableMap.of(ConsoleUtils::LINE_AUTHOR, participant_id)
    builder.element_start(ConsoleUtils::LINE, AttributesImpl.new(line_attrs))
    builder.element_end
    lines.each {|line| builder.characters(line) unless line.empty? }

    # Send the operation.
    op = WaveletDocumentOperation.new("main", builder.finish)
    send_wavelet_operation(wavelet.wavelet_name, op)
  end

  def append_line(wavelet, line)
    append_lines(wavelet, [line])
  end

  def onDocumentChanged(wavelet, operation)
    extractor = TextExtractor.new
    operation.operation.apply(extractor)
    append_lines(wavelet, extractor.lines)
  end

  def onParticipantAdded(wavelet, participant)
    append_line(wavelet, "#{participant.address} was added to this wavelet.")
  end

  def onParticipantRemoved(wavelet, participant)
    append_line(wavelet, "#{participant.added} was removed from this wavelet.")
  end

  def onSelfAdded(wavelet)
    append_line(wavelet, "I'm listening.")
  end

  def onSelfRemoved(wavelet)
    append_line(wavelet, "Goodbye.")
  end

  # Iterate over a document operation and extract all the newly-inserted text.
  class TextExtractor
    include DocOpCursor

    attr_reader :lines

    def initialize()
      @lines = []
    end

    def annotationBoundary(map) end

    def characters(chars)
      lines << chars
    end

    def deleteCharacters(chars) end
    def deleteElementEnd() end
    def deleteElementStart(type, attrs) end
    def elementEnd() end
    def elementStart(type, attrs) end
    def replaceAttributes(oldAttrs, newAttrs) end
    def retain(itemCount) end
    def updateAttributes(attrUpdate) end
  end
end

# Parse our command-line arguments and run rechoey.
if ARGV.length != 3
  STDERR.puts "Usage: jruby rechoey.rb user@domain server port"
  exit 1
end
username, hostname, port = ARGV
e = REchoey.new(username, hostname, port.to_i)
e.run