3 files changed, 127 insertions, 11 deletions
diff --git a/src/main/java/dev/isxander/yacl/api/ConfigCategory.java b/src/main/java/dev/isxander/yacl/api/ConfigCategory.java
index 1b2a2bc..27c3e95 100644
--- a/src/main/java/dev/isxander/yacl/api/ConfigCategory.java
+++ b/src/main/java/dev/isxander/yacl/api/ConfigCategory.java
@@ -90,7 +90,7 @@ public interface ConfigCategory {
          * @see OptionGroup#isRoot()
          */
         public Builder options(@NotNull Collection<Option<?>> options) {
-            Validate.notEmpty(options, "`options` must not be empty");
+            Validate.notNull(options, "`options` must not be null");
 
             this.rootOptions.addAll(options);
             return this;
diff --git a/src/main/java/dev/isxander/yacl/api/Option.java b/src/main/java/dev/isxander/yacl/api/Option.java
index ff72c4c..1c3b006 100644
--- a/src/main/java/dev/isxander/yacl/api/Option.java
+++ b/src/main/java/dev/isxander/yacl/api/Option.java
@@ -9,9 +9,11 @@ import org.apache.commons.lang3.Validate;
 import org.jetbrains.annotations.NotNull;
 
 import java.util.*;
+import java.util.function.BiConsumer;
 import java.util.function.Consumer;
 import java.util.function.Function;
 import java.util.function.Supplier;
+import java.util.stream.Stream;
 
 public interface Option<T> {
     /**
@@ -95,6 +97,8 @@ public interface Option<T> {
      */
     void requestSetDefault();
 
+    void addListener(BiConsumer<Option<T>, T> changedListener);
+
     /**
      * Creates a builder to construct an {@link Option}
      *
@@ -108,7 +112,7 @@ public interface Option<T> {
     class Builder<T> {
         private Text name = Text.literal("Name not specified!").formatted(Formatting.RED);
 
-        private final List<Text> tooltipLines = new ArrayList<>();
+        private final List<Function<T, Text>> tooltipGetters = new ArrayList<>();
 
         private Function<Option<T>, Controller<T>> controlGetter;
 
@@ -138,6 +142,20 @@ public interface Option<T> {
 
         /**
          * Sets the tooltip to be used by the option.
+         * No need to wrap the text yourself, the gui does this itself.
+         *
+         * @param tooltipGetter function to get tooltip depending on value {@link Builder#build()}.
+         */
+        @SafeVarargs
+        public final Builder<T> tooltip(@NotNull Function<T, Text>... tooltipGetter) {
+            Validate.notNull(tooltipGetter, "`tooltipGetter` cannot be null");
+
+            this.tooltipGetters.addAll(List.of(tooltipGetter));
+            return this;
+        }
+
+        /**
+         * Sets the tooltip to be used by the option.
          * Can be invoked twice to append more lines.
          * No need to wrap the text yourself, the gui does this itself.
          *
@@ -146,7 +164,7 @@ public interface Option<T> {
         public Builder<T> tooltip(@NotNull Text... tooltips) {
             Validate.notNull(tooltips, "`tooltips` cannot be empty");
 
-            tooltipLines.addAll(List.of(tooltips));
+            this.tooltipGetters.addAll(Stream.of(tooltips).map(text -> (Function<T, Text>) t -> text).toList());
             return this;
         }
 
@@ -244,16 +262,20 @@ public interface Option<T> {
             Validate.notNull(controlGetter, "`control` must not be null when building `Option`");
             Validate.notNull(binding, "`binding` must not be null when building `Option`");
 
-            MutableText concatenatedTooltip = Text.empty();
-            boolean first = true;
-            for (Text line : tooltipLines) {
-                if (!first) concatenatedTooltip.append("\n");
-                first = false;
+            Function<T, Text> concatenatedTooltipGetter = value -> {
+                MutableText concatenatedTooltip = Text.empty();
+                boolean first = true;
+                for (Function<T, Text> line : tooltipGetters) {
+                    if (!first) concatenatedTooltip.append("\n");
+                    first = false;
+
+                    concatenatedTooltip.append(line.apply(value));
+                }
 
-                concatenatedTooltip.append(line);
-            }
+                return concatenatedTooltip;
+            };
 
-            return new OptionImpl<>(name, concatenatedTooltip, controlGetter, binding, available, ImmutableSet.copyOf(flags), typeClass);
+            return new OptionImpl<>(name, concatenatedTooltipGetter, controlGetter, binding, available, ImmutableSet.copyOf(flags), typeClass);
         }
     }
 }
diff --git a/src/main/java/dev/isxander/yacl/api/PlaceholderCategory.java b/src/main/java/dev/isxander/yacl/api/PlaceholderCategory.java
new file mode 100644
index 0000000..de7441c
--- /dev/null
+++ b/src/main/java/dev/isxander/yacl/api/PlaceholderCategory.java
@@ -0,0 +1,94 @@
+package dev.isxander.yacl.api;
+
+import dev.isxander.yacl.gui.YACLScreen;
+import dev.isxander.yacl.impl.PlaceholderCategoryImpl;
+import net.minecraft.client.MinecraftClient;
+import net.minecraft.client.gui.screen.Screen;
+import net.minecraft.text.MutableText;
+import net.minecraft.text.Text;
+import org.apache.commons.lang3.Validate;
+import org.jetbrains.annotations.NotNull;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.function.BiFunction;
+
+/**
+ * A placeholder category that actually just opens another screen,
+ * instead of displaying options
+ */
+public interface PlaceholderCategory extends ConfigCategory {
+    /**
+     * Function to create a screen to open upon changing to this category
+     */
+    BiFunction<MinecraftClient, YACLScreen, Screen> screen();
+
+    static Builder createBuilder() {
+        return new Builder();
+    }
+
+    class Builder {
+        private Text name;
+
+        private final List<Text> tooltipLines = new ArrayList<>();
+
+        private BiFunction<MinecraftClient, YACLScreen, Screen> screenFunction;
+
+        private Builder() {
+
+        }
+
+        /**
+         * Sets name of the category
+         *
+         * @see ConfigCategory#name()
+         */
+        public Builder name(@NotNull Text name) {
+            Validate.notNull(name, "`name` cannot be null");
+
+            this.name = name;
+            return this;
+        }
+
+        /**
+         * Sets the tooltip to be used by the category.
+         * Can be invoked twice to append more lines.
+         * No need to wrap the text yourself, the gui does this itself.
+         *
+         * @param tooltips text lines - merged with a new-line on {@link Builder#build()}.
+         */
+        public Builder tooltip(@NotNull Text... tooltips) {
+            Validate.notEmpty(tooltips, "`tooltips` cannot be empty");
+
+            tooltipLines.addAll(List.of(tooltips));
+            return this;
+        }
+
+        /**
+         * Screen to open upon selecting this category
+         *
+         * @see PlaceholderCategory#screen()
+         */
+        public Builder screen(@NotNull BiFunction<MinecraftClient, YACLScreen, Screen> screenFunction) {
+            Validate.notNull(screenFunction, "`screenFunction` cannot be null");
+
+            this.screenFunction = screenFunction;
+            return this;
+        }
+
+        public PlaceholderCategory build() {
+            Validate.notNull(name, "`name` must not be null to build `ConfigCategory`");
+
+            MutableText concatenatedTooltip = Text.empty();
+            boolean first = true;
+            for (Text line : tooltipLines) {
+                if (!first) concatenatedTooltip.append("\n");
+                first = false;
+
+                concatenatedTooltip.append(line);
+            }
+
+            return new PlaceholderCategoryImpl(name, screenFunction, concatenatedTooltip);
+        }
+    }
+}