DDT, refresh controls.

[E B Knoppert]

I'm building a progress window using DDT.

Before the dialog's controls are painted correctly, the procedure is doing it's job already.

1 single Dialog Doevents is just not enough.

1) Multiple can solve it but when to know when it's enough.
2) I really wouldn't like to use this techn. because it gives the user the time to interfere.

Thanks,

[Semen Matusovski]

EB --
What about DIALOG SHOW MODAL inside thread (if to search, you can find how I solved the same problem for myself) ?
In main program you continue calculation without worring about dialog doevents.

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[E B Knoppert]

Yes, i thought about that.

The process takes only 3 seconds but is shown by a progressbar on a DDT dlg.
There's a button to cancel, this button is not shown properly until i do another events.

I like to have full control without using doevents if it's possible.

I tried RedrawWindow API but maybe with the wrong settings..

I think the thread will be executed after the calculations...
Unpredictable results at least i guess.
(Not my favourite)
What i could do is do the calculations in the thread instead.
Maybe speed is decreased??

Thanks,



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[Semen Matusovski]

Quick thought ...
You calculate and change fields in main task.
To be sure that DDT is redrawn, set "redrawn" flag in WM_PAINT event.
Something like this:

Global Redrawn as Long
CALLBACK FUNCTION for dialog in thread
  CASE %WM_PAINT
     Redrawn = %True

In main task

Redrawn = %False
SendMessage to DDT
While Redrawn = %False
   Sleep 50
Wend

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[Lance Edmonds]

Without discussing the non-standard (non-guaranteed) techniques suggested by others in this thread, a DIALOG DOEVENTS loop must execute for the entire duration of a MODELESS dialog.

The reason for this is simple: any time that a message is placed in the message queue for the app, it must be dispatched to the dialog callback procedure. If this message pump (loop) is not running, then messages do not get forwarded and the dialog appears to "freeze".

Consider this: If you only execute a limited number of DIALOG DOEVENTS statements in your code - what will happen when the dialog gets covered and uncovered by another app's window? The WM_PAINT (and associated messages) do not reach the modeless window procedure.

This type of problem is not "predictable' by your own code (for example, your code cannot know when to repaint itself without help from Windows), so you have no choice by to execute a message loop if you want your modeless dialog to look and execute correctly.



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Lance
PowerBASIC Support
mailto:[email protected][email protected]</A>

[E B Knoppert]

Very clear Lance..

Thanks,



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[Semen Matusovski]

Lance --
Really I offered something like this (looks that "others" means I).
What's is not according PB rules ?

 
    #Compile Exe
    #Include "WIN32API.INC"
    #Include "COMMCTRL.INC"

    %ID_ProgressBar = 501
    Global hProg As Long, hPrDlg As Long
    Global StopDn%, Redrawn As Long

    Sub StopModal (hdlgClose&)
       Local hwndact&, scan1&, scan2&
       scan1& = MapVirtualKey(%VK_MENU, 0)
       scan2& = MapVirtualKey(%VK_F4, 0)
       hwndact& = GetForegroundWindow
       SetForegroundWindow hdlgClose&
       KeyBd_Event %VK_MENU, scan1&, 0, 0: ApiSleep 20
       KeyBd_Event %VK_F4, scan2&, 0, 0: ApiSleep 20
       KeyBd_Event %VK_F4, scan2&, %KEYEVENTF_KEYUP, 0: ApiSleep 20
       KeyBd_Event %VK_MENU, scan1&, %KEYEVENTF_KEYUP, 0: ApiSleep 20
       SetForegroundWindow hwndact&
    End Sub

    CallBack Function hDlg_CB()
       Select Case CbMsg
          Case %WM_SETTEXT: Redrawn = %True
          Case %WM_DESTROY: Redrawn = %True: StopDn = 1
       End Select
   End Function

   Function ExecModeless (ByVal h&) As Long
      Dim hWindow As Long

      Dialog New %HWND_DESKTOP, "Progress Bar", _
         1, 1, 170, 50, %DS_CENTER, %WS_EX_TOPMOST To hPrDlg&
      Control Add "msctls_progress32", hPrDlg&, %ID_ProgressBar, "", 10, 10, 150, 15, %WS_BORDER Or %WS_VISIBLE Or %WS_CHILD, 0
      SendMessage GetDlgItem(hPrDlg&, %ID_ProgressBar), %PBM_SETRANGE, 0, MakLng(0,100)
      SendMessage GetDlgItem(hPrDlg&, %ID_ProgressBar), %PBM_SETPOS, 0, 0
      StopDn = 0
      Dialog Show Modal hPrDlg&, Call hDlg_CB
   End Function

   Sub StartModeless
      StopDn = -1
      Thread Create ExecModeless(h&) To hThread&
      Thread Close hThread& To lResult&
      While StopDn <> 0: Sleep 100: Wend
   End Sub
       
   Function PbMain

   Dim iPos As Long, w$
   StartModeless
   w$ = Time$
   Do
      If StopDn <> 0 Then Exit Do
      If Time$ <> w$ Then
         w$ = Time$
         iPos = iPos + 5: If iPos > 100 Then Exit Do
         Redrawn = %False
         SendMessage GetDlgItem(hPrDlg&, %ID_ProgressBar), %PBM_SETPOS, iPos, 0
         SetWindowText hPrDlg&, "Done " + Str$(iPos) + "%   (Press Alt-F4 to cancel)"
         While IsFalse(Redrawn): Sleep 20: Wend
      End If
   Loop
   If StopDn <> 1 Then StopModal hPrDlg& 
End Function

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