Limitation to resize my window

[Michael Rosner]

Hello

My window start-size is 640*480 pixel and i like to make sure that it is not possible to resize it more then up to 800*600.
What do i have to do ???

Thanks....Michael

[Chris Boss]

Michael;

Process the %WM_SIZING (not WM_SIZE) message in your Dialog procedure. This message is sent during the resizing of the Window so you can control how far a window is sized.


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[Chris Boss]

Michael;

Actually, there is a more efficient method (sorry I forgot about it in the last message). You can process the %WM_GETMINMAXINFO message. This message is where Windows will poll the Dialog procedure for the Minimum and the maximum sizes the window can be sized to.



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[Michael Rosner]

Hello Chris.

I couldn't find nothing in my (Petzolds) Windows95 programming book about %WM_GetMINMAXINFO OR %WM_SIZING ????

....Michael

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[This message has been edited by Michael Rosner (edited March 29, 2000).]

[Chris Boss]

Michael;

The code would look something like this:

(I modified it a bit and haven't tested it though. I was using similiar code in a subclass procedure for a control, not a window. I think this should work as is.)

      CASE %WM_GETMINMAXINFO
          ' TYPE MINMAXINFO
          '    ptReserved AS POINTAPI
          '    ptMaxSize AS POINTAPI
          '    ptMaxPosition AS POINTAPI
          '    ptMinTrackSize AS POINTAPI
          '    ptMaxTrackSize AS POINTAPI
          ' END TYPE
          RV&=DefWindowProc(hDlg, Msg, wParam, lParam)
          DIM MM AS MINMAXINFO PTR
          MM=lParam
          @MM.ptMinTrackSize.x=640
          @MM.ptMinTrackSize.y=480
          @MM.ptMaxSize.x=800
          @MM.ptMaxSize.y=600
          FUNCTION=0
          EXIT FUNCTION

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[Semen Matusovski]

To process %WM_SIZING also not a problem.

' This sample demonstrates, how to restrict dialog's resizing and movement
'
' Based on ideas of Lance Edmonds (subclassing) and
'                   Chris Boss (usage of %WM_SIZING)
' Tasks for this sample: width  = minX .. maxX %%
'                        height = minY .. maxY %%
'                        autocenter
#Compile Exe
#Dim All
#Register None
#Include "win32api.INC"

Global oldproc As Long
CallBack Function DlgProc
  Select Case CbMsg
     Case %WM_DESTROY: SetWindowLong CbHndl, %GWL_WNDPROC, oldproc ' Important
  End Select
End Function

CallBack Function subclass
   %minX = 20: %maxX = 80: %minY = 25: %maxY = 75 ' in %% of whole screen
   If CbMsg = %WM_SIZING Or CbMsg = %WM_MOVING Then
      Local tRect As Rect Ptr, x As Long, xx As Long, y As Long, yy As Long
      tRect = CbLparam
      xx = GetSystemMetrics(%SM_CXSCREEN): yy = GetSystemMetrics(%SM_CYSCREEN)
      x = Min(%maxX / 100 * xx, @tRect.nRight - @tRect.nLeft): x = Max(%minX / 100 * xx, x)
      y = Min(%maxY / 100 * yy, @tRect.nBottom - @tRect.nTop): y = Max(%minY / 100 * yy, y)
      @tRect.nLeft = (xx - x) / 2: @tRect.nRight = @tRect.nLeft + x
      @tRect.nTop = (yy - y) / 2: @tRect.nBottom = @tRect.nTop + y
   End If
   Function = CallWindowProc(oldproc, CbHndl, CbMsg, CbWparam, CbLparam)
End Function

Function PbMain
   Local hDlg As Long
   Dialog New 0, "Resizing's restrictions", , , 200, 200, %WS_SYSMENU Or %WS_THICKFRAME To hDlg
   OldProc = SetWindowLong(hDlg, %GWL_WNDPROC, CodePtr(subclass))
   Dialog Show Modal hDlg, Call DlgProc
End Function

[This message has been edited by Semen Matusovski (edited March 29, 2000).]