Inventory Events and Delegates¶

All delegates in FWInventorySystem are DECLARE_DYNAMIC_MULTICAST_DELEGATE variants and are marked BlueprintAssignable, making them fully available for both C++ and Blueprint binding.

Inventory Component Delegates¶

OnInventoryChanged¶

DECLARE_DYNAMIC_MULTICAST_DELEGATE(FOnInventoryChanged);

Fires whenever any modification occurs to the inventory contents. This is the most general-purpose delegate -- use it to trigger full UI refreshes.

Debouncing

When loading inventory from serialized data, OnInventoryChanged may fire once for each item added. Consider deferring UI refreshes until OnInventoryLoaded fires, which is a single event after the full load completes.

OnItemAdded¶

DECLARE_DYNAMIC_MULTICAST_DELEGATE_TwoParams(
    FOnItemAdded,
    const FFWItemInstance&, Item,
    int32, SlotIndex);

Fires when a new item is placed in the inventory. SlotIndex indicates which slot the item occupies. For stackable items being added to an existing stack, OnItemStackChanged fires instead.

OnItemRemoved¶

DECLARE_DYNAMIC_MULTICAST_DELEGATE_TwoParams(
    FOnItemRemoved,
    const FFWItemInstance&, Item,
    int32, SlotIndex);

Fires when an item is completely removed from a slot (stack depleted or single item removed).

OnItemMoved¶

DECLARE_DYNAMIC_MULTICAST_DELEGATE_ThreeParams(
    FOnItemMoved,
    const FGuid&, InstanceId,
    int32, FromSlot,
    int32, ToSlot);

Fires when an item is moved between slots within the same inventory.

OnItemStackChanged¶

DECLARE_DYNAMIC_MULTICAST_DELEGATE_ThreeParams(
    FOnItemStackChanged,
    const FGuid&, InstanceId,
    int32, OldQuantity,
    int32, NewQuantity);

Fires when a stackable item's quantity changes (partial add or partial remove). Does not fire for the initial add or final remove (those use OnItemAdded/OnItemRemoved).

OnInventoryLoaded¶

DECLARE_DYNAMIC_MULTICAST_DELEGATE(FOnInventoryLoaded);

Fires once after inventory data is deserialized and fully loaded. Use this instead of OnInventoryChanged for initial UI population.

OnInventoryFull¶

DECLARE_DYNAMIC_MULTICAST_DELEGATE_OneParam(
    FOnInventoryFull,
    const FFWItemInstance&, RejectedItem);

Fires when AddItem fails because all inventory slots are occupied. The RejectedItem is the item that could not be added.

Bank Delegates¶

OnBankCollectionChanged¶

DECLARE_DYNAMIC_MULTICAST_DELEGATE(FOnBankCollectionChanged);

Fires when any item in the bank is added, removed, or moved.

OnBankCustomTabChanged¶

DECLARE_DYNAMIC_MULTICAST_DELEGATE_OneParam(
    FOnBankCustomTabChanged,
    int32, TabIndex);

Fires when a bank tab's configuration is modified (renamed, icon changed).

OnBankLoaded¶

DECLARE_DYNAMIC_MULTICAST_DELEGATE(FOnBankLoaded);

Fires once after bank data is deserialized and fully loaded.

Equipment Component Delegates¶

OnItemEquipped¶

DECLARE_DYNAMIC_MULTICAST_DELEGATE_TwoParams(
    FOnItemEquipped,
    EFWEquipmentType, Slot,
    const FFWItemInstance&, Item);

Fires when an item is equipped to a slot. Use this to update character visuals (attach mesh, apply materials).

OnItemUnequipped¶

DECLARE_DYNAMIC_MULTICAST_DELEGATE_TwoParams(
    FOnItemUnequipped,
    EFWEquipmentType, Slot,
    const FFWItemInstance&, Item);

Fires when an item is removed from an equipment slot.

OnEquipmentStatsChanged¶

DECLARE_DYNAMIC_MULTICAST_DELEGATE(FOnEquipmentStatsChanged);

Fires whenever the total equipment stats change (equip, unequip, augmentation, set bonus change). Bind this to refresh stat display panels.

OnSetBonusActivated¶

DECLARE_DYNAMIC_MULTICAST_DELEGATE_TwoParams(
    FOnSetBonusActivated,
    const UFWItemSetDefinition*, SetDefinition,
    int32, PieceCount);

Fires when equipping an item causes a set bonus threshold to be reached.

OnSetBonusDeactivated¶

DECLARE_DYNAMIC_MULTICAST_DELEGATE_OneParam(
    FOnSetBonusDeactivated,
    const UFWItemSetDefinition*, SetDefinition);

Fires when unequipping an item causes a set bonus to drop below its minimum threshold.

Crafting Component Delegates¶

OnCraftingStarted¶

DECLARE_DYNAMIC_MULTICAST_DELEGATE_OneParam(
    FOnCraftingStarted,
    const UFWRecipeDefinition*, Recipe);

Fires when crafting begins. Use for progress bar animations or cast-bar UI.

OnCraftingCompleted¶

DECLARE_DYNAMIC_MULTICAST_DELEGATE_TwoParams(
    FOnCraftingCompleted,
    const UFWRecipeDefinition*, Recipe,
    const FFWItemInstance&, CraftedItem);

Fires when crafting succeeds. CraftedItem is the newly created item with any rolled affixes.

OnCraftingFailed¶

DECLARE_DYNAMIC_MULTICAST_DELEGATE_TwoParams(
    FOnCraftingFailed,
    const UFWRecipeDefinition*, Recipe,
    const FString&, Reason);

Fires when crafting fails validation or material checks.

OnRecipeLearned¶

DECLARE_DYNAMIC_MULTICAST_DELEGATE_OneParam(
    FOnRecipeLearned,
    const UFWRecipeDefinition*, Recipe);

Fires when a new recipe is added to the player's known recipes.

Vendor Component Delegates¶

OnItemPurchased¶

DECLARE_DYNAMIC_MULTICAST_DELEGATE_ThreeParams(
    FOnItemPurchased,
    const FFWItemInstance&, Item,
    int32, Price,
    int32, Quantity);

Fires after a successful purchase from the vendor.

OnItemSold¶

DECLARE_DYNAMIC_MULTICAST_DELEGATE_ThreeParams(
    FOnItemSold,
    const FFWItemInstance&, Item,
    int32, Price,
    int32, Quantity);

Fires after successfully selling an item to the vendor.

OnTransactionFailed¶

DECLARE_DYNAMIC_MULTICAST_DELEGATE_OneParam(
    FOnTransactionFailed,
    const FString&, Reason);

Fires when a buy or sell transaction is rejected. Common reasons: insufficient currency, inventory full, item is bound.

OnVendorInventoryRefreshed¶

DECLARE_DYNAMIC_MULTICAST_DELEGATE(FOnVendorInventoryRefreshed);

Fires when the vendor's stock is restocked.

Binding Patterns¶

C++ -- Centralized Event Handler¶

void AMyCharacter::SetupInventoryBindings()
{
    // Inventory events
    Inventory->OnItemAdded.AddDynamic(this, &AMyCharacter::OnItemAdded);
    Inventory->OnItemRemoved.AddDynamic(this, &AMyCharacter::OnItemRemoved);
    Inventory->OnInventoryFull.AddDynamic(this, &AMyCharacter::OnBagsFull);
    Inventory->OnInventoryLoaded.AddDynamic(this, &AMyCharacter::OnInventoryReady);

    // Equipment events
    Equipment->OnItemEquipped.AddDynamic(this, &AMyCharacter::OnEquipped);
    Equipment->OnItemUnequipped.AddDynamic(this, &AMyCharacter::OnUnequipped);
    Equipment->OnEquipmentStatsChanged.AddDynamic(
        this, &AMyCharacter::RefreshStatUI);
    Equipment->OnSetBonusActivated.AddDynamic(
        this, &AMyCharacter::ShowSetBonusNotification);
}

void UInventoryWidget::NativeConstruct()
{
    Super::NativeConstruct();

    auto* Inv = GetOwningPlayerPawn()
        ->FindComponentByClass<UFWInventoryComponent>();

    if (Inv)
    {
        Inv->OnInventoryChanged.AddDynamic(
            this, &UInventoryWidget::RefreshGrid);
    }
}

void UInventoryWidget::NativeDestruct()
{
    auto* Inv = GetOwningPlayerPawn()
        ->FindComponentByClass<UFWInventoryComponent>();

    if (Inv)
    {
        Inv->OnInventoryChanged.RemoveDynamic(
            this, &UInventoryWidget::RefreshGrid);
    }

    Super::NativeDestruct();
}

Blueprint¶

In your widget or actor Blueprint, get a reference to the inventory component.
Right-click the component reference, select Assign for the desired event.
The event node is created automatically with the correct signature.
Connect your UI refresh logic to the event node.

Event Flow Summary¶

AddItem()
    |
    +--> [Stack exists?]
    |       |
    |       +--> Yes: OnItemStackChanged
    |       |
    |       +--> No: OnItemAdded
    |
    +--> OnInventoryChanged

RemoveItem()
    |
    +--> [Stack depleted?]
    |       |
    |       +--> Yes: OnItemRemoved
    |       |
    |       +--> No: OnItemStackChanged
    |
    +--> OnInventoryChanged

EquipItem()
    |
    +--> [Slot occupied?]
    |       |
    |       +--> Yes: OnItemUnequipped (old item)
    |       |       |
    |       |       +--> OnItemAdded (old item to inventory)
    |       |
    |       +--> OnItemRemoved (new item from inventory)
    |
    +--> OnItemEquipped (new item)
    +--> OnEquipmentStatsChanged
    +--> [Set threshold?] --> OnSetBonusActivated
    +--> OnInventoryChanged