src/cocoa/dc.mm

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        src/cocoa/dc.mm
   3 // Purpose:     wxDC
   4 // Author:      David Elliott
   5 // Modified by:
   6 // Created:     2003/04/01
   7 // RCS-ID:      $Id$
   8 // Copyright:   (c) 2003 David Elliott
   9 // Licence:     wxWindows license
  10 /////////////////////////////////////////////////////////////////////////////
  11
  12 #include "wx/dc.h"
  13 #include "wx/log.h"
  14
  15 #include "wx/cocoa/autorelease.h"
  16
  17 #import <AppKit/NSBezierPath.h>
  18 #import <AppKit/NSTextStorage.h>
  19 #import <AppKit/NSLayoutManager.h>
  20 #import <AppKit/NSTextContainer.h>
  21 #import <AppKit/NSGraphicsContext.h>
  22 #import <AppKit/NSAffineTransform.h>
  23 #import <AppKit/NSColor.h>
  24 #import <AppKit/NSTypeSetter.h>
  25 #import <AppKit/NSImage.h>
  26
  27 #include <wx/listimpl.cpp>
  28 WX_DEFINE_LIST(wxCocoaDCStack);
  29
  30 IMPLEMENT_ABSTRACT_CLASS(wxDC, wxObject)
  31 WX_NSTextStorage wxDC::sm_cocoaNSTextStorage = nil;
  32 WX_NSLayoutManager wxDC::sm_cocoaNSLayoutManager = nil;
  33 WX_NSTextContainer wxDC::sm_cocoaNSTextContainer = nil;
  34 wxCocoaDCStack wxDC::sm_cocoaDCStack;
  35
  36 inline void CocoaSetPenForNSBezierPath(wxPen &pen, NSBezierPath *bezpath)
  37 {
  38     [pen.GetNSColor() set];
  39     const float *pattern;
  40     [bezpath setLineDash:pattern count:pen.GetCocoaLineDash(&pattern) phase:0.0];
  41     [bezpath setLineWidth:pen.GetWidth()];
  42     switch(pen.GetJoin())
  43     {
  44     case wxJOIN_BEVEL:
  45         [bezpath setLineJoinStyle:NSBevelLineJoinStyle];
  46         break;
  47     case wxJOIN_ROUND:
  48         [bezpath setLineJoinStyle:NSRoundLineJoinStyle];
  49         break;
  50     case wxJOIN_MITER:
  51         [bezpath setLineJoinStyle:NSMiterLineJoinStyle];
  52         break;
  53     }
  54     switch(pen.GetCap())
  55     {
  56     case wxCAP_ROUND:
  57         [bezpath setLineCapStyle:NSRoundLineCapStyle];
  58         break;
  59     case wxCAP_PROJECTING:
  60         [bezpath setLineCapStyle:NSSquareLineCapStyle];
  61         break;
  62     case wxCAP_BUTT:
  63         [bezpath setLineCapStyle:NSButtLineCapStyle];
  64         break;
  65     }
  66 }
  67
  68 void wxDC::CocoaInitializeTextSystem()
  69 {
  70     wxASSERT_MSG(!sm_cocoaNSTextStorage && !sm_cocoaNSLayoutManager && !sm_cocoaNSTextContainer,"Text system already initalized!  BAD PROGRAMMER!");
  71
  72     sm_cocoaNSTextStorage = [[NSTextStorage alloc] init];
  73
  74     sm_cocoaNSLayoutManager = [[NSLayoutManager alloc] init];
  75     [sm_cocoaNSTextStorage addLayoutManager:sm_cocoaNSLayoutManager];
  76     // NSTextStorage retains NSLayoutManager, but so do we
  77     // [sm_cocoaNSLayoutManager release]; [sm_cocoaNSLayoutManager retain];
  78
  79     // NOTE:  initWithContainerSize is the designated initializer, but the
  80     // Apple CircleView sample gets away with just calling init, which
  81     // is all we really need for our purposes.
  82     sm_cocoaNSTextContainer = [[NSTextContainer alloc] init];
  83     [sm_cocoaNSLayoutManager addTextContainer:sm_cocoaNSTextContainer];
  84     // NSLayoutManager retains NSTextContainer, but so do we
  85     // [sm_cocoaNSTextContainer release]; [sm_cocoaNSTextContainer retain];
  86 }
  87
  88 void wxDC::CocoaShutdownTextSystem()
  89 {
  90     [sm_cocoaNSTextContainer release]; sm_cocoaNSTextContainer = nil;
  91     [sm_cocoaNSLayoutManager release]; sm_cocoaNSLayoutManager = nil;
  92     [sm_cocoaNSTextStorage release]; sm_cocoaNSTextStorage = nil;
  93 }
  94
  95 void wxDC::CocoaUnwindStackAndLoseFocus()
  96 {
  97     wxCocoaDCStack::Node *ourNode=sm_cocoaDCStack.Find(this);
  98     if(ourNode)
  99     {
 100         wxCocoaDCStack::Node *node=sm_cocoaDCStack.GetFirst();
 101         for(;node!=ourNode; node=sm_cocoaDCStack.GetFirst())
 102         {
 103             wxDC *dc = node->GetData();
 104             wxASSERT(dc);
 105             wxASSERT(dc!=this);
 106             if(!dc->CocoaUnlockFocus())
 107             {
 108                 wxFAIL_MSG("Unable to unlock focus on higher-level DC!");
 109             }
 110             sm_cocoaDCStack.DeleteNode(node);
 111         }
 112         wxASSERT(node==ourNode);
 113         wxASSERT(ourNode->GetData() == this);
 114         ourNode->GetData()->CocoaUnlockFocus();
 115         sm_cocoaDCStack.DeleteNode(ourNode);
 116     }
 117 }
 118
 119 bool wxDC::CocoaUnwindStackAndTakeFocus()
 120 {
 121     wxCocoaDCStack::Node *node=sm_cocoaDCStack.GetFirst();
 122     for(;node;node = sm_cocoaDCStack.GetFirst())
 123     {
 124         wxDC *dc = node->GetData();
 125         wxASSERT(dc);
 126         // If we're on the stack, then it's unwound enough and we have focus
 127         if(dc==this)
 128             return true;
 129         // If unable to unlockFocus (e.g. wxPaintDC) stop here
 130         if(!dc->CocoaUnlockFocus())
 131             break;
 132         sm_cocoaDCStack.DeleteNode(node);
 133     }
 134     return CocoaLockFocus();
 135 }
 136
 137 wxDC::wxDC(void)
 138 {
 139     m_cocoaFlipped = false;
 140     m_cocoaHeight = 0.0;
 141     m_pen = *wxBLACK_PEN;
 142 }
 143
 144 wxDC::~wxDC(void)
 145 {
 146 }
 147
 148 bool wxDC::CocoaLockFocus()
 149 {
 150     return false;
 151 }
 152
 153 bool wxDC::CocoaUnlockFocus()
 154 {
 155     return false;
 156 }
 157
 158 void wxDC::CocoaApplyTransformations()
 159 {
 160     // This transform flips the graphics since wxDC uses top-left origin
 161     if(!m_cocoaFlipped)
 162     {
 163         // The transform is auto released
 164         NSAffineTransform *transform = [NSAffineTransform transform];
 165         /*  x' = 1x + 0y + 0
 166             y' = 0x + -1y + window's height
 167         */
 168         NSAffineTransformStruct matrix = {
 169             1,  0
 170         ,   0, -1
 171         ,   0, m_cocoaHeight
 172         };
 173         [transform setTransformStruct: matrix];
 174         // Apply the transform
 175         [transform concat];
 176     }
 177     // TODO: Apply scaling transformation
 178 }
 179
 180 void wxDC::DoDrawRectangle(wxCoord x, wxCoord y, wxCoord width, wxCoord height)
 181 {
 182     if(!CocoaTakeFocus()) return;
 183     NSBezierPath *bezpath = [NSBezierPath bezierPathWithRect:NSMakeRect(x,y,width,height)];
 184     CocoaSetPenForNSBezierPath(m_pen,bezpath);
 185     [bezpath stroke];
 186     [m_brush.GetNSColor() set];
 187     [bezpath fill];
 188 }
 189
 190 void wxDC::DoDrawLine(wxCoord x1, wxCoord y1, wxCoord x2, wxCoord y2)
 191 {
 192     if(!CocoaTakeFocus()) return;
 193     NSBezierPath *bezpath = [NSBezierPath bezierPath];
 194     [bezpath moveToPoint:NSMakePoint(x1,y1)];
 195     [bezpath lineToPoint:NSMakePoint(x2,y2)];
 196
 197     CocoaSetPenForNSBezierPath(m_pen,bezpath);
 198     [bezpath stroke];
 199 }
 200
 201 void wxDC::DoGetTextExtent(const wxString& text, wxCoord *x, wxCoord *y, wxCoord *descent, wxCoord *externalLeading, wxFont *theFont) const
 202 {
 203     wxAutoNSAutoreleasePool pool;
 204 // FIXME: Cache this so it can be used for DoDrawText
 205     wxASSERT_MSG(sm_cocoaNSTextStorage && sm_cocoaNSLayoutManager && sm_cocoaNSTextContainer, "Text system has not been initialized.  BAD PROGRAMMER!");
 206     NSAttributedString *attributedString = [[NSAttributedString alloc]
 207             initWithString:[NSString stringWithCString:text.c_str()]];
 208     [sm_cocoaNSTextStorage setAttributedString:attributedString];
 209     [attributedString release];
 210
 211     NSRange glyphRange = [sm_cocoaNSLayoutManager glyphRangeForTextContainer:sm_cocoaNSTextContainer];
 212     NSRect usedRect = [sm_cocoaNSLayoutManager usedRectForTextContainer:sm_cocoaNSTextContainer];
 213     if(x)
 214         *x=(int)usedRect.size.width;
 215     if(y)
 216         *y=(int)usedRect.size.height;
 217     if(descent)
 218         *descent=0;
 219     if(externalLeading)
 220         *externalLeading=0;
 221 }
 222
 223 void wxDC::DoDrawText(const wxString& text, wxCoord x, wxCoord y)
 224 {
 225     if(!CocoaTakeFocus()) return;
 226     wxASSERT_MSG(sm_cocoaNSTextStorage && sm_cocoaNSLayoutManager && sm_cocoaNSTextContainer, "Text system has not been initialized.  BAD PROGRAMMER!");
 227     NSAttributedString *attributedString = [[NSAttributedString alloc]
 228             initWithString:[NSString stringWithCString:text.c_str()]];
 229     [sm_cocoaNSTextStorage setAttributedString:attributedString];
 230     [attributedString release];
 231
 232     // Set the color (and later font) attributes
 233     NSColor *fgColor = m_textForegroundColour.GetNSColor();
 234     NSColor *bgColor = m_textBackgroundColour.GetNSColor();
 235     if(!fgColor)
 236         fgColor = [NSColor clearColor];
 237     if(!bgColor)
 238         bgColor = [NSColor clearColor];
 239     NSDictionary *attrDict = [[NSDictionary alloc] initWithObjectsAndKeys:
 240             fgColor, NSForegroundColorAttributeName,
 241             bgColor, NSBackgroundColorAttributeName,
 242             nil];
 243     [sm_cocoaNSTextStorage addAttributes: attrDict range:NSMakeRange(0,[sm_cocoaNSTextStorage length])];
 244     [attrDict release];
 245
 246     NSRange glyphRange = [sm_cocoaNSLayoutManager glyphRangeForTextContainer:sm_cocoaNSTextContainer];
 247     NSRect usedRect = [sm_cocoaNSLayoutManager usedRectForTextContainer:sm_cocoaNSTextContainer];
 248     // NOTE: We'll crash trying to get the location of glyphAtIndex:0 if
 249     // there is no length or we don't start at zero
 250     if(!glyphRange.length)
 251         return;
 252     wxASSERT_MSG(glyphRange.location==0,"glyphRange must begin at zero");
 253
 254     NSAffineTransform *transform = [NSAffineTransform transform];
 255     [transform translateXBy:x yBy:y];
 256
 257     NSAffineTransform *flipTransform = [NSAffineTransform transform];
 258     /*  x' = 1x + 0y + 0
 259         y' = 0x + -1y + window's height
 260     */
 261     NSAffineTransformStruct matrix = {
 262         1,  0
 263     ,   0, -1
 264     ,   0, usedRect.size.height
 265     };
 266     [flipTransform setTransformStruct: matrix];
 267
 268     NSGraphicsContext *context = [NSGraphicsContext currentContext];
 269     [context saveGraphicsState];
 270     [transform concat];
 271     [flipTransform concat];
 272     #if 0
 273     // Draw+fill a rectangle so we can see where the shit is supposed to be.
 274     wxLogDebug("(%f,%f) (%fx%f)",usedRect.origin.x,usedRect.origin.y,usedRect.size.width,usedRect.size.height);
 275     NSBezierPath *bezpath = [NSBezierPath bezierPathWithRect:NSMakeRect(0,0,usedRect.size.width,usedRect.size.height)];
 276     [[NSColor blackColor] set];
 277     [bezpath stroke];
 278     [[NSColor blueColor] set];
 279     [bezpath fill];
 280     #endif
 281
 282     NSPoint layoutLocation = [sm_cocoaNSLayoutManager locationForGlyphAtIndex:0];
 283     layoutLocation.x = 0.0;
 284     layoutLocation.y *= -1.0;
 285     layoutLocation.y += [[sm_cocoaNSLayoutManager typesetter] baselineOffsetInLayoutManager:sm_cocoaNSLayoutManager glyphIndex:0];
 286     if(m_backgroundMode==wxSOLID)
 287         [sm_cocoaNSLayoutManager drawBackgroundForGlyphRange:glyphRange  atPoint:NSZeroPoint];
 288     [sm_cocoaNSLayoutManager drawGlyphsForGlyphRange:glyphRange  atPoint:layoutLocation];
 289
 290     [context restoreGraphicsState];
 291 }
 292
 293 // wxDCBase functions
 294 int wxDCBase::DeviceToLogicalX(int x) const
 295 {
 296     return x;
 297 }
 298
 299 int wxDCBase::DeviceToLogicalY(int y) const
 300 {
 301     return y;
 302 }
 303
 304 int wxDCBase::DeviceToLogicalXRel(int x) const
 305 {
 306     return x;
 307 }
 308
 309 int wxDCBase::DeviceToLogicalYRel(int y) const
 310 {
 311     return y;
 312 }
 313
 314 int wxDCBase::LogicalToDeviceX(int x) const
 315 {
 316     return x;
 317 }
 318
 319 int wxDCBase::LogicalToDeviceY(int y) const
 320 {
 321     return y;
 322 }
 323
 324 int wxDCBase::LogicalToDeviceXRel(int x) const
 325 {
 326     return x;
 327 }
 328
 329 int wxDCBase::LogicalToDeviceYRel(int y) const
 330 {
 331     return y;
 332 }
 333
 334 ///////////////////////////////////////////////////////////////////////////
 335 // cut here, the rest is stubs
 336 ///////////////////////////////////////////////////////////////////////////
 337
 338 //-----------------------------------------------------------------------------
 339 // constants
 340 //-----------------------------------------------------------------------------
 341
 342 #define mm2inches               0.0393700787402
 343 #define inches2mm               25.4
 344 #define mm2twips                56.6929133859
 345 #define twips2mm                0.0176388888889
 346 #define mm2pt                   2.83464566929
 347 #define pt2mm                   0.352777777778
 348
 349 //-----------------------------------------------------------------------------
 350 // wxDC
 351 //-----------------------------------------------------------------------------
 352
 353 void wxDC::DoDrawIcon( const wxIcon &WXUNUSED(icon), int WXUNUSED(x), int WXUNUSED(y) )
 354 {
 355 };
 356
 357 void wxDC::DoDrawPoint( int x, int y )
 358 {
 359 };
 360
 361 void wxDC::DoDrawPolygon( int, wxPoint *, int, int, int)
 362 {
 363 };
 364
 365 void wxDC::DoDrawLines( int, wxPoint *, int, int )
 366 {
 367 }
 368
 369 int wxDC::GetDepth() const
 370 {
 371     return 0;
 372 }
 373
 374 wxSize wxDC::GetPPI() const
 375 {
 376     return wxSize(0,0);
 377 }
 378
 379 bool wxDC::CanGetTextExtent() const
 380 {
 381     return false;
 382 }
 383
 384 wxCoord wxDC::GetCharHeight() const
 385 {
 386     return 0;
 387 }
 388
 389 wxCoord wxDC::GetCharWidth() const
 390 {
 391     return 0;
 392 }
 393
 394 bool wxDC::CanDrawBitmap() const
 395 {
 396     return true;
 397 }
 398
 399 bool wxDC::DoGetPixel(wxCoord x, wxCoord y, wxColour *col) const
 400 {
 401     return false;
 402 }
 403
 404 void wxDC::DoDrawArc(wxCoord x1, wxCoord y1, wxCoord x2, wxCoord y2, wxCoord xc, wxCoord yc)
 405 {
 406 }
 407
 408 void wxDC::SetPen(const wxPen& pen)
 409 {
 410     m_pen = pen;
 411 }
 412
 413 void wxDC::SetBrush(const wxBrush& brush)
 414 {
 415     m_brush = brush;
 416 }
 417
 418 void wxDC::DoSetClippingRegionAsRegion(const wxRegion& region)
 419 {
 420 }
 421
 422 void wxDC::DoSetClippingRegion(wxCoord x, wxCoord y, wxCoord width, wxCoord height)
 423 {
 424 }
 425
 426 void wxDC::DestroyClippingRegion()
 427 {
 428 }
 429
 430 void wxDC::DoDrawRoundedRectangle(wxCoord x, wxCoord y, wxCoord width, wxCoord height, double radius)
 431 {
 432 }
 433
 434 void wxDC::DoDrawRotatedText(const wxString& text, wxCoord x, wxCoord y, double angle)
 435 {
 436 }
 437
 438 void wxDC::DoDrawEllipticArc(wxCoord x, wxCoord y, wxCoord w, wxCoord h, double sa, double ea)
 439 {
 440 }
 441
 442 void wxDC::DoDrawEllipse(wxCoord x, wxCoord y, wxCoord width, wxCoord height)
 443 {
 444 }
 445
 446 void wxDC::DoDrawBitmap(const wxBitmap &bmp, wxCoord x, wxCoord y, bool useMask)
 447 {
 448     if(!CocoaTakeFocus()) return;
 449     if(!bmp.Ok())
 450         return;
 451
 452 #if 0
 453     // Draw a rect so we can see where it's supposed to be
 454     wxLogDebug("image at (%d,%d) size %dx%d",x,y,bmp.GetWidth(),bmp.GetHeight());
 455     NSBezierPath *bezpath = [NSBezierPath bezierPathWithRect:NSMakeRect(x,y,bmp.GetWidth(),bmp.GetHeight())];
 456     [[NSColor blackColor] set];
 457     [bezpath stroke];
 458     [[NSColor blueColor] set];
 459     [bezpath fill];
 460 #endif // 0
 461
 462     NSAffineTransform *transform = [NSAffineTransform transform];
 463     [transform translateXBy:x yBy:y];
 464
 465     NSAffineTransform *flipTransform = [NSAffineTransform transform];
 466     /*  x' = 1x + 0y + 0
 467         y' = 0x + -1y + window's height
 468     */
 469     NSAffineTransformStruct matrix = {
 470         1,  0
 471     ,   0, -1
 472     ,   0, bmp.GetHeight()
 473     };
 474     [flipTransform setTransformStruct: matrix];
 475
 476     NSGraphicsContext *context = [NSGraphicsContext currentContext];
 477     [context saveGraphicsState];
 478     [transform concat];
 479     [flipTransform concat];
 480
 481     NSImage *nsimage = [[NSImage alloc]
 482             initWithSize:NSMakeSize(bmp.GetWidth(), bmp.GetHeight())];
 483     [nsimage addRepresentation: const_cast<wxBitmap&>(bmp).GetNSBitmapImageRep()];
 484     [nsimage drawAtPoint: NSMakePoint(0,0)
 485         fromRect: NSMakeRect(0.0,0.0,bmp.GetWidth(),bmp.GetHeight())
 486         operation: NSCompositeCopy
 487         fraction: 1.0];
 488
 489     [nsimage release];
 490     [context restoreGraphicsState];
 491 }
 492
 493 bool wxDC::DoFloodFill(wxCoord x, wxCoord y, const wxColour& col, int style)
 494 {
 495     return false;
 496 }
 497
 498 void wxDC::DoCrossHair(wxCoord x, wxCoord y)
 499 {
 500 }
 501
 502
 503 bool wxDC::DoBlit(wxCoord xdest, wxCoord ydest, wxCoord width, wxCoord height, wxDC *source, wxCoord xsrc, wxCoord ysrc, int rop, bool useMask , wxCoord xsrcMask, wxCoord ysrcMask)
 504 {
 505     if(!CocoaTakeFocus()) return false;
 506     if(!source) return false;
 507     return source->CocoaDoBlitOnFocusedDC(xdest,ydest,width,height,
 508         xsrc, ysrc, rop, useMask, xsrcMask, ysrcMask);
 509 }
 510
 511 bool wxDC::CocoaDoBlitOnFocusedDC(wxCoord xdest, wxCoord ydest,
 512     wxCoord width, wxCoord height, wxCoord xsrc, wxCoord ysrc,
 513     int logicalFunc, bool useMask, wxCoord xsrcMask, wxCoord ysrcMask)
 514 {
 515     return false;
 516 }
 517
 518 void wxDC::DoGetSize( int* width, int* height ) const
 519 {
 520   *width = m_maxX-m_minX;
 521   *height = m_maxY-m_minY;
 522 };
 523
 524 void wxDC::DoGetSizeMM( int* width, int* height ) const
 525 {
 526   int w = 0;
 527   int h = 0;
 528   GetSize( &w, &h );
 529 };
 530
 531 void wxDC::SetTextForeground( const wxColour &col )
 532 {
 533   if (!Ok()) return;
 534   m_textForegroundColour = col;
 535 };
 536
 537 void wxDC::SetTextBackground( const wxColour &col )
 538 {
 539   if (!Ok()) return;
 540   m_textBackgroundColour = col;
 541 };
 542
 543 void wxDC::Clear()
 544 {
 545 }
 546
 547 void wxDC::SetBackground(const wxBrush& brush)
 548 {
 549     m_backgroundBrush = brush;
 550 }
 551
 552 void wxDC::SetPalette(const wxPalette&)
 553 {
 554 }
 555
 556 void wxDC::SetLogicalFunction(int)
 557 {
 558 }
 559
 560
 561 void wxDC::SetMapMode( int mode )
 562 {
 563   switch (mode)
 564   {
 565     case wxMM_TWIPS:
 566       break;
 567     case wxMM_POINTS:
 568       break;
 569     case wxMM_METRIC:
 570       break;
 571     case wxMM_LOMETRIC:
 572       break;
 573     default:
 574     case wxMM_TEXT:
 575       SetLogicalScale( 1.0, 1.0 );
 576       break;
 577   };
 578   if (mode != wxMM_TEXT)
 579   {
 580   };
 581 };
 582
 583 void wxDC::SetUserScale( double x, double y )
 584 {
 585   // allow negative ? -> no
 586   m_userScaleX = x;
 587   m_userScaleY = y;
 588   ComputeScaleAndOrigin();
 589 };
 590
 591 void wxDC::SetLogicalScale( double x, double y )
 592 {
 593   // allow negative ?
 594   m_logicalScaleX = x;
 595   m_logicalScaleY = y;
 596   ComputeScaleAndOrigin();
 597 };
 598
 599 void wxDC::SetLogicalOrigin( wxCoord x, wxCoord y )
 600 {
 601   m_logicalOriginX = x * m_signX;   // is this still correct ?
 602   m_logicalOriginY = y * m_signY;
 603   ComputeScaleAndOrigin();
 604 };
 605
 606 void wxDC::SetDeviceOrigin( wxCoord x, wxCoord y )
 607 {
 608   ComputeScaleAndOrigin();
 609 };
 610
 611 void wxDC::SetAxisOrientation( bool xLeftRight, bool yBottomUp )
 612 {
 613   m_signX = (xLeftRight ?  1 : -1);
 614   m_signY = (yBottomUp  ? -1 :  1);
 615   ComputeScaleAndOrigin();
 616 };
 617
 618 void wxDC::ComputeScaleAndOrigin(void)
 619 {
 620   // CMB: copy scale to see if it changes
 621   double origScaleX = m_scaleX;
 622   double origScaleY = m_scaleY;
 623
 624   m_scaleX = m_logicalScaleX * m_userScaleX;
 625   m_scaleY = m_logicalScaleY * m_userScaleY;
 626
 627   // CMB: if scale has changed call SetPen to recalulate the line width
 628   if (m_scaleX != origScaleX || m_scaleY != origScaleY)
 629   {
 630     // this is a bit artificial, but we need to force wxDC to think
 631     // the pen has changed
 632     wxPen* pen = & GetPen();
 633     wxPen tempPen;
 634     m_pen = tempPen;
 635     SetPen(* pen);
 636   }
 637 };
 638