Combo box question

[Scott Turchin]

I have this combo box that is used to hold an array of URL's from a file (History.txt).

All goes well, and I have a hidden button set to default so that when enter is pressed on teh combobox the button is activated and grabs teh text from the combobox.

This does not work, it returns a NULL string for some reason.

I was under the impression if I wanted to pull an "ENTER" out of the combobox I would have to subclass it and that seems to be too much work for this little project.
Not to mention it's over kill, the hidden button works well...

But I can't get a return from it.
Ideas?
Thanks as always!

I created it as follows:

'Array is now loaded
Dialog New 0, g_szMine,0,0, 300,30, %WS_MINIMIZEBOX Or %WS_CAPTION Or %WS_SYSMENU Or %WS_EX_LEFT  To hDlg
Control Add ComboBox, hDlg, %IDCOMBOBOX, HistArray(), 5, 1, 290,120, %CBS_DROPDOWN Or %WS_TABSTOP
Control Add Button, hDlg, %ID_HIDDEN,"&Launch",5,50,45,14,%BS_DEFAULT
Dialog Send hDlg, %WM_SETICON, %ICON_BIG, hIcon
Menu Attach hMenu, hDlg
Dialog Show Modal hDlg Call DialogProc To g_Result


'
'


    Case %WM_COMMAND
      Select Case LoWrd(wParam)
        Case %IDM_CLEAR
             g_Result = MsgBox("Are you sure you wish to clear the history?", %MB_ICONINFORMATION Or %MB_YESNO, g_szMine)
             Control Disable hDlg, %IDM_CLEAR
             If IsTrue Exist(g_HistFile) Then
                Kill g_HistFile
                Erase HistArray()
                ReDim HistArray(1 To 1000) As String
             End If
        Case %ID_HIDDEN   'Launch
              ComboBox Get Text hDlg ,%IDCOMBOBOX To g_szDestURL
              MsgBox g_szDestURL
              If Len(g_szDestURL) Then
                  Incr HistIndex
                  g_Result = ShellExecute(ByVal %NULL, "open", g_szDestURL + Chr$(0), ByVal %NULL, ByVal %NULL,%SW_SHOWMAXIMIZED)
              Else
                 MsgBox "You must enter a valid URL", %MB_ICONSTOP,g_szMine
              End If
        Case %IDCOMBOBOX
              If LoWrd(CbCtlMsg) = %CBN_SELENDOK Then
                   ComboBox Get Text hDlg ,%IDCOMBOBOX To g_szDestURL
                   Incr HistIndex
                   ComboBox Select hDlg, %IDCOMBOBOX, HistIndex
                   g_Result = ShellExecute(ByVal %NULL, "open", g_szDestURL + Chr$(0), ByVal %NULL, ByVal %NULL,%SW_SHOWMAXIMIZED)

               End If
               Function = 1
               Exit Function

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Scott
mailto:[email protected][email protected]</A>
MCSE, MCP+Internet

[Borje Hagsten]

Subclassing is not such a big deal and gives you better possibilities
for added functionality in the future. Try the following:
(OldCBProc should be declared as GLOBAL)
'In PB Main:

  LOCAL hCtl AS LONG
  CONTROL HANDLE hDlg, %IDCOMBOBOX TO hCtl   'Sub-class, to trap keyboard events
  OldCBProc = SetWindowLong(hCtl, %GWL_WNDPROC, CODEPTR(CBProc))

'.. and at some point that is reached when the program terminates

  CONTROL HANDLE hDlg, %IDCOMBOBOX TO hCtl
  IF OldCBProc THEN SetWindowLong hCtl, %GWL_WNDPROC, OldCBProc

'..and the Combo box procedure:

'¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤
' Combobox subclass
'¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤
FUNCTION CBProc(BYVAL hWnd AS LONG, BYVAL wMsg AS LONG, _
                       BYVAL wParam AS LONG, BYVAL lParam AS LONG) AS LONG
 
  SELECT CASE wMsg
     CASE %CB_GETDROPPEDSTATE 'get enter key from a %CBS_DROPDOWN combo
        BEEP 'do something, just to show it works
 
     CASE %WM_KEYUP 'get enter key from a %CBS_DROPDOWNLIST combo
        BEEP 'do something, just to show it works
 
  END SELECT
  FUNCTION = CallWindowProc(OldCBProc, hWnd, wMsg, wParam, lParam)
 
END FUNCTION

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[Scott Turchin]

Actually that wasn't that bad, had to add this in under KEYUP tho:

KeyNum = LoWrd(wParam&) 'Actual ascii value of keystroke coming in


Thanks

Scott


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Scott
mailto:[email protected][email protected]</A>
MCSE, MCP+Internet

[Edwin Knoppert]

For subclassing i often user the GWL_USERDATA variable.


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[email protected]

[Scott Turchin]

You lost me on that one...



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Scott
mailto:[email protected][email protected]</A>
MCSE, MCP+Internet

[jcfuller]

Originally posted by Edwin Knoppert:
For subclassing i often user the GWL_USERDATA variable.

I don't think that's possible with ddt.

James


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[Semen Matusovski]

It possible to have direct access to all messages in DDT without subclassing.
(I posted such method almost half an year ago; up to now no one message about troubles)

  #Compile Exe
  #Register None
  #Dim All
  #Include "Win32Api.Inc"
  
  CallBack Function DlgProc
     If CbMsg = %WM_DESTROY Then PostQuitMessage 0
  End Function
  
  Function PbMain()
     Local Msg As tagMsg, hDlg As Long, i As Long
     Dialog New 0 ,"", , , 200, 100, %WS_CAPTION Or %WS_SYSMENU To hDlg
     Control Add TextBox, hDlg, 101, "", 10, 10, 170, 12
     Control Add TextBox, hDlg, 102, "", 10, 30, 170, 12
     Control Add ComboBox, hDlg, 301,, 10, 65, 170, 100, %CBS_DROPDOWNLIST Or %WS_TABSTOP
     For i = 1 To 10: ComboBox Add hDlg, 301, "Line"+ Str$(i): Next
     ComboBox Select hDlg, 301, 1
     Dialog Show Modeless hDlg Call DlgProc
     While GetMessage(Msg, %NULL, 0, 0)
        If Msg.message = %WM_KEYDOWN And Msg.wparam = 13 Then MsgBox "Hello, Scott"
        If IsDialogMessage(hDlg, Msg) = %FALSE Then _
           TranslateMessage Msg: DispatchMessage Msg
     Loop
     MsgBox "Finished"
  End Function

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[Scott Turchin]

This worked pretty good, rather impressed, it's the subclassed version but I like both possibilities:

'¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤
' Combobox subclass
'¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤
Function CBProc(ByVal hWnd As Long, ByVal wMsg As Long, _
                ByVal wParam As Long, ByVal lParam As Long) As Long
Local KeyNum As Long

Select Case wMsg
    Case %WM_KEYDOWN
    Case %WM_CHAR
    Case %WM_KEYUP
    Case %CB_GETDROPPEDSTATE 'get enter key from a %CBS_DROPDOWN combo
         Control Get Text hDlg ,%IDCOMBOBOX To g_szDestURL
         Incr HistIndex
         HistArray(HistIndex) = g_szDestURL 'Add to array to write to disk.
         ComboBox Select hDlg, %IDCOMBOBOX, HistIndex
         g_Result = ShellExecute(ByVal %NULL, "open", g_szDestURL + Chr$(0), ByVal %NULL, ByVal %NULL,%SW_SHOWMAXIMIZED)
End Select
Function = CallWindowProc(OldCBProc, hWnd, wMsg, wParam, lParam)
End Function

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Scott
mailto:[email protected][email protected]</A>
MCSE, MCP+Internet

[Lance Edmonds]

Originally posted by jcfuller:
I don't think that's possible with ddt.
James

James is correct... you cannot use %GWL_USERDATA with DDT controls and dialogs as this area is used internally by the DDT engine.

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