keyboard unit

Access to low-level keyboard functions.

The Keyboard unit implements a keyboard access layer which is system independent. It can be used to poll the keyboard state and wait for certain events. Waiting for a keyboard event can be done with the GetKeyEvent function, which will return a driver-dependent key event. This key event can be translated to a interpretable event by the TranslateKeyEvent function. The result of this function can be used in the other event examining functions.

A custom keyboard driver can be installed using the SetKeyboardDriver function. The current keyboard driver can be retrieved using the GetKeyboardDriver function. The last section of this chapter demonstrates how to make a keyboard driver.

Classes and records

`TEnhancedKeyEvent`	record
`TKeyboardDriver`	record	Keyboard driver structure.
`TKeyRecord`	record	Key event decoding type.

Procedures and functions

`ConvertEnhancedToLegacyShiftState`	function
`ConvertToLegacyKeyEvent`	function
`DoneKeyboard`	procedure	Deactivate keyboard driver.
`equal(TEnhancedKeyEvent,TEnhancedKeyEvent):Boolean`	operator
`FunctionKeyName`	function	Return string representation of a function key code.
`GetEnhancedKeyEvent`	function
`GetKeyboardDriver`	procedure	Return the current keyboard driver record.
`GetKeyEvent`	function	Get the next raw key event, wait if needed.
`GetKeyEventChar`	function	Get the character key part of a key event.
`GetKeyEventCode`	function	Translate function key part of a key event code.
`GetKeyEventFlags`	function	Extract the flags from a key event.
`GetKeyEventShiftState`	function	Return the current state of the shift keys.
`GetKeyEventUniCode`	function	Return the Unicode key event.
`InitKeyboard`	procedure	Initialize the keyboard driver.
`IsFunctionKey`	function	Check whether a given event is a function key event.
`KeyEventToString`	function	Return a string describing the key event.
`KeyPressed`	function	Check event queue for key press.
`PollEnhancedKeyEvent`	function
`PollKeyEvent`	function	Get next key event, but does not wait.
`PollShiftStateEvent`	function	Check current shift state.
`PutKeyEvent`	procedure	Put a key event in the event queue.
`SetKeyboardDriver`	function	Set a new keyboard driver.
`ShiftStateToString`	function	Return description of key event shift state.
`TranslateKeyEvent`	function	Translate raw event to ascii key event.
`TranslateKeyEventUniCode`	function	Translate raw event to UNICode key event.

Types

`PTreeElement`	type	Pointer to TTreeElement record.
`TEnhancedShiftState`	set
`TEnhancedShiftStateElement`	enumeration
`TKeyEvent`	type	Base type to describe all key events.
`Tprocedure`	procedure type	Procedure prototype.

Constants

`AltPrefix`	constant	Keycode for alternate prefix key for Alt key. Unix Only.
`CAPSLOCK_ON`	constant
`CtrlPrefix`	constant	Keycode for alternate prefix key for Ctrl key. Unix only.
`ENHANCED_KEY`	constant
`errKbdBase`	constant	Base of keyboard routine error reporting constants.
`errKbdInitError`	constant	Failed to initialize keyboard driver.
`errKbdNotImplemented`	constant	Keyboard driver not implemented.
`kbAlt`	constant	Alt key modifier.
`kbASCII`	constant	ASCII code key event.
`kbBack`	constant
`kbCtrl`	constant	Control key modifier.
`kbdApps`	constant	Application key (popup-menu) pressed.
`kbdDelete`	constant	Delete key pressed.
`kbdDown`	constant	Arrow down key pressed.
`kbdEnd`	constant	End key pressed.
`kbdF1`	constant	F1 function key pressed.
`kbdF10`	constant	F10 function key pressed.
`kbdF11`	constant	F12 function key pressed.
`kbdF12`	constant	F12 function key pressed.
`kbdF13`	constant	F13 function key pressed.
`kbdF14`	constant	F14 function key pressed.
`kbdF15`	constant	F15 function key pressed.
`kbdF16`	constant	F16 function key pressed.
`kbdF17`	constant	F17 function key pressed.
`kbdF18`	constant	F18 function key pressed.
`kbdF19`	constant	F19 function key pressed.
`kbdF2`	constant	F2 function key pressed.
`kbdF20`	constant	F20 function key pressed.
`kbdF3`	constant	F3 function key pressed.
`kbdF4`	constant	F4 function key pressed.
`kbdF5`	constant	F5 function key pressed.
`kbdF6`	constant	F6 function key pressed.
`kbdF7`	constant	F7 function key pressed.
`kbdF8`	constant	F8 function key pressed.
`kbdF9`	constant	F9 function key pressed.
`kbdHome`	constant	Home key pressed.
`kbdInsert`	constant	Insert key pressed.
`kbdLeft`	constant	Arrow left key pressed.
`kbdLWin`	constant	Left windows key pressed.
`kbdMiddle`	constant	Middle key pad key pressed (numerical 5).
`kbdPgDn`	constant	Page down key pressed.
`kbdPgUp`	constant	Page Up key pressed.
`kbdRight`	constant	Arrow right key pressed.
`kbdRWin`	constant	Right windows key pressed.
`kbdUp`	constant	Arrow up key pressed.
`kbEnter`	constant
`kbFnKey`	constant	function key pressed.
`kbLeftShift`	constant	Left shift key modifier.
`kbPhys`	constant	Physical key code event.
`kbReleased`	constant	Key release event (not implemented in FPC).
`kbRightShift`	constant	Right shift key modifier.
`kbShift`	constant	Shift key modifier.
`kbSpaceBar`	constant
`kbTab`	constant
`kbUniCode`	constant	Unicode code key event.
`LEFT_ALT_PRESSED`	constant
`LEFT_CTRL_PRESSED`	constant
`NilEnhancedKeyEvent`	constant
`NUMLOCK_ON`	constant
`RIGHT_ALT_PRESSED`	constant
`RIGHT_CTRL_PRESSED`	constant
`SAnd`	constant	'And' description string.
`SCROLLLOCK_ON`	constant
`SHIFT_PRESSED`	constant
`ShiftPrefix`	constant	Keycode for alternate prefix key for Shift key. Unix Only.
`SKeyPad`	constant	Names of keypad keys.
`SLeftRight`	constant	Names for left-right keys.
`SScanCode`	constant	Scancode key.
`SShift`	constant	Names of modifier keys.
`SUnicodeChar`	constant	Unicode character string.
`SUnknownFunctionKey`	constant	Unknown function key.

Topics

`kbddriver`	topic	Writing a keyboard driver.
`kbdscancode`	topic	Keyboard scan codes.
`kbdunix`	topic	Unix specific notes.

An experiment, built from development snapshots. Not the official Free Pascal or Lazarus documentation.