NTK - Main Forum  »   How to prevent users from fully reducing a window?

hi walter,
of course it's possible, see attached.
MS well known technic consists in handling the WM_GETMINMAXINFO message in the callback wndproc
of your window and adjust the ptMinTrackSize and ptMaxTrackSize values of the MINMAXINFO structure.
btw, the MINMAXINFO struct is sent by the os via the nlParam when the WM_GETMINMAXINFO event occurs. learn more:
https://msdn.microsoft.com/fr-fr/library/windows/desktop/ms632626%28v=vs.85%29.aspx

with NTK, just attach an event handler function to your window declaration

// example:
CREATE WINDOW hWndDemo;
       STYLE WS_OVERLAPPEDWINDOW;
       TITLE "my window resizable";
       AT 0,0 SIZE 800,600;
       ON PAINT DoScrPaint();
       ON MSG DoEventHandler() // <<< sth like that

then insert & adapt code below into your Prg.

STATIC FUNCTION DoEventHandler(hWnd,nMsg,nwParam,nlParam)
LOCAL nW, nH, aWndSize, aMinMaxInfo
LOCAL nMinWndWidth  := 320 // min. w. boundary
LOCAL nMinWndHeight := 200 // min. h. boundary

DO CASE
...
   CASE nMsg == WM_GETMINMAXINFO
        // get the window dimensions in screen coordinates
        aWndSize := NTK_GetWindowRect( hWnd )

        // determine the window's actual width and height
        nW := aWndSize[RECT_Right] - aWndSize[RECT_Left]
        nH := aWndSize[RECT_Bottom] - aWndSize[RECT_Top]

        // ----------------------------------------------------------------------------
        // prevent user from resizing the window outside the minimum boundaries
        // ----------------------------------------------------------------------------
        IF nW <= nMinWndWidth .OR.  nH <= nMinWndHeight
           // Convert the MINMAXINFO structure into an xhb array
           aMinMaxInfo := NTK_MinMaxInfo2A( nlParam )

           If nW <= nMinWndWidth
              // specify the new minimum width
              aMinMaxInfo[ MINMAXINFO_ptMinTrackSizeX ] := nMinWndWidth
           EndIf

           If nH <= nMinWndHeight
              // specify the new minimum height
              aMinMaxInfo[ MINMAXINFO_ptMinTrackSizeY ] := nMinWndHeight
           EndIf

           // return the MINMAXINFO structure back to MS-Windows
           NTK_SetMinMaxInfo( nlParam, aMinMaxInfo )
        ENDIF
        // ----------------------------------------------------------------------------
        RETURN( 0 )
...
ENDCASE

RETURN NTK_DefWindowProc(hWnd,nMsg,nwParam,nlParam)

nothing more. hope this helps.
wilson