Null item reference in slot render context

inventory-framework-api/src/main/java/me/devnatan/inventoryframework/component/ItemComponent.java

@@ -34,6 +34,7 @@ public class ItemComponent implements Component, InteractionHandler {
 
     private boolean isVisible;
     private volatile String lastKey;
+    private volatile Object lastRenderedItem;
 
     public ItemComponent(
             Function<? extends IFContext, String> keyFactory,
@@ -67,6 +68,7 @@ public ItemComponent(
         this.updateOnClick = updateOnClick;
         this.isVisible = isVisible;
         this.reference = reference;
+        this.lastRenderedItem = stack;
     }
 
     @Override
@@ -145,12 +147,16 @@ public void render(@NotNull IFSlotRenderContext context) {
         if (getRenderHandler() != null) {
             final int initialSlot = getPosition();
 
+            if (lastRenderedItem != null) context.setResult(lastRenderedItem);
+
             try {
                 getRenderHandler().accept(context);
             } catch (Exception e) {
                 throw new InventoryFrameworkException("Failed to render item component", e);
             }
 
+            lastRenderedItem = context.getResult();
+
             // Externally managed components have its own displacement measures
             if (!isManagedExternally()) {
                 final int updatedSlot = context.getSlot();
@@ -197,6 +203,7 @@ public void updated(@NotNull IFSlotRenderContext context) {
         boolean isWatchingAnyState =
                 getWatchingStates() != null && !getWatching().isEmpty();
         if (isVisible() && getUpdateHandler() != null) {
+            if (lastRenderedItem != null) context.setResult(lastRenderedItem);
             getUpdateHandler().accept(context);
             if (context.isCancelled()) return;
         }

inventory-framework-api/src/main/java/me/devnatan/inventoryframework/context/IFSlotRenderContext.java

@@ -7,6 +7,15 @@ public interface IFSlotRenderContext extends IFSlotContext, IFConfinedContext {
     @ApiStatus.Internal
     Object getResult();
 
+    /**
+     * Sets the item that was rendered by the owning component in a previous render.
+	 *
+	 * <p><b><i>This is an internal inventory-framework API that should not be used from outside of
+	 * this library. No compatibility guarantees are provided.</i></b>
+     */
+    @ApiStatus.Internal
+    void setResult(Object result);
+
     boolean isCancelled();
 
     void setCancelled(boolean cancelled);

inventory-framework-platform-bukkit/src/main/java/me/devnatan/inventoryframework/context/SlotRenderContext.java

@@ -54,6 +54,11 @@ public final void setItem(ItemStack item) {
         setChanged(true);
     }
 
+    @Override
+    public final void setResult(Object result) {
+        this.item = (ItemStack) result;
+    }
+
     @Override
     public final boolean isCancelled() {
         return cancelled;

inventory-framework-platform-minestom/src/main/kotlin/me/devnatan/inventoryframework/context/SlotRenderContext.kt

@@ -27,6 +27,10 @@ class SlotRenderContext
 
         override fun getResult(): ItemStack = item
 
+        override fun setResult(result: Any?) {
+            item = result as? ItemStack ?: ItemStack.AIR
+        }
+
         override fun isCancelled(): Boolean = cancelled
 
         override fun setCancelled(cancelled: Boolean) {