Timer problem

[MrHiggins]

Hi,

I have a little problem with this bit of code where I am using a timer and on the callback of the timer it just prints the time in milliseconds. I am finding that the application locks in place when trying to move the window using the titlebar. I have put a scan within the callback as the documentation mentions, but it does not seem to help?


open "graphics" for graphics as #g
   #g "trapclose [close]"
   timer 100, timerCallback
   wait

[close]
   timer 0
   close #g
   end

sub timerCallback
   timer 0
   scan
   #g "\"; time$("milliseconds")
   timer 100, timerCallback
end sub


[tsh73]

Known bug.
timer+sub+move window == freese

Cannot be helped as I can say
(I've seen working code but I could not reliably reuse it in my program even looking at it)

On the other hand, using timer with [labels] works OK.

[Walt Decker]

sub timerCallback
timer 0 '<--- remove this
scan
#g "\"; time$("milliseconds")
timer 100, timerCallback '<---- remove this
end sub

The event will return to the WAIT statement after the first TIMER statement.

EDIT:

Actually this is a serious bug.  My fix does not work and on my machine using TIMER with a SUB locks the window.  Should have been fixed many moons ago.

[Brandon Parker]

Dec 17, 2021 8:21:07 GMT -5 Walt Decker said:

sub timerCallback
timer 0 '<--- remove this
scan
#g "\"; time$("milliseconds")
timer 100, timerCallback '<---- remove this
end sub

The event will return to the WAIT statement after the first TIMER statement.

Unfortunately, this does not resolve the problem. As Anatoly stated, there is a long-standing bug with the Timer when it is used with a Subroutine.

You can use the Timer with the Label option with no issues; although, using Labels mixed with Subroutines/Functions presents its own challenges.

You could try this option I worked up years ago...
Multiple Timer Routines

Or, you could check out how my Import Architect works.
Import Architect Timer


{:0)

Brandon Parker

[MrHiggins]

Thanks tsh73 and walt Decker

I noticed that it seemed to work better using labels and had a feeling it could be a bug.

[Rod]

The code still freezes with those changes. It can be done but as tsh73 states its not recommended.

nomainwin
open "graphics" for graphics as #g
   #g "trapclose closedown"

   while 1
       call waitMilliseconds 500
       #g "cls ; place 50 50"
       #g "\";time$("ms")
       scan
   wend

sub closedown h$
   timer 0
   close #g
   end
end sub

sub waitMilliseconds ms
   timer ms, [stopWaiting]
   wait
   [stopWaiting]
   timer 0
end sub


The timer works perfectly well in a [branch] based coding structure. It gets problematic when we adopt a Sub coding structure. So this known bug that freezes the screen can be worked round. To do it the timer must be entirely encased in a sub of its own. Even then there is a danger the program flow gets hijacked at the scan or wait. Best not to mix [branch] and Subs in any case. For example your [close] branch will not be found if you click on close while it is in the timer Sub so a close Sub is needed.

[MrHiggins]

Rod very nice fix, thank you very much

[Rod]

Well it isn't really a fix it is a workaround and I would not use it other than in the simplistic demo I show. In a larger program using Subs the scope issues and multiple events will cause grief. So stick to a nice [branch] loop or be prepared to put the effort Brandon has put in to use API based timers.

[Brandon Parker]

Another option would be to use a variation of the code shown below. It uses the Windows API, but has a lower learning curve that the API solution I linked to above.

Global uElapse1 : uElapse1 = 500
Global uElapse2 : uElapse2 = 1300
Global nlDEvent1, nlDEvent2, TimerProc1, TimerProc2
nlDEvent1 = 1 : nlDEvent2 = 2

CallBack TimerProc1, Test(ulong, ulong, ulong, ulong), void
CallBack TimerProc2, Test2(ulong, ulong, ulong, ulong), void


NoMainWin
WindowWidth = 270
WindowHeight = 150
StaticText #Test.timer1, "", 90, 25, 100, 25
StaticText #Test.timer2, "", 90, 75, 100, 25
Open "Window" For Window As #Test
#Test "TrapClose Quit"

result = SetChangeTimer(Hwnd(#Test), nlDEvent1, uElapse1, TimerProc1)
result = SetChangeTimer(Hwnd(#Test), nlDEvent2, uElapse2, TimerProc2)

While isWndOpen("#Test")
   Scan
   result = Sleep(1)
Wend : End

'_________________________________________________________________________________________________________________________________________________________
'_________________________________________________________________________________________________________________________________________________________

   Sub Quit handle$
       result = KillTimer(Hwnd(#handle$), nlDEvent1)
       result = KillTimer(Hwnd(#handle$), nlDEvent2)
       Close #handle$
       End
   End Sub

'_________________________________________________________________________________________________________________________________________________________
'_________________________________________________________________________________________________________________________________________________________

   Function Test(var1, var2, var3, var4)
       #Test.timer1 Time$()
   End Function

'_________________________________________________________________________________________________________________________________________________________
'_________________________________________________________________________________________________________________________________________________________

   Function Test2(var1, var2, var3, var4)
       #Test.timer2 Time$()
   End Function

'_________________________________________________________________________________________________________________________________________________________
'_________________________________________________________________________________________________________________________________________________________

   Function isWndOpen(handle$)
       On Error GoTo [Error]
           isWndOpen = Hwnd(#handle$)
       [Error]
   End Function

'_________________________________________________________________________________________________________________________________________________________
'_________________________________________________________________________________________________________________________________________________________

   Function Sleep(milliseconds)
       CallDLL #kernel32, "Sleep", milliseconds    As ulong, _
                                   ret             As void
   End Function

'_________________________________________________________________________________________________________________________________________________________
'_________________________________________________________________________________________________________________________________________________________

   Function SetChangeTimer(hWnd, nlDEvent, uElapse, TimerProc)
       CallDLL #user32, "SetTimer", hWnd            As ulong, _
                                    nlDEvent        As ulong, _
                                    uElapse         As ulong, _
                                    TimerProc       As ulong, _
                                    SetChangeTimer  As ulong
   End Function

'_________________________________________________________________________________________________________________________________________________________
'_________________________________________________________________________________________________________________________________________________________

   Function KillTimer(hWnd, nlDEvent)
       CallDLL #user32, "KillTimer", hWnd      As ulong, _
                                     nlDEvent  As ulong, _
                                     KillTimer As ulong
   End Function


{:0)

Brandon Parker