X-Git-Url: https://git.saurik.com/wxWidgets.git/blobdiff_plain/a58a12e9b7196c339c1c1d282ede158a70644e07..7f017c64bbad70dac236202cf208889f08f75a8c:/src/generic/scrolwin.cpp

diff --git a/src/generic/scrolwin.cpp b/src/generic/scrolwin.cpp
index 513cb292f2..7cd7722062 100644
--- a/src/generic/scrolwin.cpp
+++ b/src/generic/scrolwin.cpp
@@ -1,6 +1,6 @@
 /////////////////////////////////////////////////////////////////////////////
 // Name:        generic/scrolwin.cpp
-// Purpose:     wxScrolledWindow implementation
+// Purpose:     wxGenericScrolledWindow implementation
 // Author:      Julian Smart
 // Modified by:
 // Created:     01/02/97
@@ -21,6 +21,10 @@
     #pragma implementation "scrolwin.h"
 #endif
 
+#ifdef __VMS
+#define XtDisplay XTDISPLAY
+#endif
+
 // For compilers that support precompilation, includes "wx.h".
 #include "wx/wxprec.h"
 
@@ -50,28 +54,34 @@
 #endif
 #endif
 
+#ifndef __WXGTK__
+#include "wx/scrolwin.h"
+IMPLEMENT_CLASS(wxScrolledWindow, wxGenericScrolledWindow)
+#endif
+
 // ----------------------------------------------------------------------------
 // event tables
 // ----------------------------------------------------------------------------
 
-BEGIN_EVENT_TABLE(wxScrolledWindow, wxPanel)
-    EVT_SCROLLWIN(wxScrolledWindow::OnScroll)
-    EVT_SIZE(wxScrolledWindow::OnSize)
-    EVT_PAINT(wxScrolledWindow::OnPaint)
-    EVT_KEY_DOWN(wxScrolledWindow::OnKeyDown)
+BEGIN_EVENT_TABLE(wxGenericScrolledWindow, wxPanel)
+    EVT_SCROLLWIN(wxGenericScrolledWindow::OnScroll)
+    EVT_SIZE(wxGenericScrolledWindow::OnSize)
+    EVT_PAINT(wxGenericScrolledWindow::OnPaint)
+    EVT_CHAR(wxGenericScrolledWindow::OnChar)
+    EVT_MOUSEWHEEL(wxGenericScrolledWindow::OnMouseWheel)
 END_EVENT_TABLE()
 
-IMPLEMENT_DYNAMIC_CLASS(wxScrolledWindow, wxPanel)
+IMPLEMENT_DYNAMIC_CLASS(wxGenericScrolledWindow, wxPanel)
 
 // ============================================================================
 // implementation
 // ============================================================================
 
 // ----------------------------------------------------------------------------
-// wxScrolledWindow creation
+// wxGenericScrolledWindow creation
 // ----------------------------------------------------------------------------
 
-wxScrolledWindow::wxScrolledWindow()
+wxGenericScrolledWindow::wxGenericScrolledWindow()
 {
     m_xScrollPixelsPerLine = 0;
     m_yScrollPixelsPerLine = 0;
@@ -85,9 +95,11 @@ wxScrolledWindow::wxScrolledWindow()
     m_yScrollLinesPerPage = 0;
     m_scaleX = 1.0;
     m_scaleY = 1.0;
+    m_wheelRotation = 0;
+    m_targetWindow = (wxWindow*) NULL;
 }
 
-bool wxScrolledWindow::Create(wxWindow *parent,
+bool wxGenericScrolledWindow::Create(wxWindow *parent,
                               wxWindowID id,
                               const wxPoint& pos,
                               const wxSize& size,
@@ -106,14 +118,21 @@ bool wxScrolledWindow::Create(wxWindow *parent,
     m_yScrollLinesPerPage = 0;
     m_scaleX = 1.0;
     m_scaleY = 1.0;
+    m_wheelRotation = 0;
 
     m_targetWindow = this;
 
-    // we need wxWANTS_CHARS to process arrows ourselves
-    return wxPanel::Create(parent, id, pos, size, style | wxWANTS_CHARS, name);
+    bool ok = wxPanel::Create(parent, id, pos, size, style, name);
+
+#ifdef __WXMSW__
+    // we need to process arrows ourselves for scrolling
+    m_lDlgCode |= DLGC_WANTARROWS;
+#endif // __WXMSW__
+
+    return ok;
 }
 
-wxScrolledWindow::~wxScrolledWindow()
+wxGenericScrolledWindow::~wxGenericScrolledWindow()
 {
 }
 
@@ -125,20 +144,24 @@ wxScrolledWindow::~wxScrolledWindow()
  * pixelsPerUnitX/pixelsPerUnitY: number of pixels per unit (e.g. pixels per text line)
  * noUnitsX/noUnitsY:        : no. units per scrollbar
  */
-void wxScrolledWindow::SetScrollbars (int pixelsPerUnitX, int pixelsPerUnitY,
+void wxGenericScrolledWindow::SetScrollbars (int pixelsPerUnitX, int pixelsPerUnitY,
                int noUnitsX, int noUnitsY,
                int xPos, int yPos, bool noRefresh )
 {
+    int xpos, ypos;
+
+    CalcUnscrolledPosition(xPos, yPos, &xpos, &ypos);
     bool do_refresh =
     (
       (noUnitsX != 0 && m_xScrollLines == 0) ||
-      (noUnitsX < m_xScrollLines) ||
+      (noUnitsX < m_xScrollLines && xpos > pixelsPerUnitX*noUnitsX) ||
+
       (noUnitsY != 0 && m_yScrollLines == 0) ||
-      (noUnitsY < m_yScrollLines) ||
+      (noUnitsY < m_yScrollLines && ypos > pixelsPerUnitY*noUnitsY) ||
       (xPos != m_xScrollPosition) ||
-      (yPos != m_yScrollPosition) ||
-      (pixelsPerUnitX != m_xScrollPixelsPerLine) ||
-      (pixelsPerUnitY != m_yScrollPixelsPerLine)
+      (yPos != m_yScrollPosition)
+//       (pixelsPerUnitX != m_xScrollPixelsPerLine) ||
+//       (pixelsPerUnitY != m_yScrollPixelsPerLine)
     );
 
     m_xScrollPixelsPerLine = pixelsPerUnitX;
@@ -205,13 +228,13 @@ void wxScrolledWindow::SetScrollbars (int pixelsPerUnitX, int pixelsPerUnitY,
 // target window handling
 // ----------------------------------------------------------------------------
 
-void wxScrolledWindow::SetTargetWindow( wxWindow *target )
+void wxGenericScrolledWindow::SetTargetWindow( wxWindow *target )
 {
     wxASSERT_MSG( target, wxT("target window must not be NULL") );
     m_targetWindow = target;
 }
 
-wxWindow *wxScrolledWindow::GetTargetWindow()
+wxWindow *wxGenericScrolledWindow::GetTargetWindow()
 {
     return m_targetWindow;
 }
@@ -220,7 +243,7 @@ wxWindow *wxScrolledWindow::GetTargetWindow()
 // scrolling implementation itself
 // ----------------------------------------------------------------------------
 
-void wxScrolledWindow::OnScroll(wxScrollWinEvent& event)
+void wxGenericScrolledWindow::OnScroll(wxScrollWinEvent& event)
 {
     int orient = event.GetOrientation();
 
@@ -260,74 +283,61 @@ void wxScrolledWindow::OnScroll(wxScrollWinEvent& event)
             m_targetWindow->ScrollWindow(0, -m_yScrollPixelsPerLine * nScrollInc, (const wxRect *) NULL);
         else
             m_targetWindow->Refresh();
-  }
+    }
 #ifdef __WXMAC__
     m_targetWindow->MacUpdateImmediately() ;
 #endif
 }
 
-int wxScrolledWindow::CalcScrollInc(wxScrollWinEvent& event)
+int wxGenericScrolledWindow::CalcScrollInc(wxScrollWinEvent& event)
 {
     int pos = event.GetPosition();
     int orient = event.GetOrientation();
 
     int nScrollInc = 0;
-    switch (event.GetEventType())
+    if (event.GetEventType() == wxEVT_SCROLLWIN_TOP)
     {
-        case wxEVT_SCROLLWIN_TOP:
-        {
             if (orient == wxHORIZONTAL)
                 nScrollInc = - m_xScrollPosition;
             else
                 nScrollInc = - m_yScrollPosition;
-            break;
-        }
-        case wxEVT_SCROLLWIN_BOTTOM:
-        {
+    } else
+    if (event.GetEventType() == wxEVT_SCROLLWIN_BOTTOM)
+    {
             if (orient == wxHORIZONTAL)
                 nScrollInc = m_xScrollLines - m_xScrollPosition;
             else
                 nScrollInc = m_yScrollLines - m_yScrollPosition;
-            break;
-        }
-        case wxEVT_SCROLLWIN_LINEUP:
-        {
+    } else
+    if (event.GetEventType() == wxEVT_SCROLLWIN_LINEUP)
+    {
             nScrollInc = -1;
-            break;
-        }
-        case wxEVT_SCROLLWIN_LINEDOWN:
-        {
+    } else
+    if (event.GetEventType() == wxEVT_SCROLLWIN_LINEDOWN)
+    {
             nScrollInc = 1;
-            break;
-        }
-        case wxEVT_SCROLLWIN_PAGEUP:
-        {
+    } else
+    if (event.GetEventType() == wxEVT_SCROLLWIN_PAGEUP)
+    {
             if (orient == wxHORIZONTAL)
                 nScrollInc = -GetScrollPageSize(wxHORIZONTAL);
             else
                 nScrollInc = -GetScrollPageSize(wxVERTICAL);
-            break;
-        }
-        case wxEVT_SCROLLWIN_PAGEDOWN:
-        {
+    } else
+    if (event.GetEventType() == wxEVT_SCROLLWIN_PAGEDOWN)
+    {
             if (orient == wxHORIZONTAL)
                 nScrollInc = GetScrollPageSize(wxHORIZONTAL);
             else
                 nScrollInc = GetScrollPageSize(wxVERTICAL);
-            break;
-        }
-        case wxEVT_SCROLLWIN_THUMBTRACK:
-        {
+    } else
+    if ((event.GetEventType() == wxEVT_SCROLLWIN_THUMBTRACK) ||
+        (event.GetEventType() == wxEVT_SCROLLWIN_THUMBRELEASE))
+    {
             if (orient == wxHORIZONTAL)
                 nScrollInc = pos - m_xScrollPosition;
             else
                 nScrollInc = pos - m_yScrollPosition;
-            break;
-        }
-        default:
-        {
-            break;
-        }
     }
 
     if (orient == wxHORIZONTAL)
@@ -375,7 +385,7 @@ int wxScrolledWindow::CalcScrollInc(wxScrollWinEvent& event)
 }
 
 // Adjust the scrollbars - new version.
-void wxScrolledWindow::AdjustScrollbars()
+void wxGenericScrolledWindow::AdjustScrollbars()
 {
     int w, h;
     m_targetWindow->GetClientSize(&w, &h);
@@ -385,14 +395,14 @@ void wxScrolledWindow::AdjustScrollbars()
 
     if (m_xScrollLines > 0)
     {
-            // Calculate page size i.e. number of scroll units you get on the
-            // current client window
+        // Calculate page size i.e. number of scroll units you get on the
+        // current client window
         int noPagePositions = (int) ( (w/(double)m_xScrollPixelsPerLine) + 0.5 );
         if (noPagePositions < 1) noPagePositions = 1;
 
         // Correct position if greater than extent of canvas minus
-            // the visible portion of it or if below zero
-            m_xScrollPosition = wxMin( m_xScrollLines-noPagePositions, m_xScrollPosition);
+        // the visible portion of it or if below zero
+        m_xScrollPosition = wxMin( m_xScrollLines-noPagePositions, m_xScrollPosition);
         m_xScrollPosition = wxMax( 0, m_xScrollPosition );
 
         SetScrollbar(wxHORIZONTAL, m_xScrollPosition, noPagePositions, m_xScrollLines);
@@ -407,13 +417,13 @@ void wxScrolledWindow::AdjustScrollbars()
 
     if (m_yScrollLines > 0)
     {
-            // Calculate page size i.e. number of scroll units you get on the
-            // current client window
+        // Calculate page size i.e. number of scroll units you get on the
+        // current client window
         int noPagePositions = (int) ( (h/(double)m_yScrollPixelsPerLine) + 0.5 );
         if (noPagePositions < 1) noPagePositions = 1;
 
         // Correct position if greater than extent of canvas minus
-            // the visible portion of it or if below zero
+        // the visible portion of it or if below zero
         m_yScrollPosition = wxMin( m_yScrollLines-noPagePositions, m_yScrollPosition );
         m_yScrollPosition = wxMax( 0, m_yScrollPosition );
 
@@ -444,9 +454,9 @@ void wxScrolledWindow::AdjustScrollbars()
     }
 }
 
-// Override this function if you don't want to have wxScrolledWindow
+// Override this function if you don't want to have wxGenericScrolledWindow
 // automatically change the origin according to the scroll position.
-void wxScrolledWindow::PrepareDC(wxDC& dc)
+void wxGenericScrolledWindow::PrepareDC(wxDC& dc)
 {
     dc.SetDeviceOrigin( -m_xScrollPosition * m_xScrollPixelsPerLine,
                         -m_yScrollPosition * m_yScrollPixelsPerLine );
@@ -454,13 +464,13 @@ void wxScrolledWindow::PrepareDC(wxDC& dc)
 }
 
 #if WXWIN_COMPATIBILITY
-void wxScrolledWindow::GetScrollUnitsPerPage (int *x_page, int *y_page) const
+void wxGenericScrolledWindow::GetScrollUnitsPerPage (int *x_page, int *y_page) const
 {
       *x_page = GetScrollPageSize(wxHORIZONTAL);
       *y_page = GetScrollPageSize(wxVERTICAL);
 }
 
-void wxScrolledWindow::CalcUnscrolledPosition(int x, int y, float *xx, float *yy) const
+void wxGenericScrolledWindow::CalcUnscrolledPosition(int x, int y, float *xx, float *yy) const
 {
     if ( xx )
         *xx = (float)(x + m_xScrollPosition * m_xScrollPixelsPerLine);
@@ -469,7 +479,7 @@ void wxScrolledWindow::CalcUnscrolledPosition(int x, int y, float *xx, float *yy
 }
 #endif // WXWIN_COMPATIBILITY
 
-void wxScrolledWindow::GetScrollPixelsPerUnit (int *x_unit, int *y_unit) const
+void wxGenericScrolledWindow::GetScrollPixelsPerUnit (int *x_unit, int *y_unit) const
 {
     if ( x_unit )
         *x_unit = m_xScrollPixelsPerLine;
@@ -477,7 +487,7 @@ void wxScrolledWindow::GetScrollPixelsPerUnit (int *x_unit, int *y_unit) const
         *y_unit = m_yScrollPixelsPerLine;
 }
 
-int wxScrolledWindow::GetScrollPageSize(int orient) const
+int wxGenericScrolledWindow::GetScrollPageSize(int orient) const
 {
     if ( orient == wxHORIZONTAL )
         return m_xScrollLinesPerPage;
@@ -485,7 +495,7 @@ int wxScrolledWindow::GetScrollPageSize(int orient) const
         return m_yScrollLinesPerPage;
 }
 
-void wxScrolledWindow::SetScrollPageSize(int orient, int pageSize)
+void wxGenericScrolledWindow::SetScrollPageSize(int orient, int pageSize)
 {
     if ( orient == wxHORIZONTAL )
         m_xScrollLinesPerPage = pageSize;
@@ -496,66 +506,70 @@ void wxScrolledWindow::SetScrollPageSize(int orient, int pageSize)
 /*
  * Scroll to given position (scroll position, not pixel position)
  */
-void wxScrolledWindow::Scroll( int x_pos, int y_pos )
+void wxGenericScrolledWindow::Scroll( int x_pos, int y_pos )
 {
+    if (!m_targetWindow)
+        return;
+
     if (((x_pos == -1) || (x_pos == m_xScrollPosition)) &&
         ((y_pos == -1) || (y_pos == m_yScrollPosition))) return;
 
     int w, h;
     m_targetWindow->GetClientSize(&w, &h);
 
-    if (x_pos != -1)
+    if ((x_pos != -1) && (m_xScrollPixelsPerLine))
     {
         int old_x = m_xScrollPosition;
         m_xScrollPosition = x_pos;
 
-            // Calculate page size i.e. number of scroll units you get on the
-            // current client window
+        // Calculate page size i.e. number of scroll units you get on the
+        // current client window
         int noPagePositions = (int) ( (w/(double)m_xScrollPixelsPerLine) + 0.5 );
         if (noPagePositions < 1) noPagePositions = 1;
 
         // Correct position if greater than extent of canvas minus
-            // the visible portion of it or if below zero
+        // the visible portion of it or if below zero
         m_xScrollPosition = wxMin( m_xScrollLines-noPagePositions, m_xScrollPosition );
         m_xScrollPosition = wxMax( 0, m_xScrollPosition );
 
-        m_targetWindow->SetScrollPos( wxHORIZONTAL, m_xScrollPosition, TRUE );
-
+        if (old_x != m_xScrollPosition) {
+            m_targetWindow->SetScrollPos( wxHORIZONTAL, m_xScrollPosition, TRUE );
             m_targetWindow->ScrollWindow( (old_x-m_xScrollPosition)*m_xScrollPixelsPerLine, 0 );
+        }
     }
-    if (y_pos != -1)
+    if ((y_pos != -1) && (m_yScrollPixelsPerLine))
     {
         int old_y = m_yScrollPosition;
         m_yScrollPosition = y_pos;
 
-            // Calculate page size i.e. number of scroll units you get on the
-            // current client window
+        // Calculate page size i.e. number of scroll units you get on the
+        // current client window
         int noPagePositions = (int) ( (h/(double)m_yScrollPixelsPerLine) + 0.5 );
         if (noPagePositions < 1) noPagePositions = 1;
 
         // Correct position if greater than extent of canvas minus
-            // the visible portion of it or if below zero
+        // the visible portion of it or if below zero
         m_yScrollPosition = wxMin( m_yScrollLines-noPagePositions, m_yScrollPosition );
         m_yScrollPosition = wxMax( 0, m_yScrollPosition );
 
-        m_targetWindow->SetScrollPos( wxVERTICAL, m_yScrollPosition, TRUE );
-
-        m_targetWindow->ScrollWindow( 0, (old_y-m_yScrollPosition)*m_yScrollPixelsPerLine );
+        if (old_y != m_yScrollPosition) {
+            m_targetWindow->SetScrollPos( wxVERTICAL, m_yScrollPosition, TRUE );
+            m_targetWindow->ScrollWindow( 0, (old_y-m_yScrollPosition)*m_yScrollPixelsPerLine );
+        }
     }
 
-
 #ifdef __WXMAC__
-    m_targetWindow->MacUpdateImmediately() ;
+    m_targetWindow->MacUpdateImmediately();
 #endif
 }
 
-void wxScrolledWindow::EnableScrolling (bool x_scroll, bool y_scroll)
+void wxGenericScrolledWindow::EnableScrolling (bool x_scroll, bool y_scroll)
 {
     m_xScrollingEnabled = x_scroll;
     m_yScrollingEnabled = y_scroll;
 }
 
-void wxScrolledWindow::GetVirtualSize (int *x, int *y) const
+void wxGenericScrolledWindow::GetVirtualSize (int *x, int *y) const
 {
     if ( x )
         *x = m_xScrollPixelsPerLine * m_xScrollLines;
@@ -564,7 +578,7 @@ void wxScrolledWindow::GetVirtualSize (int *x, int *y) const
 }
 
 // Where the current view starts from
-void wxScrolledWindow::GetViewStart (int *x, int *y) const
+void wxGenericScrolledWindow::GetViewStart (int *x, int *y) const
 {
     if ( x )
         *x = m_xScrollPosition;
@@ -572,7 +586,7 @@ void wxScrolledWindow::GetViewStart (int *x, int *y) const
         *y = m_yScrollPosition;
 }
 
-void wxScrolledWindow::CalcScrolledPosition(int x, int y, int *xx, int *yy) const
+void wxGenericScrolledWindow::CalcScrolledPosition(int x, int y, int *xx, int *yy) const
 {
     if ( xx )
         *xx = x - m_xScrollPosition * m_xScrollPixelsPerLine;
@@ -580,7 +594,7 @@ void wxScrolledWindow::CalcScrolledPosition(int x, int y, int *xx, int *yy) cons
         *yy = y - m_yScrollPosition * m_yScrollPixelsPerLine;
 }
 
-void wxScrolledWindow::CalcUnscrolledPosition(int x, int y, int *xx, int *yy) const
+void wxGenericScrolledWindow::CalcUnscrolledPosition(int x, int y, int *xx, int *yy) const
 {
     if ( xx )
         *xx = x + m_xScrollPosition * m_xScrollPixelsPerLine;
@@ -593,7 +607,7 @@ void wxScrolledWindow::CalcUnscrolledPosition(int x, int y, int *xx, int *yy) co
 // ----------------------------------------------------------------------------
 
 // Default OnSize resets scrollbars, if any
-void wxScrolledWindow::OnSize(wxSizeEvent& WXUNUSED(event))
+void wxGenericScrolledWindow::OnSize(wxSizeEvent& WXUNUSED(event))
 {
 #if wxUSE_CONSTRAINTS
     if (GetAutoLayout())
@@ -605,7 +619,7 @@ void wxScrolledWindow::OnSize(wxSizeEvent& WXUNUSED(event))
 
 // This calls OnDraw, having adjusted the origin according to the current
 // scroll position
-void wxScrolledWindow::OnPaint(wxPaintEvent& WXUNUSED(event))
+void wxGenericScrolledWindow::OnPaint(wxPaintEvent& WXUNUSED(event))
 {
     wxPaintDC dc(this);
     PrepareDC(dc);
@@ -613,8 +627,11 @@ void wxScrolledWindow::OnPaint(wxPaintEvent& WXUNUSED(event))
     OnDraw(dc);
 }
 
-// kbd handling
-void wxScrolledWindow::OnKeyDown(wxKeyEvent& event)
+// kbd handling: notice that we use OnChar() and not OnKeyDown() for
+// compatibility here - if we used OnKeyDown(), the programs which process
+// arrows themselves in their OnChar() would never get the message and like
+// this they always have the priority
+void wxGenericScrolledWindow::OnChar(wxKeyEvent& event)
 {
     int stx, sty,       // view origin
         szx, szy,       // view size (total)
@@ -622,17 +639,36 @@ void wxScrolledWindow::OnKeyDown(wxKeyEvent& event)
 
     ViewStart(&stx, &sty);
     GetClientSize(&clix, &cliy);
-    clix /= m_xScrollPixelsPerLine;
-    cliy /= m_yScrollPixelsPerLine;
     GetVirtualSize(&szx, &szy);
-    szx /= m_xScrollPixelsPerLine;
-    szy /= m_yScrollPixelsPerLine;
 
+    if( m_xScrollPixelsPerLine )
+    {
+        clix /= m_xScrollPixelsPerLine;
+        szx /= m_xScrollPixelsPerLine;
+    }
+    else
+    {
+        clix = 0;
+        szx = -1;
+    }
+    if( m_yScrollPixelsPerLine )
+    {
+        cliy /= m_yScrollPixelsPerLine;
+        szy /= m_yScrollPixelsPerLine;
+    }
+    else
+    {
+        cliy = 0;
+        szy = -1;
+    }
+
+    int dsty;
     switch ( event.KeyCode() )
     {
         case WXK_PAGEUP:
         case WXK_PRIOR:
-            Scroll(-1, sty - (5 * cliy / 6));
+            dsty = sty - (5 * cliy / 6);
+            Scroll(-1, (dsty == -1) ? 0 : dsty);
             break;
 
         case WXK_PAGEDOWN:
@@ -640,16 +676,12 @@ void wxScrolledWindow::OnKeyDown(wxKeyEvent& event)
             Scroll(-1, sty + (5 * cliy / 6));
             break;
 
-        // notice that handling of Ctrl-Home/End is asymmetrical: Home goes to
-        // the beginning of the current line, Ctrl-Home returns to the origin
-        // while End goes to the bottom without changing horizontal position
-        // and only Ctrl-End does go to the most rightmost position as well
         case WXK_HOME:
             Scroll(0, event.ControlDown() ? 0 : -1);
             break;
 
         case WXK_END:
-            Scroll(event.ControlDown() ? szx - clix : -1, szy - cliy);
+            Scroll(szx - clix, event.ControlDown() ? szy - cliy : -1);
             break;
 
         case WXK_UP:
@@ -673,3 +705,24 @@ void wxScrolledWindow::OnKeyDown(wxKeyEvent& event)
             event.Skip();
     }
 }
+
+
+void wxGenericScrolledWindow::OnMouseWheel(wxMouseEvent& event)
+{
+    int lines;
+    int vsx, vsy;
+
+    m_wheelRotation += event.GetWheelRotation();
+    lines = m_wheelRotation / event.GetWheelDelta();
+    m_wheelRotation -= lines * event.GetWheelDelta();
+
+    if (lines != 0) {
+        lines *= event.GetLinesPerAction();
+        GetViewStart(&vsx, &vsy);
+        Scroll(-1, vsy - lines);
+    }
+}
+
+
+
+