The On Key Down EEP will execute when the user presses a key. Within the On Key Down EEP, the GETPROPERTY LastKeyDown parameter is accepted to recognize what key is pressed.
Syntax:
GETPROPERTY FormComponentID| 'LastKeyDown' 'iKeyCode'
Where:
•The returned integer value for LastKeyDown is the virtual-key code of the of physical key on the keyboard.
Notes:
•The virtual-key code is not to be confused with the actual keyboard characters. See Virtual-Key Codes.
•The key code value returned by the LastKeyDown syntax is only recognized within the On Key Down EEP.
•It is highly recommended to create a catch mechanism within the On Key Down EEP in order to prevent a condition where the EEP will continually fire if a key is held down for a long time period. See the example below where the IsKeyDown variable is used.
Capturing Shift, Ctrl, and Alt
The GETPROPERTY command also supports the recognition if the Shift, Ctrl, and Alt keys when pressed.
GETPROPERTY FormComponentID| 'ShiftIsPressed' 'iShiftIsPressed'
GETPROPERTY FormComponentID| 'CtrlIsPressed' 'iCtrlIsPressed'
GETPROPERTY FormComponentID| 'AltIsPressed' 'iAltIsPressed'
The returned integer value for ShiftIsPressed, CtrlIsPressed, and AltIsPressedand is 1 if the appropriate key is pressed. The returned value of 1 by the syntax is recognized within the "On Key Down", "On Key Press", and "On Key Up" EEPs.
Examples:
--Example 01:
-- To catch and display the pressed Function Key (Fn) within a label
-- Form "On Before Start" EEP
SET VAR vText TEXT = NULL
SET VAR vIsKeyDown INTEGER = 0
RETURN
-- Form "On Key Down" EEP
IF vIsKeyDown = 1 THEN
RETURN
ENDIF
SET VAR vIsKeyDown = 1
SET VAR iKeyCode TEXT = NULL
GETPROPERTY TrapFunctionKeyForm| 'LastKeyDown' 'iKeyCode'
SWITCH (.iKeyCode)
CASE '112'
PROPERTY FKeyLabel CAPTION 'F1'
BREAK
CASE '113'
PROPERTY FKeyLabel CAPTION 'F2'
BREAK
CASE '114'
PROPERTY FKeyLabel CAPTION 'F3'
BREAK
CASE '115'
PROPERTY FKeyLabel CAPTION 'F4'
BREAK
CASE '116'
PROPERTY FKeyLabel CAPTION 'F5'
BREAK
CASE '117'
PROPERTY FKeyLabel CAPTION 'F6'
BREAK
CASE '118'
PROPERTY FKeyLabel CAPTION 'F7'
BREAK
CASE '119'
PROPERTY FKeyLabel CAPTION 'F8'
BREAK
CASE '120'
PROPERTY FKeyLabel CAPTION 'F9'
BREAK
CASE '121'
PROPERTY FKeyLabel CAPTION 'F10'
BREAK
CASE '122'
PROPERTY FKeyLabel CAPTION 'F11'
BREAK
CASE '123'
PROPERTY FKeyLabel CAPTION 'F12'
BREAK
ENDSW
SET VAR vIsKeyDown = 0
RETURN
Example 02:
-- To catch and display if [Ctrl]+[Alt]+[F5] is pressed
-- Form "On Before Start" EEP
SET VAR vIsKeyDown INTEGER = 0
RETURN
-- Form "On Key Down" EEP
IF vIsKeyDown = 1 THEN
RETURN
ENDIF
SET VAR vIsKeyDown = 1
SET VAR iCtrlIsPressed TEXT = NULL
SET VAR iAltIsPressed TEXT = NULL
SET VAR iKeyCode TEXT = NULL
GETPROPERTY CtrlAltF5Form| 'CtrlIsPressed' 'iCtrlIsPressed'
GETPROPERTY CtrlAltF5Form| 'AltIsPressed' 'iAltIsPressed'
GETPROPERTY CtrlAltF5Form| 'LastKeyDown' 'iKeyCode'
IF iCtrlIsPressed = '1' AND iAltIsPressed = '1' AND iKeyCode = '116' THEN
PAUSE 2 USING 'Ctrl + Alt + F5 was pressed.' ICON INFO BUTTON 'OK'
ENDIF
SET VAR vIsKeyDown = 0
RETURN
