Stopping A Window Moving

[RichardL]

I have written an application to program some hardware via the serial port (using MVCOM) and it works well and is crash free in the hands of inexpert users, except... on some machines... programming fails and has to be re-started...

When the window is moved it hogs sufficient resources to introduce some timing errors. Is there a neat way to force the window to the front, keep it there and prevent it being dragged while the time critical functions are being carried out, then return to normal operation after programming is finished?

RichardL

[gnozal]

To lock a window

Easy way :

Code: Select all

PureRESIZE_SetWindowMonitoring(WindowNumber.l, Flag.l) ; Monitor a window [forbids moving or resizing]

Or :
Check #WM_WINDOWPOSCHANGING message in callback

Code: Select all

Procedure myWindowCallback(hwnd, msg, wParam, lParam) 
  result = #PB_ProcessPureBasicEvents 
  Select msg 
    Case #WM_WINDOWPOSCHANGING 
      If hwnd = WindowID(0) 
        *WinPos.WINDOWPOS = lParam 
        *WinPos\flags = #SWP_NOMOVE | #SWP_NOSIZE ; delete this line and it will move ...
        result = #False
      EndIf 
  EndSelect 
  ProcedureReturn result 
EndProcedure

If OpenWindow(0, 100, 200, 200, 200, "Locked Window", #PB_Window_SystemMenu) And CreateGadgetList(WindowID(0)) 
  SetWindowCallback(@myWindowCallback()) 
  Repeat 
    event = WaitWindowEvent() 
  Until event = #PB_Event_CloseWindow 
EndIf

[netmaestro]

Something else you might consider is putting the programming function in a thread and giving it "Time Critical" priority, which will cause the OS to give all the resources to it while it runs. If moving a window can make it crash it's an option I'd be looking at quite seriously. (assuming the programming is accomplished in a reasonably short time)

[RichardL]

The timing problem that started this thread was very specific to the hardware that was being programmed via the RS232 port.

Genearally the serial comms are very reliable and have sufficient buffering to cater for most things. For example, on a USB interface I wrote, which used RS232 comms to tell remote hardware which packets to send via USB, I could scrub a half screen window around as much as I liked, the transfer just slowed down.

However, in the current case there are some absolute timings that the peripheral imposes and these were causing the problem. I'm going to try Gnozal's library as a solution... the next cut of the software is due next month and I will see if that fixes the problem.

Thanks guys.

[Rescator]

In your main/gui loop, make sure to put something like Delay(20) after any window resizing or move code. Resizing a window (esp. on WindowsXP if the "show window contents while moving" is very cpu intensive.