Hotbar / Action Bar Example

A simple hotbar / action bar example where items from the player inventory can be equipped to it. Usable items equipped on the hotbar should use the selected item when the keybinding for the slot is pressed. The hotbar slot count should be adjustable, and dragging and dropping an item should add the item to the slot the item was dropped in. If a different item is already in the slot, it should swap with the item being dropped into it. If the same item exists in the slot, the slot stack should be topped off. Hotbar slots should also have an easy way to perform visual effects, like flashing and shaking the slot item. The hotbar should be able to be hidden, while maintaining the functionality of the keybindings linked to the hotbar slots.