KEY: Difference between revisions

Latest revision as of 16:56, 24 February 2023

The KEY n statement is used to assign a "soft key" string or a flag and scan code to a function key or display function soft key assignments.

Syntax

KEY n%, textString$

KEY n%, CHR$(keyFlag%) + CHR$(scanCode)

Function Soft Key Strings (1 to 10, 30 & 31)

Assigning "Softkey" STRING values to function key press events

n% is the number 1 to 10 (F1 to F10), 30 or 31 (F11 or F12) of the function key to assign the soft key string.
Instead of using an ON KEY(n) GOSUB statement, Function keys F1 to F12 can be assigned a "soft key" string value to return.
KEY n, text$ defines a literal or variable STRING "soft key" function key return value.

        KEY 1, "Help" 'returns the string "Help" to INPUT variable when F1 is pressed

KEY LIST displays each of the 12 softkey function key (F1 to F12) string values going down left side of screen.
KEY {ON|OFF} displays or hides the softkey values of function keys F1 to F10 at the bottom of the screen.

Number Pad Arrow Keys (11 to 14)

Arrow keys on the Number Pad are predefined KEY numbers 11 to 14 and only work with Number Lock off.
Soft Key STRINGs cannot be assigned to these key numbers!
To use the extended arrow keys on a keyboard use the Extended Key Flag 128 with corresponding Scan code as User Defined Keys.

User Defined Keys (15 to 29)

Assigning user defined keys or combinations with: KEY n, CHR$(keyflag) + CHR$(scancode)

                   Function Key Flag Combination Values

                  0 = no function key combination flag(single key)
                  1 = Left Shift key flag
                  2 = Right Shift key flag
                  4 = Ctrl flag
                  8 = Alt flag
                 32 = Number Lock flag
                 64 = Caps Lock flag
                128 = Extended keys (see trapping extended keys below)

          Flag values can be added to monitor multiple function key combinations.

After the keyflag code character the scancode character is added using one of the two trapping methods that follow:

'                           Soft Key Scan Code Values
'
'      1  2  3  4  5  6  7  8  9  10   30  31                       Predefined Keys
' Esc  F1 F2 F3 F4 F5 F6 F7 F8 F9 F10  F11 F12   SysReq ScrL Pause
'  1   59 60 61 62 63 64 65 66 67 68   87  88     --    70    29
' `~  1! 2@ 3# 4$ 5% 6^ 7& 8* 9( 0) -_ =+ BkSpc  Insert Home PgUp   NumL   /     *    -
'  41 2  3  4  5  6  7  8  9  10 11 12 13  14     82    71    73    32/69  53    55   74
' Tab  Q  W  E  R  T  Y  U  I  O  P  [{ ]} \|    Delete End  PgDn   7/Home 8/▲  9/PU  + 
'  15  16 17 18 19 20 21 22 23 24 25 26 27 43     83    79    81     71   11/72  73   78
' CapL  A  S  D  F  G  H  J  K  L  ;: '"  Enter                     4/◄-   5    6/-►  E
' 64/58 30 31 32 33 34 35 36 37 38 39 40   28                       12/75  76   13/77 n
' Shift  Z  X  C  V  B  N  M  ,< .> /?    Shift         ▲           1/End  2/▼  3/PD  t
' 1/42   44 45 46 47 48 49 50 51 52 53    2/54          72           79   14/80  81   e
' Ctrl Win Alt    Spacebar    Alt Win Menu Ctrl     ◄-  ▼   -►      0/Insert    ./Del r
' 4/29  91 8/56      57       56  92   93  29       75  80  77       82          83   28
'
'  Keyflag: Function(0, 1, 2, 4, 8, 32, 64), Extended(128) Scan Code: 1-88, QB64 only(91-93)
'
'        Reserved and function key combinations can be made using the scan code instead.
'             Add function flag values to 128 for Extended key combinations.

NOTE: The above commented table can be copied and pasted directly into the QB64 IDE

Trapping Ctrl, Alt and Shift key combinations

Keyboard Flag values can be added to monitor more than one control key. For example, flag combination 12 would flag both the Ctrl and Alt key presses. Since the flag already determines the function key to monitor, you don't necessarily have to use it's scancode. You can look for a key combination such as Ctrl + by using the plus key's scancode which is 13 as shown below:

      KEY 15, CHR$(4) + CHR$(13) 'enabled event when Ctrl and + key are pressed

Trapping Extended keys (Insert, Home, Page Up, Right Ctrl, R.Alt, and cursor arrow pad)

On a 101-key keyboard, you can trap any of the keys on the dedicated cursorpad by assigning the string to any of the keynumber values from 15 to 25 using the 128 keyboard flag. The cursor arrows are not the same as the pre-assigned number pad arrows:

      KEY n, CHR$(128) + CHR$(scancode) ' where n = 15 to 29. See: Scancodes

              KEY 15, CHR$(128) + CHR$(75)  'left arrow cursor pad

              KEY 16, CHR$(128) + CHR$(72)  'up arrow cursor pad

              KEY 17, CHR$(128) + CHR$(77)  'right arrow cursor pad

              KEY 18, CHR$(128) + CHR$(80)  'down arrow cursor pad

Use CHR$(0) for the first byte flag for non-function keys. You can substitute a literal STRING value to trap as shown in Example 2.

(Return to Table of Contents)

Examples

Example 1: Shows a list of all the string assignments to the function keys F1-F12 (Prints help every time F1 is pressed in the input)

KEY 1, "Help"
KEY LIST
INPUT "Press F1 or to quit press ENTER: ", a$

F1 Help
F2
F3
F4
F5
F6
F7
F8
F9
F10
F11
F12
Press F1 or to quit press ENTER: HelpHelpHelpHelp

Example 2: Trapping the Control + key combination. Use the Control Keyboard flag 4 and + key scancode 13.

CLS
KEY 15, CHR$(4) + CHR$(13)     'scancode for "=" or "+" key is 13
ON KEY(15) GOSUB control       'action of user defined key press
KEY(15) ON                     'turn ON event trapping for key combination
PRINT "Press Ctrl and plus key combination, escape quits!"
DO: SLEEP
count = count + 1
PRINT count;
IF INKEY$ = CHR$(27) THEN END  'escape key exit
LOOP

control:                             'NUMBER LOCK MUST BE OFF!
PRINT "Control and + keys pressed!";
RETURN

Code by Ted Weissgerber

Example 3: Differentiating the extended cursor keypad arrows from the predefined Number Pad arrow keys.

'predefined keys 11 to 14 for number pad arrows only
ON KEY(11) GOSUB UpNum: KEY(11) ON 'up
ON KEY(12) GOSUB LNum: KEY(12) ON  'left
ON KEY(13) GOSUB RNum: KEY(13) ON  'right
ON KEY(14) GOSUB DnNum: KEY(14) ON 'down
'user defined keys use extended key flag 128 + scan code
ON KEY(15) GOSUB UpPad
KEY 15, CHR$(128) + CHR$(72): KEY(15) ON 'cursor up
ON KEY(16) GOSUB LPad
KEY 16, CHR$(128) + CHR$(75): KEY(16) ON 'cursor left
ON KEY(17) GOSUB RPad
KEY 17, CHR$(128) + CHR$(77): KEY(17) ON 'cursor right
ON KEY(18) GOSUB DnPad
KEY 18, CHR$(128) + CHR$(80): KEY(18) ON 'cursor down

DEF SEG = 0
DO
  numL = PEEK(1047) AND 32 '32 if on
  capL = PEEK(1047) AND 64 '64 on
  IF numL OR capL THEN
    COLOR 12: LOCATE 13, 50: PRINT "Turn Num or Cap Lock OFF!"
  ELSE : COLOR 10: LOCATE 13, 50: PRINT "Number and Cap Lock OK!  "
    SLEEP                  ' KEY or TIMER event breaks a sleep
  END IF
LOOP UNTIL INKEY$ = CHR$(27)
DEF SEG

KEY(15) OFF: KEY(16) OFF: KEY(17) OFF: KEY(18) OFF
KEY(11) OFF: KEY(12) OFF: KEY(13) OFF: KEY(14) OFF
END

UpPad:
COLOR 14: LOCATE 11, 26: PRINT " Up cursor pad  "
RETURN
LPad:
COLOR 14: LOCATE 11, 26: PRINT "Left cursor pad "
RETURN
RPad:
COLOR 14: LOCATE 11, 26: PRINT "Right cursor pad"
RETURN
DnPad:
COLOR 14: LOCATE 11, 26: PRINT "Down cursor pad "
RETURN
UpNum:
COLOR 11: LOCATE 11, 26: PRINT " Up number pad  "
RETURN
LNum:
COLOR 11: LOCATE 11, 26: PRINT "Left number pad "
RETURN
RNum:
COLOR 11: LOCATE 11, 26: PRINT "Right number pad"
RETURN
DnNum:
COLOR 11: LOCATE 11, 26: PRINT "Down number pad "
RETURN

Explanation: The Number Lock or Caps Lock keys ON may hinder extended key reads in QBasic but not QB64!

(Return to Table of Contents)

@@ Line 1: / Line 1: @@
 The [[KEY n]] statement is used to assign a "soft key" string or a flag and scan code to a function key or display function soft key assignments.
-{{PageSyntax}}
+{{PageSyntax}}
 : '''KEY ''n%'', ''textString$'''''
@@ Line 8: / Line 9: @@
-==Function Soft Key Strings (1 to 10, 30 & 31)==
+== Function Soft Key Strings (1 to 10, 30 & 31) ==
 <center>'''Assigning "Softkey" [[STRING]] values to function key press events'''</center>
@@ Line 16: / Line 17: @@
 * {{InlineCode}}KEY n, text${{InlineCodeEnd}} defines a literal or variable [[STRING]] "soft key" function key return value.
-{{WhiteStart}}        '''KEY 1, "Help"''' 'returns the string "Help" to [[INPUT]] variable when F1 is pressed{{WhiteEnd}}
+{{FixedStart}}        '''KEY 1, "Help"''' 'returns the string "Help" to [[INPUT]] variable when F1 is pressed{{FixedEnd}}
 * [[KEY LIST]] displays each of the 12 softkey '''function key''' (F1 to F12) string values going down left side of screen.
@@ Line 22: / Line 23: @@
-==Number Pad Arrow Keys (11 to 14)==
+== Number Pad Arrow Keys (11 to 14) ==
 * Arrow keys on the Number Pad are predefined KEY numbers 11 to 14 and only work with Number Lock off.
@@ Line 29: / Line 30: @@
-==User Defined Keys (15 to 29)==
+== User Defined Keys (15 to 29) ==
 <center>'''Assigning user defined keys or combinations with: KEY n, CHR$(keyflag) + CHR$(scancode)'''</center>
-{{WhiteStart}}                   '''Function Key Flag Combination Values'''
+{{FixedStart}}                   '''Function Key Flag Combination Values'''
                    '''0''' = no function key combination flag(single key)
@@ Line 44: / Line 45: @@
            Flag values can be added to monitor multiple function key combinations.
-{{WhiteEnd}}
+{{FixedEnd}}
 * After the keyflag code character the [[Scancodes|scancode]] character is added using one of the two '''trapping methods''' that follow:
-{{WhiteStart}}'                           '''Soft Key Scan Code Values'''
+{{FixedStart}}'                           '''Soft Key Scan Code Values'''
 '
-'       {{text|1  2  3  4  5  6  7  8  9  10   30  31                       Predefined Keys|red}}
+'      {{Text|1  2  3  4  5  6  7  8  9  10   30  31                       Predefined Keys|red}}
-''''  Esc  F1 F2 F3 F4 F5 F6 F7 F8 F9 F10  F11 F12   SysReq ScrL Pause'''
+' '''Esc  F1 F2 F3 F4 F5 F6 F7 F8 F9 F10  F11 F12   SysReq ScrL Pause'''
-'   1   59 60 61 62 63 64 65 66 67 68   87  88     --    70    29
+'  1   59 60 61 62 63 64 65 66 67 68   87  88     --    70    29
-'  '''`~  1! 2@ 3# 4$ 5% 6^ 7& 8* 9( 0) -_ =+ BkSpc  Insert Home PgUp   NumL   /     *    -'''
+' '''`~  1! 2@ 3# 4$ 5% 6^ 7& 8* 9( 0) -_ =+ BkSpc  Insert Home PgUp   NumL   /     *    -'''
-'   41 2  3  4  5  6  7  8  9  10 11 12 13  14     {{text|82    71    73|blue}}    {{text|32|purple}}/69  {{text|53|blue}}    55   74
+'  41 2  3  4  5  6  7  8  9  10 11 12 13  14     {{Text|82    71    73|blue}}    {{Text|32|purple}}/69  {{Text|53|blue}}    55   74
-'  '''Tab  Q  W  E  R  T  Y  U  I  O  P  [{ ]} \|    Delete End  PgDn   7/Home 8/▲  9/PU  + '''
+' '''Tab  Q  W  E  R  T  Y  U  I  O  P  [{ ]} \|    Delete End  PgDn   7/Home 8/▲  9/PU  + '''
-'   15  16 17 18 19 20 21 22 23 24 25 26 27 43     {{text|83    79    81|blue}}     71   {{text|11|red}}/72  73   78
+'  15  16 17 18 19 20 21 22 23 24 25 26 27 43     {{Text|83    79    81|blue}}     71   {{Text|11|red}}/72  73   78
-'  '''CapL  A  S  D  F  G  H  J  K  L  ;: '"  Enter                     4/◄-   5    6/-►  E'''
+' '''CapL  A  S  D  F  G  H  J  K  L  ;: '"  Enter                     4/◄-   5    6/-►  E'''
-'  {{text|64|purple}}/58 30 31 32 33 34 35 36 37 38 39 40   28                       {{text|12|red}}/75  76   {{text|13|red}}/77 '''n'''
+' {{Text|64|purple}}/58 30 31 32 33 34 35 36 37 38 39 40   28                       {{Text|12|red}}/75  76   {{Text|13|red}}/77 '''n'''
-'  '''Shift  Z  X  C  V  B  N  M  ,< .> /?    Shift         ▲           1/End  2/▼  3/PD  t'''
+' '''Shift  Z  X  C  V  B  N  M  ,< .> /?    Shift         ▲           1/End  2/▼  3/PD  t'''
-'  {{text|1|purple}}/42   44 45 46 47 48 49 50 51 52 53    {{text|2|purple}}/54          {{text|72|blue}}           79   {{text|14|red}}/80  81   '''e'''
+' {{Text|1|purple}}/42   44 45 46 47 48 49 50 51 52 53    {{Text|2|purple}}/54          {{Text|72|blue}}           79   {{Text|14|red}}/80  81   '''e'''
-'  '''Ctrl Win Alt    Spacebar    Alt Win Menu Ctrl     ◄-  ▼   -►      0/Insert    ./Del r'''
+' '''Ctrl Win Alt    Spacebar    Alt Win Menu Ctrl     ◄-  ▼   -►      0/Insert    ./Del r'''
-'  {{text|4|purple}}/29  {{text|91|orange}} {{text|8|purple}}/56      57       {{text|56|blue}}  {{text|92   93|orange}}  {{text|29       75  80  77|blue}}       82          83   {{text|28|blue}}
+' {{Text|4|purple}}/29  {{Text|91|orange}} {{Text|8|purple}}/56      57       {{Text|56|blue}}  {{Text|92   93|orange}}  {{Text|29       75  80  77|blue}}       82          83   {{Text|28|blue}}
 '
-'   '''Keyflag:''' {{text|Function(0, 1, 2, 4, 8, 32, 64)|purple}}, {{text|Extended(128)|blue}} '''Scan Code: '''1-88, {{text|QB64 only(91-93)|orange}}
+'  '''Keyflag:''' {{Text|Function(0, 1, 2, 4, 8, 32, 64)|purple}}, {{Text|Extended(128)|blue}} '''Scan Code: '''1-88, {{Text|QB64 only(91-93)|orange}}
 '
 '        Reserved and function key combinations can be made using the scan code instead.
 '             Add function flag values to 128 for Extended key combinations.
-{{WhiteEnd}}{{small|NOTE: The above commented table can be copied and pasted directly into the QB64 IDE}}
+{{FixedEnd}}
+{{Small|NOTE: The above commented table can be copied and pasted directly into the QB64 IDE}}
 <center>'''Trapping Ctrl, Alt and Shift key combinations'''</center>
 :Keyboard Flag values can be added to monitor more than one control key. For example, flag combination 12 would flag both the Ctrl and Alt key presses. Since the flag already determines the function key to monitor, you don't necessarily have to use it's scancode. You can look for a key combination such as Ctrl + by using the plus key's scancode which is 13 as shown below:
-{{WhiteStart}}      '''KEY 15, CHR$(4) + CHR$(13)''' 'enabled event when Ctrl and + key are pressed{{WhiteEnd}}
+{{FixedStart}}      '''KEY 15, CHR$(4) + CHR$(13)''' 'enabled event when Ctrl and + key are pressed{{FixedEnd}}
 <center>'''Trapping Extended keys (Insert, Home, Page Up, Right Ctrl, R.Alt, and cursor arrow pad)'''</center>
 * On a 101-key keyboard, you can trap any of the keys on the dedicated cursorpad by assigning the string to any of the keynumber values from 15 to 25 using the 128 keyboard flag. The cursor arrows are not the same as the pre-assigned number pad arrows:
-{{WhiteStart}}      '''KEY n, [[CHR$]](128) + [[CHR$]](scancode) ' where n = 15 to 29. See: [[Scancodes]]'''
+{{FixedStart}}      '''KEY n, [[CHR$]](128) + [[CHR$]](scancode) ' where n = 15 to 29. See: [[Scancodes]]'''
                KEY 15, CHR$(128) + CHR$(75)  'left arrow cursor pad
                KEY 16, CHR$(128) + CHR$(72)  'up arrow cursor pad
                KEY 17, CHR$(128) + CHR$(77)  'right arrow cursor pad
                KEY 18, CHR$(128) + CHR$(80)  'down arrow cursor pad
-{{WhiteEnd}}
+{{FixedEnd}}
 <center>Use CHR$(0) for the first byte flag for non-function keys. You can substitute a literal [[STRING]] value to trap as shown in Example 2.</center>
@@ Line 93: / Line 95: @@
-==Examples==
+{{PageExamples}}
 ''Example 1:'' Shows a list of all the string assignments to the function keys F1-F12 (Prints help every time F1 is pressed in the input)
-{{CodeStart}} '' ''
+{{CodeStart}}
 {{Cl|KEY n|KEY}} 1, "Help"
 {{Cl|KEY LIST}}
@@ Line 122: / Line 122: @@
 ''Example 2:'' Trapping the Control + key combination. Use the Control Keyboard flag 4 and + key scancode 13.
 {{CodeStart}}
-{{Cl|CLS}} '' ''
+{{Cl|CLS}}
 {{Cl|KEY n|KEY}} 15, {{Cl|CHR$}}(4) + {{Cl|CHR$}}(13)     'scancode for "=" or "+" key is 13
-{{Cl|ON KEY (n)|ON KEY}}(15) {{Cl|GOSUB}} control       'action of user defined key press
+{{Cl|ON KEY(n)|ON KEY}}(15) {{Cl|GOSUB}} control       'action of user defined key press
 {{Cl|KEY(n)|KEY}}(15) ON                     'turn ON event trapping for key combination
 {{Cl|PRINT}} "Press Ctrl and plus key combination, escape quits!"
 {{Cl|DO}}: {{Cl|SLEEP}}
@@ Line 135: / Line 135: @@
 control:                             'NUMBER LOCK MUST BE OFF!
 {{Cl|PRINT}} "Control and + keys pressed!";
-{{Cl|RETURN}} '' ''
+{{Cl|RETURN}}
 {{CodeEnd}}
-{{small|Code by Ted Weissgerber}}
+{{Small|Code by Ted Weissgerber}}
 ''Example 3:'' Differentiating the extended cursor keypad arrows from the predefined Number Pad arrow keys.
-{{CodeStart}} '' ''
+{{CodeStart}}
 'predefined keys 11 to 14 for number pad arrows only
 {{Cl|ON KEY(n)|ON KEY}}(11) {{Cl|GOSUB}} UpNum: {{Cl|KEY(n)|KEY}}(11) ON 'up
@@ Line 147: / Line 147: @@
 {{Cl|ON KEY(n)|ON KEY}}(13) {{Cl|GOSUB}} RNum: {{Cl|KEY(n)|KEY}}(13) ON  'right
 {{Cl|ON KEY(n)|ON KEY}}(14) {{Cl|GOSUB}} DnNum: {{Cl|KEY(n)|KEY}}(14) ON 'down
 'user defined keys use extended key flag 128 + scan code
 {{Cl|ON KEY(n)|ON KEY}}(15) {{Cl|GOSUB}} UpPad
 {{Cl|KEY n|KEY}} 15, {{Cl|CHR$}}(128) + {{Cl|CHR$}}(72): {{Cl|KEY(n)|KEY}}(15) ON 'cursor up
 {{Cl|ON KEY(n)|ON KEY}}(16) {{Cl|GOSUB}} LPad
 {{Cl|KEY n|KEY}} 16, {{Cl|CHR$}}(128) + {{Cl|CHR$}}(75): {{Cl|KEY(n)|KEY}}(16) ON 'cursor left
 {{Cl|ON KEY(n)|ON KEY}}(17) {{Cl|GOSUB}} RPad
 {{Cl|KEY n|KEY}} 17, {{Cl|CHR$}}(128) + {{Cl|CHR$}}(77): {{Cl|KEY(n)|KEY}}(17) ON 'cursor right
 {{Cl|ON KEY(n)|ON KEY}}(18) {{Cl|GOSUB}} DnPad
 {{Cl|KEY n|KEY}} 18, {{Cl|CHR$}}(128) + {{Cl|CHR$}}(80): {{Cl|KEY(n)|KEY}}(18) ON 'cursor down
@@ Line 165: / Line 165: @@
    {{Cl|ELSE}} : {{Cl|COLOR}} 10: {{Cl|LOCATE}} 13, 50: {{Cl|PRINT}} "Number and Cap Lock OK!  "
      {{Cl|SLEEP}}                  ' {{Cl|KEY n|KEY}} or {{Cl|TIMER}} event breaks a sleep
    {{Cl|END IF}}
 {{Cl|LOOP}} {{Cl|UNTIL}} {{Cl|INKEY$}} = {{Cl|CHR$}}(27)
 {{Cl|DEF SEG}}
@@ Line 196: / Line 196: @@
 DnNum:
 COLOR 11: LOCATE 11, 26: PRINT "Down number pad "
-{{Cl|RETURN}} '' ''
+{{Cl|RETURN}}
 {{CodeEnd}}
-: ''Explanation:'' The Number Lock or Caps Lock keys ON may hinder extended key reads in Qbasic but not QB64!
+: ''Explanation:'' The Number Lock or Caps Lock keys ON may hinder extended key reads in QBasic but not QB64!
@@ Line 204: / Line 204: @@
 {{PageSeeAlso}}
 * [[KEY LIST]], [[ON KEY(n)]]
 * [[KEY(n)]], [[INKEY$]]
 * [[_KEYHIT]], [[_KEYDOWN]]

KEY: Difference between revisions

Latest revision as of 16:56, 24 February 2023

Contents

Syntax

Function Soft Key Strings (1 to 10, 30 & 31)

Number Pad Arrow Keys (11 to 14)

User Defined Keys (15 to 29)

Examples

See also

Navigation menu

KEY: Difference between revisions

Latest revision as of 16:56, 24 February 2023

Syntax

Function Soft Key Strings (1 to 10, 30 & 31)

Number Pad Arrow Keys (11 to 14)

User Defined Keys (15 to 29)

Examples

See also

Navigation menu

Search