Implement Collapsible Groups

src/main/java/mezz/jei/Internal.java

@@ -5,6 +5,7 @@
 import mezz.jei.bookmarks.BookmarkList;
 import mezz.jei.color.ColorNamer;
 import mezz.jei.gui.GuiEventHandler;
+import mezz.jei.ingredients.CollapsibleEntryRegistry;
 import mezz.jei.ingredients.IngredientFilter;
 import mezz.jei.ingredients.IngredientRegistry;
 import mezz.jei.input.InputHandler;
@@ -40,6 +41,8 @@ public final class Internal {
 	private static InputHandler inputHandler;
 	@Nullable
 	private static BookmarkList bookmarkList;
+	@Nullable
+	private static CollapsibleEntryRegistry collapsibleEntryRegistry;
 
 	private Internal() {
 
@@ -151,4 +154,16 @@ public static BookmarkList getBookmarkList() {
 		Preconditions.checkState(bookmarkList != null, "Bookmark List has not been created yet.");
         return bookmarkList;
     }
+
+	public static CollapsibleEntryRegistry getCollapsibleEntryRegistry() {
+		if (collapsibleEntryRegistry == null) {
+			collapsibleEntryRegistry = CollapsibleEntryRegistry.getInstance();
+		}
+		return collapsibleEntryRegistry;
+	}
+
+	public static void setCollapsibleEntryRegistry(CollapsibleEntryRegistry registry) {
+		Internal.collapsibleEntryRegistry = registry;
+		CollapsibleEntryRegistry.setInstance(registry);
+	}
 }

src/main/java/mezz/jei/config/Config.java

@@ -16,6 +16,7 @@
 import mezz.jei.startup.ForgeModIdHelper;
 import mezz.jei.startup.IModIdHelper;
 import mezz.jei.util.GiveMode;
+import mezz.jei.util.CollapsedClickAction;
 import mezz.jei.util.Log;
 import mezz.jei.util.Translator;
 import net.minecraft.init.Items;
@@ -49,6 +50,7 @@ public final class Config {
 	public static final String CATEGORY_RENDERING = "rendering";
 	public static final String CATEGORY_MISC = "misc";
 	public static final String CATEGORY_CATEGORY = "category";
+	public static final String CATEGORY_COLLAPSIBLE = "collapsible";
 
 	public static final String defaultModNameFormatFriendly = "blue italic";
 	public static final int smallestNumColumns = 4;
@@ -65,6 +67,8 @@ public final class Config {
 	@Nullable
 	private static LocalizedConfiguration searchColorsConfig;
 	@Nullable
+	private static CustomGroupsConfig customGroupsConfig;
+	@Nullable
 	private static File bookmarkFile;
 	@Nullable
 	private static File favoriteFile;
@@ -89,6 +93,39 @@ public static boolean isOverlayEnabled() {
 			KeyBindings.toggleOverlay.getKeyCode() == 0; // if there is no key binding to enable it, don't allow the overlay to be disabled
 	}
 
+	public static boolean isCollapsibleGroupsEnabled() {
+		return values.collapsibleGroupsEnabled;
+	}
+
+	public static boolean isCollapseOnClose() {
+		return values.collapseOnClose;
+	}
+
+	public static CollapsedClickAction getCollapsedClickAction() {
+		return values.collapsedClickAction;
+	}
+
+	@Nullable
+	public static CustomGroupsConfig getCustomGroupsConfig() {
+		return customGroupsConfig;
+	}
+
+	public static Set<String> getDisabledGroups() {
+		return values.disabledGroups;
+	}
+
+	public static void saveDisabledGroups(Set<String> disabledGroups) {
+		values.disabledGroups.clear();
+		values.disabledGroups.addAll(disabledGroups);
+		if (config != null) {
+			Property property = config.get(CATEGORY_COLLAPSIBLE, "disabledGroups", new String[]{});
+			property.set(disabledGroups.toArray(new String[0]));
+			if (config.hasChanged()) {
+				config.save();
+			}
+		}
+	}
+
 	public static void toggleOverlayEnabled() {
 		values.overlayEnabled = !values.overlayEnabled;
 
@@ -412,6 +449,9 @@ public static void preInit(FMLPreInitializationEvent event) {
 		itemBlacklistConfig = new LocalizedConfiguration(configKeyPrefix, itemBlacklistConfigFile, "0.1.0");
 		searchColorsConfig = new LocalizedConfiguration(configKeyPrefix, searchColorsConfigFile, "0.1.0");
 
+		customGroupsConfig = new CustomGroupsConfig(jeiConfigurationDir);
+		customGroupsConfig.load();
+
 		syncConfig();
 		syncItemBlacklistConfig();
 		syncSearchColorsConfig();
@@ -448,6 +488,7 @@ private static boolean syncConfig() {
 		config.addCategory(CATEGORY_SEARCH);
 		config.addCategory(CATEGORY_ADVANCED);
 		config.addCategory(CATEGORY_MISC);
+		config.addCategory(CATEGORY_COLLAPSIBLE);
 
 		ConfigCategory modeCategory = config.getCategory("mode");
 		if (modeCategory != null) {
@@ -533,6 +574,33 @@ private static boolean syncConfig() {
 
         values.hideBottomLeftCornerBookmarkButton = config.getBoolean(CATEGORY_MISC, "hideBottomLeftCornerBookmarkButton", defaultValues.hideBottomLeftCornerBookmarkButton);
 
+		{
+			boolean prev = values.collapsibleGroupsEnabled;
+			values.collapsibleGroupsEnabled = config.getBoolean(CATEGORY_COLLAPSIBLE, "collapsibleGroupsEnabled", defaultValues.collapsibleGroupsEnabled);
+			if (prev != values.collapsibleGroupsEnabled) {
+				needsReload = true;
+			}
+		}
+
+		values.collapseOnClose = config.getBoolean(CATEGORY_COLLAPSIBLE, "collapseOnClose", defaultValues.collapseOnClose);
+
+		values.collapsedClickAction = config.getEnum("collapsedClickAction", CATEGORY_COLLAPSIBLE, defaultValues.collapsedClickAction, CollapsedClickAction.values());
+
+		// Explicit property order so the GUI shows collapsibleGroupsEnabled first, then collapseOnClose.
+		java.util.List<String> collapsibleOrder = new java.util.ArrayList<>();
+		collapsibleOrder.add("collapsibleGroupsEnabled");
+		collapsibleOrder.add("collapseOnClose");
+		collapsibleOrder.add("collapsedClickAction");
+		config.setCategoryPropertyOrder(CATEGORY_COLLAPSIBLE, collapsibleOrder);
+
+		{
+			String[] disabledGroupsArray = config.getStringList("disabledGroups", CATEGORY_COLLAPSIBLE, new String[]{});
+			Property disabledProp = config.get(CATEGORY_COLLAPSIBLE, "disabledGroups", new String[]{});
+			disabledProp.setShowInGui(false);
+			values.disabledGroups.clear();
+			Collections.addAll(values.disabledGroups, disabledGroupsArray);
+		}
+
 		{
 			Property property = config.get(CATEGORY_ADVANCED, "debugModeEnabled", defaultValues.debugModeEnabled);
 			property.setShowInGui(false);

src/main/java/mezz/jei/config/ConfigValues.java

@@ -5,7 +5,9 @@
 import net.minecraft.item.ItemStack;
 
 import java.util.ArrayList;
+import java.util.HashSet;
 import java.util.List;
+import java.util.Set;
 
 public class ConfigValues {
 	// advanced
@@ -53,4 +55,10 @@ public class ConfigValues {
 
     // category
 	public List<String> categoryUidOrder = new ArrayList<>();
+
+	// collapsible groups
+	public boolean collapsibleGroupsEnabled = true;
+	public boolean collapseOnClose = false;
+	public mezz.jei.util.CollapsedClickAction collapsedClickAction = mezz.jei.util.CollapsedClickAction.OPEN_GROUP;
+	public Set<String> disabledGroups = new HashSet<>();
 }

src/main/java/mezz/jei/config/CustomGroupsConfig.java

@@ -0,0 +1,103 @@
+package mezz.jei.config;
+
+import com.google.gson.Gson;
+import com.google.gson.GsonBuilder;
+import com.google.gson.reflect.TypeToken;
+import mezz.jei.util.Log;
+
+import javax.annotation.Nullable;
+import java.io.*;
+import java.lang.reflect.Type;
+import java.nio.charset.StandardCharsets;
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * Manages custom collapsible groups persistence as JSON.
+ * File: config/jei/customCollapsibleGroups.json
+ */
+public class CustomGroupsConfig {
+	private static final Gson GSON = new GsonBuilder().setPrettyPrinting().create();
+	private static final Type GROUP_LIST_TYPE = new TypeToken<List<CustomGroup>>() {}.getType();
+
+	private final File configFile;
+	private List<CustomGroup> customGroups = new ArrayList<>();
+
+	public CustomGroupsConfig(File configDir) {
+		this.configFile = new File(configDir, "customCollapsibleGroups.json");
+	}
+
+	public void load() {
+		if (!configFile.exists()) {
+			customGroups = new ArrayList<>();
+			return;
+		}
+		try (Reader reader = new InputStreamReader(new FileInputStream(configFile), StandardCharsets.UTF_8)) {
+			List<CustomGroup> loaded = GSON.fromJson(reader, GROUP_LIST_TYPE);
+			customGroups = loaded != null ? loaded : new ArrayList<>();
+		} catch (Exception e) {
+			Log.get().error("Failed to load custom collapsible groups from {}", configFile, e);
+			customGroups = new ArrayList<>();
+		}
+	}
+
+	public void save() {
+		try (Writer writer = new OutputStreamWriter(new FileOutputStream(configFile), StandardCharsets.UTF_8)) {
+			GSON.toJson(customGroups, GROUP_LIST_TYPE, writer);
+		} catch (Exception e) {
+			Log.get().error("Failed to save custom collapsible groups to {}", configFile, e);
+		}
+	}
+
+	public List<CustomGroup> getCustomGroups() {
+		return customGroups;
+	}
+
+	public void addGroup(CustomGroup group) {
+		customGroups.add(group);
+		save();
+	}
+
+	public void removeGroup(String id) {
+		customGroups.removeIf(g -> g.id.equals(id));
+		save();
+	}
+
+	public void updateGroup(CustomGroup updated) {
+		for (int i = 0; i < customGroups.size(); i++) {
+			if (customGroups.get(i).id.equals(updated.id)) {
+				customGroups.set(i, updated);
+				save();
+				return;
+			}
+		}
+		// Not found — add as new
+		addGroup(updated);
+	}
+
+	/**
+	 * A user-defined collapsible group stored as JSON.
+	 * Items are identified by their unique identifier string from StackHelper.
+	 */
+	public static class CustomGroup {
+		public String id;
+		public String displayName;
+		public List<String> itemUids;
+
+		public CustomGroup() {
+			this.id = "";
+			this.displayName = "";
+			this.itemUids = new ArrayList<>();
+		}
+
+		public CustomGroup(String id, String displayName, List<String> itemUids) {
+			this.id = id;
+			this.displayName = displayName;
+			this.itemUids = new ArrayList<>(itemUids);
+		}
+
+		public CustomGroup copy() {
+			return new CustomGroup(id, displayName, new ArrayList<>(itemUids));
+		}
+	}
+}