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+---- Thread: keyhit functions (/showthread.php?tid=394)
keyhit functions - James D Jarvis - 05-11-2022
Just some functions and subs I worked up exploring how to use the _keyhit command. All pretty simple but as I've been an inkey$ user for year it's new to me. There's a super simple parser for using a comma separated list of options as input selection. The program is dull, the routines much more useful.
Code: (Select All)
'keyhit functions
'by James D. Jarvis
'just playing about with the _keyhit command and sharing
'I found waiting for a key release got results I like more than a keypress
'also has simple parser to break a comma separated list into an entry list for selection
'$dynamic
Dim Shared tlist$(0)
Print "Waiting for any key to be pressed and released"
Do
_Limit 1000
kyp = waitup
Loop Until kyp <> 0
kyp = 0
Color 15
Print "Get key pressed (press ESC to move on)"
Do
_Limit 1000
kyp = getkey
If Abs(kyp) > 0 And Abs(kyp) < 256 Then Print Chr$(Abs(kyp))
Loop Until kyp = 27
kyp = 0
Color 15
Print "Waiting for Q to be pressed and released"
Do
_Limit 1000
kyp = waitfor("Q")
Loop Until kyp <> 0
kyp = 0
Color 15
Print "Gonna keep counting until esc key is pressed and released"
x = 0
Do
_Limit 20
x = x + 1
Print x;
kyp = getkeyrelease
Loop Until kyp = -27
Print "Return the character pressed"
Do
k$ = anykey$
Loop Until k$ <> ""
Print k$
Print "Press X,Y or Z (upper or lower case)"
kk$ = pickkey$("XYZxyz")
Print "you picked "; kk$
Print "Press any key"
Do
_Limit 1000
kyp = waitup
Loop Until kyp <> 0
Cls
Print "TAB to selection and press Enter to select"
nlist$ = "1,2,3,4,5,6,7,8,9,10"
build_tablist nlist$
tp1$ = tablistpick$(2, 2)
Locate 1, 15
Print "You selected #"; tp1$
'Cls
Locate 1, 1
Print "TAB to selection and press Enter to select"
nlist$ = "a,bb,ccc,dddd,eee,ff,g"
build_tablist nlist$
tp2$ = tablistpick$(12, 2)
Print "Selected "; tp2$
nlist$ = "I,II,III,IV,V"
build_tablist nlist$
tp3$ = tablistpick$(25, 2)
Print "Selected "; tp3$
Sub build_tablist (text$)
baselist$ = text$ + ","
For cc = 1 To Len(baselist$)
If Mid$(baselist$, cc, 1) = "," Then
ccount = ccount + 1
End If
Next cc
Dim comma(ccount)
ReDim tlist$(ccount)
cid = 0
For cc = 1 To Len(baselist$)
If Mid$(baselist$, cc, 1) = "," Then
cid = cid + 1
comma(cid) = cc
End If
Next cc
comma(0) = 0
For c = 1 To ccount
' Print Mid$(baselist$, comma(c - 1) + 1, comma(c) - comma(c - 1) - 1)
tlist$(c) = Mid$(baselist$, comma(c - 1) + 1, comma(c) - comma(c - 1) - 1)
Next c
End Sub
Function getkey
x = _KeyHit
getkey = x
End Function
Function getkeyrelease
x = _KeyHit
If x > 0 Then x = 0 'returns 0 unless a key was released
getkeyrelease = x
End Function
Function anykey$
x = _KeyHit
If x < 0 Then x = -x
If x > 256 Then x = x \ 256
If x > 0 Then
anykey$ = Chr$(x)
Else
anykey$ = ""
End If
End Function
Function pickkey$ (list$)
pickflag = 0
Do
x = _KeyHit
x = -x
If x > 0 And x < 256 Then
A$ = Chr$(x)
If InStr(list$, A$) Then pickflag = 1
pickkey$ = A$
End If
Loop Until pickflag = 1
End Function
Function waitfor (kk$)
Do
x = _KeyHit
x1 = x
If Abs(x) > 256 Then
x1 = x1 \ 256
End If
Loop Until x < 0 And Abs(x1) = Asc(kk$)
waitfor = x
End Function
Function waitup
Do
x = _KeyHit
Loop Until x < 0
waitup = x
End Function
Function tablistpick$ (xx, yy)
choicelimit = UBound(tlist$)
choice = 0
For y = 1 To choicelimit
Locate yy + y, xx + 1
Print tlist$(y)
Next y
Do
_Limit 30
kk = getkeyrelease
kk = -kk
If kk = 9 Or kk = 20480 Then
newchoice = choice + 1
Else
newchoice = choice
End If
If kk = 18432 Then newchoice = choice - 1
If newchoice < 1 Then newchoice = choicelimit
If newchoice > choicelimit Then newchoice = 1
If kk <> 0 And newchoice <> choice Then
choice = newchoice
For y = 1 To choicelimit
Locate yy + y, xx
Print " "; tlist$(y); " "
Next y
Locate yy + choice, xx
Print "["; tlist$(choice); "]"
kk = 0
End If
Loop Until kk = 13
Locate yy + y + 11, xx + 1
tablistpick$ = tlist$(choice)
End FunctionRE: keyhit functions - SMcNeill - 05-11-2022
One thing you might want to watch out for is super-high CPU usage loops. For example:
Code: (Select All)
Function waitup
Do
x = _KeyHit
Loop Until x < 0
waitup = x
End FunctionWritten as the above, that code is going to use as much CPU power as it possibly can, and it's going to make the fans on your PC scream like an airplane engine...
Be user friendly and always remember to add a _LIMIT or a _DELAY to such loops so that your program will play nice with the OS and not try to hog resources which it doesn't need. Example:
Code: (Select All)
Function waitup
Do
x = _KeyHit
_DELAY .05 '1/20th of a second pause between loops
Loop Until x < 0
waitup = x
End FunctionIt'll keep CPU usage down, and you'll never notice a change in your program's usage at all.
RE: keyhit functions - James D Jarvis - 05-11-2022
I used _limit in the main input loops but I did seem to not use it in many of the loops inside the subs and functions, thanks for the pointer.