/// <summary>
/// Creates a new KeyboardEventArgs, given a time for the event, the key that was pressed, and
/// the modifiers that were applied at the time of the press, as well as the keyboard state at
/// the time the event occurred.
/// </summary>
public KeyboardEventArgs(TimeSpan time, Keys key, Modifiers modifiers, KeyboardState state)
: base(time)
{
Character = KeyboardUtil.ToChar(key, modifiers);
State = state;
Modifiers = modifiers;
Key = key;
}
private void OnCharacterPressed(object sender, KeyboardKeyEventArgs args)
{
if (CharacterTyped == null)
{
return;
}
var character = KeyboardUtil.ToChar(args.Key, args.Modifiers);
if (character.HasValue)
{
CharacterTyped(this, new KeyboardCharacterEventArgs(character.Value));
}
}
/// <summary>
/// Updates the component, turning XNA's polling model into an event-based model, raising
/// events as they happen.
/// </summary>
/// <param name="gameTime"></param>
public void Update(GameTime gameTime)
{
var current = Keyboard.GetState();
// Build the modifiers that currently apply to the current situation.
var modifiers = Modifiers.None;
if (current.IsKeyDown(Keys.LeftControl) || current.IsKeyDown(Keys.RightControl))
{
modifiers |= Modifiers.Control;
}
if (current.IsKeyDown(Keys.LeftShift) || current.IsKeyDown(Keys.RightShift))
{
modifiers |= Modifiers.Shift;
}
if (current.IsKeyDown(Keys.LeftAlt) || current.IsKeyDown(Keys.RightAlt))
{
modifiers |= Modifiers.Alt;
}
// Key pressed and initial key typed events for all keys.
foreach (Keys key in Enum.GetValues(typeof(Keys)))
{
if (current.IsKeyDown(key) && _previous.IsKeyUp(key))
{
OnKeyPressed(this, new KeyEventArgs(gameTime.TotalGameTime, key, modifiers, current));
var ch = KeyboardUtil.ToChar(key, modifiers);
if (ch.HasValue)
{
OnKeyTyped(this, new CharacterEventArgs(gameTime.TotalGameTime, ch.Value, modifiers, current));
}
// Maintain the state of last key pressed.
_lastKey = key;
_lastPress = gameTime.TotalGameTime;
_isInitial = true;
}
}
// Key released events for all keys.
foreach (Keys key in Enum.GetValues(typeof(Keys)))
{
if (current.IsKeyUp(key) && _previous.IsKeyDown(key))
{
OnKeyReleased(this, new KeyEventArgs(gameTime.TotalGameTime, key, modifiers, current));
}
}
// Handle keys being held down and getting multiple KeyTyped events in sequence.
var elapsedTime = (gameTime.TotalGameTime - _lastPress).TotalMilliseconds;
if (current.IsKeyDown(_lastKey) &&
((_isInitial && elapsedTime > InitialDelay) ||
(!_isInitial && elapsedTime > RepeatDelay)))
{
var ch = KeyboardUtil.ToChar(_lastKey, modifiers);
if (ch.HasValue)
{
OnKeyTyped(this, new CharacterEventArgs(gameTime.TotalGameTime, ch.Value, modifiers, current));
_lastPress = gameTime.TotalGameTime;
_isInitial = false;
}
}
_previous = current;
}
private static void UpdateKeyboardEvents(GameTime gameTime)
{
KeyboardState current = Keyboard.GetState();
// Build the modifiers that currently apply to the current situation.
var modifiers = Modifiers.None;
if (current.IsKeyDown(Keys.LeftControl) || current.IsKeyDown(Keys.RightControl))
{
modifiers |= Modifiers.Control;
}
if (current.IsKeyDown(Keys.LeftShift) || current.IsKeyDown(Keys.RightShift))
{
modifiers |= Modifiers.Shift;
}
if (current.IsKeyDown(Keys.LeftAlt) || current.IsKeyDown(Keys.RightAlt))
{
modifiers |= Modifiers.Alt;
}
// Key pressed and initial key typed events for all keys.
foreach (Keys key in Enum.GetValues(typeof(Keys)))
{
if (current.IsKeyDown(key) && _previousKeyboardState.IsKeyUp(key))
{
RaiseKeyDownEvent(key, modifiers);
char?keyChar = KeyboardUtil.ToChar(key, modifiers);
if (keyChar.HasValue)
{
RaiseCharacterEvent(keyChar.Value);
}
// Maintain the state of last key pressed.
_lastKey = key;
_lastPress = gameTime.TotalGameTime;
_isInitial = true;
}
if (current.IsKeyUp(key) && _previousKeyboardState.IsKeyDown(key))
{
RaiseKeyUpEvent(key, modifiers);
}
}
// Handle keys being held down and getting multiple KeyTyped events in sequence.
var elapsedTime = (gameTime.TotalGameTime - _lastPress).TotalMilliseconds;
if (current.IsKeyDown(_lastKey) &&
((_isInitial && elapsedTime > _initialDelay) || (!_isInitial && elapsedTime > _repeatDelay)))
{
RaiseKeyDownEvent(_lastKey, modifiers);
char?lastKeyChar = KeyboardUtil.ToChar(_lastKey, modifiers);
if (lastKeyChar.HasValue)
{
RaiseCharacterEvent(lastKeyChar.Value);
_lastPress = gameTime.TotalGameTime;
_isInitial = false;
}
}
_previousKeyboardState = current;
}
