class

PointClickEngine::Inventory::InventorySystem

Inherits PointClickEngine::Core::Drawable < YAML::Serializable < Reference < Object

Manages the player's inventory of items and item interactions

The InventorySystem provides a visual grid-based interface for managing collected items, supports item combination mechanics, and handles item usage on scene objects. Items can be selected, combined with other items, or used on hotspots and characters in the game world.

Key Features

Grid-based visual inventory display
Item selection and combination system
Drag-and-drop style interactions
Item usage callbacks for scene integration
Automatic item icon rendering
YAML serialization for save/load functionality

Usage Example

inventory = InventorySystem.new(Vector2.new(10, 10))
inventory.add_item(key_item)
inventory.add_item(potion_item)

inventory.on_item_used = ->(item : InventoryItem, target : String) {
  handle_item_usage(item, target)
}

inventory.on_items_combined = ->(item1, item2, action) {
  create_combined_item(item1, item2, action)
}

NOTE: The inventory automatically handles screen coordinate conversion when used with the display manager.

Constructors

new(ctx : YAML::ParseContext, node : YAML::Nodes::Node)

new(position : RL::Vector2 = RL::Vector2.new(x: 10, y: 10))

Creates an inventory system at the specified position

position : Screen position for the inventory panel (default: 10,10)

new(*, __context_for_yaml_serializable ctx : YAML::ParseContext, __node_for_yaml_serializable node : YAML::Nodes::Node)

Instance methods

add_item(item : InventoryItem)

Adds an item to the inventory

Prevents duplicate items with the same name from being added. If an item with the same name already exists, it won't be added again.

item : The inventory item to add

after_yaml_deserialize(ctx : YAML::ParseContext)

Restores runtime state after YAML deserialization

Restores item state and reconnects the selected item reference.

ctx : YAML parsing context

background_color

Background color for the inventory panel (runtime only)

background_color=(background_color : RL::Color)

Background color for the inventory panel (runtime only)

clear

Clears all items from the inventory

Removes all items, deselects any selected item, and exits combination mode.

combination_mode

Whether the system is in combination mode (runtime only)

combination_mode=(combination_mode : Bool)

Whether the system is in combination mode (runtime only)

deselect_item

Deselects the currently selected item

Also exits combination mode if active.

draw

Renders the inventory panel and all contained items

Draws the background panel, item slots, icons or names, selection highlights, and combination mode indicators.

event_bus

Optional EventBus for publishing inventory events

event_bus=(event_bus : Core::Events::EventBus | Nil)

Optional EventBus for publishing inventory events

get_item(name : String) : InventoryItem | Nil

Gets an item from the inventory by name

name : Name of the item to retrieve

Returns: The inventory item, or nil if not found

get_item_at_position(pos : RL::Vector2) : InventoryItem | Nil

Gets the item at a specific screen position

Used for mouse interaction to determine which item was clicked. Only works when the inventory is visible.

pos : Screen position to check

Returns: The item at that position, or nil if none found

has_item?(name : String) : Bool

Checks if an item with the specified name exists in the inventory

name : Name of the item to check for

Returns: true if the item exists, false otherwise

items

Collection of items currently in the inventory

items=(items : Array(InventoryItem))

Collection of items currently in the inventory

on_item_used

Callback for when an item is used on a target (runtime only)

on_item_used=(on_item_used : Proc(InventoryItem, String, Nil) | Nil)

Callback for when an item is used on a target (runtime only)

on_items_combined

Callback for when two items are combined (runtime only)

on_items_combined=(on_items_combined : Proc(InventoryItem, InventoryItem, String | Nil, Nil) | Nil)

Callback for when two items are combined (runtime only)

padding

Padding between inventory slots in pixels

padding=(padding : Float32)

Padding between inventory slots in pixels

remove_item(item_name : String)

Removes an item from the inventory by name

If the removed item was selected, it will be deselected.

item_name : Name of the item to remove

remove_item(item : InventoryItem)

Removes an item from the inventory

item : The inventory item to remove

select_item(name : String)

Selects an item by name

The selected item will be highlighted and available for use or combination.

name : Name of the item to select

selected_item

Reference to currently selected item (runtime only)

selected_item=(selected_item : InventoryItem | Nil)

Reference to currently selected item (runtime only)

selected_item_name

Name of currently selected item for serialization

selected_item_name=(selected_item_name : String | Nil)

Name of currently selected item for serialization

slot_size

Size of each inventory slot in pixels

slot_size=(slot_size : Float32)

Size of each inventory slot in pixels

start_combination_mode

Enters combination mode for the selected item

Only works if an item is currently selected. In combination mode, clicking another item will attempt to combine them.

update(dt : Float32)

Updates inventory interaction and input handling

Processes mouse clicks on inventory items, handles selection and combination mode, and manages coordinate conversion for proper display scaling.

dt : Delta time in seconds since last update

use_selected_item_on(target_name : String)

Uses the selected item on a target object

Checks if the selected item can be used on the specified target, then executes the usage callback. Removes consumable items after use.

target_name : Name of the target object/character/hotspot