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