using Chernobyl.Collections.Generic.Event;
using Chernobyl.Input.Controls;
using Chernobyl.Input.Controls.Axis;
using Chernobyl.Mathematics.Mechanics;

namespace Chernobyl.Input.Xna.Controls.Mouse
{
    /// <summary>
    /// Represents the scroll wheel on a mouse device.
    /// </summary>
    public class MouseScrollWheel : AxisControl
    {
        /// <summary>
        /// Constructor.
        /// </summary>
        /// <param name="services">The services to inject into this control and 
        /// it's children.</param>
        /// <param name="mouse">The mouse that this mouse position belongs to.</param>
        public MouseScrollWheel(IEventCollection<object> services, IMouse mouse) : base(services) 
        {
            Name = "ScrollWheel";
            MakeParentChild(mouse, this);
        }

        /// <summary>
        /// The amount of change, from the axis' <see cref="IAxis.PreviousValue"/>
        /// to its <see cref="IAxis.CurrentValue"/>. Implementors should return
        /// the raw change amount and not try to apply
        /// <see cref="IAxis.Sensitivity"/> to the returned value. The
        /// <see cref="AxisControl"/> class will apply the
        /// <see cref="IAxis.Sensitivity"/> value for you.
        /// </summary>
        protected override float OverridableChangeAmount
        {
            get { return Microsoft.Xna.Framework.Input.Mouse.GetState().ScrollWheelValue - PreviousValue; }
        }
    }
}