]> git.saurik.com Git - wxWidgets.git/blobdiff - src/generic/splitter.cpp
added renderer.h/.cpp
[wxWidgets.git] / src / generic / splitter.cpp
index 6208dfff2f242b90f4062fd4cca08ee49231f94e..6c5965e49aba1355fda8709a7b37f30a9096c383 100644 (file)
@@ -1,12 +1,12 @@
 /////////////////////////////////////////////////////////////////////////////
-// Name:        splitter.cpp
+// Name:        src/generic/splitter.cpp
 // Purpose:     wxSplitterWindow implementation
 // Author:      Julian Smart
 // Modified by:
 // Created:     01/02/97
 // RCS-ID:      $Id$
-// Copyright:   (c) Julian Smart and Markus Holzem
-// Licence:     wxWindows license
+// Copyright:   (c) Julian Smart
+// Licence:     wxWindows licence
 /////////////////////////////////////////////////////////////////////////////
 
 #ifdef __GNUG__
 // For compilers that support precompilation, includes "wx.h".
 #include "wx/wxprec.h"
 
+#if wxUSE_SPLITTER
 #ifdef __BORLANDC__
     #pragma hdrstop
 #endif
 
 #ifndef WX_PRECOMP
+    #include "wx/string.h"
+    #include "wx/utils.h"
+    #include "wx/log.h"
+
+    #include "wx/dcscreen.h"
+
     #include "wx/window.h"
     #include "wx/dialog.h"
     #include "wx/frame.h"
-#endif
 
-#include <stdlib.h>
+    #include "wx/settings.h"
+#endif
 
-#include "wx/string.h"
 #include "wx/splitter.h"
-#include "wx/dcscreen.h"
-#include "wx/settings.h"
-#include "wx/log.h"
-#include "wx/utils.h"
+
+#include <stdlib.h>
 
 DEFINE_EVENT_TYPE(wxEVT_COMMAND_SPLITTER_SASH_POS_CHANGED)
 DEFINE_EVENT_TYPE(wxEVT_COMMAND_SPLITTER_SASH_POS_CHANGING)
@@ -41,22 +45,16 @@ DEFINE_EVENT_TYPE(wxEVT_COMMAND_SPLITTER_DOUBLECLICKED)
 DEFINE_EVENT_TYPE(wxEVT_COMMAND_SPLITTER_UNSPLIT)
 
 IMPLEMENT_DYNAMIC_CLASS(wxSplitterWindow, wxWindow)
-IMPLEMENT_DYNAMIC_CLASS(wxSplitterEvent, wxCommandEvent)
+IMPLEMENT_DYNAMIC_CLASS(wxSplitterEvent, wxNotifyEvent)
 
 BEGIN_EVENT_TABLE(wxSplitterWindow, wxWindow)
     EVT_PAINT(wxSplitterWindow::OnPaint)
     EVT_SIZE(wxSplitterWindow::OnSize)
-    EVT_IDLE(wxSplitterWindow::OnIdle)
     EVT_MOUSE_EVENTS(wxSplitterWindow::OnMouseEvent)
 
+#if defined( __WXMSW__ ) || defined( __WXMAC__)
     EVT_SET_CURSOR(wxSplitterWindow::OnSetCursor)
-
-    EVT_SPLITTER_SASH_POS_CHANGED(-1, wxSplitterWindow::OnSashPosChanged)
-    // NB: we borrow OnSashPosChanged for purposes of
-    // EVT_SPLITTER_SASH_POS_CHANGING since default implementation is identical
-    EVT_SPLITTER_SASH_POS_CHANGING(-1, wxSplitterWindow::OnSashPosChanged)
-    EVT_SPLITTER_DCLICK(-1,           wxSplitterWindow::OnDoubleClick)
-    EVT_SPLITTER_UNSPLIT(-1,          wxSplitterWindow::OnUnsplitEvent)
+#endif // wxMSW
 
     WX_EVENT_TABLE_CONTROL_CONTAINER(wxSplitterWindow)
 END_EVENT_TABLE()
@@ -112,12 +110,12 @@ void wxSplitterWindow::Init()
     m_oldY = 0;
     m_firstX = 0;
     m_firstY = 0;
-    m_sashSize = 7;
-    m_borderSize = 2;
-    m_sashPosition = 0;
+    m_sashSize = 3;
+    m_borderSize = 0;
+    m_sashPosition = m_requestedSashPosition = 0;
     m_minimumPaneSize = 0;
-    m_sashCursorWE = new wxCursor(wxCURSOR_SIZEWE);
-    m_sashCursorNS = new wxCursor(wxCURSOR_SIZENS);
+    m_sashCursorWE = wxCursor(wxCURSOR_SIZEWE);
+    m_sashCursorNS = wxCursor(wxCURSOR_SIZENS);
     m_sashTrackerPen = new wxPen(*wxBLACK, 2, wxSOLID);
     m_lightShadowPen = (wxPen *) NULL;
     m_mediumShadowPen = (wxPen *) NULL;
@@ -126,9 +124,6 @@ void wxSplitterWindow::Init()
     m_facePen = (wxPen *) NULL;
     m_hilightPen = (wxPen *) NULL;
 
-    m_borderSize = 0;
-    m_sashSize = 3;
-
     InitColours();
 
     m_needUpdating = FALSE;
@@ -136,8 +131,6 @@ void wxSplitterWindow::Init()
 
 wxSplitterWindow::~wxSplitterWindow()
 {
-    delete m_sashCursorWE;
-    delete m_sashCursorNS;
     delete m_sashTrackerPen;
     delete m_lightShadowPen;
     delete m_darkShadowPen;
@@ -147,6 +140,12 @@ wxSplitterWindow::~wxSplitterWindow()
     delete m_faceBrush;
 }
 
+void wxSplitterWindow::SetResizeCursor()
+{
+    SetCursor(m_splitMode == wxSPLIT_VERTICAL ? m_sashCursorWE
+                                              : m_sashCursorNS);
+}
+
 void wxSplitterWindow::OnPaint(wxPaintEvent& WXUNUSED(event))
 {
     wxPaintDC dc(this);
@@ -156,12 +155,12 @@ void wxSplitterWindow::OnPaint(wxPaintEvent& WXUNUSED(event))
     DrawSash(dc);
 }
 
-void wxSplitterWindow::OnIdle(wxIdleEvent& event)
+void wxSplitterWindow::OnInternalIdle()
 {
+    wxWindow::OnInternalIdle();
+    
     if (m_needUpdating)
         SizeWindows();
-
-    event.Skip();
 }
 
 void wxSplitterWindow::OnMouseEvent(wxMouseEvent& event)
@@ -169,41 +168,43 @@ void wxSplitterWindow::OnMouseEvent(wxMouseEvent& event)
     int x = (int)event.GetX(),
         y = (int)event.GetY();
 
-    // reset the cursor
-#ifdef __WXMOTIF__
-    SetCursor(* wxSTANDARD_CURSOR);
-#endif
-#ifdef __WXMSW__
-    SetCursor(wxCursor());
+#if defined(__WXMSW__)
+    // SetCursor(wxCursor());   // Is this required?
 #endif
 
     if (GetWindowStyle() & wxSP_NOSASH)
         return;
 
+    // with wxSP_LIVE_UPDATE style the splitter windows are always resized
+    // following the mouse movement while it drags the sash, without it we only
+    // draw the sash at the new position but only resize the windows when the
+    // dragging is finished
+    bool isLive = (GetWindowStyleFlag() & wxSP_LIVE_UPDATE) != 0;
+
     if (event.LeftDown())
     {
         if ( SashHitTest(x, y) )
         {
-            CaptureMouse();
-
+            // Start the drag now
             m_dragMode = wxSPLIT_DRAG_DRAGGING;
+            
+            // Capture mouse and set the cursor
+            CaptureMouse();
+            SetResizeCursor();
 
-            if ((GetWindowStyleFlag() & wxSP_LIVE_UPDATE) == 0)
+            if ( !isLive )
             {
+                // remember the initial sash position and draw the initial
+                // shadow sash
+                m_sashPositionCurrent = m_sashPosition;
+
                 DrawSashTracker(x, y);
             }
 
             m_oldX = x;
             m_oldY = y;
 
-            if ( m_splitMode == wxSPLIT_VERTICAL )
-            {
-                SetCursor(*m_sashCursorWE);
-            }
-            else
-            {
-                SetCursor(*m_sashCursorNS);
-            }
+            SetResizeCursor();
             return;
         }
     }
@@ -211,136 +212,116 @@ void wxSplitterWindow::OnMouseEvent(wxMouseEvent& event)
     {
         // We can stop dragging now and see what we've got.
         m_dragMode = wxSPLIT_DRAG_NONE;
+        
+        // Release mouse and unset the cursor
         ReleaseMouse();
+        SetCursor(* wxSTANDARD_CURSOR);
+
+        // exit if unsplit after doubleclick
+        if ( !IsSplit() )
+        {
+            return;
+        }
 
         // Erase old tracker
-        if ((GetWindowStyleFlag() & wxSP_LIVE_UPDATE) == 0)
+        if ( !isLive )
         {
             DrawSashTracker(m_oldX, m_oldY);
         }
 
-        // Obtain window size. We are only interested in the dimension the sash
-        // splits up
-        int window_size = GetWindowSize();
-        int new_sash_position = m_splitMode == wxSPLIT_VERTICAL ? x : y;
+        // the position of the click doesn't exactly correspond to
+        // m_sashPosition, rather it changes it by the distance by which the
+        // mouse has moved
+        int diff = m_splitMode == wxSPLIT_VERTICAL ? x - m_oldX : y - m_oldY;
 
-        wxSplitterEvent eventSplitter(wxEVT_COMMAND_SPLITTER_SASH_POS_CHANGED,
-                                      this);
-        eventSplitter.m_data.pos = new_sash_position;
-        if ( GetEventHandler()->ProcessEvent(eventSplitter) )
+        int posSashOld = isLive ? m_sashPosition : m_sashPositionCurrent;
+        int posSashNew = OnSashPositionChanging(posSashOld + diff);
+        if ( posSashNew == -1 )
         {
-            new_sash_position = eventSplitter.GetSashPosition();
-            if ( new_sash_position == -1 )
-            {
-                // change not allowed
-                return;
-            }
+            // change not allowed
+            return;
         }
 
         if ( m_permitUnsplitAlways || m_minimumPaneSize == 0 )
         {
             // Deal with possible unsplit scenarios
-            if ( new_sash_position == 0 )
+            if ( posSashNew == 0 )
             {
                 // We remove the first window from the view
                 wxWindow *removedWindow = m_windowOne;
                 m_windowOne = m_windowTwo;
                 m_windowTwo = (wxWindow *) NULL;
-                SendUnsplitEvent(removedWindow);
-                m_sashPosition = 0;
+                OnUnsplit(removedWindow);
+                wxSplitterEvent event(wxEVT_COMMAND_SPLITTER_UNSPLIT, this);
+                event.m_data.win = removedWindow;
+                (void)DoSendEvent(event);
+                SetSashPositionAndNotify(0);
             }
-            else if ( new_sash_position == window_size )
+            else if ( posSashNew == GetWindowSize() )
             {
                 // We remove the second window from the view
                 wxWindow *removedWindow = m_windowTwo;
                 m_windowTwo = (wxWindow *) NULL;
-                SendUnsplitEvent(removedWindow);
-                m_sashPosition = 0;
+                OnUnsplit(removedWindow);
+                wxSplitterEvent event(wxEVT_COMMAND_SPLITTER_UNSPLIT, this);
+                event.m_data.win = removedWindow;
+                (void)DoSendEvent(event);
+                SetSashPositionAndNotify(0);
             }
             else
             {
-                m_sashPosition = new_sash_position;
+                SetSashPositionAndNotify(posSashNew);
             }
         }
         else
         {
-            m_sashPosition = new_sash_position;
+            SetSashPositionAndNotify(posSashNew);
         }
 
         SizeWindows();
     }  // left up && dragging
-    else if (event.Moving() && !event.Dragging())
+    else if ((event.Moving() || event.Leaving() || event.Entering()) && (m_dragMode == wxSPLIT_DRAG_NONE))
     {
-        // Just change the cursor if required
-        if ( SashHitTest(x, y) )
+        // Just change the cursor as required
+        if ( !event.Leaving() && SashHitTest(x, y) )
         {
-                if ( m_splitMode == wxSPLIT_VERTICAL )
-                {
-                    SetCursor(*m_sashCursorWE);
-                }
-                else
-                {
-                    SetCursor(*m_sashCursorNS);
-                }
+            SetResizeCursor();
         }
-#if defined(__WXGTK__) || defined(__WXMSW__)
         else
         {
-            // We must set the normal cursor in MSW, because
-            // if the child window doesn't have a cursor, the
-            // parent's (splitter window) will be used, and this
-            // must be the standard cursor.
-
-            // where else do we unset the cursor?
             SetCursor(* wxSTANDARD_CURSOR);
         }
-#endif // __WXGTK__
     }
     else if (event.Dragging() && (m_dragMode == wxSPLIT_DRAG_DRAGGING))
     {
-#ifdef __WXMSW__
-        // Otherwise, the cursor sometimes reverts to the normal cursor
-        // during dragging.
-        if ( m_splitMode == wxSPLIT_VERTICAL )
-        {
-            SetCursor(*m_sashCursorWE);
-        }
-        else
+        int diff = m_splitMode == wxSPLIT_VERTICAL ? x - m_oldX : y - m_oldY;
+        if ( !diff )
         {
-            SetCursor(*m_sashCursorNS);
+            // nothing to do, mouse didn't really move far enough
+            return;
         }
-#endif
 
-        // Obtain window size. We are only interested in the dimension the sash
-        // splits up
-        int new_sash_position = m_splitMode == wxSPLIT_VERTICAL ? x : y;
-
-        wxSplitterEvent eventSplitter(wxEVT_COMMAND_SPLITTER_SASH_POS_CHANGING,
-                                      this);
-        eventSplitter.m_data.pos = new_sash_position;
-        if ( GetEventHandler()->ProcessEvent(eventSplitter) )
+        int posSashOld = isLive ? m_sashPosition : m_sashPositionCurrent;
+        int posSashNew = OnSashPositionChanging(posSashOld + diff);
+        if ( posSashNew == -1 )
         {
-            new_sash_position = eventSplitter.GetSashPosition();
-            if ( new_sash_position == -1 )
-            {
-                // change not allowed
-                return;
-            }
+            // change not allowed
+            return;
         }
 
-        if (new_sash_position == m_sashPosition)
+        if ( posSashNew == m_sashPosition )
             return;
 
         // Erase old tracker
-        if ((GetWindowStyleFlag() & wxSP_LIVE_UPDATE) == 0)
+        if ( !isLive )
         {
             DrawSashTracker(m_oldX, m_oldY);
         }
 
         if (m_splitMode == wxSPLIT_VERTICAL)
-            x = new_sash_position;
+            x = posSashNew;
         else
-            y = new_sash_position;
+            y = posSashNew;
 
         // Remember old positions
         m_oldX = x;
@@ -360,24 +341,21 @@ void wxSplitterWindow::OnMouseEvent(wxMouseEvent& event)
 #endif // __WXMSW__
 
         // Draw new one
-        if ((GetWindowStyleFlag() & wxSP_LIVE_UPDATE) == 0)
+        if ( !isLive )
         {
+            m_sashPositionCurrent = posSashNew;
+
             DrawSashTracker(m_oldX, m_oldY);
         }
         else
         {
-            m_sashPosition = new_sash_position;
+            SetSashPositionAndNotify(posSashNew);
             m_needUpdating = TRUE;
         }
     }
-    else if ( event.LeftDClick() )
+    else if ( event.LeftDClick() && m_windowTwo )
     {
-        wxSplitterEvent eventSplitter(wxEVT_COMMAND_SPLITTER_DOUBLECLICKED,
-                                      this);
-        eventSplitter.m_data.pt.x = x;
-        eventSplitter.m_data.pt.y = y;
-
-        (void)GetEventHandler()->ProcessEvent(eventSplitter);
+        OnDoubleClickSash(x, y);
     }
 }
 
@@ -392,19 +370,26 @@ void wxSplitterWindow::OnSize(wxSizeEvent& event)
         parent = parent->GetParent();
     }
 
-    bool iconized;
+    bool iconized = FALSE;
 
+    // wxMotif doesn't yet have a wxTopLevelWindow implementation
+#ifdef __WXMOTIF__
+    wxFrame *winTop = wxDynamicCast(parent, wxFrame);
+#else
     wxTopLevelWindow *winTop = wxDynamicCast(parent, wxTopLevelWindow);
+#endif
     if ( winTop )
     {
         iconized = winTop->IsIconized();
     }
+#ifndef __WXMOTIF__
     else
     {
         wxFAIL_MSG(wxT("should have a top level parent!"));
 
         iconized = FALSE;
     }
+#endif
 
     if ( iconized )
     {
@@ -420,12 +405,12 @@ void wxSplitterWindow::OnSize(wxSizeEvent& event)
         if ( m_splitMode == wxSPLIT_VERTICAL )
         {
             if ( m_sashPosition >= (cw - 5) )
-                m_sashPosition = wxMax(10, cw - 40);
+                SetSashPositionAndNotify(wxMax(10, cw - 40));
         }
         else // m_splitMode == wxSPLIT_HORIZONTAL
         {
             if ( m_sashPosition >= (ch - 5) )
-                m_sashPosition = wxMax(10, ch - 40);
+                SetSashPositionAndNotify(wxMax(10, ch - 40));
         }
     }
 
@@ -553,7 +538,7 @@ void wxSplitterWindow::DrawSash(wxDC& dc)
                 dc.DrawLine(m_sashPosition+1, h-m_borderSize-1, m_sashPosition+m_sashSize-1, h-m_borderSize-1);
             }
         }
-        else
+        else // wxSPLIT_HORIZONTAL
         {
             dc.SetPen(*m_facePen);
             if (HasFlag( wxSP_SASH_AQUA ))
@@ -593,12 +578,12 @@ void wxSplitterWindow::DrawSash(wxDC& dc)
             }
         }
     }
-    else
+    else // !wxSP_3DSASH
     {
+        dc.SetPen(*wxTRANSPARENT_PEN);
+        dc.SetBrush(*m_faceBrush);
         if ( m_splitMode == wxSPLIT_VERTICAL )
         {
-            dc.SetPen(*wxBLACK_PEN);
-            dc.SetBrush(*wxBLACK_BRUSH);
             int h1 = h-1;
             int y1 = 0;
             if ( (GetWindowStyleFlag() & wxSP_BORDER) != wxSP_BORDER && (GetWindowStyleFlag() & wxSP_3DBORDER) != wxSP_3DBORDER )
@@ -609,10 +594,8 @@ void wxSplitterWindow::DrawSash(wxDC& dc)
             }
             dc.DrawRectangle(m_sashPosition, y1, m_sashSize, h1);
         }
-        else
+        else // wxSPLIT_HORIZONTAL
         {
-            dc.SetPen(*wxBLACK_PEN);
-            dc.SetBrush(*wxBLACK_BRUSH);
             int w1 = w-1;
             int x1 = 0;
             if ( (GetWindowStyleFlag() & wxSP_BORDER) != wxSP_BORDER && (GetWindowStyleFlag() & wxSP_3DBORDER) != wxSP_3DBORDER )
@@ -623,7 +606,6 @@ void wxSplitterWindow::DrawSash(wxDC& dc)
             }
             dc.DrawRectangle(x1, m_sashPosition, w1, m_sashSize);
         }
-
     }
 
     dc.SetPen(wxNullPen);
@@ -697,14 +679,6 @@ int wxSplitterWindow::AdjustSashPosition(int sashPos) const
 {
     int window_size = GetWindowSize();
 
-    if ( !window_size )
-    {
-        // don't do anything before the window has a valid size, otherwise we
-        // put the sash to 0 at the very beginning and it doesn't move from
-        // there any more
-        return sashPos;
-    }
-
     wxWindow *win;
 
     win = GetWindow1();
@@ -741,18 +715,58 @@ int wxSplitterWindow::AdjustSashPosition(int sashPos) const
     return sashPos;
 }
 
+bool wxSplitterWindow::DoSetSashPosition(int sashPos)
+{
+    int newSashPosition = AdjustSashPosition(sashPos);
+
+    if ( newSashPosition == m_sashPosition )
+        return FALSE;
+
+    m_sashPosition = newSashPosition;
+
+    return TRUE;
+}
+
+void wxSplitterWindow::SetSashPositionAndNotify(int sashPos)
+{
+    if ( DoSetSashPosition(sashPos) )
+    {
+        wxSplitterEvent event(wxEVT_COMMAND_SPLITTER_SASH_POS_CHANGED, this);
+        event.m_data.pos = m_sashPosition;
+
+        (void)DoSendEvent(event);
+    }
+}
+
 // Position and size subwindows.
 // Note that the border size applies to each subwindow, not
 // including the edges next to the sash.
 void wxSplitterWindow::SizeWindows()
 {
+    // check if we have delayed setting the real sash position
+    if ( m_requestedSashPosition != INT_MAX )
+    {
+        int newSashPosition = ConvertSashPosition(m_requestedSashPosition);
+        if ( newSashPosition != m_sashPosition )
+        {
+            DoSetSashPosition(newSashPosition);
+        }
+
+        if ( newSashPosition <= m_sashPosition
+            && newSashPosition >= m_sashPosition - GetBorderSize() )
+        {
+            // don't update it any more
+            m_requestedSashPosition = INT_MAX;
+        }
+    }
+
     int w, h;
     GetClientSize(&w, &h);
 
     if ( GetWindow1() && !GetWindow2() )
     {
-        GetWindow1()->SetSize(GetBorderSize(), GetBorderSize(), w - 2*GetBorderSize(), h - 2*GetBorderSize());
-
+        GetWindow1()->SetSize(GetBorderSize(), GetBorderSize(),
+                              w - 2*GetBorderSize(), h - 2*GetBorderSize());
     }
     else if ( GetWindow1() && GetWindow2() )
     {
@@ -790,9 +804,12 @@ void wxSplitterWindow::SizeWindows()
 // Set pane for unsplit window
 void wxSplitterWindow::Initialize(wxWindow *window)
 {
+    wxASSERT_MSG( window && window->GetParent() == this,
+                  _T("windows in the splitter should have it as parent!") );
+
     m_windowOne = window;
     m_windowTwo = (wxWindow *) NULL;
-    m_sashPosition = 0;
+    DoSetSashPosition(0);
 }
 
 // Associates the given window with window 2, drawing the appropriate sash
@@ -805,38 +822,43 @@ bool wxSplitterWindow::DoSplit(wxSplitMode mode,
     if ( IsSplit() )
         return FALSE;
 
-    int window_size = GetWindowSize();
+    wxCHECK_MSG( window1 && window2, FALSE,
+                 _T("can not split with NULL window(s)") );
+
+    wxCHECK_MSG( window1->GetParent() == this && window2->GetParent() == this, FALSE,
+                  _T("windows in the splitter should have it as parent!") );
 
     m_splitMode = mode;
     m_windowOne = window1;
     m_windowTwo = window2;
 
+    // remember the sash position we want to set for later if we can't set it
+    // right now (e.g. because the window is too small)
+    m_requestedSashPosition = sashPosition;
+
+    DoSetSashPosition(ConvertSashPosition(sashPosition));
+
+    SizeWindows();
+
+    return TRUE;
+}
+
+int wxSplitterWindow::ConvertSashPosition(int sashPosition) const
+{
     if ( sashPosition > 0 )
     {
-        m_sashPosition = sashPosition;
+        return sashPosition;
     }
     else if ( sashPosition < 0 )
     {
         // It's negative so adding is subtracting
-        m_sashPosition = window_size + sashPosition;
-    }
-    else
-    {
-        // default
-        m_sashPosition = window_size/2;
+        return GetWindowSize() + sashPosition;
     }
-
-    // don't do it initially, i.e. when creating the window because it doesn't
-    // have a proper size yet and AdjustSashPosition() would happily set the
-    // sash position to 0!
-    if ( window_size > 0 )
+    else // sashPosition == 0
     {
-        m_sashPosition = AdjustSashPosition(m_sashPosition);
+        // default, put it in the centre
+        return GetWindowSize() / 2;
     }
-
-    SizeWindows();
-
-    return TRUE;
 }
 
 // Remove the specified (or second) window from the view
@@ -865,8 +887,8 @@ bool wxSplitterWindow::Unsplit(wxWindow *toRemove)
         return FALSE;
     }
 
-    SendUnsplitEvent(win);
-    m_sashPosition = 0;
+    OnUnsplit(win);
+    DoSetSashPosition(0);
     SizeWindows();
 
     return TRUE;
@@ -898,9 +920,15 @@ bool wxSplitterWindow::ReplaceWindow(wxWindow *winOld, wxWindow *winNew)
     return TRUE;
 }
 
+void wxSplitterWindow::SetMinimumPaneSize(int min)
+{
+    m_minimumPaneSize = min;
+    SetSashPosition(m_sashPosition); // re-check limits
+}
+
 void wxSplitterWindow::SetSashPosition(int position, bool redraw)
 {
-    m_sashPosition = AdjustSashPosition(position);
+    DoSetSashPosition(position);
 
     if ( redraw )
     {
@@ -945,31 +973,38 @@ void wxSplitterWindow::InitColours()
 #endif // __WIN16__
 }
 
-void wxSplitterWindow::SendUnsplitEvent(wxWindow *winRemoved)
+bool wxSplitterWindow::DoSendEvent(wxSplitterEvent& event)
 {
-    wxSplitterEvent event(wxEVT_COMMAND_SPLITTER_UNSPLIT, this);
-    event.m_data.win = winRemoved;
-
-    (void)GetEventHandler()->ProcessEvent(event);
+    return !GetEventHandler()->ProcessEvent(event) || event.IsAllowed();
 }
 
 // ---------------------------------------------------------------------------
-// splitter event handlers
+// wxSplitterWindow virtual functions: they now just generate the events
 // ---------------------------------------------------------------------------
 
-void wxSplitterWindow::OnSashPosChanged(wxSplitterEvent& event)
+bool wxSplitterWindow::OnSashPositionChange(int WXUNUSED(newSashPosition))
+{
+    // always allow by default
+    return TRUE;
+}
+
+int wxSplitterWindow::OnSashPositionChanging(int newSashPosition)
 {
     // If within UNSPLIT_THRESHOLD from edge, set to edge to cause closure.
     const int UNSPLIT_THRESHOLD = 4;
 
-    int newSashPosition = event.GetSashPosition();
+    // first of all, check if OnSashPositionChange() doesn't forbid this change
+    if ( !OnSashPositionChange(newSashPosition) )
+    {
+        // it does
+        return -1;
+    }
 
     // Obtain relevant window dimension for bottom / right threshold check
     int window_size = GetWindowSize();
 
     bool unsplit_scenario = FALSE;
-    if ( m_permitUnsplitAlways
-            || m_minimumPaneSize == 0 )
+    if ( m_permitUnsplitAlways || m_minimumPaneSize == 0 )
     {
         // Do edge detection if unsplit premitted
         if ( newSashPosition <= UNSPLIT_THRESHOLD )
@@ -997,50 +1032,64 @@ void wxSplitterWindow::OnSashPosChanged(wxSplitterEvent& event)
     if ( newSashPosition < 0 || newSashPosition > window_size )
         newSashPosition = window_size / 2;
 
-    // for compatibility, call the virtual function
-    if ( !OnSashPositionChange(newSashPosition) )
+    // now let the event handler have it
+    //
+    // FIXME: shouldn't we do it before the adjustments above so as to ensure
+    //        that the sash position is always reasonable?
+    wxSplitterEvent event(wxEVT_COMMAND_SPLITTER_SASH_POS_CHANGING, this);
+    event.m_data.pos = newSashPosition;
+
+    if ( !DoSendEvent(event) )
     {
+        // the event handler vetoed the change
         newSashPosition = -1;
     }
+    else
+    {
+        // it could have been changed by it
+        newSashPosition = event.GetSashPosition();
+    }
 
-    event.SetSashPosition(newSashPosition);
+    return newSashPosition;
 }
 
 // Called when the sash is double-clicked. The default behaviour is to remove
 // the sash if the minimum pane size is zero.
-void wxSplitterWindow::OnDoubleClick(wxSplitterEvent& event)
+void wxSplitterWindow::OnDoubleClickSash(int x, int y)
 {
-    // for compatibility, call the virtual function
-    OnDoubleClickSash(event.GetX(), event.GetY());
+    wxCHECK_RET(m_windowTwo, wxT("splitter: no window to remove"));
 
-    if ( GetMinimumPaneSize() == 0 || m_permitUnsplitAlways )
+    // new code should handle events instead of using the virtual functions
+    wxSplitterEvent event(wxEVT_COMMAND_SPLITTER_DOUBLECLICKED, this);
+    event.m_data.pt.x = x;
+    event.m_data.pt.y = y;
+    if ( DoSendEvent(event) )
     {
-        Unsplit();
+        if ( GetMinimumPaneSize() == 0 || m_permitUnsplitAlways )
+        {
+            wxWindow* win = m_windowTwo;
+            if ( Unsplit(win) )
+            {
+                wxSplitterEvent unsplitEvent(wxEVT_COMMAND_SPLITTER_UNSPLIT, this);
+                unsplitEvent.m_data.win = win;
+                (void)DoSendEvent(unsplitEvent);
+            }
+        }
     }
+    //else: blocked by user
 }
 
-void wxSplitterWindow::OnUnsplitEvent(wxSplitterEvent& event)
+void wxSplitterWindow::OnUnsplit(wxWindow *winRemoved)
 {
-    wxWindow *win = event.GetWindowBeingRemoved();
-
-    // do it before calling OnUnsplit() which may delete the window
-    win->Show(FALSE);
-
-    // for compatibility, call the virtual function
-    OnUnsplit(win);
+    // call this before calling the event handler which may delete the window
+    winRemoved->Show(FALSE);
 }
 
-#if defined(__WXMSW__)
-    #define WXUNUSED_UNLESS_MSW(identifier)    identifier
-#else
-    #define WXUNUSED_UNLESS_MSW(identifier)    WXUNUSED(identifier)
-#endif
+#if defined( __WXMSW__ ) || defined( __WXMAC__)
 
-void wxSplitterWindow::OnSetCursor(wxSetCursorEvent& WXUNUSED_UNLESS_MSW(event))
+// this is currently called (and needed) under MSW only...
+void wxSplitterWindow::OnSetCursor(wxSetCursorEvent& event)
 {
-    // this is currently called (and needed) under MSW only...
-#ifdef __WXMSW__
-
     // if we don't do it, the resizing cursor might be set for child window:
     // and like this we explicitly say that our cursor should not be used for
     // children windows which overlap us
@@ -1051,5 +1100,8 @@ void wxSplitterWindow::OnSetCursor(wxSetCursorEvent& WXUNUSED_UNLESS_MSW(event))
         event.Skip();
     }
     //else: do nothing, in particular, don't call Skip()
-#endif // wxMSW
 }
+
+#endif // wxUSE_SPLITTER
+#endif // wxMSW
+