I've begun writing a game using XNA Framework and have hit some simple problem I do not know how to solve correctly.
I'm displaying a menu using Texture2D and using the keyboard (or gamepad) I change the menu item that is selected. My problem is that the current function used to toggle between menu items is way too fast. I might click the down button and it will go down 5 or 6 menu items (due to the fact that Update() is called many time thus updating the selected item).
ex.
(> indicate selected)
> MenuItem1
MenuItem2
MenuItem3
MenuItem4
MenuItem5
I press the down key for just a second), then I have this state:
MenuItem1
MenuItem2
MenuItem3
> MenuItem4
MenuItem5
What I want is (until I press the key again)
MenuItem1
> MenuItem2
MenuItem3
MenuItem4
MenuItem5
What I am looking for is a way to either have the player click the up/down key many time in order to go from one menu item to the other, or to have some sort of minimum wait time before going to the next menu item.
I've built a (large) class that helps a lot with any and all XNA input related tasks, it makes what you're asking for easy.
using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Input;
namespace YourNamespaceHere
{
/// <summary>
/// an enum of all available mouse buttons.
/// </summary>
public enum MouseButtons
{
LeftButton,
MiddleButton,
RightButton,
ExtraButton1,
ExtraButton2
}
public class InputHelper
{
private GamePadState _lastGamepadState;
private GamePadState _currentGamepadState;
#if (!XBOX)
private KeyboardState _lastKeyboardState;
private KeyboardState _currentKeyboardState;
private MouseState _lastMouseState;
private MouseState _currentMouseState;
#endif
private PlayerIndex _index = PlayerIndex.One;
private bool refreshData = false;
/// <summary>
/// Fetches the latest input states.
/// </summary>
public void Update()
{
if (!refreshData)
refreshData = true;
if (_lastGamepadState == null && _currentGamepadState == null)
{
_lastGamepadState = _currentGamepadState = GamePad.GetState(_index);
}
else
{
_lastGamepadState = _currentGamepadState;
_currentGamepadState = GamePad.GetState(_index);
}
#if (!XBOX)
if (_lastKeyboardState == null && _currentKeyboardState == null)
{
_lastKeyboardState = _currentKeyboardState = Keyboard.GetState();
}
else
{
_lastKeyboardState = _currentKeyboardState;
_currentKeyboardState = Keyboard.GetState();
}
if (_lastMouseState == null && _currentMouseState == null)
{
_lastMouseState = _currentMouseState = Mouse.GetState();
}
else
{
_lastMouseState = _currentMouseState;
_currentMouseState = Mouse.GetState();
}
#endif
}
/// <summary>
/// The previous state of the gamepad.
/// Exposed only for convenience.
/// </summary>
public GamePadState LastGamepadState
{
get { return _lastGamepadState; }
}
/// <summary>
/// the current state of the gamepad.
/// Exposed only for convenience.
/// </summary>
public GamePadState CurrentGamepadState
{
get { return _currentGamepadState; }
}
/// <summary>
/// the index that is used to poll the gamepad.
/// </summary>
public PlayerIndex Index
{
get { return _index; }
set {
_index = value;
if (refreshData)
{
Update();
Update();
}
}
}
#if (!XBOX)
/// <summary>
/// The previous keyboard state.
/// Exposed only for convenience.
/// </summary>
public KeyboardState LastKeyboardState
{
get { return _lastKeyboardState; }
}
/// <summary>
/// The current state of the keyboard.
/// Exposed only for convenience.
/// </summary>
public KeyboardState CurrentKeyboardState
{
get { return _currentKeyboardState; }
}
/// <summary>
/// The previous mouse state.
/// Exposed only for convenience.
/// </summary>
public MouseState LastMouseState
{
get { return _lastMouseState; }
}
/// <summary>
/// The current state of the mouse.
/// Exposed only for convenience.
/// </summary>
public MouseState CurrentMouseState
{
get { return _currentMouseState; }
}
#endif
/// <summary>
/// The current position of the left stick.
/// Y is automatically reversed for you.
/// </summary>
public Vector2 LeftStickPosition
{
get
{
return new Vector2(
_currentGamepadState.ThumbSticks.Left.X,
-CurrentGamepadState.ThumbSticks.Left.Y);
}
}
/// <summary>
/// The current position of the right stick.
/// Y is automatically reversed for you.
/// </summary>
public Vector2 RightStickPosition
{
get
{
return new Vector2(
_currentGamepadState.ThumbSticks.Right.X,
-_currentGamepadState.ThumbSticks.Right.Y);
}
}
/// <summary>
/// The current velocity of the left stick.
/// Y is automatically reversed for you.
/// expressed as:
/// current stick position - last stick position.
/// </summary>
public Vector2 LeftStickVelocity
{
get
{
Vector2 temp =
_currentGamepadState.ThumbSticks.Left -
_lastGamepadState.ThumbSticks.Left;
return new Vector2(temp.X, -temp.Y);
}
}
/// <summary>
/// The current velocity of the right stick.
/// Y is automatically reversed for you.
/// expressed as:
/// current stick position - last stick position.
/// </summary>
public Vector2 RightStickVelocity
{
get
{
Vector2 temp =
_currentGamepadState.ThumbSticks.Right -
_lastGamepadState.ThumbSticks.Right;
return new Vector2(temp.X, -temp.Y);
}
}
/// <summary>
/// the current position of the left trigger.
/// </summary>
public float LeftTriggerPosition
{
get { return _currentGamepadState.Triggers.Left; }
}
/// <summary>
/// the current position of the right trigger.
/// </summary>
public float RightTriggerPosition
{
get { return _currentGamepadState.Triggers.Right; }
}
/// <summary>
/// the velocity of the left trigger.
/// expressed as:
/// current trigger position - last trigger position.
/// </summary>
public float LeftTriggerVelocity
{
get
{
return
_currentGamepadState.Triggers.Left -
_lastGamepadState.Triggers.Left;
}
}
/// <summary>
/// the velocity of the right trigger.
/// expressed as:
/// current trigger position - last trigger position.
/// </summary>
public float RightTriggerVelocity
{
get
{
return _currentGamepadState.Triggers.Right -
_lastGamepadState.Triggers.Right;
}
}
#if (!XBOX)
/// <summary>
/// the current mouse position.
/// </summary>
public Vector2 MousePosition
{
get { return new Vector2(_currentMouseState.X, _currentMouseState.Y); }
}
/// <summary>
/// the current mouse velocity.
/// Expressed as:
/// current mouse position - last mouse position.
/// </summary>
public Vector2 MouseVelocity
{
get
{
return (
new Vector2(_currentMouseState.X, _currentMouseState.Y) -
new Vector2(_lastMouseState.X, _lastMouseState.Y)
);
}
}
/// <summary>
/// the current mouse scroll wheel position.
/// See the Mouse's ScrollWheel property for details.
/// </summary>
public float MouseScrollWheelPosition
{
get
{
return _currentMouseState.ScrollWheelValue;
}
}
/// <summary>
/// the mouse scroll wheel velocity.
/// Expressed as:
/// current scroll wheel position -
/// the last scroll wheel position.
/// </summary>
public float MouseScrollWheelVelocity
{
get
{
return (_currentMouseState.ScrollWheelValue - _lastMouseState.ScrollWheelValue);
}
}
#endif
/// <summary>
/// Used for debug purposes.
/// Indicates if the user wants to exit immediately.
/// </summary>
public bool ExitRequested
{
#if (!XBOX)
get
{
return (
(IsCurPress(Buttons.Start) &&
IsCurPress(Buttons.Back)) ||
IsCurPress(Keys.Escape));
}
#else
get { return (IsCurPress(Buttons.Start) && IsCurPress(Buttons.Back)); }
#endif
}
/// <summary>
/// Checks if the requested button is a new press.
/// </summary>
/// <param name="button">
/// The button to check.
/// </param>
/// <returns>
/// a bool indicating whether the selected button is being
/// pressed in the current state but not the last state.
/// </returns>
public bool IsNewPress(Buttons button)
{
return (
_lastGamepadState.IsButtonUp(button) &&
_currentGamepadState.IsButtonDown(button));
}
/// <summary>
/// Checks if the requested button is a current press.
/// </summary>
/// <param name="button">
/// the button to check.
/// </param>
/// <returns>
/// a bool indicating whether the selected button is being
/// pressed in the current state and in the last state.
/// </returns>
public bool IsCurPress(Buttons button)
{
return (
_lastGamepadState.IsButtonDown(button) &&
_currentGamepadState.IsButtonDown(button));
}
/// <summary>
/// Checks if the requested button is an old press.
/// </summary>
/// <param name="button">
/// the button to check.
/// </param>
/// <returns>
/// a bool indicating whether the selected button is not being
/// pressed in the current state and is being pressed in the last state.
/// </returns>
public bool IsOldPress(Buttons button)
{
return (
_lastGamepadState.IsButtonDown(button) &&
_currentGamepadState.IsButtonUp(button));
}
#if (!XBOX)
/// <summary>
/// Checks if the requested key is a new press.
/// </summary>
/// <param name="key">
/// the key to check.
/// </param>
/// <returns>
/// a bool that indicates whether the selected key is being
/// pressed in the current state and not in the last state.
/// </returns>
public bool IsNewPress(Keys key)
{
return (
_lastKeyboardState.IsKeyUp(key) &&
_currentKeyboardState.IsKeyDown(key));
}
/// <summary>
/// Checks if the requested key is a current press.
/// </summary>
/// <param name="key">
/// the key to check.
/// </param>
/// <returns>
/// a bool that indicates whether the selected key is being
/// pressed in the current state and in the last state.
/// </returns>
public bool IsCurPress(Keys key)
{
return (
_lastKeyboardState.IsKeyDown(key) &&
_currentKeyboardState.IsKeyDown(key));
}
/// <summary>
/// Checks if the requested button is an old press.
/// </summary>
/// <param name="key">
/// the key to check.
/// </param>
/// <returns>
/// a bool indicating whether the selectde button is not being
/// pressed in the current state and being pressed in the last state.
/// </returns>
public bool IsOldPress(Keys key)
{
return (
_lastKeyboardState.IsKeyDown(key) &&
_currentKeyboardState.IsKeyUp(key));
}
/// <summary>
/// Checks if the requested mosue button is a new press.
/// </summary>
/// <param name="button">
/// teh mouse button to check.
/// </param>
/// <returns>
/// a bool indicating whether the selected mouse button is being
/// pressed in the current state but not in the last state.
/// </returns>
public bool IsNewPress(MouseButtons button)
{
switch (button)
{
case MouseButtons.LeftButton:
return (
_lastMouseState.LeftButton == ButtonState.Released &&
_currentMouseState.LeftButton == ButtonState.Pressed);
case MouseButtons.MiddleButton:
return (
_lastMouseState.MiddleButton == ButtonState.Released &&
_currentMouseState.MiddleButton == ButtonState.Pressed);
case MouseButtons.RightButton:
return (
_lastMouseState.RightButton == ButtonState.Released &&
_currentMouseState.RightButton == ButtonState.Pressed);
case MouseButtons.ExtraButton1:
return (
_lastMouseState.XButton1 == ButtonState.Released &&
_currentMouseState.XButton1 == ButtonState.Pressed);
case MouseButtons.ExtraButton2:
return (
_lastMouseState.XButton2 == ButtonState.Released &&
_currentMouseState.XButton2 == ButtonState.Pressed);
default:
return false;
}
}
/// <summary>
/// Checks if the requested mosue button is a current press.
/// </summary>
/// <param name="button">
/// the mouse button to be checked.
/// </param>
/// <returns>
/// a bool indicating whether the selected mouse button is being
/// pressed in the current state and in the last state.
/// </returns>
public bool IsCurPress(MouseButtons button)
{
switch (button)
{
case MouseButtons.LeftButton:
return (
_lastMouseState.LeftButton == ButtonState.Pressed &&
_currentMouseState.LeftButton == ButtonState.Pressed);
case MouseButtons.MiddleButton:
return (
_lastMouseState.MiddleButton == ButtonState.Pressed &&
_currentMouseState.MiddleButton == ButtonState.Pressed);
case MouseButtons.RightButton:
return (
_lastMouseState.RightButton == ButtonState.Pressed &&
_currentMouseState.RightButton == ButtonState.Pressed);
case MouseButtons.ExtraButton1:
return (
_lastMouseState.XButton1 == ButtonState.Pressed &&
_currentMouseState.XButton1 == ButtonState.Pressed);
case MouseButtons.ExtraButton2:
return (
_lastMouseState.XButton2 == ButtonState.Pressed &&
_currentMouseState.XButton2 == ButtonState.Pressed);
default:
return false;
}
}
/// <summary>
/// Checks if the requested mosue button is an old press.
/// </summary>
/// <param name="button">
/// the mouse button to check.
/// </param>
/// <returns>
/// a bool indicating whether the selected mouse button is not being
/// pressed in the current state and is being pressed in the old state.
/// </returns>
public bool IsOldPress(MouseButtons button)
{
switch (button)
{
case MouseButtons.LeftButton:
return (
_lastMouseState.LeftButton == ButtonState.Pressed &&
_currentMouseState.LeftButton == ButtonState.Released);
case MouseButtons.MiddleButton:
return (
_lastMouseState.MiddleButton == ButtonState.Pressed &&
_currentMouseState.MiddleButton == ButtonState.Released);
case MouseButtons.RightButton:
return (
_lastMouseState.RightButton == ButtonState.Pressed &&
_currentMouseState.RightButton == ButtonState.Released);
case MouseButtons.ExtraButton1:
return (
_lastMouseState.XButton1 == ButtonState.Pressed &&
_currentMouseState.XButton1 == ButtonState.Released);
case MouseButtons.ExtraButton2:
return (
_lastMouseState.XButton2 == ButtonState.Pressed &&
_currentMouseState.XButton2 == ButtonState.Released);
default:
return false;
}
}
#endif
}
}
Just copy it into a separate class fie and move it to your namespace, then declare one (inputHelper variable), initialize it in the initialiaze portion, and call inputHelper.Update() in your update loop before the update logic. Then whenever you need something related to input, just use the InputHelper! for instance, in your situation, you would use InputHelper.IsNewPress([type of input button/key here]) to check if you want to move the menu item down or up. For this example: inputHelper.IsNewPress(Keys.Down)