u3d-clicker-game/Assets/Scripts/StoreItem.cs

using UnityEngine;
using UnityEngine.UI;

// The item can do one of two things, increase the power of the
// player's click on the main button, or increase the amount of
// resources generated each second during the game loop.
public enum ItemType
{
	ClickPower,
	PerSecondIncrease
}

/// <summary>
/// This class is attached to each store button in the store menu. It represents the
/// behavior of each upgrade that the player may purchase in the game. 
/// </summary>
public class StoreItem : MonoBehaviour {

	#region Properties
	// What does this upgrade affect? Power per second or power per click
	public ItemType itemType;

	[Tooltip("How much will this upgrade cost")]
	public int cost;

	[Tooltip("If purchased, how much will it increase this")]
	public float increaseAmount;

	// In the Hierarchy panel, select the button for this upgrade,
	// drag and drop each game object onto these properties in the inspector panel.
	[Header("Object References")]
	public Text costText;
	public Text qtyText;
	#endregion

	#region Local Properties
	// Total number of this item purchased by the player.
	private int qty;
	// A reference to the game controller script
	private GameController controller;
	// A reference to the button that this script is attached to
	private Button button;
	#endregion

	#region Methods
	/*****
	 * This is a button event handler for the button that this script is attached to.
	 * There is no need to wire this handler to the button in the Inspector panel,
	 * rather this method is assigned in the Start method using AddListener(). 
	 * The purpose of this method is to apply the upgrade values to the properties
	 * of the Game Controller, and to update the properties(statistics) of this script.
	 *****/ 
	public void ButtonClicked()
	{
		// Remove the cost of this upgrade from the player's pool
		controller.Pool -= cost;
		// Increment the Game Controller value based on the type of this upgrade.
		switch (itemType)
		{
			case ItemType.ClickPower:
				controller.powerPerClick += increaseAmount;
				break;
			case ItemType.PerSecondIncrease:
				controller.IncreasePerSecond += increaseAmount;
				break;
		}

		// increase the number of times this upgrade was purchased
		qty++;
		qtyText.text = qty.ToString();
	} 
	#endregion

	#region MonoBehavior
	// Use this for initialization
	void Start()
	{
		// Set the initial properties of this upgrade
		qty = 0;
		qtyText.text = qty.ToString();
		costText.text = cost.ToString();

		// Get a reference to the button that this script is attached to
		// and assign and event listener
		button = transform.GetComponent<Button>();
		button.onClick.AddListener(this.ButtonClicked);

		// Get a reference to the Game Controller
		controller = GameObject.FindObjectOfType<GameController>();
	}

	// Update is called once per frame
	void Update()
	{
		// Make the button disabled until the player has enough money to pay
		// for the upgrade.
		button.interactable = (controller.Pool >= cost);
	} 
	#endregion

}