]> git.saurik.com Git - wxWidgets.git/blobdiff - src/os2/window.cpp
More make install tweaks.
[wxWidgets.git] / src / os2 / window.cpp
index 96e10ba3cd34536867af41512d8282b997f3b4af..61e1e636019b5e32fbeb0c17f62cda623eda9285 100644 (file)
@@ -1,4 +1,3 @@
-/////////////////////////////////////////////////////////////////////////////
 // Name:        windows.cpp
 // Purpose:     wxWindow
 // Author:      David Webster
@@ -759,15 +758,39 @@ void wxWindowOS2::SetScrollbar(
 , bool                              WXUNUSED(bRefresh)
 )
 {
+    HWND                            hWnd = GetHwnd();
     int                             nOldRange = nRange - nThumbVisible;
     int                             nRange1 = nOldRange;
     int                             nPageSize = nThumbVisible;
+
     SBCDATA                         vInfo;
-    HWND                            hWnd = GetHwnd();
     ULONG                           ulStyle = WS_VISIBLE | WS_SYNCPAINT;
+    SWP                             vSwp;
+    SWP                             vSwpOwner;
     RECTL                           vRect;
+    HWND                            hWndParent;
+    HWND                            hWndClient;
+    wxWindow*                       pParent = GetParent();
+
+    if (pParent && pParent->IsKindOf(CLASSINFO(wxFrame)))
+    {
+        wxFrame*                    pFrame;
+
+        pFrame = wxDynamicCast(pParent, wxFrame);
+        hWndParent = pFrame->GetFrame();
+        hWndClient = GetHwndOf(pParent);
+    }
+    else
+    {
+        if (pParent)
+            hWndParent = GetHwndOf(pParent);
+        else
+            hWndParent = GetHwnd();
+        hWndClient = hWndParent;
+    }
+    ::WinQueryWindowPos(hWndClient, &vSwp);
+    ::WinQueryWindowPos(hWnd, &vSwpOwner);
 
-    ::WinQueryWindowRect(hWnd, &vRect);
     if (nPageSize > 1 && nRange > 0)
     {
         nRange1 += (nPageSize - 1);
@@ -784,53 +807,65 @@ void wxWindowOS2::SetScrollbar(
         if (m_hWndScrollBarHorz == 0L)
         {
             //
-            // We create the scrollbars with the desktop so that they are not
-            // registered as child windows of the window in order that child
-            // windows may be scrolled without scrolling the scrollbars themselves!
+            // Since the scrollbars are usually created before the owner is
+            // sized either via an OnSize event directly or via sizers or
+            // layout constraints, we will initially just use the coords of
+            // the parent window (this is usually a frame client window). But
+            // the bars themselves, are children of the parent frame (i.e
+            // siblings of the frame client.  The owner, however is the actual
+            // window being scrolled (or at least the one responsible for
+            // handling the scroll events). The owner will be resized later,
+            // as it is usually a child of a top level window, and when that
+            // is done its scrollbars will be resized and repositioned as well.
             //
-            m_hWndScrollBarHorz = ::WinCreateWindow( hWnd
+            m_hWndScrollBarHorz = ::WinCreateWindow( hWndParent
                                                     ,WC_SCROLLBAR
                                                     ,(PSZ)NULL
                                                     ,ulStyle
-                                                    ,vRect.xLeft
-                                                    ,vRect.yBottom
-                                                    ,vRect.xRight - vRect.xLeft
+                                                    ,vSwp.x
+                                                    ,vSwp.y
+                                                    ,vSwp.cx - 20
                                                     ,20
                                                     ,hWnd
                                                     ,HWND_TOP
-                                                    ,FID_HORZSCROLL
+                                                    ,60000
                                                     ,&vInfo
                                                     ,NULL
                                                    );
         }
         else
         {
-            RECTL                   vRect2;
-
             //
-            // Only want to resize the scrollbar if it changes, otherwise
-            // we'd probably end up in a recursive loop until we crash the call stack
-            // because this method is called in a ScrolledWindow OnSize event and SWP_MOVE | SWP_SIZE
-            // generates those events.
+            // The owner (the scrolled window) is a child of the Frame's
+            // client window, usually.  The scrollbars are children of the
+            // frame, itself, and thus are positioned relative to the frame's
+            // origin, not the frame's client window origin.
+            // The starting x position is the same as the starting x position
+            // of the owner, but in terms of the parent frame.
+            // The starting y position is 20 pels below the origin of the
+            // owner in terms of the parent frame.
+            // The horz bar is the same width as the owner and 20 pels high.
             //
-            ::WinQueryWindowRect(m_hWndScrollBarHorz, &vRect2);
-            if (!(vRect2.xLeft == vRect.xLeft     &&
-                  vRect2.xRight == vRect.xRight   &&
-                  vRect2.yBottom == vRect.yBottom &&
-                  vRect2.yTop == vRect.yTop
-                ) )
-            {
-                ::WinSetWindowPos( m_hWndScrollBarHorz
-                                  ,HWND_TOP
-                                  ,vRect.xLeft
-                                  ,vRect.yBottom
-                                  ,vRect.xRight - vRect.xLeft
-                                  ,20
-                                  ,SWP_ACTIVATE | SWP_MOVE | SWP_SIZE | SWP_SHOW
-                                 );
-            }
-            ::WinSendMsg(m_hWndScrollBarHorz, SBM_SETSCROLLBAR, (MPARAM)nPos, MPFROM2SHORT(0, (SHORT)nRange1));
-            ::WinSendMsg(m_hWndScrollBarHorz, SBM_SETTHUMBSIZE, MPFROM2SHORT((SHORT)nThumbVisible, (SHORT)nRange1), (MPARAM)0);
+            ::WinSetWindowPos( m_hWndScrollBarHorz
+                              ,HWND_TOP
+                              ,vSwp.x + vSwpOwner.x
+                              ,(vSwp.y + vSwpOwner.y) - 20
+                              ,vSwpOwner.cx
+                              ,20
+                              ,SWP_MOVE | SWP_SIZE | SWP_SHOW | SWP_ACTIVATE | SWP_ZORDER
+                             );
+            ::WinSendMsg( m_hWndScrollBarHorz
+                         ,SBM_SETSCROLLBAR
+                         ,(MPARAM)nPos
+                         ,MPFROM2SHORT(0, (SHORT)nRange1)
+                        );
+            ::WinSendMsg( m_hWndScrollBarHorz
+                         ,SBM_SETTHUMBSIZE
+                         ,MPFROM2SHORT( (SHORT)nThumbVisible
+                                       ,(SHORT)nRange1
+                                      )
+                         ,(MPARAM)0
+                        );
         }
     }
     else
@@ -838,49 +873,71 @@ void wxWindowOS2::SetScrollbar(
         ulStyle |= SBS_VERT;
         if (m_hWndScrollBarVert == 0L)
         {
-            m_hWndScrollBarVert = ::WinCreateWindow( hWnd
+            //
+            // Since the scrollbars are usually created before the owner is
+            // sized either via an OnSize event directly or via sizers or
+            // layout constraints, we will initially just use the coords of
+            // the parent window (this is usually a frame client window). But
+            // the bars themselves, are children of the parent frame (i.e
+            // siblings of the frame client.  The owner, however is the actual
+            // window being scrolled (or at least the one responsible for
+            // handling the scroll events). The owner will be resized later,
+            // as it is usually a child of a top level window, and when that
+            // is done its scrollbars will be resized and repositioned as well.
+            //
+            m_hWndScrollBarVert = ::WinCreateWindow( hWndParent
                                                     ,WC_SCROLLBAR
                                                     ,(PSZ)NULL
                                                     ,ulStyle
-                                                    ,vRect.xRight - 20
-                                                    ,vRect.yBottom + 20
+                                                    ,vSwp.x + vSwp.cx - 20
+                                                    ,vSwp.y + 20
                                                     ,20
-                                                    ,vRect.yTop - (vRect.yBottom + 20)
+                                                    ,vSwp.cy - 20
                                                     ,hWnd
                                                     ,HWND_TOP
-                                                    ,FID_VERTSCROLL
+                                                    ,60001
                                                     ,&vInfo
                                                     ,NULL
                                                    );
         }
         else
         {
-            RECTL                   vRect2;
-
+            ::WinQueryWindowPos(hWnd, &vSwpOwner);
             //
-            // Only want to resize the scrollbar if it changes, otherwise
-            // we'd probably end up in a recursive loop until we crash the call stack
-            // because this method is called in a ScrolledWindow OnSize event and SWP_MOVE | SWP_SIZE
-            // generates those events.
+            // The owner (the scrolled window) is a child of the Frame's
+            // client window, usually.  The scrollbars are children of the
+            // frame, itself and thus are positioned relative to the frame's
+            // origin, not the frame's client window's origin.
+            // Thus, the x position will be frame client's x (usually a few
+            // pels inside the parent frame, plus the width of the owner.
+            // Since we may be using sizers or layout constraints for multiple
+            // child scrolled windows, the y position will be the frame client's
+            // y pos plus the scrolled windows y position, yielding the y
+            // position of the scrollbar relative to the parent frame (the vert
+            // scrollbar is on the right and starts at the bottom of the
+            // owner window).
+            // It is 20 pels wide and the same height as the owner.
             //
-            ::WinQueryWindowRect(m_hWndScrollBarVert, &vRect2);
-            if (!(vRect2.xLeft == vRect.xLeft     &&
-                  vRect2.xRight == vRect.xRight   &&
-                  vRect2.yBottom == vRect.yBottom &&
-                  vRect2.yTop == vRect.yTop
-                ) )
-            {
-                ::WinSetWindowPos( m_hWndScrollBarVert
-                                  ,HWND_TOP
-                                  ,vRect.xRight - 20
-                                  ,vRect.yBottom + 20
-                                  ,20
-                                  ,vRect.yTop - (vRect.yBottom + 20)
-                                  ,SWP_ACTIVATE | SWP_MOVE | SWP_SIZE | SWP_SHOW
-                                 );
-            }
-            ::WinSendMsg(m_hWndScrollBarVert, SBM_SETSCROLLBAR, (MPARAM)nPos, MPFROM2SHORT(0, (SHORT)nRange1));
-            ::WinSendMsg(m_hWndScrollBarVert, SBM_SETTHUMBSIZE, MPFROM2SHORT((SHORT)nThumbVisible, (SHORT)nRange1), (MPARAM)0);
+            ::WinSetWindowPos( m_hWndScrollBarVert
+                              ,HWND_TOP
+                              ,vSwp.x + vSwpOwner.x + vSwpOwner.cx
+                              ,vSwp.y + vSwpOwner.y
+                              ,20
+                              ,vSwpOwner.cy
+                              ,SWP_ACTIVATE | SWP_MOVE | SWP_SIZE | SWP_SHOW
+                             );
+            ::WinSendMsg( m_hWndScrollBarVert
+                         ,SBM_SETSCROLLBAR
+                         ,(MPARAM)nPos
+                         ,MPFROM2SHORT(0, (SHORT)nRange1)
+                        );
+            ::WinSendMsg( m_hWndScrollBarVert
+                         ,SBM_SETTHUMBSIZE
+                         ,MPFROM2SHORT( (SHORT)nThumbVisible
+                                       ,(SHORT)nRange1
+                                      )
+                         ,(MPARAM)0
+                        );
         }
         m_nYThumbSize = nThumbVisible;
     }
@@ -893,86 +950,31 @@ void wxWindowOS2::ScrollWindow(
 )
 {
     RECTL                           vRect;
-    RECTL                           vRect2;
+    RECTL                           vRectHorz;
+    RECTL                           vRectVert;
+    RECTL                           vRectChild;
 
-    nDy *= -1; // flip the sign of Dy as OS/2 is opposite wxWin.
     if (pRect)
     {
-        vRect2.xLeft   = pRect->x;
-        vRect2.yTop    = pRect->y + pRect->height;
-        vRect2.xRight  = pRect->x + pRect->width;
-        vRect2.yBottom = pRect->y;
+        vRect.xLeft   = pRect->x;
+        vRect.yTop    = pRect->y + pRect->height;
+        vRect.xRight  = pRect->x + pRect->width;
+        vRect.yBottom = pRect->y;
     }
     else
     {
-        ::WinQueryWindowRect(GetHwnd(), &vRect2);
-        ::WinQueryWindowRect(m_hWndScrollBarHorz, &vRect);
-        vRect2.yBottom += vRect.yTop - vRect.yBottom;
-        ::WinQueryWindowRect(m_hWndScrollBarVert, &vRect);
-        vRect2.xRight -= vRect.xRight - vRect.xLeft;
-
-    }
-    if (pRect)
-        ::WinScrollWindow( GetHwnd()
-                          ,(LONG)nDx
-                          ,(LONG)nDy
-                          ,&vRect2
-                          ,NULL
-                          ,NULLHANDLE
-                          ,NULL
-                          ,SW_INVALIDATERGN
-                         );
-    else
-        ::WinScrollWindow( GetHwnd()
-                          ,nDx
-                          ,nDy
-                          ,NULL
-                          ,NULL
-                          ,NULLHANDLE
-                          ,NULL
-                          ,SW_INVALIDATERGN
-                         );
-
-    //
-    // Move the children
-    wxWindowList::Node*             pCurrent = GetChildren().GetFirst();
-    SWP                             vSwp;
-
-    while (pCurrent)
-    {
-        wxWindow*                   pChildWin = pCurrent->GetData();
-
-        if (pChildWin->GetHWND() != NULLHANDLE)
-        {
-            ::WinQueryWindowPos(pChildWin->GetHWND(), &vSwp);
-            ::WinQueryWindowRect(pChildWin->GetHWND(), &vRect);
-            if (pChildWin->GetHWND() == m_hWndScrollBarVert ||
-                pChildWin->GetHWND() == m_hWndScrollBarHorz)
-            {
-                ::WinSetWindowPos( pChildWin->GetHWND()
-                                  ,HWND_TOP
-                                  ,vSwp.x + nDx
-                                  ,vSwp.y + nDy
-                                  ,0
-                                  ,0
-                                  ,SWP_MOVE | SWP_SHOW | SWP_ZORDER
-                                 );
-            }
-            else
-            {
-                ::WinSetWindowPos( pChildWin->GetHWND()
-                                  ,HWND_BOTTOM
-                                  ,vSwp.x + nDx
-                                  ,vSwp.y + nDy
-                                  ,0
-                                  ,0
-                                  ,SWP_MOVE | SWP_ZORDER
-                                 );
-                ::WinInvalidateRect(pChildWin->GetHWND(), &vRect, FALSE);
-            }
-        }
-        pCurrent = pCurrent->GetNext();
+        ::WinQueryWindowRect(GetHwnd(), &vRect);
     }
+    nDy *= -1; // flip the sign of Dy as OS/2 is opposite Windows.
+    ::WinScrollWindow( GetHwnd()
+                      ,(LONG)nDx
+                      ,(LONG)nDy
+                      ,&vRect
+                      ,&vRect
+                      ,NULLHANDLE
+                      ,NULL
+                      ,SW_SCROLLCHILDREN | SW_INVALIDATERGN
+                     );
 } // end of wxWindowOS2::ScrollWindow
 
 // ---------------------------------------------------------------------------
@@ -1302,6 +1304,10 @@ void wxWindowOS2::Refresh(
         }
         else
             ::WinInvalidateRect(hWnd, NULL, bEraseBack);
+        if (m_hWndScrollBarHorz != NULLHANDLE)
+            ::WinInvalidateRect(m_hWndScrollBarHorz, NULL, TRUE);
+        if (m_hWndScrollBarVert != NULLHANDLE)
+            ::WinInvalidateRect(m_hWndScrollBarVert, NULL, TRUE);
     }
 } // end of wxWindowOS2::Refresh
 
@@ -1569,6 +1575,55 @@ void wxWindowOS2::DoMoveWindow(
                       ,(LONG)nHeight
                       ,SWP_ZORDER | SWP_SIZE | SWP_MOVE | SWP_SHOW
                      );
+    if (m_vWinSwp.cx == 0 && m_vWinSwp.cy == 0 && m_vWinSwp.fl == 0)
+        //
+        // Uninitialized
+        //
+        ::WinQueryWindowPos(GetHwnd(), &m_vWinSwp);
+    else
+    {
+        int                         nYDiff = m_vWinSwp.cy - nHeight;
+
+        //
+        // Handle resizing of scrolled windows.  The target or window to
+        // be scrolled is the owner (gets the scroll notificaitons).  The
+        // parent is usually the parent frame of the scrolled panel window.
+        // In order to show the scrollbars the target window will be shrunk
+        // by the size of the scroll bar widths (20) and moved in the X and Y
+        // directon.  That value will be computed as part of the diff for
+        // moving the children.  Everytime the window is sized the
+        // toplevel OnSize is going to resize the panel to fit the client
+        // or the whole sizer and will need to me resized. This will send
+        // a WM_SIZE out which will be intercepted by the ScrollHelper
+        // which will cause the scrollbars to be displayed via the SetScrollbar
+        // call in CWindow.
+        //
+        if ( pParent->IsKindOf(CLASSINFO(wxGenericScrolledWindow)) ||
+             pParent->IsKindOf(CLASSINFO(wxScrolledWindow))
+           )
+        {
+            int                     nAdjustWidth  = 0;
+            int                     nAdjustHeight = 0;
+            SWP                     vSwpScroll;
+
+            if (GetScrollBarHorz() != NULLHANDLE)
+                nAdjustHeight = 20L;
+            if (GetScrollBarVert() != NULLHANDLE)
+                nAdjustWidth = 20L;
+            ::WinQueryWindowPos(GetHWND(), &vSwpScroll);
+            ::WinSetWindowPos( GetHWND()
+                              ,HWND_TOP
+                              ,vSwpScroll.x
+                              ,vSwpScroll.y + nAdjustHeight
+                              ,vSwpScroll.cx - nAdjustWidth
+                              ,vSwpScroll.cy - nAdjustHeight
+                              ,SWP_MOVE | SWP_SIZE
+                             );
+            nYDiff += 20;
+        }
+        MoveChildren(nYDiff);
+        ::WinQueryWindowPos(GetHwnd(), &m_vWinSwp);
+    }
 } // end of wxWindowOS2::DoMoveWindow
 
 //
@@ -1947,8 +2002,8 @@ static void wxYieldForCommandsOnly()
     //
     QMSG                            vMsg;
 
-    while (::WinPeekMsg(vHabmain, &vMsg, (HWND)0, WM_COMMAND,
-           WM_COMMAND,PM_REMOVE) && vMsg.msg != WM_QUIT)
+    while (::WinPeekMsg(vHabmain, &vMsg, (HWND)0, WM_COMMAND, WM_COMMAND, PM_REMOVE)
+           && vMsg.msg != WM_QUIT)
     {
         wxTheApp->DoMessage((WXMSG*)&vMsg);
     }
@@ -1962,9 +2017,10 @@ bool wxWindowOS2::DoPopupMenu(
 , int                               nY
 )
 {
-    HWND                            hWnd = GetHwnd();
-    HWND                            hWndParent = GetParent() ? GetWinHwnd(GetParent()) : (HWND)0;
+    HWND                            hWndOwner = GetHwnd();
+    HWND                            hWndParent = GetHwnd();
     HWND                            hMenu = GetHmenuOf(pMenu);
+    bool                            bIsWaiting = TRUE;
 
     pMenu->SetInvokingWindow(this);
     pMenu->UpdateUI();
@@ -1975,23 +2031,27 @@ bool wxWindowOS2::DoPopupMenu(
     wxCurrentPopupMenu = pMenu;
 
     ::WinPopupMenu( hWndParent
-                   ,hWnd
+                   ,hWndOwner
                    ,hMenu
                    ,nX
                    ,nY
                    ,0L
-                   ,PU_MOUSEBUTTON2DOWN | PU_MOUSEBUTTON2 | PU_KEYBOARD
+                   ,PU_HCONSTRAIN | PU_VCONSTRAIN | PU_MOUSEBUTTON1 | PU_KEYBOARD
                   );
-    // we need to do it righ now as otherwise the events are never going to be
-    // sent to wxCurrentPopupMenu from ;()
-    //
-    // note that even eliminating (ugly) wxCurrentPopupMenu global wouldn't
-    // help and we'd still need wxYieldForCommandsOnly() as the menu may be
-    // destroyed as soon as we return (it can be a local variable in the caller
-    // for example) and so we do need to process the event immediately
-    wxYieldForCommandsOnly();
-    wxCurrentPopupMenu = NULL;
 
+    while(bIsWaiting)
+    {
+        QMSG                            vMsg;
+        BOOL                            bRc = ::WinGetMsg(vHabmain, &vMsg, HWND(NULL), 0, 0);
+
+        if (vMsg.msg == WM_MENUEND || vMsg.msg == WM_COMMAND)
+        {
+            bIsWaiting = FALSE;
+        }
+        ::WinDispatchMsg(vHabmain, (PQMSG)&vMsg);
+
+    }
+    wxCurrentPopupMenu = NULL;
     pMenu->SetInvokingWindow(NULL);
     return TRUE;
 } // end of wxWindowOS2::DoPopupMenu
@@ -2338,7 +2398,18 @@ MRESULT EXPENTRY wxWndProc(
     else
     {
         if (pWnd)
+        {
             rc = pWnd->OS2WindowProc(ulMsg, wParam, lParam);
+            if ( (pWnd->GetScrollBarHorz() != NULLHANDLE ||
+                  pWnd->GetScrollBarVert() != NULLHANDLE) &&
+                  ulMsg == WM_PAINT)
+            {
+                if (pWnd->GetScrollBarHorz() != NULLHANDLE)
+                    ::WinInvalidateRect(pWnd->GetScrollBarHorz(), NULL, TRUE);
+                if (pWnd->GetScrollBarVert() != NULLHANDLE)
+                    ::WinInvalidateRect(pWnd->GetScrollBarVert(), NULL, TRUE);
+            }
+        }
         else
             rc = ::WinDefWindowProc(hWnd, ulMsg, wParam, lParam);
     }
@@ -2416,7 +2487,7 @@ MRESULT wxWindowOS2::OS2WindowProc(
             // child controls, so we need to already be sized
             // in order to get the child controls positoned properly.
             //
-            if (IsKindOf(CLASSINFO(wxDialog)))
+            if (IsKindOf(CLASSINFO(wxDialog)) || IsKindOf(CLASSINFO(wxFrame)))
             {
                 PSWP                pSwp = (PSWP)PVOIDFROMMP(wParam);
                 PSWP                pSwp2 = pSwp++;
@@ -2427,6 +2498,16 @@ MRESULT wxWindowOS2::OS2WindowProc(
                                             ,pSwp->cy
                                             ,(WXUINT)lParam
                                            );
+                if (IsKindOf(CLASSINFO(wxFrame)))
+                {
+                    wxFrame*            pFrame = wxDynamicCast(this, wxFrame);
+
+                    if (pFrame)
+                    {
+                        if (pFrame->GetStatusBar())
+                            pFrame->PositionStatusBar();
+                    }
+                }
             }
             break;
 
@@ -2493,8 +2574,8 @@ MRESULT wxWindowOS2::OS2WindowProc(
         case WM_BUTTON3MOTIONEND:
         case WM_BUTTON3MOTIONSTART:
             {
-                short x = LOWORD(lParam);
-                short y = HIWORD(lParam);
+                short x = LOWORD(wParam);
+                short y = HIWORD(wParam);
 
                 bProcessed = HandleMouseEvent(uMsg, x, y, (WXUINT)wParam);
             }
@@ -4031,13 +4112,14 @@ void wxWindowOS2::MoveChildren(
             vSwp.x -= pCtrl->GetXComp();
         }
         ::WinSetWindowPos( GetHwndOf(pWin)
-                          ,HWND_TOP
+                          ,HWND_BOTTOM
                           ,vSwp.x
                           ,vSwp.y - nDiff
                           ,vSwp.cx
                           ,vSwp.cy
-                          ,SWP_MOVE
+                          ,SWP_MOVE | SWP_ZORDER
                          );
+        ::WinQueryWindowPos(GetHwndOf(pWin), pWin->GetSwp());
         if (pWin->IsKindOf(CLASSINFO(wxRadioBox)))
         {
             wxRadioBox*     pRadioBox;
@@ -4082,6 +4164,8 @@ void wxWindowOS2::MoveChildren(
 //
 //  3)  The controls are children of a panel, which in turn is a child of
 //      a frame.
+//      The panel may be one of many, in which case the same treatment
+//      as 1 applies. It may be the only child, though.
 //      This is the nastiest case.  A panel is created as the only child of
 //      the frame and as such, when a frame has only one child, the child is
 //      expanded to fit the entire client area of the frame.  Because the
@@ -4122,12 +4206,16 @@ int wxWindowOS2::GetOS2ParentHeight(
         else
             return(pParent->GetClientSize().y);
     }
-
     //
-    // Case 3 -- this is for any window that is the sole child of a Frame.
-    //           The grandparent must exist and it must be of type CFrame
-    //           and it's height must be different. Otherwise the standard
-    //           applies.
+    // Case 3a -- One of many Frame children.  Will be positioned normally
+    //
+    else if (pParent->GetChildren().GetCount() > 1)
+        return(pParent->GetClientSize().y);
+    //
+    // Case 3b -- this is for any window that is the sole child of a Frame.
+    //            The grandparent must exist and it must be of type CFrame
+    //            and it's height must be different. Otherwise the standard
+    //            applies.
     //
     else
     {
@@ -4158,6 +4246,10 @@ int wxWindowOS2::GetOS2ParentHeight(
     return(0L);
 } // end of wxWindowOS2::GetOS2ParentHeight
 
+//
+// OS/2 needs a lot extra manipulation to deal with layouts
+// for canvas windows, particularly scrolled ones.
+//
 wxWindowCreationHook::wxWindowCreationHook(
   wxWindow*                         pWinBeingCreated
 )