Improve exception messages for binding items to incorrect gui type

Author: NichtStudioCode

invui/src/main/java/xyz/xenondevs/invui/item/AbstractPagedGuiBoundItem.java

@@ -15,7 +15,7 @@ public abstract class AbstractPagedGuiBoundItem extends AbstractBoundItem {
     @Override
     public void bind(Gui gui) {
         if (!(gui instanceof PagedGui<?> pagedGui))
-            throw new IllegalArgumentException("PageItem can only be used in a PagedGui");
+            throw new IllegalArgumentException("AbstractPagedGuiBoundItem can only be bound to a PagedGui");
 
         super.bind(gui);
         pagedGui.addPageChangeHandler(notifier);

invui/src/main/java/xyz/xenondevs/invui/item/AbstractScrollGuiBoundItem.java

@@ -15,7 +15,7 @@ public abstract class AbstractScrollGuiBoundItem extends AbstractBoundItem {
     @Override
     public void bind(Gui gui) {
         if (!(gui instanceof ScrollGui<?> scrollGui))
-            throw new IllegalArgumentException("ScrollItem can only be used in a ScrollGui");
+            throw new IllegalArgumentException("AbstractScrollGuiBoundItem can only be bound to a ScrollGui");
 
         super.bind(gui);
         scrollGui.addScrollHandler(notifier);

invui/src/main/java/xyz/xenondevs/invui/item/AbstractTabGuiBoundItem.java

@@ -15,7 +15,7 @@ public abstract class AbstractTabGuiBoundItem extends AbstractBoundItem {
     @Override
     public void bind(Gui gui) {
         if (!(gui instanceof TabGui tabGui))
-            throw new IllegalArgumentException("TabItem can only be used in a TabGui");
+            throw new IllegalArgumentException("AbstractTabGuiBoundItem can only be bound to a TabGui");
 
         super.bind(gui);
         tabGui.addTabChangeHandler(notifier);

invui/src/main/java/xyz/xenondevs/invui/item/BoundItem.java

@@ -55,7 +55,7 @@ public sealed interface BoundItem extends Item permits AbstractBoundItem {
      * @return A new {@link Builder} for a {@link BoundItem}.
      */
     static Builder<Gui> builder() {
-        return new CustomBoundItem.Builder<>();
+        return new CustomBoundItem.Builder<>(Gui.class);
     }
 
     /**

invui/src/main/java/xyz/xenondevs/invui/item/CustomBoundItem.java

@@ -23,6 +23,7 @@
 
 class CustomBoundItem<G extends Gui> extends AbstractBoundItem {
 
+    private final Class<? extends Gui> guiClass;
     private final TriConsumer<? super Item, ? super G, ? super Click> clickHandler;
     private final QuadConsumer<? super Item, ? super G, ? super Player, ? super Integer> selectHandler;
     private volatile BiFunction<? super Player, ? super G, ? extends ItemProvider> itemProvider;
@@ -32,13 +33,15 @@ class CustomBoundItem<G extends Gui> extends AbstractBoundItem {
     private @Nullable BukkitTask updateTask;
 
     public CustomBoundItem(
+        Class<? extends Gui> guiClass,
         BiConsumer<? super Item, ? super G> bindHandler,
         BiConsumer<? super Item, ? super G> unbindHandler,
         TriConsumer<? super Item, ? super G, ? super Click> clickHandler,
         QuadConsumer<? super Item, ? super G, ? super Player, ? super Integer> selectHandler,
         BiFunction<? super Player, ? super G, ? extends ItemProvider> itemProvider,
         int updatePeriod
     ) {
+        this.guiClass = guiClass;
         this.bindHandler = bindHandler;
         this.unbindHandler = unbindHandler;
         this.clickHandler = clickHandler;
@@ -61,6 +64,8 @@ public ItemProvider getItemProvider(Player viewer) {
     @SuppressWarnings("unchecked")
     @Override
     public void bind(Gui gui) {
+        if (!guiClass.isAssignableFrom(gui.getClass()))
+            throw new IllegalArgumentException("This item can only be bound to a " + guiClass.getSimpleName());
         bindHandler.accept(this, (G) gui);
         super.bind(gui);
     }
@@ -105,6 +110,7 @@ public void removeViewer(AbstractWindow<?> who, int how) {
 
     non-sealed static class Builder<G extends Gui> implements BoundItem.Builder<G> {
 
+        private final Class<? extends Gui> guiClass;
         protected BiConsumer<Item, G> bindHandler = (item, gui) -> {};
         protected BiConsumer<Item, G> unbindHandler = (item, gui) -> {};
         private TriConsumer<Item, G, Click> clickHandler = (item, gui, click) -> {};
@@ -117,6 +123,10 @@ non-sealed static class Builder<G extends Gui> implements BoundItem.Builder<G> {
         private boolean updateOnClick;
         private int updatePeriod = -1;
 
+        public Builder(Class<? extends Gui> guiClass) {
+            this.guiClass = guiClass;
+        }
+        
         @Override
         public Builder<G> setItemProvider(ItemProvider itemProvider) {
             this.itemProviderFn = (viewer, gui) -> itemProvider;
@@ -229,6 +239,7 @@ public BoundItem build() {
             CustomBoundItem<G> customItem;
             if (asyncPlaceholder != null && itemProviderFn != null) {
                 customItem = new CustomBoundItem<>(
+                    guiClass,
                     bindHandler,
                     unbindHandler,
                     clickHandler,
@@ -254,6 +265,7 @@ public BoundItem build() {
                 }
             } else {
                 customItem = new CustomBoundItem<>(
+                    guiClass,
                     bindHandler,
                     unbindHandler,
                     clickHandler,
@@ -271,6 +283,8 @@ public BoundItem build() {
         static class Paged extends Builder<PagedGui<?>> {
 
             Paged() {
+                super(PagedGui.class);
+                
                 var pageChangeHandler = new AtomicReference<BiConsumer<Integer, Integer>>();
                 var pageCountChangeHandler = new AtomicReference<BiConsumer<Integer, Integer>>();
 
@@ -292,6 +306,8 @@ static class Paged extends Builder<PagedGui<?>> {
         static class Scroll extends Builder<ScrollGui<?>> {
 
             Scroll() {
+                super(ScrollGui.class);
+                
                 var scrollHandler = new AtomicReference<BiConsumer<Integer, Integer>>();
                 var lineCountChangeHandler = new AtomicReference<BiConsumer<Integer, Integer>>();
 
@@ -314,6 +330,8 @@ static class Scroll extends Builder<ScrollGui<?>> {
         static class Tab extends Builder<TabGui> {
 
             Tab() {
+                super(TabGui.class);
+                
                 var tabChangeHandler = new AtomicReference<BiConsumer<Integer, Integer>>();
 
                 bindHandler = bindHandler.andThen((item, gui) -> {