src/generic/splitter.cpp

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        src/generic/splitter.cpp
   3 // Purpose:     wxSplitterWindow implementation
   4 // Author:      Julian Smart
   5 // Modified by:
   6 // Created:     01/02/97
   7 // RCS-ID:      $Id$
   8 // Copyright:   (c) Julian Smart
   9 // Licence:     wxWindows licence
  10 /////////////////////////////////////////////////////////////////////////////
  11
  12 #if defined(__GNUG__) && !defined(NO_GCC_PRAGMA)
  13     #pragma implementation "splitter.h"
  14 #endif
  15
  16 // For compilers that support precompilation, includes "wx.h".
  17 #include "wx/wxprec.h"
  18
  19 #if wxUSE_SPLITTER
  20
  21 #ifdef __BORLANDC__
  22     #pragma hdrstop
  23 #endif
  24
  25 #ifndef WX_PRECOMP
  26     #include "wx/string.h"
  27     #include "wx/utils.h"
  28     #include "wx/log.h"
  29
  30     #include "wx/dcscreen.h"
  31
  32     #include "wx/window.h"
  33     #include "wx/dialog.h"
  34     #include "wx/frame.h"
  35
  36     #include "wx/settings.h"
  37 #endif
  38
  39 #include "wx/renderer.h"
  40
  41 #include "wx/splitter.h"
  42
  43 #include <stdlib.h>
  44
  45 DEFINE_EVENT_TYPE(wxEVT_COMMAND_SPLITTER_SASH_POS_CHANGED)
  46 DEFINE_EVENT_TYPE(wxEVT_COMMAND_SPLITTER_SASH_POS_CHANGING)
  47 DEFINE_EVENT_TYPE(wxEVT_COMMAND_SPLITTER_DOUBLECLICKED)
  48 DEFINE_EVENT_TYPE(wxEVT_COMMAND_SPLITTER_UNSPLIT)
  49
  50 IMPLEMENT_DYNAMIC_CLASS(wxSplitterWindow, wxWindow)
  51
  52 /*
  53         TODO PROPERTIES
  54                 style wxSP_3D
  55                 sashpos (long , 0 )
  56                 minsize (long -1 )
  57                 object, object_ref
  58                 orientation
  59 */
  60
  61 IMPLEMENT_DYNAMIC_CLASS(wxSplitterEvent, wxNotifyEvent)
  62
  63 BEGIN_EVENT_TABLE(wxSplitterWindow, wxWindow)
  64     EVT_PAINT(wxSplitterWindow::OnPaint)
  65     EVT_SIZE(wxSplitterWindow::OnSize)
  66     EVT_MOUSE_EVENTS(wxSplitterWindow::OnMouseEvent)
  67
  68 #if defined( __WXMSW__ ) || defined( __WXMAC__)
  69     EVT_SET_CURSOR(wxSplitterWindow::OnSetCursor)
  70 #endif // wxMSW
  71
  72     WX_EVENT_TABLE_CONTROL_CONTAINER(wxSplitterWindow)
  73 END_EVENT_TABLE()
  74
  75 WX_DELEGATE_TO_CONTROL_CONTAINER(wxSplitterWindow);
  76
  77 bool wxSplitterWindow::Create(wxWindow *parent, wxWindowID id,
  78                                    const wxPoint& pos,
  79                                    const wxSize& size,
  80                                    long style,
  81                                    const wxString& name)
  82 {
  83     // allow TABbing from one window to the other
  84     style |= wxTAB_TRAVERSAL;
  85
  86     // we draw our border ourselves to blend the sash with it
  87     style &= ~wxBORDER_MASK;
  88     style |= wxBORDER_NONE;
  89
  90     if ( !wxWindow::Create(parent, id, pos, size, style, name) )
  91         return FALSE;
  92
  93     m_permitUnsplitAlways = (style & wxSP_PERMIT_UNSPLIT) != 0;
  94
  95     return TRUE;
  96 }
  97
  98 void wxSplitterWindow::Init()
  99 {
 100     m_container.SetContainerWindow(this);
 101
 102     m_splitMode = wxSPLIT_VERTICAL;
 103     m_permitUnsplitAlways = TRUE;
 104     m_windowOne = (wxWindow *) NULL;
 105     m_windowTwo = (wxWindow *) NULL;
 106     m_dragMode = wxSPLIT_DRAG_NONE;
 107     m_oldX = 0;
 108     m_oldY = 0;
 109     m_firstX = 0;
 110     m_firstY = 0;
 111     m_sashPosition = m_requestedSashPosition = 0;
 112     m_minimumPaneSize = 0;
 113     m_sashCursorWE = wxCursor(wxCURSOR_SIZEWE);
 114     m_sashCursorNS = wxCursor(wxCURSOR_SIZENS);
 115     m_sashTrackerPen = new wxPen(*wxBLACK, 2, wxSOLID);
 116
 117     m_needUpdating = FALSE;
 118     m_isHot = false;
 119 }
 120
 121 wxSplitterWindow::~wxSplitterWindow()
 122 {
 123     delete m_sashTrackerPen;
 124 }
 125
 126 // ----------------------------------------------------------------------------
 127 // entering/leaving sash
 128 // ----------------------------------------------------------------------------
 129
 130 void wxSplitterWindow::RedrawIfHotSensitive(bool isHot)
 131 {
 132     if ( wxRendererNative::Get().GetSplitterParams(this).isHotSensitive )
 133     {
 134         m_isHot = isHot;
 135
 136         wxClientDC dc(this);
 137         DrawSash(dc);
 138     }
 139     //else: we don't change our appearance, don't redraw to avoid flicker
 140 }
 141
 142 void wxSplitterWindow::OnEnterSash()
 143 {
 144     SetResizeCursor();
 145
 146     RedrawIfHotSensitive(true);
 147 }
 148
 149 void wxSplitterWindow::OnLeaveSash()
 150 {
 151     SetCursor(*wxSTANDARD_CURSOR);
 152
 153     RedrawIfHotSensitive(false);
 154 }
 155
 156 void wxSplitterWindow::SetResizeCursor()
 157 {
 158     SetCursor(m_splitMode == wxSPLIT_VERTICAL ? m_sashCursorWE
 159                                               : m_sashCursorNS);
 160 }
 161
 162 // ----------------------------------------------------------------------------
 163 // other event handlers
 164 // ----------------------------------------------------------------------------
 165
 166 void wxSplitterWindow::OnPaint(wxPaintEvent& WXUNUSED(event))
 167 {
 168     wxPaintDC dc(this);
 169
 170     DrawSash(dc);
 171 }
 172
 173 void wxSplitterWindow::OnInternalIdle()
 174 {
 175     wxWindow::OnInternalIdle();
 176
 177     if (m_needUpdating)
 178         SizeWindows();
 179 }
 180
 181 void wxSplitterWindow::OnMouseEvent(wxMouseEvent& event)
 182 {
 183     int x = (int)event.GetX(),
 184         y = (int)event.GetY();
 185
 186     if (GetWindowStyle() & wxSP_NOSASH)
 187         return;
 188
 189     // with wxSP_LIVE_UPDATE style the splitter windows are always resized
 190     // following the mouse movement while it drags the sash, without it we only
 191     // draw the sash at the new position but only resize the windows when the
 192     // dragging is finished
 193     bool isLive = (GetWindowStyleFlag() & wxSP_LIVE_UPDATE) != 0;
 194
 195     if (event.LeftDown())
 196     {
 197         if ( SashHitTest(x, y) )
 198         {
 199             // Start the drag now
 200             m_dragMode = wxSPLIT_DRAG_DRAGGING;
 201
 202             // Capture mouse and set the cursor
 203             CaptureMouse();
 204             SetResizeCursor();
 205
 206             if ( !isLive )
 207             {
 208                 // remember the initial sash position and draw the initial
 209                 // shadow sash
 210                 m_sashPositionCurrent = m_sashPosition;
 211
 212                 DrawSashTracker(x, y);
 213             }
 214
 215             m_oldX = x;
 216             m_oldY = y;
 217
 218             SetResizeCursor();
 219             return;
 220         }
 221     }
 222     else if (event.LeftUp() && m_dragMode == wxSPLIT_DRAG_DRAGGING)
 223     {
 224         // We can stop dragging now and see what we've got.
 225         m_dragMode = wxSPLIT_DRAG_NONE;
 226
 227         // Release mouse and unset the cursor
 228         ReleaseMouse();
 229         SetCursor(* wxSTANDARD_CURSOR);
 230
 231         // exit if unsplit after doubleclick
 232         if ( !IsSplit() )
 233         {
 234             return;
 235         }
 236
 237         // Erase old tracker
 238         if ( !isLive )
 239         {
 240             DrawSashTracker(m_oldX, m_oldY);
 241         }
 242
 243         // the position of the click doesn't exactly correspond to
 244         // m_sashPosition, rather it changes it by the distance by which the
 245         // mouse has moved
 246         int diff = m_splitMode == wxSPLIT_VERTICAL ? x - m_oldX : y - m_oldY;
 247
 248         int posSashOld = isLive ? m_sashPosition : m_sashPositionCurrent;
 249         int posSashNew = OnSashPositionChanging(posSashOld + diff);
 250         if ( posSashNew == -1 )
 251         {
 252             // change not allowed
 253             return;
 254         }
 255
 256         if ( m_permitUnsplitAlways || m_minimumPaneSize == 0 )
 257         {
 258             // Deal with possible unsplit scenarios
 259             if ( posSashNew == 0 )
 260             {
 261                 // We remove the first window from the view
 262                 wxWindow *removedWindow = m_windowOne;
 263                 m_windowOne = m_windowTwo;
 264                 m_windowTwo = (wxWindow *) NULL;
 265                 OnUnsplit(removedWindow);
 266                 wxSplitterEvent event(wxEVT_COMMAND_SPLITTER_UNSPLIT, this);
 267                 event.m_data.win = removedWindow;
 268                 (void)DoSendEvent(event);
 269                 SetSashPositionAndNotify(0);
 270             }
 271             else if ( posSashNew == GetWindowSize() )
 272             {
 273                 // We remove the second window from the view
 274                 wxWindow *removedWindow = m_windowTwo;
 275                 m_windowTwo = (wxWindow *) NULL;
 276                 OnUnsplit(removedWindow);
 277                 wxSplitterEvent event(wxEVT_COMMAND_SPLITTER_UNSPLIT, this);
 278                 event.m_data.win = removedWindow;
 279                 (void)DoSendEvent(event);
 280                 SetSashPositionAndNotify(0);
 281             }
 282             else
 283             {
 284                 SetSashPositionAndNotify(posSashNew);
 285             }
 286         }
 287         else
 288         {
 289             SetSashPositionAndNotify(posSashNew);
 290         }
 291
 292         SizeWindows();
 293     }  // left up && dragging
 294     else if ((event.Moving() || event.Leaving() || event.Entering()) && (m_dragMode == wxSPLIT_DRAG_NONE))
 295     {
 296         if ( event.Leaving() || !SashHitTest(x, y) )
 297             OnLeaveSash();
 298         else
 299             OnEnterSash();
 300     }
 301     else if (event.Dragging() && (m_dragMode == wxSPLIT_DRAG_DRAGGING))
 302     {
 303         int diff = m_splitMode == wxSPLIT_VERTICAL ? x - m_oldX : y - m_oldY;
 304         if ( !diff )
 305         {
 306             // nothing to do, mouse didn't really move far enough
 307             return;
 308         }
 309
 310         int posSashOld = isLive ? m_sashPosition : m_sashPositionCurrent;
 311         int posSashNew = OnSashPositionChanging(posSashOld + diff);
 312         if ( posSashNew == -1 )
 313         {
 314             // change not allowed
 315             return;
 316         }
 317
 318         if ( posSashNew == m_sashPosition )
 319             return;
 320
 321         // Erase old tracker
 322         if ( !isLive )
 323         {
 324             DrawSashTracker(m_oldX, m_oldY);
 325         }
 326
 327         if (m_splitMode == wxSPLIT_VERTICAL)
 328             x = posSashNew;
 329         else
 330             y = posSashNew;
 331
 332         // Remember old positions
 333         m_oldX = x;
 334         m_oldY = y;
 335
 336 #ifdef __WXMSW__
 337         // As we captured the mouse, we may get the mouse events from outside
 338         // our window - for example, negative values in x, y. This has a weird
 339         // consequence under MSW where we use unsigned values sometimes and
 340         // signed ones other times: the coordinates turn as big positive
 341         // numbers and so the sash is drawn on the *right* side of the window
 342         // instead of the left (or bottom instead of top). Correct this.
 343         if ( (short)m_oldX < 0 )
 344             m_oldX = 0;
 345         if ( (short)m_oldY < 0 )
 346             m_oldY = 0;
 347 #endif // __WXMSW__
 348
 349         // Draw new one
 350         if ( !isLive )
 351         {
 352             m_sashPositionCurrent = posSashNew;
 353
 354             DrawSashTracker(m_oldX, m_oldY);
 355         }
 356         else
 357         {
 358             SetSashPositionAndNotify(posSashNew);
 359             m_needUpdating = TRUE;
 360         }
 361     }
 362     else if ( event.LeftDClick() && m_windowTwo )
 363     {
 364         OnDoubleClickSash(x, y);
 365     }
 366 }
 367
 368 void wxSplitterWindow::OnSize(wxSizeEvent& event)
 369 {
 370     // only process this message if we're not iconized - otherwise iconizing
 371     // and restoring a window containing the splitter has a funny side effect
 372     // of changing the splitter position!
 373     wxWindow *parent = GetParent();
 374     while ( parent && !parent->IsTopLevel() )
 375     {
 376         parent = parent->GetParent();
 377     }
 378
 379     bool iconized;
 380
 381     wxTopLevelWindow *winTop = wxDynamicCast(parent, wxTopLevelWindow);
 382     if ( winTop )
 383     {
 384         iconized = winTop->IsIconized();
 385     }
 386     else
 387     {
 388         wxFAIL_MSG(wxT("should have a top level parent!"));
 389
 390         iconized = FALSE;
 391     }
 392
 393     if ( iconized )
 394     {
 395         event.Skip();
 396
 397         return;
 398     }
 399
 400     if ( m_windowTwo )
 401     {
 402         int w, h;
 403         GetClientSize(&w, &h);
 404
 405         int size = m_splitMode == wxSPLIT_VERTICAL ? w : h;
 406         if ( m_sashPosition >= size - 5 )
 407             SetSashPositionAndNotify(wxMax(10, size - 40));
 408     }
 409
 410     SizeWindows();
 411 }
 412
 413 bool wxSplitterWindow::SashHitTest(int x, int y, int tolerance)
 414 {
 415     if ( m_windowTwo == NULL || m_sashPosition == 0)
 416         return FALSE; // No sash
 417
 418     int z = m_splitMode == wxSPLIT_VERTICAL ? x : y;
 419
 420     return z >= m_sashPosition - tolerance &&
 421             z <= m_sashPosition + GetSashSize() + tolerance;
 422 }
 423
 424 int wxSplitterWindow::GetSashSize() const
 425 {
 426     return wxRendererNative::Get().GetSplitterParams(this).widthSash;
 427 }
 428
 429 int wxSplitterWindow::GetBorderSize() const
 430 {
 431     return wxRendererNative::Get().GetSplitterParams(this).border;
 432 }
 433
 434 // Draw the sash
 435 void wxSplitterWindow::DrawSash(wxDC& dc)
 436 {
 437     if (HasFlag(wxSP_3DBORDER))
 438         wxRendererNative::Get().DrawSplitterBorder
 439                             (
 440                                 this,
 441                                 dc,
 442                                 GetClientRect()
 443                             );
 444
 445     // don't draw sash if we're not split
 446     if ( m_sashPosition == 0 || !m_windowTwo )
 447         return;
 448
 449     // nor if we're configured to not show it
 450     if ( HasFlag(wxSP_NOSASH) )
 451         return;
 452
 453     wxRendererNative::Get().DrawSplitterSash
 454                             (
 455                                 this,
 456                                 dc,
 457                                 GetClientSize(),
 458                                 m_sashPosition,
 459                                 m_splitMode == wxSPLIT_VERTICAL ? wxVERTICAL
 460                                                                 : wxHORIZONTAL,
 461                                 m_isHot ? wxCONTROL_CURRENT : 0
 462                             );
 463 }
 464
 465 // Draw the sash tracker (for whilst moving the sash)
 466 void wxSplitterWindow::DrawSashTracker(int x, int y)
 467 {
 468     int w, h;
 469     GetClientSize(&w, &h);
 470
 471     wxScreenDC screenDC;
 472     int x1, y1;
 473     int x2, y2;
 474
 475     if ( m_splitMode == wxSPLIT_VERTICAL )
 476     {
 477         x1 = x; y1 = 2;
 478         x2 = x; y2 = h-2;
 479
 480         if ( x1 > w )
 481         {
 482             x1 = w; x2 = w;
 483         }
 484         else if ( x1 < 0 )
 485         {
 486             x1 = 0; x2 = 0;
 487         }
 488     }
 489     else
 490     {
 491         x1 = 2; y1 = y;
 492         x2 = w-2; y2 = y;
 493
 494         if ( y1 > h )
 495         {
 496             y1 = h;
 497             y2 = h;
 498         }
 499         else if ( y1 < 0 )
 500         {
 501             y1 = 0;
 502             y2 = 0;
 503         }
 504     }
 505
 506     ClientToScreen(&x1, &y1);
 507     ClientToScreen(&x2, &y2);
 508
 509     screenDC.SetLogicalFunction(wxINVERT);
 510     screenDC.SetPen(*m_sashTrackerPen);
 511     screenDC.SetBrush(*wxTRANSPARENT_BRUSH);
 512
 513     screenDC.DrawLine(x1, y1, x2, y2);
 514
 515     screenDC.SetLogicalFunction(wxCOPY);
 516 }
 517
 518 int wxSplitterWindow::GetWindowSize() const
 519 {
 520     wxSize size = GetClientSize();
 521
 522     return m_splitMode == wxSPLIT_VERTICAL ? size.x : size.y;
 523 }
 524
 525 int wxSplitterWindow::AdjustSashPosition(int sashPos) const
 526 {
 527     int window_size = GetWindowSize();
 528
 529     wxWindow *win;
 530
 531     win = GetWindow1();
 532     if ( win )
 533     {
 534         // the window shouldn't be smaller than its own minimal size nor
 535         // smaller than the minimual pane size specified for this splitter
 536         int minSize = m_splitMode == wxSPLIT_VERTICAL ? win->GetMinWidth()
 537                                                       : win->GetMinHeight();
 538
 539         if ( minSize == -1 || m_minimumPaneSize > minSize )
 540             minSize = m_minimumPaneSize;
 541
 542         minSize += GetBorderSize();
 543
 544         if ( sashPos < minSize )
 545             sashPos = minSize;
 546     }
 547
 548     win = GetWindow2();
 549     if ( win )
 550     {
 551         int minSize = m_splitMode == wxSPLIT_VERTICAL ? win->GetMinWidth()
 552                                                       : win->GetMinHeight();
 553
 554         if ( minSize == -1 || m_minimumPaneSize > minSize )
 555             minSize = m_minimumPaneSize;
 556
 557         int maxSize = window_size - minSize - GetBorderSize();
 558         if ( sashPos > maxSize )
 559             sashPos = maxSize;
 560     }
 561
 562     return sashPos;
 563 }
 564
 565 bool wxSplitterWindow::DoSetSashPosition(int sashPos)
 566 {
 567     int newSashPosition = AdjustSashPosition(sashPos);
 568
 569     if ( newSashPosition == m_sashPosition )
 570         return FALSE;
 571
 572     m_sashPosition = newSashPosition;
 573
 574     return TRUE;
 575 }
 576
 577 void wxSplitterWindow::SetSashPositionAndNotify(int sashPos)
 578 {
 579     if ( DoSetSashPosition(sashPos) )
 580     {
 581         wxSplitterEvent event(wxEVT_COMMAND_SPLITTER_SASH_POS_CHANGED, this);
 582         event.m_data.pos = m_sashPosition;
 583
 584         (void)DoSendEvent(event);
 585     }
 586 }
 587
 588 // Position and size subwindows.
 589 // Note that the border size applies to each subwindow, not
 590 // including the edges next to the sash.
 591 void wxSplitterWindow::SizeWindows()
 592 {
 593     // check if we have delayed setting the real sash position
 594     if ( m_requestedSashPosition != INT_MAX )
 595     {
 596         int newSashPosition = ConvertSashPosition(m_requestedSashPosition);
 597         if ( newSashPosition != m_sashPosition )
 598         {
 599             DoSetSashPosition(newSashPosition);
 600         }
 601
 602         if ( newSashPosition <= m_sashPosition
 603             && newSashPosition >= m_sashPosition - GetBorderSize() )
 604         {
 605             // don't update it any more
 606             m_requestedSashPosition = INT_MAX;
 607         }
 608     }
 609
 610     int w, h;
 611     GetClientSize(&w, &h);
 612
 613     if ( GetWindow1() && !GetWindow2() )
 614     {
 615         GetWindow1()->SetSize(GetBorderSize(), GetBorderSize(),
 616                               w - 2*GetBorderSize(), h - 2*GetBorderSize());
 617     }
 618     else if ( GetWindow1() && GetWindow2() )
 619     {
 620         const int border = GetBorderSize(),
 621                   sash = GetSashSize();
 622
 623         int size1 = GetSashPosition() - border,
 624             size2 = GetSashPosition() + sash;
 625
 626         int x2, y2, w1, h1, w2, h2;
 627         if ( GetSplitMode() == wxSPLIT_VERTICAL )
 628         {
 629             w1 = size1;
 630             w2 = w - 2*border - sash - w1;
 631             h1 =
 632             h2 = h - 2*border;
 633             x2 = size2;
 634             y2 = border;
 635         }
 636         else // horz splitter
 637         {
 638             w1 =
 639             w2 = w - 2*border;
 640             h1 = size1;
 641             h2 = h - 2*border - sash - h1;
 642             x2 = border;
 643             y2 = size2;
 644         }
 645
 646         GetWindow1()->SetSize(border, border, w1, h1);
 647         GetWindow2()->SetSize(x2, y2, w2, h2);
 648     }
 649
 650     wxClientDC dc(this);
 651     DrawSash(dc);
 652
 653     SetNeedUpdating(FALSE);
 654 }
 655
 656 // Set pane for unsplit window
 657 void wxSplitterWindow::Initialize(wxWindow *window)
 658 {
 659     wxASSERT_MSG( window && window->GetParent() == this,
 660                   _T("windows in the splitter should have it as parent!") );
 661
 662     m_windowOne = window;
 663     m_windowTwo = (wxWindow *) NULL;
 664     DoSetSashPosition(0);
 665 }
 666
 667 // Associates the given window with window 2, drawing the appropriate sash
 668 // and changing the split mode.
 669 // Does nothing and returns FALSE if the window is already split.
 670 bool wxSplitterWindow::DoSplit(wxSplitMode mode,
 671                                wxWindow *window1, wxWindow *window2,
 672                                int sashPosition)
 673 {
 674     if ( IsSplit() )
 675         return FALSE;
 676
 677     wxCHECK_MSG( window1 && window2, FALSE,
 678                  _T("can not split with NULL window(s)") );
 679
 680     wxCHECK_MSG( window1->GetParent() == this && window2->GetParent() == this, FALSE,
 681                   _T("windows in the splitter should have it as parent!") );
 682
 683     m_splitMode = mode;
 684     m_windowOne = window1;
 685     m_windowTwo = window2;
 686
 687     // remember the sash position we want to set for later if we can't set it
 688     // right now (e.g. because the window is too small)
 689     m_requestedSashPosition = sashPosition;
 690
 691     DoSetSashPosition(ConvertSashPosition(sashPosition));
 692
 693     SizeWindows();
 694
 695     return TRUE;
 696 }
 697
 698 int wxSplitterWindow::ConvertSashPosition(int sashPosition) const
 699 {
 700     if ( sashPosition > 0 )
 701     {
 702         return sashPosition;
 703     }
 704     else if ( sashPosition < 0 )
 705     {
 706         // It's negative so adding is subtracting
 707         return GetWindowSize() + sashPosition;
 708     }
 709     else // sashPosition == 0
 710     {
 711         // default, put it in the centre
 712         return GetWindowSize() / 2;
 713     }
 714 }
 715
 716 // Remove the specified (or second) window from the view
 717 // Doesn't actually delete the window.
 718 bool wxSplitterWindow::Unsplit(wxWindow *toRemove)
 719 {
 720     if ( ! IsSplit() )
 721         return FALSE;
 722
 723     wxWindow *win;
 724     if ( toRemove == NULL || toRemove == m_windowTwo)
 725     {
 726         win = m_windowTwo ;
 727         m_windowTwo = (wxWindow *) NULL;
 728     }
 729     else if ( toRemove == m_windowOne )
 730     {
 731         win = m_windowOne ;
 732         m_windowOne = m_windowTwo;
 733         m_windowTwo = (wxWindow *) NULL;
 734     }
 735     else
 736     {
 737         wxFAIL_MSG(wxT("splitter: attempt to remove a non-existent window"));
 738
 739         return FALSE;
 740     }
 741
 742     OnUnsplit(win);
 743     DoSetSashPosition(0);
 744     SizeWindows();
 745
 746     return TRUE;
 747 }
 748
 749 // Replace a window with another one
 750 bool wxSplitterWindow::ReplaceWindow(wxWindow *winOld, wxWindow *winNew)
 751 {
 752     wxCHECK_MSG( winOld, FALSE, wxT("use one of Split() functions instead") );
 753     wxCHECK_MSG( winNew, FALSE, wxT("use Unsplit() functions instead") );
 754
 755     if ( winOld == m_windowTwo )
 756     {
 757         m_windowTwo = winNew;
 758     }
 759     else if ( winOld == m_windowOne )
 760     {
 761         m_windowOne = winNew;
 762     }
 763     else
 764     {
 765         wxFAIL_MSG(wxT("splitter: attempt to replace a non-existent window"));
 766
 767         return FALSE;
 768     }
 769
 770     SizeWindows();
 771
 772     return TRUE;
 773 }
 774
 775 void wxSplitterWindow::SetMinimumPaneSize(int min)
 776 {
 777     m_minimumPaneSize = min;
 778     SetSashPosition(m_sashPosition); // re-check limits
 779 }
 780
 781 void wxSplitterWindow::SetSashPosition(int position, bool redraw)
 782 {
 783     DoSetSashPosition(position);
 784
 785     if ( redraw )
 786     {
 787         SizeWindows();
 788     }
 789 }
 790
 791 bool wxSplitterWindow::DoSendEvent(wxSplitterEvent& event)
 792 {
 793     return !GetEventHandler()->ProcessEvent(event) || event.IsAllowed();
 794 }
 795
 796 // ---------------------------------------------------------------------------
 797 // wxSplitterWindow virtual functions: they now just generate the events
 798 // ---------------------------------------------------------------------------
 799
 800 bool wxSplitterWindow::OnSashPositionChange(int WXUNUSED(newSashPosition))
 801 {
 802     // always allow by default
 803     return TRUE;
 804 }
 805
 806 int wxSplitterWindow::OnSashPositionChanging(int newSashPosition)
 807 {
 808     // If within UNSPLIT_THRESHOLD from edge, set to edge to cause closure.
 809     const int UNSPLIT_THRESHOLD = 4;
 810
 811     // first of all, check if OnSashPositionChange() doesn't forbid this change
 812     if ( !OnSashPositionChange(newSashPosition) )
 813     {
 814         // it does
 815         return -1;
 816     }
 817
 818     // Obtain relevant window dimension for bottom / right threshold check
 819     int window_size = GetWindowSize();
 820
 821     bool unsplit_scenario = FALSE;
 822     if ( m_permitUnsplitAlways || m_minimumPaneSize == 0 )
 823     {
 824         // Do edge detection if unsplit premitted
 825         if ( newSashPosition <= UNSPLIT_THRESHOLD )
 826         {
 827             // threshold top / left check
 828             newSashPosition = 0;
 829             unsplit_scenario = TRUE;
 830         }
 831         if ( newSashPosition >= window_size - UNSPLIT_THRESHOLD )
 832         {
 833             // threshold bottom/right check
 834             newSashPosition = window_size;
 835             unsplit_scenario = TRUE;
 836         }
 837     }
 838
 839     if ( !unsplit_scenario )
 840     {
 841         // If resultant pane would be too small, enlarge it
 842         newSashPosition = AdjustSashPosition(newSashPosition);
 843     }
 844
 845     // If the result is out of bounds it means minimum size is too big,
 846     // so split window in half as best compromise.
 847     if ( newSashPosition < 0 || newSashPosition > window_size )
 848         newSashPosition = window_size / 2;
 849
 850     // now let the event handler have it
 851     //
 852     // FIXME: shouldn't we do it before the adjustments above so as to ensure
 853     //        that the sash position is always reasonable?
 854     wxSplitterEvent event(wxEVT_COMMAND_SPLITTER_SASH_POS_CHANGING, this);
 855     event.m_data.pos = newSashPosition;
 856
 857     if ( !DoSendEvent(event) )
 858     {
 859         // the event handler vetoed the change
 860         newSashPosition = -1;
 861     }
 862     else
 863     {
 864         // it could have been changed by it
 865         newSashPosition = event.GetSashPosition();
 866     }
 867
 868     return newSashPosition;
 869 }
 870
 871 // Called when the sash is double-clicked. The default behaviour is to remove
 872 // the sash if the minimum pane size is zero.
 873 void wxSplitterWindow::OnDoubleClickSash(int x, int y)
 874 {
 875     wxCHECK_RET(m_windowTwo, wxT("splitter: no window to remove"));
 876
 877     // new code should handle events instead of using the virtual functions
 878     wxSplitterEvent event(wxEVT_COMMAND_SPLITTER_DOUBLECLICKED, this);
 879     event.m_data.pt.x = x;
 880     event.m_data.pt.y = y;
 881     if ( DoSendEvent(event) )
 882     {
 883         if ( GetMinimumPaneSize() == 0 || m_permitUnsplitAlways )
 884         {
 885             wxWindow* win = m_windowTwo;
 886             if ( Unsplit(win) )
 887             {
 888                 wxSplitterEvent unsplitEvent(wxEVT_COMMAND_SPLITTER_UNSPLIT, this);
 889                 unsplitEvent.m_data.win = win;
 890                 (void)DoSendEvent(unsplitEvent);
 891             }
 892         }
 893     }
 894     //else: blocked by user
 895 }
 896
 897 void wxSplitterWindow::OnUnsplit(wxWindow *winRemoved)
 898 {
 899     // call this before calling the event handler which may delete the window
 900     winRemoved->Show(FALSE);
 901 }
 902
 903 #if defined( __WXMSW__ ) || defined( __WXMAC__)
 904
 905 // this is currently called (and needed) under MSW only...
 906 void wxSplitterWindow::OnSetCursor(wxSetCursorEvent& event)
 907 {
 908     // if we don't do it, the resizing cursor might be set for child window:
 909     // and like this we explicitly say that our cursor should not be used for
 910     // children windows which overlap us
 911
 912     if ( SashHitTest(event.GetX(), event.GetY()) )
 913     {
 914         // default processing is ok
 915         event.Skip();
 916     }
 917     //else: do nothing, in particular, don't call Skip()
 918 }
 919
 920 #endif // wxMSW || wxMac
 921
 922 #endif // wxUSE_SPLITTER
 923