Duality-BackgroundScroller-Example/Source/Packages/AdamsLair.Duality.Samples.BasicMenu.2.0.4/source/Controllers/UpdateMenuController.cs

using System;
using System.Collections.Generic;
using System.Linq;

using Duality;
using Duality.Components;
using Duality.Drawing;
using Duality.Components.Renderers;

namespace BasicMenu
{
	/// <summary>
	/// This Component implements an OnUpdate-based MenuController.
	/// Pros: Easier to set up, requires only to implement OnUpdate.
	/// Cons: The controller logic is called on every frame, even when nothing is happening.
	/// </summary>
	[RequiredComponent(typeof(Camera))]
	public class UpdateMenuController : MenuController, ICmpUpdatable
	{
		[DontSerialize]
		private Vector2 mousePosition;
		[DontSerialize]
		private MenuComponent currentComponent;

		void ICmpUpdatable.OnUpdate()
		{
			// No menus currently active? Switch to StartingMenu - this is checked everytime
			if (this.currentMenu == null)
			{
				this.SwitchToMenu(this.StartingMenu);
			}

			mousePosition.X = DualityApp.Mouse.X;
			mousePosition.Y = DualityApp.Mouse.Y;

			// check all MenuComponents under the mouse and sort them by Z,
			// to find the one nearest to the Camera
			MenuComponent hoveredComponent = this.GameObj.ParentScene.FindComponents<MenuComponent>()
				.Where(mc => mc.GameObj.Active && mc.GetAreaOnScreen().Contains(mousePosition))
				.OrderBy(mc => mc.GameObj.Transform.Pos.Z)
				.FirstOrDefault();

			// I found my hovered menu component.. is it different from the current one?
			if (hoveredComponent != currentComponent)
			{
				// if the old one is not null, leave it.
				if (currentComponent != null)
				{
					currentComponent.MouseLeave();
				}

				// if the new one is not null, enter it.
				if (hoveredComponent != null)
				{
					hoveredComponent.MouseEnter();
				}
			}


			// set the current component to the hovered one.
			currentComponent = hoveredComponent;

			// did I click the left button and am I hovering a component? do something!
			if (DualityApp.Mouse.ButtonHit(Duality.Input.MouseButton.Left) && currentComponent != null)
			{
				currentComponent.DoAction();
			}
		}
	}
}