[Problem with adding item to inventory]

I don't know what to change in code

[Problem with adding item to inventory]

Could you write it for me because i don't know english so good and i don't understand what is wrong

[Problem with adding item to inventory]

I created gui that change input item to specified output item that is added to inventory. When i insert item and press button output item is added to inventory, but when i quit gui output item dissapears and change into input item.

protected void actionPerformed(GuiButton button)
{
MinecraftServer server = FMLCommonHandler.instance().getMinecraftServerInstance();
World world = server.worldServers[0];


if (button.id == 0){

if((Filamencik.getStackInSlot(0) !=null ) &&Filamencik.getStackInSlot(0).getItem() == pomaranczowyfilament.block){
if(entity instanceof EntityPlayer)((EntityPlayer)entity).inventory.addItemStackToInventory(new ItemStack(pomaranczowyMarfin.block, 1));
}

if((Filamencik.getStackInSlot(00) !=null ) &&Filamencik.getStackInSlot(00).getItem() == bialyfilament.block){
if(entity instanceof EntityPlayer)((EntityPlayer)entity).inventory.addItemStackToInventory(new ItemStack(bialymarfin.block, 1));
}

if((Filamencik.getStackInSlot(00) !=null ) &&Filamencik.getStackInSlot(00).getItem() == bialyfilament.block){
Filamencik.decrStackSize(00, 1);
}

if((Filamencik.getStackInSlot(00) !=null ) &&Filamencik.getStackInSlot(00).getItem() == pomaranczowyfilament.block){
Filamencik.decrStackSize(00, 1);
}

}


}

Version is 1.12.2

[Problem with taking item from slot]

1.7.10

[Problem with taking item from slot]

8 minutes ago, diesieben07 said:

Your code is unreadable.

I fixed it. Now yoy can read it

 

[Problem with taking item from slot]

I created code that recognize what object is in input slot and if it's white it add white item to output slot and if it's orange it outputs orange item.
if (button.id == 0){

if((Filamencik.getStackInSlot(00) !=null ) &&Filamencik.getStackInSlot(00).getItem() == bialyfilament.block){ Filamencik.setInventorySlotContents(01, new ItemStack(bialymarfin.block, 1)); }

if((Filamencik.getStackInSlot(00) !=null ) &&Filamencik.getStackInSlot(00).getItem() == bialyfilament.block){ Filamencik.setInventorySlotContents(00, null); }

if((Filamencik.getStackInSlot( 00) !=null ) &&Filamencik.getStackInSlot( 00).getItem() == pomaranczowyfilament.block){ Filamencik.setInventorySlotContents(01, new ItemStack(pomaranczowyMarfin.block, 1)); }

if((Filamencik.getStackInSlot( 00) !=null ) &&Filamencik.getStackInSlot( 00).getItem() == pomaranczowyfilament.block){ Filamencik.setInventorySlotContents(00, null); } } }
 

if i insert item to input slot and press event button input item dissapear, output item shows. If i quit GUI in that moment output item will come out, but when i click output item in GUI it disappears and input item shows again