On Map Party Shift By Shanghai

#===============================================================================
#
# Shanghai Simple Script - On-Map Party Shift
# Last Date Updated: 2010.05.11
# Level: Normal
#
# Press the L or R buttons (Q and W respectively for keyboard) to switch out
# who is the lead member. Switches with the next member.
#===============================================================================
# Instructions
# -----------------------------------------------------------------------------
# To install this script, open up your script editor and copy/paste this script
# to an open slot below ▼ Materials but above ▼ Main. Remember to save.
#
# If you want to prevent actor shifting, make a script call event and insert:
#   $game_system.prevent_actor_shift = true
#   $game_system.prevent_actor_shift = false
# How true and false works is self explanatory.
#===============================================================================

$imported = {} if $imported == nil
$imported["On-MapPartyShift"] = true

#==============================================================================
# ** Game_System
#==============================================================================

class Game_System
  #--------------------------------------------------------------------------
  # * Public Instance Variables
  #--------------------------------------------------------------------------
  attr_accessor :prevent_actor_shift
end

#==============================================================================
# ** Game_Party
#==============================================================================

class Game_Party < Game_Unit
  #--------------------------------------------------------------------------
  # * Swap Actor
  #--------------------------------------------------------------------------
  def swap_actor(reverse = false)
    if reverse
      swap_actor = @actors.pop
      @actors.insert(0, swap_actor)
    else
      swap_actor = @actors.shift
      @actors.push(swap_actor)
    end
  end
end

#==============================================================================
# ** Scene_Map
#==============================================================================

class Scene_Map < Scene_Base
  #--------------------------------------------------------------------------
  # * Frame Update
  #--------------------------------------------------------------------------
  alias update_sss_on_map_party_shift update unless $@
  def update
    update_sss_on_map_party_shift
    unless $game_map.interpreter.running? or $game_message.visible
      update_on_map_party_shift
    end
  end
  #--------------------------------------------------------------------------
  # * Update On-Map Party Shift
  #--------------------------------------------------------------------------
  def update_on_map_party_shift
    return if $game_party.members.size < 2
    return if $game_system.prevent_actor_shift
    if Input.trigger?(Input::L)
      $game_party.swap_actor(true)
      $game_player.refresh
    elsif Input.trigger?(Input::R)
      $game_party.swap_actor(false)
      $game_player.refresh
    end
  end
end

#===============================================================================
#
# END OF FILE
#
#===============================================================================