INKEY
INKEY
Returns the last key-code in keyboard buffer, or an empty string if there are no keys. Special key-codes like the function-keys are returned as 2-byte string.
Example 1
WHILE(1)
k = INKEY
IF LEN(k)
IF LEN(k)=2
? "H/W #"+ASC(RIGHT(k,1))
ELSE
? k; " "; ASC(k)
FI
FI
SHOWPAGE
WENDExample 2
The following program will return the keycode and a string for every pressed key. The string can be used in an if-statement to querry if the key was pressed. See example 3 how to use the string.
while(1)
k = INKEY
if len(k)
if len(k) == 2
print "2-Byte key code : " + asc(mid(k,1,1)) + " " + asc(mid(k,2,1));
print " -> s = chr(";asc(mid(k,1,1));") + chr(";asc(mid(k,2,1));")"
else
if(asc(k) > 37)
print "Printable key code: "; asc(k); " -> s = \"";k;"\""
else
print "1-Byte key code : "; asc(k);
print " -> s = chr(";asc(k);")"
endif
endif
endif
showpage
wendExample 3: Querry if a key was pressed
See example 2 to get the keycodes for the keys.
const KeyUp = chr(27) + chr(9)
const KeyDown = chr(27) + chr(10)
const KeySpace = " "
const KeyEsc = chr(27)
const KeyReturn = chr(13)
while(1)
k = INKEY
if len(k)
select case k
case KeyUp: print "Up"
case KeyDown: print "Down"
case KeySpace: print "Space"
case KeyEsc: print "Esc"
case KeyReturn: print "Return"
case "a": print "a"
case "A": print "A"
case else: print "other key"
end select
endif
showpage
wendExample 4: Input form
' Key values:
Const K_BKSP = Chr(0x08) ' BackSpace
Const K_TAB = Chr(0x09)
Const K_ENTER = Chr(0x0D)
Const K_ESC = Chr(0x1B) ' Escape
Const K_DELETE = Chr(0x7F)
Const K_PGUP = K_ESC + Chr(0x01) ' Page Up
Const K_PGDN = K_ESC + Chr(0x02) ' Page Down
Const K_LEFT = K_ESC + Chr(0x04) ' Arrow Left
Const K_RIGHT = K_ESC + Chr(0x05) ' Arrow Right
Const K_UP = K_ESC + Chr(0x09) ' Arrow Up
Const K_DOWN = K_ESC + Chr(0x0A) ' Arrow Down
Const K_INSERT = K_ESC + Chr(0x10)
Const K_HOME = K_ESC + Chr(0x11)
Const K_END = K_ESC + Chr(0x12)
' Edit string:
Def edit_char(txt, pos, char, ins_mode) = Replace(txt, pos, char, ins_mode = 0)
Def delete_char(txt, pos) = Replace(txt, pos, "", 1)
' Initialize three demo fields:
f_lbl = ["First Name:", "Last Name: ", "Your Hobby:"] ' field label
f_row = [3, 5, 7] ' label row
f_col = [1, 1, 1] ' label column
f_len = [10, 10, 20] ' variable length
f_var = ["", "", ""] ' variable value
' Index of fields:
Const MIN_IX = Lbound(f_lbl)
Const MAX_IX = Ubound(f_lbl)
ix = MIN_IX ' Start on first field index
ins_mode = 1 ' Start in insert character mode
' Main demo loop:
While True
' Update variables:
eol = Len(f_var(ix)) + 1 ' End Of Line
If pos > eol Or pos < 1 Then pos = eol ' Adjust cursor pos on new field
' Update screen:
For i = MIN_IX To MAX_IX
' Print all fields:
s = Cat(0) + f_lbl(i) + " "
s += Cat(3) + f_var(i) + Spc(f_len(i) - Len(f_var(i))) + " " ' + eol
Locate f_row(i), f_col(i)
Print s + Cat(0);
' Print the cursor:
If i = ix Then
If Not ins_mode Then Color 15
Locate f_row(i), f_col(i) + Len(f_lbl(i)) + pos
Print Cat(2) + Mid(f_var(i) + " ", pos, 1); ' (+ " " for eol)
Fi
Next i
' Update status line:
s = " (Esc=Stop) | " + Iff(ins_mode, "Insert ", "Replace") + Spc(3)
s += Format("| 00:", ix) + Iff(pos = eol, "EOL", Format("000", pos)) + Spc(1)
Locate 0, 0: Print Cat(0) + Cat(3) + s;
Showpage ' SHOWPAGE makes INKEY works smoother (using SB 0.12.2)
' Wait for a key:
Repeat: key = Inkey
Until key <> ""
' Check key:
Select Case key
Case K_ESC: Stop
Case K_INSERT: ins_mode = Not ins_mode
Case K_ENTER, K_TAB: ix++: If ix > MAX_IX Then ix = MIN_IX
Case K_DOWN: If ix < MAX_IX Then ix++
Case K_UP: If ix > MIN_IX Then ix--
Case K_PGDN: ix = MAX_IX
Case K_PGUP: ix = MIN_IX
Case K_HOME: pos = 1
Case K_END: pos = eol
Case K_LEFT: If pos > 1 Then pos--
Case K_RIGHT: If pos < eol Then pos++
Case K_DELETE: If pos < eol Then f_var(ix) = delete_char(f_var(ix), pos)
Case K_BKSP: If pos > 1 Then pos--: f_var(ix) = delete_char(f_var(ix), pos)
Case Else
If Len(key) = 1 And Asc(key) >= 32 Then ' Regular character?
ins = ins_mode And (Len(f_var(ix)) < f_len(ix)) ' Insert mode
rep = (Not ins_mode) And (pos <= f_len(ix)) ' Replace mode
If ins Or rep Then
f_var(ix) = edit_char(f_var(ix), pos, key, ins_mode)
pos++ ' Move cursor to next character
Fi
Fi
End Select
WendExample 5: A basic key code UNIT
REM Language: SmallBASIC 0.12.6 (Linux 32-bit)
REM Purpose: Special key values returned by INKEY.
REM (Values returned by INKEY cannot be used for DEFINEKEY).
REM File name: key.bas
REM Unit name: key
REM Version: 1.0.0 24/05/2016
REM Author: shian
' --- Start demo code ------------------------------------
'
'Import key
'
'? "Press Escape to stop..."
'Repeat: k = Inkey
' Select Case k
' Case Key.ENTER : ? "Key.ENTER"
' Case Key.TABK : ? "Key.TABK"
' Case Key.CLICK : ? "Key.CLICK"
' Case Key.FN(1) : ? "Key.FN(1)"
' Case Key.FN(12) : ? "Key.FN(12)"
' Case Key.CTRL("A"): ? "Key.CTRL(a)"
' Case Key.ALT("A") : ? "Key.ALT(a)"
' Case Key.CTRL(Key.Enter) : ? "Key.CTRL(Key.Enter)"
' Case Key.ALT(Key.Enter) : ? "Key.ALT(Key.Enter)"
' Case Key.SHIFT(Key.Enter): ? "Key.SHIFT(Key.Enter)"
' End Select
'Until k = Key.ESC
'
' --- End demo code ------------------------------------
Unit key
' Useful Constants:
Export BKSP, TABK, ENTER, ESC, BLANK, DEL
Export PGUP, PGDN, LEFTK, RIGHTK, UP, DOWN
Export INS, HOMEK, ENDK, CLICK
' Useful Functions:
Export FN, CTRL, ALT, SHIFT
Export CTRL_ALT, ALT_SHIFT, CTRL_SHIFT ' (used by system)
' The left character of INKEY (Useful only for special cases):
Export CTRL_CHR, ALT_CHR, SHIFT_CHR
Export CTRL_ALT_CHR, ALT_SHIFT_CHR, CTRL_SHIFT_CHR
Const CTRL_CHR = Chr(0x01) ' for Ctrl+Char
Const ALT_CHR = Chr(0x02) ' for Alt+Char
Const SHIFT_CHR = Chr(0x03) ' for Shift+Char
Const CTRL_ALT_CHR = Chr(0x04) ' for Ctrl+Alt+Char (used by system)
Const ALT_SHIFT_CHR = Chr(0x05) ' for Alt+Shift+Char (used by system)
Const CTRL_SHIFT_CHR = Chr(0x06) ' for Ctrl+Shift+Char (used by system)
Const BKSP = Chr(0x08) ' BackSpace
Const TABK = Chr(0x09) ' Tab key
Const ENTER = Chr(0x0D)
Const ESC = Chr(0x1B) ' Escape
Const BLANK = Chr(0x20) ' Space key
Const DEL = Chr(0x7F) ' Delete
Const PGUP = ESC + Chr(0x01) ' Page Up
Const PGDN = ESC + Chr(0x02) ' Page Down
Const LEFTK = ESC + Chr(0x04) ' Arrow Left key
Const RIGHTK = ESC + Chr(0x05) ' Arrow Right key
Const UP = ESC + Chr(0x09) ' Arrow Up
Const DOWN = ESC + Chr(0x0A) ' Arrow Down
Const INS = ESC + Chr(0x10) ' Insert
Const HOMEK = ESC + Chr(0x11) ' Home key
Const ENDK = ESC + Chr(0x12) ' End key
Const CLICK = ESC + Chr(0xC0) ' Left Mouse Button Click
Def FN(n) = ESC + Chr(0xF0 + n) ' FN(1) is F1 (up to 12).
Def CTRL(c) = CTRL_CHR + Lcase(c) ' Ctrl+a, Ctrl+Enter, etc
Def ALT(c) = ALT_CHR + Lcase(c) ' Alt+a, Alt+Enter, etc
Def SHIFT(c) = SHIFT_CHR + c ' Shift+Enter, Shift+Tab, etc
' These are system shortcuts - so it's advisable NOT to use them at all!
' (however, it's possible to detect them when not used by the system).
Def CTRL_ALT(c) = CTRL_ALT_CHR + Lcase(c) ' Ctrl+Alt+a, etc
Def ALT_SHIFT(c) = ALT_SHIFT_CHR + Lcase(c) ' Alt+Shift+a, etc
Def CTRL_SHIFT(c) = CTRL_SHIFT_CHR + Lcase(c) ' Ctrl+Shift+a, etc
' ' Use this code to test and print key codes as hexa:
' ' --------------------------------------------------
' Print "Press Ctrl+B to stop..."
' While 1: k = Inkey: l = Len(k)
' If l Then
' ? "0x"; Right("00" + Hex(Asc(k)), 2);
' If l = 2 Then ? Right("00" + Hex(Asc(Mid(k, 2))), 2);
' Print
' Fi
' WendCode samples using INKEY
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