Stuck with interface

library CodSlide initializer init requires TerrainPathability

//Setup===============================================
globals
    private constant real DEFAULT_SPEED = 20.
endglobals
//EndSetup============================================
private interface eventHandler
    method onFinish takes nothing returns nothing defaults nothing
    method onLoop takes nothing returns nothing defaults nothing
endinterface

struct Slide extends eventHandler
    unit u
    real angle
    real dis
    real speed = DEFAULT_SPEED

    real discount = 0.
    
    
    
    private method periodic takes nothing returns nothing
        local timer t
        
        local real mX = PolarProjectionX(GetUnitX(.u),.speed,angle)
        local real mY = PolarProjectionY(GetUnitY(.u),.speed,angle)
        
        //check if col
        if .discount >= .dis then 
            if(this.onFinish.exists) then
                call .onFinish()
            endif
            
            call .stopPeriodic()
            call .destroy()
            return
        endif
        
        //move
        if IsTerrainWalkable(mX,mY) then
            call SetUnitPosition(.u,mX,mY)
        endif
        set .discount = .discount + speed
        
        if(.onLoop.exists) then
            call .onLoop()
        endif
    endmethod
    implement T32x
    
    static method start takes unit u,real dis,real angle returns nothing
        local thistype s = thistype.create()
        set s.u = u
        set s.dis = dis
        set s.angle = angle
        
        call s.startPeriodic()
    endmethod
    
endstruct

private function init takes nothing returns nothing
    
endfunction

endlibrary

//=========================================================================//
//Spell:
//Author:
//MUI:
//MPI:
//Credit:
//Require:
//=========================================================================//
scope FlashMove initializer init
//=========================================================================//
//Setup                                                                    //
//=========================================================================//
    globals
           private constant integer SPELL_ID = 'A00R'
           
           private constant integer WAIT_4_EFF = 2
           private constant real SPEED = 25.
           
           private constant real EFF_TIME_LIFE = 0.6
           private constant string MODEL_PATH = "Codart\\Model\\Cloud2\\accloud by raphthegreat.mdl"
           private constant integer A = 150
           private constant integer R = 100
           private constant integer G = 200
           private constant integer B = 255
           
           private constant real GROUP_RADIUS = 200
           
           private constant integer ARM_CRK_TIME = T32_FPS * 2
    endglobals
    
    private function filt takes nothing returns boolean
        return IsUnitEnemy(GetSpellTargetUnit(),GetOwningPlayer(GetTriggerUnit())) and IsUnitAliveBJ(GetSpellTargetUnit()) 
    endfunction

//=========================================================================//
//End Setup                                                                //
//=========================================================================//

//Misc=======================================================================
    globals
    
    endglobals
    
    private struct SlideX extends Slide
        integer timecount = 0
        
        private static method removeModel takes nothing returns nothing
            local timer t = GetExpiredTimer()
            local xefx fx = xefx(GetTimerData(t))
            
            
            call fx.hiddenDestroy()
            call ReleaseTimer(t)
        endmethod
        
        method onLoop takes nothing returns nothing
            local xefx fx
            local timer t
            
            call BJDebugMsg("xit")
            //eff
            set timecount = timecount + 1
            if timecount >= WAIT_4_EFF then
                set fx = xefx.create(GetUnitX(u),GetUnitY(u),Deg2Rad(angle))
                set fx.fxpath = MODEL_PATH
                call fx.recolor(R,G,B,A)
                
                set t = NewTimer()
                call SetTimerData(t,fx)
                call TimerStart(t,EFF_TIME_LIFE,false,function thistype.removeModel)
                
                set timecount = 0
            endif
        endmethod
        
        method onFinish takes nothing returns nothing
            local real x = GetUnitX(.u)
            local real y = GetUnitY(.u)
            local ArmCrack a
            local unit enum
            
            call GroupUnitsInArea(ENUM_GROUP, x, y, GROUP_RADIUS)
            loop
                set enum = FirstOfGroup(ENUM_GROUP)
                exitwhen enum == null
                
                if IsUnitEnemy(enum,GetOwningPlayer(.u)) and IsUnitAliveBJ(enum) then
                    set a = ArmCrack.create(enum)
                    call a.setup(ARM_CRK_TIME)
                endif
            
                call GroupRemoveUnit(ENUM_GROUP,enum)
            endloop
            
            call ReleaseGroup(ENUM_GROUP)
            set enum = null
        endmethod
        
    endstruct
    
//Condition==================================================================
    private function Con takes nothing returns boolean
        return GetSpellAbilityId() == SPELL_ID
    endfunction

//Action=====================================================================
    private function Actions takes nothing returns nothing
        local real tX = GetSpellTarX()
        local real tY = GetSpellTarY()
        local unit c = GetTriggerUnit()
        local real cX = GetUnitX(c)
        local real cY = GetUnitY(c)
        local real dis = DistanceBetweenCords(cX,cY,tX,tY)
        
        call SlideX.start(c,dis,AngleBetweenCord(cX,cY,tX,tY))
        //call SetUnitAnimation( c, "spell two")
        //call AddSpecialEffectTarget("Abilities\\Spells\\Undead\\Cripple\\CrippleTarget.mdl",c,"weapon")
        //call AddSpecialEffectTarget("Abilities\\Weapons\\IllidanMissile\\IllidanMissile.mdl",c,"weapon")
        //call AddSpecialEffectTarget("Abilities\\Weapons\\PhoenixMissile\\Phoenix_Missile_mini.mdl",c,"weapon")
        
        set c = null
    endfunction

//Init=======================================================================
    private function init takes nothing returns nothing
        local trigger t = CreateTrigger(  )
        call TriggerRegisterAnyUnitEventBJ( t, EVENT_PLAYER_UNIT_SPELL_EFFECT )
        call TriggerAddAction( t, function Actions )
        call TriggerAddCondition(t, Condition( function Con))
    endfunction

endscope