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 #ifdef __VMS
  25 #define XtDisplay XTDISPLAY
  26 #endif
  27
  28 // For compilers that support precompilation, includes "wx.h".
  29 #include "wx/wxprec.h"
  30
  31 #ifdef __BORLANDC__
  32     #pragma hdrstop
  33 #endif
  34
  35 #include "wx/utils.h"
  36 #include "wx/dcclient.h"
  37
  38 #include "wx/generic/scrolwin.h"
  39 #include "wx/panel.h"
  40
  41 #ifdef __WXMSW__
  42     #include "windows.h"
  43 #endif
  44
  45 #ifdef __WXMOTIF__
  46 // For wxRETAINED implementation
  47 #ifdef __VMS__ //VMS's Xm.h is not (yet) compatible with C++
  48                //This code switches off the compiler warnings
  49 # pragma message disable nosimpint
  50 #endif
  51 #include <Xm/Xm.h>
  52 #ifdef __VMS__
  53 # pragma message enable nosimpint
  54 #endif
  55 #endif
  56
  57 // ----------------------------------------------------------------------------
  58 // event tables
  59 // ----------------------------------------------------------------------------
  60
  61 BEGIN_EVENT_TABLE(wxScrolledWindow, wxPanel)
  62     EVT_SCROLLWIN(wxScrolledWindow::OnScroll)
  63     EVT_SIZE(wxScrolledWindow::OnSize)
  64     EVT_PAINT(wxScrolledWindow::OnPaint)
  65     EVT_CHAR(wxScrolledWindow::OnChar)
  66 END_EVENT_TABLE()
  67
  68 IMPLEMENT_DYNAMIC_CLASS(wxScrolledWindow, wxPanel)
  69
  70 // ============================================================================
  71 // implementation
  72 // ============================================================================
  73
  74 // ----------------------------------------------------------------------------
  75 // wxScrolledWindow creation
  76 // ----------------------------------------------------------------------------
  77
  78 wxScrolledWindow::wxScrolledWindow()
  79 {
  80     m_xScrollPixelsPerLine = 0;
  81     m_yScrollPixelsPerLine = 0;
  82     m_xScrollingEnabled = TRUE;
  83     m_yScrollingEnabled = TRUE;
  84     m_xScrollPosition = 0;
  85     m_yScrollPosition = 0;
  86     m_xScrollLines = 0;
  87     m_yScrollLines = 0;
  88     m_xScrollLinesPerPage = 0;
  89     m_yScrollLinesPerPage = 0;
  90     m_scaleX = 1.0;
  91     m_scaleY = 1.0;
  92     m_targetWindow = (wxWindow*) NULL;
  93 }
  94
  95 bool wxScrolledWindow::Create(wxWindow *parent,
  96                               wxWindowID id,
  97                               const wxPoint& pos,
  98                               const wxSize& size,
  99                               long style,
 100                               const wxString& name)
 101 {
 102     m_xScrollPixelsPerLine = 0;
 103     m_yScrollPixelsPerLine = 0;
 104     m_xScrollingEnabled = TRUE;
 105     m_yScrollingEnabled = TRUE;
 106     m_xScrollPosition = 0;
 107     m_yScrollPosition = 0;
 108     m_xScrollLines = 0;
 109     m_yScrollLines = 0;
 110     m_xScrollLinesPerPage = 0;
 111     m_yScrollLinesPerPage = 0;
 112     m_scaleX = 1.0;
 113     m_scaleY = 1.0;
 114
 115     m_targetWindow = this;
 116
 117     bool ok = wxPanel::Create(parent, id, pos, size, style, name);
 118
 119 #ifdef __WXMSW__
 120     // we need to process arrows ourselves for scrolling
 121     m_lDlgCode |= DLGC_WANTARROWS;
 122 #endif // __WXMSW__
 123
 124     return ok;
 125 }
 126
 127 wxScrolledWindow::~wxScrolledWindow()
 128 {
 129 }
 130
 131 // ----------------------------------------------------------------------------
 132 // setting scrolling parameters
 133 // ----------------------------------------------------------------------------
 134
 135 /*
 136  * pixelsPerUnitX/pixelsPerUnitY: number of pixels per unit (e.g. pixels per text line)
 137  * noUnitsX/noUnitsY:        : no. units per scrollbar
 138  */
 139 void wxScrolledWindow::SetScrollbars (int pixelsPerUnitX, int pixelsPerUnitY,
 140                int noUnitsX, int noUnitsY,
 141                int xPos, int yPos, bool noRefresh )
 142 {
 143     int xpos, ypos;
 144
 145     CalcUnscrolledPosition(xPos, yPos, &xpos, &ypos);
 146     bool do_refresh =
 147     (
 148       (noUnitsX != 0 && m_xScrollLines == 0) ||
 149       (noUnitsX < m_xScrollLines && xpos > pixelsPerUnitX*noUnitsX) ||
 150
 151       (noUnitsY != 0 && m_yScrollLines == 0) ||
 152       (noUnitsY < m_yScrollLines && ypos > pixelsPerUnitY*noUnitsY) ||
 153       (xPos != m_xScrollPosition) ||
 154       (yPos != m_yScrollPosition)
 155 //       (pixelsPerUnitX != m_xScrollPixelsPerLine) ||
 156 //       (pixelsPerUnitY != m_yScrollPixelsPerLine)
 157     );
 158
 159     m_xScrollPixelsPerLine = pixelsPerUnitX;
 160     m_yScrollPixelsPerLine = pixelsPerUnitY;
 161     m_xScrollPosition = xPos;
 162     m_yScrollPosition = yPos;
 163     m_xScrollLines = noUnitsX;
 164     m_yScrollLines = noUnitsY;
 165
 166 #ifdef __WXMOTIF__
 167     // Sorry, some Motif-specific code to implement a backing pixmap
 168     // for the wxRETAINED style. Implementing a backing store can't
 169     // be entirely generic because it relies on the wxWindowDC implementation
 170     // to duplicate X drawing calls for the backing pixmap.
 171
 172     if ((m_windowStyle & wxRETAINED) == wxRETAINED)
 173     {
 174         Display* dpy = XtDisplay((Widget) GetMainWidget());
 175
 176         int totalPixelWidth = m_xScrollLines * m_xScrollPixelsPerLine;
 177         int totalPixelHeight = m_yScrollLines * m_yScrollPixelsPerLine;
 178         if (m_backingPixmap &&
 179            !((m_pixmapWidth == totalPixelWidth) &&
 180              (m_pixmapHeight == totalPixelHeight)))
 181         {
 182             XFreePixmap (dpy, (Pixmap) m_backingPixmap);
 183             m_backingPixmap = (WXPixmap) 0;
 184         }
 185
 186         if (!m_backingPixmap &&
 187            (noUnitsX != 0) && (noUnitsY != 0))
 188         {
 189             int depth = wxDisplayDepth();
 190             m_pixmapWidth = totalPixelWidth;
 191             m_pixmapHeight = totalPixelHeight;
 192             m_backingPixmap = (WXPixmap) XCreatePixmap (dpy, RootWindow (dpy, DefaultScreen (dpy)),
 193             m_pixmapWidth, m_pixmapHeight, depth);
 194         }
 195
 196     }
 197 #endif // Motif
 198
 199     AdjustScrollbars();
 200
 201     if (do_refresh && !noRefresh)
 202         m_targetWindow->Refresh();
 203
 204 #ifdef __WXMSW__
 205     // GRG: if this turns out to be really necessary, we could
 206     //   at least move it to the above if { ... } so that it is
 207     //   only done if noRefresh = FALSE (the default). OTOH, if
 208     //   this doesn't break anything, which seems to be the
 209     //   case, we could just leave it out.
 210
 211     // Necessary?
 212     // UpdateWindow ((HWND) m_targetWindow->GetHWND());
 213 #endif
 214 #ifdef __WXMAC__
 215     m_targetWindow->MacUpdateImmediately() ;
 216 #endif
 217 }
 218
 219 // ----------------------------------------------------------------------------
 220 // target window handling
 221 // ----------------------------------------------------------------------------
 222
 223 void wxScrolledWindow::SetTargetWindow( wxWindow *target )
 224 {
 225     wxASSERT_MSG( target, wxT("target window must not be NULL") );
 226     m_targetWindow = target;
 227 }
 228
 229 wxWindow *wxScrolledWindow::GetTargetWindow()
 230 {
 231     return m_targetWindow;
 232 }
 233
 234 // ----------------------------------------------------------------------------
 235 // scrolling implementation itself
 236 // ----------------------------------------------------------------------------
 237
 238 void wxScrolledWindow::OnScroll(wxScrollWinEvent& event)
 239 {
 240     int orient = event.GetOrientation();
 241
 242     int nScrollInc = CalcScrollInc(event);
 243     if (nScrollInc == 0) return;
 244
 245     if (orient == wxHORIZONTAL)
 246     {
 247         int newPos = m_xScrollPosition + nScrollInc;
 248         SetScrollPos(wxHORIZONTAL, newPos, TRUE );
 249     }
 250     else
 251     {
 252         int newPos = m_yScrollPosition + nScrollInc;
 253         SetScrollPos(wxVERTICAL, newPos, TRUE );
 254     }
 255
 256     if (orient == wxHORIZONTAL)
 257     {
 258         m_xScrollPosition += nScrollInc;
 259     }
 260     else
 261     {
 262         m_yScrollPosition += nScrollInc;
 263     }
 264
 265     if (orient == wxHORIZONTAL)
 266     {
 267        if (m_xScrollingEnabled)
 268             m_targetWindow->ScrollWindow(-m_xScrollPixelsPerLine * nScrollInc, 0, (const wxRect *) NULL);
 269        else
 270             m_targetWindow->Refresh();
 271     }
 272     else
 273     {
 274         if (m_yScrollingEnabled)
 275             m_targetWindow->ScrollWindow(0, -m_yScrollPixelsPerLine * nScrollInc, (const wxRect *) NULL);
 276         else
 277             m_targetWindow->Refresh();
 278     }
 279 #ifdef __WXMAC__
 280     m_targetWindow->MacUpdateImmediately() ;
 281 #endif
 282 }
 283
 284 int wxScrolledWindow::CalcScrollInc(wxScrollWinEvent& event)
 285 {
 286     int pos = event.GetPosition();
 287     int orient = event.GetOrientation();
 288
 289     int nScrollInc = 0;
 290     if (event.GetEventType() == wxEVT_SCROLLWIN_TOP)
 291     {
 292             if (orient == wxHORIZONTAL)
 293                 nScrollInc = - m_xScrollPosition;
 294             else
 295                 nScrollInc = - m_yScrollPosition;
 296     } else
 297     if (event.GetEventType() == wxEVT_SCROLLWIN_BOTTOM)
 298     {
 299             if (orient == wxHORIZONTAL)
 300                 nScrollInc = m_xScrollLines - m_xScrollPosition;
 301             else
 302                 nScrollInc = m_yScrollLines - m_yScrollPosition;
 303     } else
 304     if (event.GetEventType() == wxEVT_SCROLLWIN_LINEUP)
 305     {
 306             nScrollInc = -1;
 307     } else
 308     if (event.GetEventType() == wxEVT_SCROLLWIN_LINEDOWN)
 309     {
 310             nScrollInc = 1;
 311     } else
 312     if (event.GetEventType() == wxEVT_SCROLLWIN_PAGEUP)
 313     {
 314             if (orient == wxHORIZONTAL)
 315                 nScrollInc = -GetScrollPageSize(wxHORIZONTAL);
 316             else
 317                 nScrollInc = -GetScrollPageSize(wxVERTICAL);
 318     } else
 319     if (event.GetEventType() == wxEVT_SCROLLWIN_PAGEDOWN)
 320     {
 321             if (orient == wxHORIZONTAL)
 322                 nScrollInc = GetScrollPageSize(wxHORIZONTAL);
 323             else
 324                 nScrollInc = GetScrollPageSize(wxVERTICAL);
 325     } else
 326     if ((event.GetEventType() == wxEVT_SCROLLWIN_THUMBTRACK) ||
 327         (event.GetEventType() == wxEVT_SCROLLWIN_THUMBRELEASE))
 328     {
 329             if (orient == wxHORIZONTAL)
 330                 nScrollInc = pos - m_xScrollPosition;
 331             else
 332                 nScrollInc = pos - m_yScrollPosition;
 333     }
 334
 335     if (orient == wxHORIZONTAL)
 336     {
 337         if (m_xScrollPixelsPerLine > 0)
 338         {
 339             int w, h;
 340             m_targetWindow->GetClientSize(&w, &h);
 341
 342             int nMaxWidth = m_xScrollLines*m_xScrollPixelsPerLine;
 343             int noPositions = (int) ( ((nMaxWidth - w)/(double)m_xScrollPixelsPerLine) + 0.5 );
 344             if (noPositions < 0)
 345                 noPositions = 0;
 346
 347             if ( (m_xScrollPosition + nScrollInc) < 0 )
 348                 nScrollInc = -m_xScrollPosition; // As -ve as we can go
 349             else if ( (m_xScrollPosition + nScrollInc) > noPositions )
 350                 nScrollInc = noPositions - m_xScrollPosition; // As +ve as we can go
 351         }
 352         else
 353             m_targetWindow->Refresh();
 354     }
 355     else
 356     {
 357         if (m_yScrollPixelsPerLine > 0)
 358         {
 359             int w, h;
 360             m_targetWindow->GetClientSize(&w, &h);
 361
 362             int nMaxHeight = m_yScrollLines*m_yScrollPixelsPerLine;
 363             int noPositions = (int) ( ((nMaxHeight - h)/(double)m_yScrollPixelsPerLine) + 0.5 );
 364             if (noPositions < 0)
 365                 noPositions = 0;
 366
 367             if ( (m_yScrollPosition + nScrollInc) < 0 )
 368                 nScrollInc = -m_yScrollPosition; // As -ve as we can go
 369             else if ( (m_yScrollPosition + nScrollInc) > noPositions )
 370                 nScrollInc = noPositions - m_yScrollPosition; // As +ve as we can go
 371         }
 372         else
 373             m_targetWindow->Refresh();
 374     }
 375
 376     return nScrollInc;
 377 }
 378
 379 // Adjust the scrollbars - new version.
 380 void wxScrolledWindow::AdjustScrollbars()
 381 {
 382     int w, h;
 383     m_targetWindow->GetClientSize(&w, &h);
 384
 385     int oldXScroll = m_xScrollPosition;
 386     int oldYScroll = m_yScrollPosition;
 387
 388     if (m_xScrollLines > 0)
 389     {
 390         // Calculate page size i.e. number of scroll units you get on the
 391         // current client window
 392         int noPagePositions = (int) ( (w/(double)m_xScrollPixelsPerLine) + 0.5 );
 393         if (noPagePositions < 1) noPagePositions = 1;
 394
 395         // Correct position if greater than extent of canvas minus
 396         // the visible portion of it or if below zero
 397         m_xScrollPosition = wxMin( m_xScrollLines-noPagePositions, m_xScrollPosition);
 398         m_xScrollPosition = wxMax( 0, m_xScrollPosition );
 399
 400         SetScrollbar(wxHORIZONTAL, m_xScrollPosition, noPagePositions, m_xScrollLines);
 401         // The amount by which we scroll when paging
 402         SetScrollPageSize(wxHORIZONTAL, noPagePositions);
 403     }
 404     else
 405     {
 406         m_xScrollPosition = 0;
 407         SetScrollbar (wxHORIZONTAL, 0, 0, 0, FALSE);
 408     }
 409
 410     if (m_yScrollLines > 0)
 411     {
 412         // Calculate page size i.e. number of scroll units you get on the
 413         // current client window
 414         int noPagePositions = (int) ( (h/(double)m_yScrollPixelsPerLine) + 0.5 );
 415         if (noPagePositions < 1) noPagePositions = 1;
 416
 417         // Correct position if greater than extent of canvas minus
 418         // the visible portion of it or if below zero
 419         m_yScrollPosition = wxMin( m_yScrollLines-noPagePositions, m_yScrollPosition );
 420         m_yScrollPosition = wxMax( 0, m_yScrollPosition );
 421
 422         SetScrollbar(wxVERTICAL, m_yScrollPosition, noPagePositions, m_yScrollLines);
 423         // The amount by which we scroll when paging
 424         SetScrollPageSize(wxVERTICAL, noPagePositions);
 425     }
 426     else
 427     {
 428         m_yScrollPosition = 0;
 429         SetScrollbar (wxVERTICAL, 0, 0, 0, FALSE);
 430     }
 431
 432     if (oldXScroll != m_xScrollPosition)
 433     {
 434        if (m_xScrollingEnabled)
 435             m_targetWindow->ScrollWindow( m_xScrollPixelsPerLine * (oldXScroll-m_xScrollPosition), 0, (const wxRect *) NULL );
 436        else
 437             m_targetWindow->Refresh();
 438     }
 439
 440     if (oldYScroll != m_yScrollPosition)
 441     {
 442         if (m_yScrollingEnabled)
 443             m_targetWindow->ScrollWindow( 0, m_yScrollPixelsPerLine * (oldYScroll-m_yScrollPosition), (const wxRect *) NULL );
 444         else
 445             m_targetWindow->Refresh();
 446     }
 447 }
 448
 449 // Override this function if you don't want to have wxScrolledWindow
 450 // automatically change the origin according to the scroll position.
 451 void wxScrolledWindow::PrepareDC(wxDC& dc)
 452 {
 453     dc.SetDeviceOrigin( -m_xScrollPosition * m_xScrollPixelsPerLine,
 454                         -m_yScrollPosition * m_yScrollPixelsPerLine );
 455     dc.SetUserScale( m_scaleX, m_scaleY );
 456 }
 457
 458 #if WXWIN_COMPATIBILITY
 459 void wxScrolledWindow::GetScrollUnitsPerPage (int *x_page, int *y_page) const
 460 {
 461       *x_page = GetScrollPageSize(wxHORIZONTAL);
 462       *y_page = GetScrollPageSize(wxVERTICAL);
 463 }
 464
 465 void wxScrolledWindow::CalcUnscrolledPosition(int x, int y, float *xx, float *yy) const
 466 {
 467     if ( xx )
 468         *xx = (float)(x + m_xScrollPosition * m_xScrollPixelsPerLine);
 469     if ( yy )
 470         *yy = (float)(y + m_yScrollPosition * m_yScrollPixelsPerLine);
 471 }
 472 #endif // WXWIN_COMPATIBILITY
 473
 474 void wxScrolledWindow::GetScrollPixelsPerUnit (int *x_unit, int *y_unit) const
 475 {
 476     if ( x_unit )
 477         *x_unit = m_xScrollPixelsPerLine;
 478     if ( y_unit )
 479         *y_unit = m_yScrollPixelsPerLine;
 480 }
 481
 482 int wxScrolledWindow::GetScrollPageSize(int orient) const
 483 {
 484     if ( orient == wxHORIZONTAL )
 485         return m_xScrollLinesPerPage;
 486     else
 487         return m_yScrollLinesPerPage;
 488 }
 489
 490 void wxScrolledWindow::SetScrollPageSize(int orient, int pageSize)
 491 {
 492     if ( orient == wxHORIZONTAL )
 493         m_xScrollLinesPerPage = pageSize;
 494     else
 495         m_yScrollLinesPerPage = pageSize;
 496 }
 497
 498 /*
 499  * Scroll to given position (scroll position, not pixel position)
 500  */
 501 void wxScrolledWindow::Scroll( int x_pos, int y_pos )
 502 {
 503     if (!m_targetWindow)
 504         return;
 505
 506     if (((x_pos == -1) || (x_pos == m_xScrollPosition)) &&
 507         ((y_pos == -1) || (y_pos == m_yScrollPosition))) return;
 508
 509     int w, h;
 510     m_targetWindow->GetClientSize(&w, &h);
 511
 512     if ((x_pos != -1) && (m_xScrollPixelsPerLine))
 513     {
 514         int old_x = m_xScrollPosition;
 515         m_xScrollPosition = x_pos;
 516
 517         // Calculate page size i.e. number of scroll units you get on the
 518         // current client window
 519         int noPagePositions = (int) ( (w/(double)m_xScrollPixelsPerLine) + 0.5 );
 520         if (noPagePositions < 1) noPagePositions = 1;
 521
 522         // Correct position if greater than extent of canvas minus
 523         // the visible portion of it or if below zero
 524         m_xScrollPosition = wxMin( m_xScrollLines-noPagePositions, m_xScrollPosition );
 525         m_xScrollPosition = wxMax( 0, m_xScrollPosition );
 526
 527         if (old_x != m_xScrollPosition) {
 528             m_targetWindow->SetScrollPos( wxHORIZONTAL, m_xScrollPosition, TRUE );
 529             m_targetWindow->ScrollWindow( (old_x-m_xScrollPosition)*m_xScrollPixelsPerLine, 0 );
 530         }
 531     }
 532     if ((y_pos != -1) && (m_yScrollPixelsPerLine))
 533     {
 534         int old_y = m_yScrollPosition;
 535         m_yScrollPosition = y_pos;
 536
 537         // Calculate page size i.e. number of scroll units you get on the
 538         // current client window
 539         int noPagePositions = (int) ( (h/(double)m_yScrollPixelsPerLine) + 0.5 );
 540         if (noPagePositions < 1) noPagePositions = 1;
 541
 542         // Correct position if greater than extent of canvas minus
 543         // the visible portion of it or if below zero
 544         m_yScrollPosition = wxMin( m_yScrollLines-noPagePositions, m_yScrollPosition );
 545         m_yScrollPosition = wxMax( 0, m_yScrollPosition );
 546
 547         if (old_y != m_yScrollPosition) {
 548             m_targetWindow->SetScrollPos( wxVERTICAL, m_yScrollPosition, TRUE );
 549             m_targetWindow->ScrollWindow( 0, (old_y-m_yScrollPosition)*m_yScrollPixelsPerLine );
 550         }
 551     }
 552
 553 #ifdef __WXMAC__
 554     m_targetWindow->MacUpdateImmediately();
 555 #endif
 556 }
 557
 558 void wxScrolledWindow::EnableScrolling (bool x_scroll, bool y_scroll)
 559 {
 560     m_xScrollingEnabled = x_scroll;
 561     m_yScrollingEnabled = y_scroll;
 562 }
 563
 564 void wxScrolledWindow::GetVirtualSize (int *x, int *y) const
 565 {
 566     if ( x )
 567         *x = m_xScrollPixelsPerLine * m_xScrollLines;
 568     if ( y )
 569         *y = m_yScrollPixelsPerLine * m_yScrollLines;
 570 }
 571
 572 // Where the current view starts from
 573 void wxScrolledWindow::GetViewStart (int *x, int *y) const
 574 {
 575     if ( x )
 576         *x = m_xScrollPosition;
 577     if ( y )
 578         *y = m_yScrollPosition;
 579 }
 580
 581 void wxScrolledWindow::CalcScrolledPosition(int x, int y, int *xx, int *yy) const
 582 {
 583     if ( xx )
 584         *xx = x - m_xScrollPosition * m_xScrollPixelsPerLine;
 585     if ( yy )
 586         *yy = y - m_yScrollPosition * m_yScrollPixelsPerLine;
 587 }
 588
 589 void wxScrolledWindow::CalcUnscrolledPosition(int x, int y, int *xx, int *yy) const
 590 {
 591     if ( xx )
 592         *xx = x + m_xScrollPosition * m_xScrollPixelsPerLine;
 593     if ( yy )
 594         *yy = y + m_yScrollPosition * m_yScrollPixelsPerLine;
 595 }
 596
 597 // ----------------------------------------------------------------------------
 598 // event handlers
 599 // ----------------------------------------------------------------------------
 600
 601 // Default OnSize resets scrollbars, if any
 602 void wxScrolledWindow::OnSize(wxSizeEvent& WXUNUSED(event))
 603 {
 604 #if wxUSE_CONSTRAINTS
 605     if (GetAutoLayout())
 606         Layout();
 607 #endif
 608
 609     AdjustScrollbars();
 610 }
 611
 612 // This calls OnDraw, having adjusted the origin according to the current
 613 // scroll position
 614 void wxScrolledWindow::OnPaint(wxPaintEvent& WXUNUSED(event))
 615 {
 616     wxPaintDC dc(this);
 617     PrepareDC(dc);
 618
 619     OnDraw(dc);
 620 }
 621
 622 // kbd handling: notice that we use OnChar() and not OnKeyDown() for
 623 // compatibility here - if we used OnKeyDown(), the programs which process
 624 // arrows themselves in their OnChar() would never get the message and like
 625 // this they always have the priority
 626 void wxScrolledWindow::OnChar(wxKeyEvent& event)
 627 {
 628     int stx, sty,       // view origin
 629         szx, szy,       // view size (total)
 630         clix, cliy;     // view size (on screen)
 631
 632     ViewStart(&stx, &sty);
 633     GetClientSize(&clix, &cliy);
 634     GetVirtualSize(&szx, &szy);
 635
 636     if( m_xScrollPixelsPerLine )
 637     {
 638         clix /= m_xScrollPixelsPerLine;
 639         szx /= m_xScrollPixelsPerLine;
 640     }
 641     else
 642     {
 643         clix = 0;
 644         szx = -1;
 645     }
 646     if( m_yScrollPixelsPerLine )
 647     {
 648         cliy /= m_yScrollPixelsPerLine;
 649         szy /= m_yScrollPixelsPerLine;
 650     }
 651     else
 652     {
 653         cliy = 0;
 654         szy = -1;
 655     }
 656
 657     int dsty;
 658     switch ( event.KeyCode() )
 659     {
 660         case WXK_PAGEUP:
 661         case WXK_PRIOR:
 662             dsty = sty - (5 * cliy / 6);
 663             Scroll(-1, (dsty == -1) ? 0 : dsty);
 664             break;
 665
 666         case WXK_PAGEDOWN:
 667         case WXK_NEXT:
 668             Scroll(-1, sty + (5 * cliy / 6));
 669             break;
 670
 671         case WXK_HOME:
 672             Scroll(0, event.ControlDown() ? 0 : -1);
 673             break;
 674
 675         case WXK_END:
 676             Scroll(szx - clix, event.ControlDown() ? szy - cliy : -1);
 677             break;
 678
 679         case WXK_UP:
 680             Scroll(-1, sty - 1);
 681             break;
 682
 683         case WXK_DOWN:
 684             Scroll(-1, sty + 1);
 685             break;
 686
 687         case WXK_LEFT:
 688             Scroll(stx - 1, -1);
 689             break;
 690
 691         case WXK_RIGHT:
 692             Scroll(stx + 1, -1);
 693             break;
 694
 695         default:
 696             // not for us
 697             event.Skip();
 698     }
 699 }