Evolution during Battle

#===========================================
# EVO DURING BATTLE BY Zeak6464, Credit: Vendily
#===========================================
# UPDATED TO VERSION 1.2. This script is for Pokémon Essentials 17.
#
# This Script allows a pokemon to evolve after a level up while still in battle. Then you can continue battling with your evolved pokemon.
# This Script is based on EVO DURING BATTLE BY Zeak6464 (Credit: Vendily), and added bug fix by WolfPP.
# However I did some editing to make it drag and drop and removed some bugs.
#
# FEATURES:
# - Includes evolution during battle
# - activate and deactivate it by setting the parameter EVODURINGBATTLE
#
# BUG FIXES FROM PREVIOUS VERSIONS: 
# - prevents a small bug from the previous version, that a pokemon can evolve twice (first during battle and second after battle) with just one level up - by derFischae
# -  prevents bug that after battle the overworld music does not start -  by WolfPP
# -  removed bug that pokemon that learned a new move on evolving  during battle could not use it until switching in and out  - by derFischae
#
# INSTALLATION:
# Installation as simple as it can be. Insert a new file in the script editor above main, name it Evo_During_Battle and copy this code into it.
#
# PROPERTIES:
# If you don't want to have evo during battle, you also have to change the value of the upcoming parameter EVODURINGBATTLE to false i.e.
#      EVODURINGBATTLE = false

#============================================
#    SETTINGS
#============================================
 
EVODURINGBATTLE = true
#true - means that your pokemon can evolve during battle
#false - means that they can only evolve after a battle as usual

#============================================
#adding new method in PokeBattle_Battler
#============================================

class PokeBattle_Battler
  def name=(value)
    @name=value
  end
end

#============================================
#overriding pbEvolutionCheck in PField_Battles
#pbEvolutionCheck originally was used to be added 
#via Event.onEndBattle in (in PField_Battles)
#============================================

alias original_pbEvolutionCheck pbEvolutionCheck

def pbEvolutionCheck(currentlevels)
  return if EVODURINGBATTLE
  original_pbEvolutionCheck(currentlevels)
end


#============================================
#overriding pbGainExpOne in PokeBattle_Battle
#here I include the evolution procedure at 
#the end of this this method that does exp
#gain level up and learning new moves...
#
#deviding pbGainExpOne into smaller parts
#for better overview:
#   pbGainEvOne
#============================================
class PokeBattle_Battle
  alias original_pbGainExpOne pbGainExpOne
  def pbGainExpOne(index,defeated,partic,expshare,haveexpall,showmessages=true)
    thispoke=@party1[index]
    # Original species, not current species
    level=defeated.level
    baseexp=defeated.pokemon.baseExp
    evyield=defeated.pokemon.evYield
    # Gain effort value points, using RS effort values
    pbGainEvOne(thispoke,evyield)
    # Calculate experience
    isOutsider=(thispoke.trainerID!=self.pbPlayer.id ||
               (thispoke.language!=0 && thispoke.language!=self.pbPlayer.language))
    exp=pbCalculateExpOne(index, defeated, level, expshare, partic, haveexpall, thispoke, baseexp, isOutsider)
    growthrate=thispoke.growthrate
    newexp=PBExperience.pbAddExperience(thispoke.exp,exp,growthrate)
    exp=newexp-thispoke.exp
    # Gain experience
    if exp>0
      if showmessages
        if isOutsider
          pbDisplayPaused(_INTL("{1} gained a boosted {2} Exp. Points!",thispoke.name,exp))
        else
          pbDisplayPaused(_INTL("{1} gained {2} Exp. Points!",thispoke.name,exp))
        end
      end
      newlevel=PBExperience.pbGetLevelFromExperience(newexp,growthrate)
      tempexp=0
      curlevel=thispoke.level
      if newlevel<curlevel
        debuginfo="#{thispoke.name}: #{thispoke.level}/#{newlevel} | #{thispoke.exp}/#{newexp} | gain: #{exp}"
        raise RuntimeError.new(_INTL("The new level ({1}) is less than the Pokémon's\r\ncurrent level ({2}), which shouldn't happen.\r\n[Debug: {3}]",
                               newlevel,curlevel,debuginfo))
        return
      end
      if thispoke.respond_to?("isShadow?") && thispoke.isShadow?
        thispoke.exp+=exp
      else
        tempexp1=thispoke.exp
        tempexp2=0
        # Find battler
        battler=pbFindPlayerBattler(index)
        loop do
          # EXP Bar animation
          startexp=PBExperience.pbGetStartExperience(curlevel,growthrate)
          endexp=PBExperience.pbGetStartExperience(curlevel+1,growthrate)
          tempexp2=(endexp<newexp) ? endexp : newexp
          thispoke.exp=tempexp2
          @scene.pbEXPBar(thispoke,battler,startexp,endexp,tempexp1,tempexp2)
          tempexp1=tempexp2
          curlevel+=1
          if curlevel>newlevel
            thispoke.calcStats 
            battler.pbUpdate(false) if battler
            @scene.pbRefresh
            break
          end
          oldtotalhp=thispoke.totalhp
          oldattack=thispoke.attack
          olddefense=thispoke.defense
          oldspeed=thispoke.speed
          oldspatk=thispoke.spatk
          oldspdef=thispoke.spdef
          if battler && battler.pokemon && @internalbattle
            battler.pokemon.changeHappiness("levelup")
          end
          thispoke.calcStats
          battler.pbUpdate(false) if battler
          @scene.pbRefresh
          pbDisplayPaused(_INTL("{1} grew to Level {2}!",thispoke.name,curlevel))
          @scene.pbLevelUp(thispoke,battler,oldtotalhp,oldattack,
                           olddefense,oldspeed,oldspatk,oldspdef)
          # Finding all moves learned at this level
          movelist=thispoke.getMoveList
          for k in movelist
            if k[0]==thispoke.level   # Learned a new move
              pbLearnMove(index,k[1])
            end
          end
        # Evo During Battle
          return if !EVODURINGBATTLE
          newspecies=pbCheckEvolution(thispoke)
          if newspecies>0
            pbFadeOutInWithMusic(99999){
              evo=PokemonEvolutionScene.new
              evo.pbStartScreen(thispoke,newspecies)
              evo.pbEvolution
              evo.pbEndScreen
              $game_map.autoplayAsCue
              if battler
                @scene.pbChangePokemon(@battlers[battler.index],@battlers[battler.index].pokemon)
                battler.pbInitPokemon(thispoke,battler.pokemonIndex)
                battler.name=thispoke.name
              end
            }
          end
        end
      end
    end
  end

# Gain effort value points, using RS effort values
  def pbGainEvOne(thispoke,evyield)
    totalev=0
    for k in 0...6
      totalev+=thispoke.ev[k]
    end
    for k in 0...6
      evgain=evyield[k]
      evgain*=2 if isConst?(thispoke.item,PBItems,:MACHOBRACE) ||
                   isConst?(thispoke.itemInitial,PBItems,:MACHOBRACE)
      case k
      when PBStats::HP
        evgain+=4 if isConst?(thispoke.item,PBItems,:POWERWEIGHT) ||
                     isConst?(thispoke.itemInitial,PBItems,:POWERWEIGHT)
      when PBStats::ATTACK
        evgain+=4 if isConst?(thispoke.item,PBItems,:POWERBRACER) ||
                     isConst?(thispoke.itemInitial,PBItems,:POWERBRACER)
      when PBStats::DEFENSE
        evgain+=4 if isConst?(thispoke.item,PBItems,:POWERBELT) ||
                     isConst?(thispoke.itemInitial,PBItems,:POWERBELT)
      when PBStats::SPATK
        evgain+=4 if isConst?(thispoke.item,PBItems,:POWERLENS) ||
                     isConst?(thispoke.itemInitial,PBItems,:POWERLENS)
      when PBStats::SPDEF
        evgain+=4 if isConst?(thispoke.item,PBItems,:POWERBAND) ||
                     isConst?(thispoke.itemInitial,PBItems,:POWERBAND)
      when PBStats::SPEED
        evgain+=4 if isConst?(thispoke.item,PBItems,:POWERANKLET) ||
                     isConst?(thispoke.itemInitial,PBItems,:POWERANKLET)
      end
      evgain*=2 if thispoke.pokerusStage>=1 # Infected or cured
      if evgain>0
        # Can't exceed overall limit
        evgain-=totalev+evgain-PokeBattle_Pokemon::EVLIMIT if totalev+evgain>PokeBattle_Pokemon::EVLIMIT
        # Can't exceed stat limit
        evgain-=thispoke.ev[k]+evgain-PokeBattle_Pokemon::EVSTATLIMIT if thispoke.ev[k]+evgain>PokeBattle_Pokemon::EVSTATLIMIT
        # Add EV gain
        thispoke.ev[k]+=evgain
        if thispoke.ev[k]>PokeBattle_Pokemon::EVSTATLIMIT
          print "Single-stat EV limit #{PokeBattle_Pokemon::EVSTATLIMIT} exceeded.\r\nStat: #{k}  EV gain: #{evgain}  EVs: #{thispoke.ev.inspect}"
          thispoke.ev[k]=PokeBattle_Pokemon::EVSTATLIMIT
        end
        totalev+=evgain
        if totalev>PokeBattle_Pokemon::EVLIMIT
          print "EV limit #{PokeBattle_Pokemon::EVLIMIT} exceeded.\r\nTotal EVs: #{totalev} EV gain: #{evgain}  EVs: #{thispoke.ev.inspect}"
        end
      end
    end
  end
  
# Calculate experience
  def pbCalculateExpOne(index, defeated, level, expshare, partic, haveexpall, thispoke, baseexp, isOutsider)
    ispartic=0
    ispartic=1 if defeated.participants.include?(index)
    haveexpshare=(isConst?(thispoke.item,PBItems,:EXPSHARE) ||
                  isConst?(thispoke.itemInitial,PBItems,:EXPSHARE)) ? 1 : 0
    exp=0
    if expshare>0
      if partic==0 # No participants, all Exp goes to Exp Share holders
        exp=(level*baseexp).floor
        exp=(exp/(NOSPLITEXP ? 1 : expshare)).floor*haveexpshare
      else
        if NOSPLITEXP
          exp=(level*baseexp).floor*ispartic
          exp=(level*baseexp/2).floor*haveexpshare if ispartic==0
        else
          exp=(level*baseexp/2).floor
          exp=(exp/partic).floor*ispartic + (exp/expshare).floor*haveexpshare
        end
      end
    elsif ispartic==1
      exp=(level*baseexp/(NOSPLITEXP ? 1 : partic)).floor
    elsif haveexpall
      exp=(level*baseexp/2).floor
    end
    return if exp<=0
    exp=(exp*3/2).floor if @opponent
    if USESCALEDEXPFORMULA
      exp=(exp/5).floor
      leveladjust=(2*level+10.0)/(level+thispoke.level+10.0)
      leveladjust=leveladjust**5
      leveladjust=Math.sqrt(leveladjust)
      exp=(exp*leveladjust).floor
      exp+=1 if ispartic>0 || haveexpshare>0
    else
      exp=(exp/7).floor
    end
    #isOutsider=(thispoke.trainerID!=self.pbPlayer.id ||
    #           (thispoke.language!=0 && thispoke.language!=self.pbPlayer.language))
    if isOutsider
      if thispoke.language!=0 && thispoke.language!=self.pbPlayer.language
        exp=(exp*1.7).floor
      else
        exp=(exp*3/2).floor
      end
    end
    exp=(exp*3/2).floor if isConst?(thispoke.item,PBItems,:LUCKYEGG) ||
                           isConst?(thispoke.itemInitial,PBItems,:LUCKYEGG)
    return exp
  end
  
end

$game_map.autoplayAsCue

                battler.pbInitialize(thispoke,thispoke,true)

                @scene.pbChangePokemon(@battlers[battler.index],@battlers[battler.index].pokemon)

                battler.pbInitialize(thispoke,thispoke,true)

                @scene.pbChangePokemon(@battlers[battler.index],@battlers[battler.index].pokemon)

                battler.pbInitialize(thispoke,thispoke,true)

                battler.pbInitPokemon(thispoke,battler.pokemonIndex)