NotEnoughItems/src/main/java/codechicken/nei/NEIDummySlotHandler.java

package codechicken.nei;

import net.minecraft.client.gui.inventory.GuiContainer;
import net.minecraft.inventory.Slot;
import net.minecraft.item.ItemStack;

import codechicken.lib.inventory.ContainerExtended;
import codechicken.lib.inventory.SlotDummy;
import codechicken.nei.api.INEIGuiAdapter;

public class NEIDummySlotHandler extends INEIGuiAdapter {

    @Override
    public boolean handleDragNDrop(GuiContainer gui, int mousex, int mousey, ItemStack draggedStack, int button) {
        Slot slot = gui.getSlotAtPosition(mousex, mousey);
        if (slot instanceof SlotDummy && slot.isItemValid(draggedStack)
                && gui.inventorySlots instanceof ContainerExtended) {
            ((SlotDummy) slot).slotClick(draggedStack, button, NEIClientUtils.shiftKey());
            NEICPH.sendDummySlotSet(slot.slotNumber, slot.getStack());
            return true;
        }
        return false;
    }
}