#region File Description

//-----------------------------------------------------------------------------

// InputState.cs

//

// Microsoft XNA Community Game Platform

// Copyright (C) Microsoft Corporation. All rights reserved.

//-----------------------------------------------------------------------------

#endregion



#region Using Statements

using Microsoft.Xna.Framework;

using Microsoft.Xna.Framework.Input;

#endregion



namespace TankA

{

    /// <summary>

    /// Helper for reading input from keyboard and gamepad. This class tracks both

    /// the current and previous state of both input devices, and implements query

    /// methods for high level input actions such as "move up through the menu"

    /// or "pause the game".

    /// </summary>

    public class InputState

    {

        #region Fields



        public const int MaxInputs = 4;



        public readonly KeyboardState[] CurrentKeyboardStates;

        public readonly GamePadState[] CurrentGamePadStates;



        public readonly KeyboardState[] LastKeyboardStates;

        public readonly GamePadState[] LastGamePadStates;



        public readonly bool[] GamePadWasConnected;



        #endregion



        #region Initialization





        /// <summary>

        /// Constructs a new input state.

        /// </summary>

        public InputState()

        {

            CurrentKeyboardStates = new KeyboardState[MaxInputs];

            CurrentGamePadStates = new GamePadState[MaxInputs];



            LastKeyboardStates = new KeyboardState[MaxInputs];

            LastGamePadStates = new GamePadState[MaxInputs];



            GamePadWasConnected = new bool[MaxInputs];

        }





        #endregion



        #region Public Methods





        /// <summary>

        /// Reads the latest state of the keyboard and gamepad.

        /// </summary>

        public void Update()

        {

            for (int i = 0; i < MaxInputs; i++)

            {

                LastKeyboardStates[i] = CurrentKeyboardStates[i];

                LastGamePadStates[i] = CurrentGamePadStates[i];



                CurrentKeyboardStates[i] = Keyboard.GetState((PlayerIndex)i);

                CurrentGamePadStates[i] = GamePad.GetState((PlayerIndex)i);



                // Keep track of whether a gamepad has ever been

                // connected, so we can detect if it is unplugged.

                if (CurrentGamePadStates[i].IsConnected)

                {

                    GamePadWasConnected[i] = true;

                }

            }

        }





        /// <summary>

        /// Helper for checking if a key was newly pressed during this update. The

        /// controllingPlayer parameter specifies which player to read input for.

        /// If this is null, it will accept input from any player. When a keypress

        /// is detected, the output playerIndex reports which player pressed it.

        /// </summary>

        public bool IsNewKeyPress(Keys key, PlayerIndex? controllingPlayer,

                                            out PlayerIndex playerIndex)

        {

            if (controllingPlayer.HasValue)

            {

                // Read input from the specified player.

                playerIndex = controllingPlayer.Value;



                int i = (int)playerIndex;



                return (CurrentKeyboardStates[i].IsKeyDown(key) &&

                        LastKeyboardStates[i].IsKeyUp(key));

            }

            else

            {

                // Accept input from any player.

                return (IsNewKeyPress(key, PlayerIndex.One, out playerIndex) ||

                        IsNewKeyPress(key, PlayerIndex.Two, out playerIndex) ||

                        IsNewKeyPress(key, PlayerIndex.Three, out playerIndex) ||

                        IsNewKeyPress(key, PlayerIndex.Four, out playerIndex));

            }

        }





        /// <summary>

        /// Helper for checking if a button was newly pressed during this update.

        /// The controllingPlayer parameter specifies which player to read input for.

        /// If this is null, it will accept input from any player. When a button press

        /// is detected, the output playerIndex reports which player pressed it.

        /// </summary>

        public bool IsNewButtonPress(Buttons button, PlayerIndex? controllingPlayer,

                                                     out PlayerIndex playerIndex)

        {

            if (controllingPlayer.HasValue)

            {

                // Read input from the specified player.

                playerIndex = controllingPlayer.Value;



                int i = (int)playerIndex;



                return (CurrentGamePadStates[i].IsButtonDown(button) &&

                        LastGamePadStates[i].IsButtonUp(button));

            }

            else

            {

                // Accept input from any player.

                return (IsNewButtonPress(button, PlayerIndex.One, out playerIndex) ||

                        IsNewButtonPress(button, PlayerIndex.Two, out playerIndex) ||

                        IsNewButtonPress(button, PlayerIndex.Three, out playerIndex) ||

                        IsNewButtonPress(button, PlayerIndex.Four, out playerIndex));

            }

        }





        /// <summary>

        /// Checks for a "menu select" input action.

        /// The controllingPlayer parameter specifies which player to read input for.

        /// If this is null, it will accept input from any player. When the action

        /// is detected, the output playerIndex reports which player pressed it.

        /// </summary>

        public bool IsMenuSelect(PlayerIndex? controllingPlayer,

                                 out PlayerIndex playerIndex)

        {

            return IsNewKeyPress(Keys.Space, controllingPlayer, out playerIndex) ||

                   IsNewKeyPress(Keys.Enter, controllingPlayer, out playerIndex) ||

                   IsNewButtonPress(Buttons.A, controllingPlayer, out playerIndex) ||

                   IsNewButtonPress(Buttons.Start, controllingPlayer, out playerIndex);

        }





        /// <summary>

        /// Checks for a "menu cancel" input action.

        /// The controllingPlayer parameter specifies which player to read input for.

        /// If this is null, it will accept input from any player. When the action

        /// is detected, the output playerIndex reports which player pressed it.

        /// </summary>

        public bool IsMenuCancel(PlayerIndex? controllingPlayer,

                                 out PlayerIndex playerIndex)

        {

            return IsNewKeyPress(Keys.Escape, controllingPlayer, out playerIndex) ||

                   IsNewButtonPress(Buttons.B, controllingPlayer, out playerIndex) ||

                   IsNewButtonPress(Buttons.Back, controllingPlayer, out playerIndex);

        }





        /// <summary>

        /// Checks for a "menu up" input action.

        /// The controllingPlayer parameter specifies which player to read

        /// input for. If this is null, it will accept input from any player.

        /// </summary>

        public bool IsMenuUp(PlayerIndex? controllingPlayer)

        {

            PlayerIndex playerIndex;



            return IsNewKeyPress(Keys.Up, controllingPlayer, out playerIndex) ||

                   IsNewButtonPress(Buttons.DPadUp, controllingPlayer, out playerIndex) ||

                   IsNewButtonPress(Buttons.LeftThumbstickUp, controllingPlayer, out playerIndex);

        }





        /// <summary>

        /// Checks for a "menu down" input action.

        /// The controllingPlayer parameter specifies which player to read

        /// input for. If this is null, it will accept input from any player.

        /// </summary>

        public bool IsMenuDown(PlayerIndex? controllingPlayer)

        {

            PlayerIndex playerIndex;



            return IsNewKeyPress(Keys.Down, controllingPlayer, out playerIndex) ||

                   IsNewButtonPress(Buttons.DPadDown, controllingPlayer, out playerIndex) ||

                   IsNewButtonPress(Buttons.LeftThumbstickDown, controllingPlayer, out playerIndex);

        }





        /// <summary>

        /// Checks for a "pause the game" input action.

        /// The controllingPlayer parameter specifies which player to read

        /// input for. If this is null, it will accept input from any player.

        /// </summary>

        public bool IsPauseGame(PlayerIndex? controllingPlayer)

        {

            PlayerIndex playerIndex;



            return IsNewKeyPress(Keys.Escape, controllingPlayer, out playerIndex) ||

                   IsNewButtonPress(Buttons.Back, controllingPlayer, out playerIndex) ||

                   IsNewButtonPress(Buttons.Start, controllingPlayer, out playerIndex);

        }





        #endregion

    }

}