LKeyboard Class Reference

The keyboard handler. More...

#include <Keyboard.h>

Inheritance diagram for LKeyboard:

Public Member Functions
	LKeyboard ()
	Constructor. More...
void	GetState ()
	Poll the keyboard state. More...
const bool	Down (const WPARAM) const
	Check for key down. More...
bool	TriggerDown (const WPARAM)
	Check for key changing from up to down. More...
bool	TriggerUp (const WPARAM)
	Check for key changing from down to up. More...
bool	TriggerDown ()
	Check for any key changing from up to down. More...
bool	TriggerUp ()
	Check for any key changing from down to up. More...

Private Member Functions
bool	Trigger (const WPARAM, bool)
	Check for key changing state. More...
bool	Trigger (bool)
	Check for any key changing state. More...

Private Attributes
unsigned char	m_pState [NUMKEYS]
	Space for current state of keys.
unsigned char	m_pOldState [NUMKEYS]
	Space for current state of keys.

Static Private Attributes
static const int	NUMKEYS = 256
	Number of keys on the keyboard.

Additional Inherited Members
Static Protected Attributes inherited from LWindowDesc
static HWND	m_Hwnd = 0
	Window handle.
static HINSTANCE	m_hInst = 0
	Instance handle.
static bool	m_bExitSizeMove
	User just finished moving/resizing window.

Detailed Description

This is a polled keyboard handler. Its GetState() function must be called once per frame. The keyboard state from the previous frame is retained so that queries can determine whether a key changed state.

Constructor & Destructor Documentation

LKeyboard()

LKeyboard::LKeyboard

(

)

The constructor initializes all key states to zero.

Member Function Documentation

Down()

const bool LKeyboard::Down

(

const WPARAM

k

)

const

Check whether a key is currently down. This function assumes that GetState() has been called recently to get the current keyboard state.

Parameters

k	Virtual key code of key to check.

Returns

True if key k is down.

GetState()

void LKeyboard::GetState

(

)

Use the Windows API GetKeyboardState function to get the state of all 256 keys on the keyboard. The results are stored as an array of bytes in m_pState, while the previous state is also stored in m_pOldState.

Trigger() [1/2]

bool LKeyboard::Trigger ( bool  bDown )

private

Check whether any key changed state in a particular direction, not including the ESC key or the function keys F1 through F12. This function assumes that GetState() has been called recently to get the current keyboard state.

Parameters

bDown

True if we're checking for key down, false if up.

Returns

True if a key changed state.

Trigger() [2/2]

bool LKeyboard::Trigger ( const WPARAM  k, bool  bDown  )

private

Check whether a key has just changed state, ie. whether it just went up or just went down. This function assumes that GetState() has been called recently to get the current keyboard state.

Parameters

k	Virtual key code of key to check.
bDown	True if we are checking for key down, false for key up.

Returns

True if key k was changed to the desired state.

TriggerDown() [1/2]

bool LKeyboard::TriggerDown

(

)

Check whether any key went down, not including the ESC key or the function keys F1 through F12. This includes the mouse buttons. This function assumes that GetState() has been called recently to get the current keyboard state.

Returns

True if a key went down.

TriggerDown() [2/2]

bool LKeyboard::TriggerDown

(

const WPARAM

k

)

Check whether a key went down. This function assumes that GetState() has been called recently to get the current keyboard state.

Parameters

k	Virtual key code of key to check.

Returns

True if key k went down.

TriggerUp() [1/2]

bool LKeyboard::TriggerUp

(

)

Check whether any key went up, not including the ESC key or the function keys F1 through F12. This includes the mouse buttons. This function assumes that GetState() has been called recently to get the current keyboard state.

Returns

True if a key went up.

TriggerUp() [2/2]

bool LKeyboard::TriggerUp

(

const WPARAM

k

)

Check whether a key went up. This function assumes that GetState() has been called recently to get the current keyboard state.

Parameters

k	Virtual key code of key to check.

Returns

True if key k went up.