src/generic/scrolwin.cpp

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        generic/scrolwin.cpp
   3 // Purpose:     wxScrolledWindow implementation
   4 // Author:      Julian Smart
   5 // Modified by:
   6 // Created:     01/02/97
   7 // RCS-ID:      $Id$
   8 // Copyright:   (c) Julian Smart and Markus Holzem
   9 // Licence:     wxWindows license
  10 /////////////////////////////////////////////////////////////////////////////
  11
  12 // ============================================================================
  13 // declarations
  14 // ============================================================================
  15
  16 // ----------------------------------------------------------------------------
  17 // headers
  18 // ----------------------------------------------------------------------------
  19
  20 #ifdef __GNUG__
  21     #pragma implementation "scrolwin.h"
  22 #endif
  23
  24 // For compilers that support precompilation, includes "wx.h".
  25 #include "wx/wxprec.h"
  26
  27 #ifdef __BORLANDC__
  28     #pragma hdrstop
  29 #endif
  30
  31 #include "wx/utils.h"
  32 #include "wx/dcclient.h"
  33
  34 #include "wx/generic/scrolwin.h"
  35 #include "wx/panel.h"
  36
  37 #ifdef __WXMSW__
  38     #include "windows.h"
  39 #endif
  40
  41 #ifdef __WXMOTIF__
  42 // For wxRETAINED implementation
  43 #ifdef __VMS__ //VMS's Xm.h is not (yet) compatible with C++
  44                //This code switches off the compiler warnings
  45 # pragma message disable nosimpint
  46 #endif
  47 #include <Xm/Xm.h>
  48 #ifdef __VMS__
  49 # pragma message enable nosimpint
  50 #endif
  51 #endif
  52
  53 // ----------------------------------------------------------------------------
  54 // event tables
  55 // ----------------------------------------------------------------------------
  56
  57 BEGIN_EVENT_TABLE(wxScrolledWindow, wxPanel)
  58     EVT_SCROLLWIN(wxScrolledWindow::OnScroll)
  59     EVT_SIZE(wxScrolledWindow::OnSize)
  60     EVT_PAINT(wxScrolledWindow::OnPaint)
  61     EVT_CHAR(wxScrolledWindow::OnChar)
  62 END_EVENT_TABLE()
  63
  64 IMPLEMENT_DYNAMIC_CLASS(wxScrolledWindow, wxPanel)
  65
  66 // ============================================================================
  67 // implementation
  68 // ============================================================================
  69
  70 // ----------------------------------------------------------------------------
  71 // wxScrolledWindow creation
  72 // ----------------------------------------------------------------------------
  73
  74 wxScrolledWindow::wxScrolledWindow()
  75 {
  76     m_xScrollPixelsPerLine = 0;
  77     m_yScrollPixelsPerLine = 0;
  78     m_xScrollingEnabled = TRUE;
  79     m_yScrollingEnabled = TRUE;
  80     m_xScrollPosition = 0;
  81     m_yScrollPosition = 0;
  82     m_xScrollLines = 0;
  83     m_yScrollLines = 0;
  84     m_xScrollLinesPerPage = 0;
  85     m_yScrollLinesPerPage = 0;
  86     m_scaleX = 1.0;
  87     m_scaleY = 1.0;
  88 }
  89
  90 bool wxScrolledWindow::Create(wxWindow *parent,
  91                               wxWindowID id,
  92                               const wxPoint& pos,
  93                               const wxSize& size,
  94                               long style,
  95                               const wxString& name)
  96 {
  97     m_xScrollPixelsPerLine = 0;
  98     m_yScrollPixelsPerLine = 0;
  99     m_xScrollingEnabled = TRUE;
 100     m_yScrollingEnabled = TRUE;
 101     m_xScrollPosition = 0;
 102     m_yScrollPosition = 0;
 103     m_xScrollLines = 0;
 104     m_yScrollLines = 0;
 105     m_xScrollLinesPerPage = 0;
 106     m_yScrollLinesPerPage = 0;
 107     m_scaleX = 1.0;
 108     m_scaleY = 1.0;
 109
 110     m_targetWindow = this;
 111
 112     // we need wxWANTS_CHARS to process arrows ourselves
 113     return wxPanel::Create(parent, id, pos, size, style | wxWANTS_CHARS, name);
 114 }
 115
 116 wxScrolledWindow::~wxScrolledWindow()
 117 {
 118 }
 119
 120 // ----------------------------------------------------------------------------
 121 // setting scrolling parameters
 122 // ----------------------------------------------------------------------------
 123
 124 /*
 125  * pixelsPerUnitX/pixelsPerUnitY: number of pixels per unit (e.g. pixels per text line)
 126  * noUnitsX/noUnitsY:        : no. units per scrollbar
 127  */
 128 void wxScrolledWindow::SetScrollbars (int pixelsPerUnitX, int pixelsPerUnitY,
 129                int noUnitsX, int noUnitsY,
 130                int xPos, int yPos, bool noRefresh )
 131 {
 132     bool do_refresh =
 133     (
 134       (noUnitsX != 0 && m_xScrollLines == 0) ||
 135       (noUnitsX < m_xScrollLines) ||
 136       (noUnitsY != 0 && m_yScrollLines == 0) ||
 137       (noUnitsY < m_yScrollLines) ||
 138       (xPos != m_xScrollPosition) ||
 139       (yPos != m_yScrollPosition) ||
 140       (pixelsPerUnitX != m_xScrollPixelsPerLine) ||
 141       (pixelsPerUnitY != m_yScrollPixelsPerLine)
 142     );
 143
 144     m_xScrollPixelsPerLine = pixelsPerUnitX;
 145     m_yScrollPixelsPerLine = pixelsPerUnitY;
 146     m_xScrollPosition = xPos;
 147     m_yScrollPosition = yPos;
 148     m_xScrollLines = noUnitsX;
 149     m_yScrollLines = noUnitsY;
 150
 151 #ifdef __WXMOTIF__
 152     // Sorry, some Motif-specific code to implement a backing pixmap
 153     // for the wxRETAINED style. Implementing a backing store can't
 154     // be entirely generic because it relies on the wxWindowDC implementation
 155     // to duplicate X drawing calls for the backing pixmap.
 156
 157     if ((m_windowStyle & wxRETAINED) == wxRETAINED)
 158     {
 159         Display* dpy = XtDisplay((Widget) GetMainWidget());
 160
 161         int totalPixelWidth = m_xScrollLines * m_xScrollPixelsPerLine;
 162         int totalPixelHeight = m_yScrollLines * m_yScrollPixelsPerLine;
 163         if (m_backingPixmap &&
 164            !((m_pixmapWidth == totalPixelWidth) &&
 165              (m_pixmapHeight == totalPixelHeight)))
 166         {
 167             XFreePixmap (dpy, (Pixmap) m_backingPixmap);
 168             m_backingPixmap = (WXPixmap) 0;
 169         }
 170
 171         if (!m_backingPixmap &&
 172            (noUnitsX != 0) && (noUnitsY != 0))
 173         {
 174             int depth = wxDisplayDepth();
 175             m_pixmapWidth = totalPixelWidth;
 176             m_pixmapHeight = totalPixelHeight;
 177             m_backingPixmap = (WXPixmap) XCreatePixmap (dpy, RootWindow (dpy, DefaultScreen (dpy)),
 178             m_pixmapWidth, m_pixmapHeight, depth);
 179         }
 180
 181     }
 182 #endif // Motif
 183
 184     AdjustScrollbars();
 185
 186     if (do_refresh && !noRefresh)
 187         m_targetWindow->Refresh();
 188
 189 #ifdef __WXMSW__
 190     // GRG: if this turns out to be really necessary, we could
 191     //   at least move it to the above if { ... } so that it is
 192     //   only done if noRefresh = FALSE (the default). OTOH, if
 193     //   this doesn't break anything, which seems to be the
 194     //   case, we could just leave it out.
 195
 196     // Necessary?
 197     // UpdateWindow ((HWND) m_targetWindow->GetHWND());
 198 #endif
 199 #ifdef __WXMAC__
 200     m_targetWindow->MacUpdateImmediately() ;
 201 #endif
 202 }
 203
 204 // ----------------------------------------------------------------------------
 205 // target window handling
 206 // ----------------------------------------------------------------------------
 207
 208 void wxScrolledWindow::SetTargetWindow( wxWindow *target )
 209 {
 210     wxASSERT_MSG( target, wxT("target window must not be NULL") );
 211     m_targetWindow = target;
 212 }
 213
 214 wxWindow *wxScrolledWindow::GetTargetWindow()
 215 {
 216     return m_targetWindow;
 217 }
 218
 219 // ----------------------------------------------------------------------------
 220 // scrolling implementation itself
 221 // ----------------------------------------------------------------------------
 222
 223 void wxScrolledWindow::OnScroll(wxScrollWinEvent& event)
 224 {
 225     int orient = event.GetOrientation();
 226
 227     int nScrollInc = CalcScrollInc(event);
 228     if (nScrollInc == 0) return;
 229
 230     if (orient == wxHORIZONTAL)
 231     {
 232         int newPos = m_xScrollPosition + nScrollInc;
 233         SetScrollPos(wxHORIZONTAL, newPos, TRUE );
 234     }
 235     else
 236     {
 237         int newPos = m_yScrollPosition + nScrollInc;
 238         SetScrollPos(wxVERTICAL, newPos, TRUE );
 239     }
 240
 241     if (orient == wxHORIZONTAL)
 242     {
 243         m_xScrollPosition += nScrollInc;
 244     }
 245     else
 246     {
 247         m_yScrollPosition += nScrollInc;
 248     }
 249
 250     if (orient == wxHORIZONTAL)
 251     {
 252        if (m_xScrollingEnabled)
 253             m_targetWindow->ScrollWindow(-m_xScrollPixelsPerLine * nScrollInc, 0, (const wxRect *) NULL);
 254        else
 255             m_targetWindow->Refresh();
 256     }
 257     else
 258     {
 259         if (m_yScrollingEnabled)
 260             m_targetWindow->ScrollWindow(0, -m_yScrollPixelsPerLine * nScrollInc, (const wxRect *) NULL);
 261         else
 262             m_targetWindow->Refresh();
 263   }
 264 #ifdef __WXMAC__
 265     m_targetWindow->MacUpdateImmediately() ;
 266 #endif
 267 }
 268
 269 int wxScrolledWindow::CalcScrollInc(wxScrollWinEvent& event)
 270 {
 271     int pos = event.GetPosition();
 272     int orient = event.GetOrientation();
 273
 274     int nScrollInc = 0;
 275     switch (event.GetEventType())
 276     {
 277         case wxEVT_SCROLLWIN_TOP:
 278         {
 279             if (orient == wxHORIZONTAL)
 280                 nScrollInc = - m_xScrollPosition;
 281             else
 282                 nScrollInc = - m_yScrollPosition;
 283             break;
 284         }
 285         case wxEVT_SCROLLWIN_BOTTOM:
 286         {
 287             if (orient == wxHORIZONTAL)
 288                 nScrollInc = m_xScrollLines - m_xScrollPosition;
 289             else
 290                 nScrollInc = m_yScrollLines - m_yScrollPosition;
 291             break;
 292         }
 293         case wxEVT_SCROLLWIN_LINEUP:
 294         {
 295             nScrollInc = -1;
 296             break;
 297         }
 298         case wxEVT_SCROLLWIN_LINEDOWN:
 299         {
 300             nScrollInc = 1;
 301             break;
 302         }
 303         case wxEVT_SCROLLWIN_PAGEUP:
 304         {
 305             if (orient == wxHORIZONTAL)
 306                 nScrollInc = -GetScrollPageSize(wxHORIZONTAL);
 307             else
 308                 nScrollInc = -GetScrollPageSize(wxVERTICAL);
 309             break;
 310         }
 311         case wxEVT_SCROLLWIN_PAGEDOWN:
 312         {
 313             if (orient == wxHORIZONTAL)
 314                 nScrollInc = GetScrollPageSize(wxHORIZONTAL);
 315             else
 316                 nScrollInc = GetScrollPageSize(wxVERTICAL);
 317             break;
 318         }
 319         case wxEVT_SCROLLWIN_THUMBTRACK:
 320         {
 321             if (orient == wxHORIZONTAL)
 322                 nScrollInc = pos - m_xScrollPosition;
 323             else
 324                 nScrollInc = pos - m_yScrollPosition;
 325             break;
 326         }
 327         default:
 328         {
 329             break;
 330         }
 331     }
 332
 333     if (orient == wxHORIZONTAL)
 334     {
 335         if (m_xScrollPixelsPerLine > 0)
 336         {
 337             int w, h;
 338             m_targetWindow->GetClientSize(&w, &h);
 339
 340             int nMaxWidth = m_xScrollLines*m_xScrollPixelsPerLine;
 341             int noPositions = (int) ( ((nMaxWidth - w)/(double)m_xScrollPixelsPerLine) + 0.5 );
 342             if (noPositions < 0)
 343                 noPositions = 0;
 344
 345             if ( (m_xScrollPosition + nScrollInc) < 0 )
 346                 nScrollInc = -m_xScrollPosition; // As -ve as we can go
 347             else if ( (m_xScrollPosition + nScrollInc) > noPositions )
 348                 nScrollInc = noPositions - m_xScrollPosition; // As +ve as we can go
 349         }
 350         else
 351             m_targetWindow->Refresh();
 352     }
 353     else
 354     {
 355         if (m_yScrollPixelsPerLine > 0)
 356         {
 357             int w, h;
 358             m_targetWindow->GetClientSize(&w, &h);
 359
 360             int nMaxHeight = m_yScrollLines*m_yScrollPixelsPerLine;
 361             int noPositions = (int) ( ((nMaxHeight - h)/(double)m_yScrollPixelsPerLine) + 0.5 );
 362             if (noPositions < 0)
 363                 noPositions = 0;
 364
 365             if ( (m_yScrollPosition + nScrollInc) < 0 )
 366                 nScrollInc = -m_yScrollPosition; // As -ve as we can go
 367             else if ( (m_yScrollPosition + nScrollInc) > noPositions )
 368                 nScrollInc = noPositions - m_yScrollPosition; // As +ve as we can go
 369         }
 370         else
 371             m_targetWindow->Refresh();
 372     }
 373
 374     return nScrollInc;
 375 }
 376
 377 // Adjust the scrollbars - new version.
 378 void wxScrolledWindow::AdjustScrollbars()
 379 {
 380     int w, h;
 381     m_targetWindow->GetClientSize(&w, &h);
 382
 383     int oldXScroll = m_xScrollPosition;
 384     int oldYScroll = m_yScrollPosition;
 385
 386     if (m_xScrollLines > 0)
 387     {
 388             // Calculate page size i.e. number of scroll units you get on the
 389             // current client window
 390         int noPagePositions = (int) ( (w/(double)m_xScrollPixelsPerLine) + 0.5 );
 391         if (noPagePositions < 1) noPagePositions = 1;
 392
 393         // Correct position if greater than extent of canvas minus
 394             // the visible portion of it or if below zero
 395             m_xScrollPosition = wxMin( m_xScrollLines-noPagePositions, m_xScrollPosition);
 396         m_xScrollPosition = wxMax( 0, m_xScrollPosition );
 397
 398         SetScrollbar(wxHORIZONTAL, m_xScrollPosition, noPagePositions, m_xScrollLines);
 399         // The amount by which we scroll when paging
 400         SetScrollPageSize(wxHORIZONTAL, noPagePositions);
 401     }
 402     else
 403     {
 404         m_xScrollPosition = 0;
 405         SetScrollbar (wxHORIZONTAL, 0, 0, 0, FALSE);
 406     }
 407
 408     if (m_yScrollLines > 0)
 409     {
 410             // Calculate page size i.e. number of scroll units you get on the
 411             // current client window
 412         int noPagePositions = (int) ( (h/(double)m_yScrollPixelsPerLine) + 0.5 );
 413         if (noPagePositions < 1) noPagePositions = 1;
 414
 415         // Correct position if greater than extent of canvas minus
 416             // the visible portion of it or if below zero
 417         m_yScrollPosition = wxMin( m_yScrollLines-noPagePositions, m_yScrollPosition );
 418         m_yScrollPosition = wxMax( 0, m_yScrollPosition );
 419
 420         SetScrollbar(wxVERTICAL, m_yScrollPosition, noPagePositions, m_yScrollLines);
 421         // The amount by which we scroll when paging
 422         SetScrollPageSize(wxVERTICAL, noPagePositions);
 423     }
 424     else
 425     {
 426         m_yScrollPosition = 0;
 427         SetScrollbar (wxVERTICAL, 0, 0, 0, FALSE);
 428     }
 429
 430     if (oldXScroll != m_xScrollPosition)
 431     {
 432        if (m_xScrollingEnabled)
 433             m_targetWindow->ScrollWindow( m_xScrollPixelsPerLine * (oldXScroll-m_xScrollPosition), 0, (const wxRect *) NULL );
 434        else
 435             m_targetWindow->Refresh();
 436     }
 437
 438     if (oldYScroll != m_yScrollPosition)
 439     {
 440         if (m_yScrollingEnabled)
 441             m_targetWindow->ScrollWindow( 0, m_yScrollPixelsPerLine * (oldYScroll-m_yScrollPosition), (const wxRect *) NULL );
 442         else
 443             m_targetWindow->Refresh();
 444     }
 445 }
 446
 447 // Override this function if you don't want to have wxScrolledWindow
 448 // automatically change the origin according to the scroll position.
 449 void wxScrolledWindow::PrepareDC(wxDC& dc)
 450 {
 451     dc.SetDeviceOrigin( -m_xScrollPosition * m_xScrollPixelsPerLine,
 452                         -m_yScrollPosition * m_yScrollPixelsPerLine );
 453     dc.SetUserScale( m_scaleX, m_scaleY );
 454 }
 455
 456 #if WXWIN_COMPATIBILITY
 457 void wxScrolledWindow::GetScrollUnitsPerPage (int *x_page, int *y_page) const
 458 {
 459       *x_page = GetScrollPageSize(wxHORIZONTAL);
 460       *y_page = GetScrollPageSize(wxVERTICAL);
 461 }
 462
 463 void wxScrolledWindow::CalcUnscrolledPosition(int x, int y, float *xx, float *yy) const
 464 {
 465     if ( xx )
 466         *xx = (float)(x + m_xScrollPosition * m_xScrollPixelsPerLine);
 467     if ( yy )
 468         *yy = (float)(y + m_yScrollPosition * m_yScrollPixelsPerLine);
 469 }
 470 #endif // WXWIN_COMPATIBILITY
 471
 472 void wxScrolledWindow::GetScrollPixelsPerUnit (int *x_unit, int *y_unit) const
 473 {
 474     if ( x_unit )
 475         *x_unit = m_xScrollPixelsPerLine;
 476     if ( y_unit )
 477         *y_unit = m_yScrollPixelsPerLine;
 478 }
 479
 480 int wxScrolledWindow::GetScrollPageSize(int orient) const
 481 {
 482     if ( orient == wxHORIZONTAL )
 483         return m_xScrollLinesPerPage;
 484     else
 485         return m_yScrollLinesPerPage;
 486 }
 487
 488 void wxScrolledWindow::SetScrollPageSize(int orient, int pageSize)
 489 {
 490     if ( orient == wxHORIZONTAL )
 491         m_xScrollLinesPerPage = pageSize;
 492     else
 493         m_yScrollLinesPerPage = pageSize;
 494 }
 495
 496 /*
 497  * Scroll to given position (scroll position, not pixel position)
 498  */
 499 void wxScrolledWindow::Scroll( int x_pos, int y_pos )
 500 {
 501     if (((x_pos == -1) || (x_pos == m_xScrollPosition)) &&
 502         ((y_pos == -1) || (y_pos == m_yScrollPosition))) return;
 503
 504     int w, h;
 505     m_targetWindow->GetClientSize(&w, &h);
 506
 507     if (x_pos != -1)
 508     {
 509         int old_x = m_xScrollPosition;
 510         m_xScrollPosition = x_pos;
 511
 512             // Calculate page size i.e. number of scroll units you get on the
 513             // current client window
 514         int noPagePositions = (int) ( (w/(double)m_xScrollPixelsPerLine) + 0.5 );
 515         if (noPagePositions < 1) noPagePositions = 1;
 516
 517         // Correct position if greater than extent of canvas minus
 518             // the visible portion of it or if below zero
 519         m_xScrollPosition = wxMin( m_xScrollLines-noPagePositions, m_xScrollPosition );
 520         m_xScrollPosition = wxMax( 0, m_xScrollPosition );
 521
 522         m_targetWindow->SetScrollPos( wxHORIZONTAL, m_xScrollPosition, TRUE );
 523
 524             m_targetWindow->ScrollWindow( (old_x-m_xScrollPosition)*m_xScrollPixelsPerLine, 0 );
 525     }
 526     if (y_pos != -1)
 527     {
 528         int old_y = m_yScrollPosition;
 529         m_yScrollPosition = y_pos;
 530
 531             // Calculate page size i.e. number of scroll units you get on the
 532             // current client window
 533         int noPagePositions = (int) ( (h/(double)m_yScrollPixelsPerLine) + 0.5 );
 534         if (noPagePositions < 1) noPagePositions = 1;
 535
 536         // Correct position if greater than extent of canvas minus
 537             // the visible portion of it or if below zero
 538         m_yScrollPosition = wxMin( m_yScrollLines-noPagePositions, m_yScrollPosition );
 539         m_yScrollPosition = wxMax( 0, m_yScrollPosition );
 540
 541         m_targetWindow->SetScrollPos( wxVERTICAL, m_yScrollPosition, TRUE );
 542
 543         m_targetWindow->ScrollWindow( 0, (old_y-m_yScrollPosition)*m_yScrollPixelsPerLine );
 544     }
 545
 546
 547 #ifdef __WXMAC__
 548     m_targetWindow->MacUpdateImmediately() ;
 549 #endif
 550 }
 551
 552 void wxScrolledWindow::EnableScrolling (bool x_scroll, bool y_scroll)
 553 {
 554     m_xScrollingEnabled = x_scroll;
 555     m_yScrollingEnabled = y_scroll;
 556 }
 557
 558 void wxScrolledWindow::GetVirtualSize (int *x, int *y) const
 559 {
 560     if ( x )
 561         *x = m_xScrollPixelsPerLine * m_xScrollLines;
 562     if ( y )
 563         *y = m_yScrollPixelsPerLine * m_yScrollLines;
 564 }
 565
 566 // Where the current view starts from
 567 void wxScrolledWindow::GetViewStart (int *x, int *y) const
 568 {
 569     if ( x )
 570         *x = m_xScrollPosition;
 571     if ( y )
 572         *y = m_yScrollPosition;
 573 }
 574
 575 void wxScrolledWindow::CalcScrolledPosition(int x, int y, int *xx, int *yy) const
 576 {
 577     if ( xx )
 578         *xx = x - m_xScrollPosition * m_xScrollPixelsPerLine;
 579     if ( yy )
 580         *yy = y - m_yScrollPosition * m_yScrollPixelsPerLine;
 581 }
 582
 583 void wxScrolledWindow::CalcUnscrolledPosition(int x, int y, int *xx, int *yy) const
 584 {
 585     if ( xx )
 586         *xx = x + m_xScrollPosition * m_xScrollPixelsPerLine;
 587     if ( yy )
 588         *yy = y + m_yScrollPosition * m_yScrollPixelsPerLine;
 589 }
 590
 591 // ----------------------------------------------------------------------------
 592 // event handlers
 593 // ----------------------------------------------------------------------------
 594
 595 // Default OnSize resets scrollbars, if any
 596 void wxScrolledWindow::OnSize(wxSizeEvent& WXUNUSED(event))
 597 {
 598 #if wxUSE_CONSTRAINTS
 599     if (GetAutoLayout())
 600         Layout();
 601 #endif
 602
 603     AdjustScrollbars();
 604 }
 605
 606 // This calls OnDraw, having adjusted the origin according to the current
 607 // scroll position
 608 void wxScrolledWindow::OnPaint(wxPaintEvent& WXUNUSED(event))
 609 {
 610     wxPaintDC dc(this);
 611     PrepareDC(dc);
 612
 613     OnDraw(dc);
 614 }
 615
 616 // kbd handling: notice that we use OnChar() and not OnKeyDown() for
 617 // compatibility here - if we used OnKeyDown(), the programs which process
 618 // arrows themselves in their OnChar() would never get the message and like
 619 // this they always have the priority
 620 void wxScrolledWindow::OnChar(wxKeyEvent& event)
 621 {
 622     if ( !m_xScrollPixelsPerLine || !m_yScrollPixelsPerLine )
 623     {
 624         // stop now - no scroll line size
 625         event.Skip();
 626
 627         return;
 628     }
 629
 630     int stx, sty,       // view origin
 631         szx, szy,       // view size (total)
 632         clix, cliy;     // view size (on screen)
 633
 634     ViewStart(&stx, &sty);
 635     GetClientSize(&clix, &cliy);
 636     clix /= m_xScrollPixelsPerLine;
 637     cliy /= m_yScrollPixelsPerLine;
 638     GetVirtualSize(&szx, &szy);
 639     szx /= m_xScrollPixelsPerLine;
 640     szy /= m_yScrollPixelsPerLine;
 641
 642     switch ( event.KeyCode() )
 643     {
 644         case WXK_PAGEUP:
 645         case WXK_PRIOR:
 646             Scroll(-1, sty - (5 * cliy / 6));
 647             break;
 648
 649         case WXK_PAGEDOWN:
 650         case WXK_NEXT:
 651             Scroll(-1, sty + (5 * cliy / 6));
 652             break;
 653
 654         // notice that handling of Ctrl-Home/End is asymmetrical: Home goes to
 655         // the beginning of the current line, Ctrl-Home returns to the origin
 656         // while End goes to the bottom without changing horizontal position
 657         // and only Ctrl-End does go to the most rightmost position as well
 658         case WXK_HOME:
 659             Scroll(0, event.ControlDown() ? 0 : -1);
 660             break;
 661
 662         case WXK_END:
 663             Scroll(event.ControlDown() ? szx - clix : -1, szy - cliy);
 664             break;
 665
 666         case WXK_UP:
 667             Scroll(-1, sty - 1);
 668             break;
 669
 670         case WXK_DOWN:
 671             Scroll(-1, sty + 1);
 672             break;
 673
 674         case WXK_LEFT:
 675             Scroll(stx - 1, -1);
 676             break;
 677
 678         case WXK_RIGHT:
 679             Scroll(stx + 1, -1);
 680             break;
 681
 682         default:
 683             // not for us
 684             event.Skip();
 685     }
 686 }