Allow plugins to force fill mode for overlay button (#960)

src/main/java/codechicken/nei/api/IOverlayHandler.java

@@ -8,6 +8,7 @@ import java.util.stream.Collectors;
 import net.minecraft.client.gui.inventory.GuiContainer;
 import net.minecraft.item.ItemStack;
 
+import codechicken.nei.NEIClientConfig;
 import codechicken.nei.PositionedStack;
 import codechicken.nei.recipe.GuiOverlayButton.ItemOverlayState;
 import codechicken.nei.recipe.IRecipeHandler;
@@ -32,6 +33,10 @@ public interface IOverlayHandler {
         return false;
     }
 
+    default boolean requireShiftForOverlayRecipe() {
+        return NEIClientConfig.requireShiftForOverlayRecipe();
+    }
+
     default List<ItemOverlayState> presenceOverlay(GuiContainer firstGui, IRecipeHandler recipe, int recipeIndex) {
         final List<ItemOverlayState> itemPresenceSlots = new ArrayList<>();
         final List<PositionedStack> ingredients = recipe.getIngredientStacks(recipeIndex);

src/main/java/codechicken/nei/recipe/GuiOverlayButton.java

@@ -19,6 +19,7 @@ import codechicken.nei.LayoutManager;
 import codechicken.nei.NEIClientConfig;
 import codechicken.nei.NEIClientUtils;
 import codechicken.nei.PositionedStack;
+import codechicken.nei.api.IOverlayHandler;
 import codechicken.nei.bookmark.BookmarkGrid;
 import codechicken.nei.drawable.DrawableBuilder;
 import codechicken.nei.drawable.DrawableResource;
@@ -96,13 +97,18 @@ public class GuiOverlayButton extends GuiRecipeButton {
         super(handlerRef, x, y, handlerRef.recipeIndex + BUTTON_ID_SHIFT, "+");
         this.firstGui = firstGui != null && firstGui.inventorySlots != null ? firstGui : null;
 
+        IOverlayHandler overlayHandler = null;
+
         if (this.firstGui != null) {
+            overlayHandler = this.handlerRef.getOverlayHandler(this.firstGui);
             this.canUseOverlayRenderer = this.handlerRef.getRecipeOverlayRenderer(this.firstGui) != null;
             this.canFillCraftingGrid = this.handlerRef.canFillCraftingGrid(this.firstGui);
-            this.hasOverlay = this.canUseOverlayRenderer || this.handlerRef.getOverlayHandler(this.firstGui) != null;
+            this.hasOverlay = this.canUseOverlayRenderer || overlayHandler != null;
         }
 
-        setRequireShiftForOverlayRecipe(NEIClientConfig.requireShiftForOverlayRecipe());
+        setRequireShiftForOverlayRecipe(
+                overlayHandler != null ? overlayHandler.requireShiftForOverlayRecipe()
+                        : NEIClientConfig.requireShiftForOverlayRecipe());
         ingredientsOverlay();
     }