interface/wx/dc.h

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        dc.h
   3 // Purpose:     interface of wxDC
   4 // Author:      wxWidgets team
   5 // RCS-ID:      $Id$
   6 // Licence:     wxWindows licence
   7 /////////////////////////////////////////////////////////////////////////////
   8
   9
  10 /**
  11     Logical raster operations which can be used with wxDC::SetLogicalFunction
  12     and some other wxDC functions (e.g. wxDC::Blit and wxDC::StretchBlit).
  13
  14     The description of the values below refer to how a generic @e src source pixel
  15     and the corresponding @e dst destination pixel gets combined together to produce
  16     the final pixel. E.g. @c wxCLEAR and @c wxSET completely ignore the source
  17     and the destination pixel and always put zeroes or ones in the final surface.
  18 */
  19 enum wxRasterOperationMode
  20 {
  21     wxCLEAR,       //!< 0
  22     wxXOR,         //!< @e src XOR @e dst
  23     wxINVERT,      //!< NOT @e dst
  24     wxOR_REVERSE,  //!< @e src OR (NOT @e dst)
  25     wxAND_REVERSE, //!< @e src AND (NOT @e dst)
  26     wxCOPY,        //!< @e src
  27     wxAND,         //!< @e src AND @e dst
  28     wxAND_INVERT,  //!< (NOT @e src) AND @e dst
  29     wxNO_OP,       //!< @e dst
  30     wxNOR,         //!< (NOT @e src) AND (NOT @e dst)
  31     wxEQUIV,       //!< (NOT @e src) XOR @e dst
  32     wxSRC_INVERT,  //!< (NOT @e src)
  33     wxOR_INVERT,   //!< (NOT @e src) OR @e dst
  34     wxNAND,        //!< (NOT @e src) OR (NOT @e dst)
  35     wxOR,          //!< @e src OR @e dst
  36     wxSET          //!< 1
  37 };
  38
  39 /**
  40     Flood styles used by wxDC::FloodFill.
  41 */
  42 enum wxFloodFillStyle
  43 {
  44     /** The flooding occurs until a colour other than the given colour is encountered. */
  45     wxFLOOD_SURFACE = 1,
  46
  47     /** The area to be flooded is bounded by the given colour. */
  48     wxFLOOD_BORDER
  49 };
  50
  51 /**
  52     The mapping used to transform @e logical units to @e device units.
  53     See wxDC::SetMapMode.
  54 */
  55 enum wxMappingMode
  56 {
  57     /**
  58         Each logical unit is 1 device pixel.
  59         This is the default mapping mode for all wxDC-derived classes.
  60     */
  61     wxMM_TEXT = 1,
  62
  63     /** Each logical unit is 1 millimeter. */
  64     wxMM_METRIC,
  65
  66     /** Each logical unit is 1/10 of a millimeter. */
  67     wxMM_LOMETRIC,
  68
  69     /**
  70         Each logical unit is 1/20 of a @e "printer point", or 1/1440 of an inch
  71         (also known as "twip"). Equivalent to about 17.64 micrometers.
  72     */
  73     wxMM_TWIPS,
  74
  75     /**
  76         Each logical unit is a @e "printer point" i.e. 1/72 of an inch.
  77         Equivalent to about 353 micrometers.
  78     */
  79     wxMM_POINTS
  80 };
  81
  82 /**
  83     Simple collection of various font metrics.
  84
  85     This object is returned by wxDC::GetFontMetrics().
  86
  87     @since 2.9.2
  88
  89     @library{wxcore}
  90     @category{dc,gdi}
  91  */
  92 struct wxFontMetrics
  93 {
  94     /// Constructor initializes all fields to 0.
  95     wxFontMetrics();
  96
  97     int height,             ///< Total character height.
  98         ascent,             ///< Part of the height above the baseline.
  99         descent,            ///< Part of the height below the baseline.
 100         internalLeading,    ///< Intra-line spacing.
 101         externalLeading,    ///< Inter-line spacing.
 102         averageWidth;       ///< Average font width, a.k.a. "x-width".
 103 };
 104
 105
 106 /**
 107     @class wxDC
 108
 109     A wxDC is a @e "device context" onto which graphics and text can be drawn.
 110     It is intended to represent different output devices and offers a common
 111     abstract API for drawing on any of them.
 112
 113     wxWidgets offers an alternative drawing API based on the modern drawing
 114     backends GDI+, CoreGraphics and Cairo. See wxGraphicsContext, wxGraphicsRenderer
 115     and related classes. There is also a wxGCDC linking the APIs by offering
 116     the wxDC API on top of a wxGraphicsContext.
 117
 118     wxDC is an abstract base class and cannot be created directly.
 119     Use wxPaintDC, wxClientDC, wxWindowDC, wxScreenDC, wxMemoryDC or
 120     wxPrinterDC. Notice that device contexts which are associated with windows
 121     (i.e. wxClientDC, wxWindowDC and wxPaintDC) use the window font and colours
 122     by default (starting with wxWidgets 2.9.0) but the other device context
 123     classes use system-default values so you always must set the appropriate
 124     fonts and colours before using them.
 125
 126     In addition to the versions of the methods documented below, there
 127     are also versions which accept single wxPoint parameter instead
 128     of the two wxCoord ones or wxPoint and wxSize instead of the four
 129     wxCoord parameters.
 130
 131     Beginning with wxWidgets 2.9.0 the entire wxDC code has been
 132     reorganized. All platform dependent code (actually all drawing code)
 133     has been moved into backend classes which derive from a common
 134     wxDCImpl class. The user-visible classes such as wxClientDC and
 135     wxPaintDC merely forward all calls to the backend implementation.
 136
 137
 138     @section dc_units Device and logical units
 139
 140     In the wxDC context there is a distinction between @e logical units and @e device units.
 141
 142     @b Device units are the units native to the particular device; e.g. for a screen,
 143     a device unit is a @e pixel. For a printer, the device unit is defined by the
 144     resolution of the printer (usually given in @c DPI: dot-per-inch).
 145
 146     All wxDC functions use instead @b logical units, unless where explicitly
 147     stated. Logical units are arbitrary units mapped to device units using
 148     the current mapping mode (see wxDC::SetMapMode).
 149
 150     This mechanism allows to reuse the same code which prints on e.g. a window
 151     on the screen to print on e.g. a paper.
 152
 153
 154     @section dc_alpha_support Support for Transparency / Alpha Channel
 155
 156     In general wxDC methods don't support alpha transparency and the alpha
 157     component of wxColour is simply ignored and you need to use wxGraphicsContext
 158     for full transparency support. There are, however, a few exceptions: first,
 159     under Mac OS X colours with alpha channel are supported in all the normal
 160     wxDC-derived classes as they use wxGraphicsContext internally. Second,
 161     under all platforms wxSVGFileDC also fully supports alpha channel. In both
 162     of these cases the instances of wxPen or wxBrush that are built from
 163     wxColour use the colour's alpha values when stroking or filling.
 164
 165
 166     @section Support for Transformation Matrix
 167
 168     On some platforms (currently only under MSW and only on Windows NT, i.e.
 169     not Windows 9x/ME, systems) wxDC has support for applying an arbitrary
 170     affine transformation matrix to its coordinate system. Call
 171     CanUseTransformMatrix() to check if this support is available and then call
 172     SetTransformMatrix() if it is. If the transformation matrix is not
 173     supported, SetTransformMatrix() always simply returns false and doesn't do
 174     anything.
 175
 176
 177     @library{wxcore}
 178     @category{dc,gdi}
 179
 180     @see @ref overview_dc, wxGraphicsContext, wxDCFontChanger, wxDCTextColourChanger,
 181          wxDCPenChanger, wxDCBrushChanger, wxDCClipper
 182
 183     @todo Precise definition of default/initial state.
 184     @todo Pixelwise definition of operations (e.g. last point of a line not
 185           drawn).
 186 */
 187 class wxDC : public wxObject
 188 {
 189 public:
 190     /**
 191         @name Coordinate conversion functions
 192     */
 193     //@{
 194
 195     /**
 196         Convert @e device X coordinate to logical coordinate, using the current
 197         mapping mode, user scale factor, device origin and axis orientation.
 198     */
 199     wxCoord DeviceToLogicalX(wxCoord x) const;
 200
 201     /**
 202         Convert @e device X coordinate to relative logical coordinate, using the
 203         current mapping mode and user scale factor but ignoring the
 204         axis orientation. Use this for converting a width, for example.
 205     */
 206     wxCoord DeviceToLogicalXRel(wxCoord x) const;
 207
 208     /**
 209         Converts @e device Y coordinate to logical coordinate, using the current
 210         mapping mode, user scale factor, device origin and axis orientation.
 211     */
 212     wxCoord DeviceToLogicalY(wxCoord y) const;
 213
 214     /**
 215         Convert @e device Y coordinate to relative logical coordinate, using the
 216         current mapping mode and user scale factor but ignoring the
 217         axis orientation. Use this for converting a height, for example.
 218     */
 219     wxCoord DeviceToLogicalYRel(wxCoord y) const;
 220
 221     /**
 222         Converts logical X coordinate to device coordinate, using the current
 223         mapping mode, user scale factor, device origin and axis orientation.
 224     */
 225     wxCoord LogicalToDeviceX(wxCoord x) const;
 226
 227     /**
 228         Converts logical X coordinate to relative device coordinate, using the
 229         current mapping mode and user scale factor but ignoring the
 230         axis orientation. Use this for converting a width, for example.
 231     */
 232     wxCoord LogicalToDeviceXRel(wxCoord x) const;
 233
 234     /**
 235         Converts logical Y coordinate to device coordinate, using the current
 236         mapping mode, user scale factor, device origin and axis orientation.
 237     */
 238     wxCoord LogicalToDeviceY(wxCoord y) const;
 239
 240     /**
 241         Converts logical Y coordinate to relative device coordinate, using the
 242         current mapping mode and user scale factor but ignoring the
 243         axis orientation. Use this for converting a height, for example.
 244     */
 245     wxCoord LogicalToDeviceYRel(wxCoord y) const;
 246
 247     //@}
 248
 249
 250
 251     /**
 252         @name Drawing functions
 253     */
 254     //@{
 255
 256     /**
 257         Clears the device context using the current background brush.
 258     */
 259     void Clear();
 260
 261     /**
 262         Draws an arc of a circle, centred on (@a xc, @a yc), with starting
 263         point (@a xStart, @a yStart) and ending at (@a xEnd, @a yEnd).
 264         The current pen is used for the outline and the current brush for
 265         filling the shape.
 266
 267         The arc is drawn in a counter-clockwise direction from the start point
 268         to the end point.
 269     */
 270     void DrawArc(wxCoord xStart, wxCoord yStart, wxCoord xEnd, wxCoord yEnd,
 271                  wxCoord xc, wxCoord yc);
 272
 273     /**
 274         @overload
 275     */
 276     void DrawArc(const wxPoint& ptStart, const wxPoint& ptEnd, const wxPoint& centre);
 277
 278     /**
 279         Draw a bitmap on the device context at the specified point. If
 280         @a transparent is @true and the bitmap has a transparency mask, the
 281         bitmap will be drawn transparently.
 282
 283         When drawing a mono-bitmap, the current text foreground colour will be
 284         used to draw the foreground of the bitmap (all bits set to 1), and the
 285         current text background colour to draw the background (all bits set to
 286         0).
 287
 288         @see SetTextForeground(), SetTextBackground(), wxMemoryDC
 289     */
 290     void DrawBitmap(const wxBitmap& bitmap, wxCoord x, wxCoord y,
 291                     bool useMask = false);
 292
 293     /**
 294         @overload
 295     */
 296     void DrawBitmap(const wxBitmap &bmp, const wxPoint& pt,
 297                     bool useMask = false);
 298
 299     /**
 300         Draws a check mark inside the given rectangle.
 301     */
 302     void DrawCheckMark(wxCoord x, wxCoord y, wxCoord width, wxCoord height);
 303
 304     /**
 305         @overload
 306     */
 307     void DrawCheckMark(const wxRect& rect);
 308
 309     /**
 310         Draws a circle with the given centre and radius.
 311
 312         @see DrawEllipse()
 313     */
 314     void DrawCircle(wxCoord x, wxCoord y, wxCoord radius);
 315
 316     /**
 317         @overload
 318     */
 319     void DrawCircle(const wxPoint& pt, wxCoord radius);
 320
 321     /**
 322         Draws an ellipse contained in the rectangle specified either with the
 323         given top left corner and the given size or directly. The current pen
 324         is used for the outline and the current brush for filling the shape.
 325
 326         @see DrawCircle()
 327     */
 328     void DrawEllipse(wxCoord x, wxCoord y, wxCoord width, wxCoord height);
 329
 330     /**
 331         @overload
 332     */
 333     void DrawEllipse(const wxPoint& pt, const wxSize& size);
 334
 335     /**
 336         @overload
 337     */
 338     void DrawEllipse(const wxRect& rect);
 339
 340     /**
 341         Draws an arc of an ellipse. The current pen is used for drawing the arc
 342         and the current brush is used for drawing the pie.
 343
 344         @a x and @a y specify the x and y coordinates of the upper-left corner
 345         of the rectangle that contains the ellipse.
 346
 347         @a width and @a height specify the width and height of the rectangle
 348         that contains the ellipse.
 349
 350         @a start and @a end specify the start and end of the arc relative to
 351         the three-o'clock position from the center of the rectangle. Angles are
 352         specified in degrees (360 is a complete circle). Positive values mean
 353         counter-clockwise motion. If @a start is equal to @e end, a complete
 354         ellipse will be drawn.
 355     */
 356     void DrawEllipticArc(wxCoord x, wxCoord y, wxCoord width, wxCoord height,
 357                           double start, double end);
 358
 359     /**
 360         @overload
 361     */
 362     void DrawEllipticArc(const wxPoint& pt, const wxSize& sz,
 363                          double sa, double ea);
 364
 365     /**
 366         Draw an icon on the display (does nothing if the device context is
 367         PostScript). This can be the simplest way of drawing bitmaps on a
 368         window.
 369     */
 370     void DrawIcon(const wxIcon& icon, wxCoord x, wxCoord y);
 371
 372     /**
 373         @overload
 374     */
 375     void DrawIcon(const wxIcon& icon, const wxPoint& pt);
 376
 377     /**
 378         Draw optional bitmap and the text into the given rectangle and aligns
 379         it as specified by alignment parameter; it also will emphasize the
 380         character with the given index if it is != -1 and return the bounding
 381         rectangle if required.
 382     */
 383     void DrawLabel(const wxString& text, const wxBitmap& bitmap,
 384                    const wxRect& rect,
 385                    int alignment = wxALIGN_LEFT | wxALIGN_TOP,
 386                    int indexAccel = -1, wxRect* rectBounding = NULL);
 387
 388     /**
 389         @overload
 390     */
 391     void DrawLabel(const wxString& text, const wxRect& rect,
 392                    int alignment = wxALIGN_LEFT | wxALIGN_TOP,
 393                    int indexAccel = -1);
 394
 395     /**
 396         Draws a line from the first point to the second. The current pen is
 397         used for drawing the line. Note that the point (@a x2, @a y2) is not
 398         part of the line and is not drawn by this function (this is consistent
 399         with the behaviour of many other toolkits).
 400     */
 401     void DrawLine(wxCoord x1, wxCoord y1, wxCoord x2, wxCoord y2);
 402
 403     /**
 404         @overload
 405     */
 406     void DrawLine(const wxPoint& pt1, const wxPoint& pt2);
 407
 408     /**
 409         Draws lines using an array of points of size @a n adding the optional
 410         offset coordinate. The current pen is used for drawing the lines.
 411
 412         @beginWxPythonOnly
 413         The wxPython version of this method accepts a Python list of wxPoint
 414         objects.
 415         @endWxPythonOnly
 416
 417         @beginWxPerlOnly
 418         Not supported by wxPerl.
 419         @endWxPerlOnly
 420     */
 421     void DrawLines(int n, wxPoint points[], wxCoord xoffset = 0,
 422                    wxCoord yoffset = 0);
 423     /**
 424         This method uses a list of wxPoints, adding the optional offset
 425         coordinate. The programmer is responsible for deleting the list of
 426         points.
 427
 428         @beginWxPythonOnly
 429         The wxPython version of this method accepts a Python list of wxPoint
 430         objects.
 431         @endWxPythonOnly
 432
 433         @beginWxPerlOnly
 434         The wxPerl version of this method accepts
 435         as its first parameter a reference to an array
 436         of wxPoint objects.
 437         @endWxPerlOnly
 438     */
 439     void DrawLines(const wxPointList* points,
 440                    wxCoord xoffset = 0, wxCoord yoffset = 0);
 441
 442     /**
 443         Draws a point using the color of the current pen. Note that the other
 444         properties of the pen are not used, such as width.
 445     */
 446     void DrawPoint(wxCoord x, wxCoord y);
 447
 448     /**
 449         @overload
 450     */
 451     void DrawPoint(const wxPoint& pt);
 452
 453     /**
 454         Draws a filled polygon using an array of points of size @a n, adding
 455         the optional offset coordinate. The first and last points are
 456         automatically closed.
 457
 458         The last argument specifies the fill rule: @b wxODDEVEN_RULE (the
 459         default) or @b wxWINDING_RULE.
 460
 461         The current pen is used for drawing the outline, and the current brush
 462         for filling the shape. Using a transparent brush suppresses filling.
 463
 464         @beginWxPerlOnly
 465         Not supported by wxPerl.
 466         @endWxPerlOnly
 467     */
 468     void DrawPolygon(int n, wxPoint points[], wxCoord xoffset = 0,
 469                      wxCoord yoffset = 0,
 470                      wxPolygonFillMode fill_style = wxODDEVEN_RULE);
 471     /**
 472         This method draws a filled polygon using a list of wxPoints, adding the
 473         optional offset coordinate. The first and last points are automatically
 474         closed.
 475
 476         The last argument specifies the fill rule: @b wxODDEVEN_RULE (the
 477         default) or @b wxWINDING_RULE.
 478
 479         The current pen is used for drawing the outline, and the current brush
 480         for filling the shape. Using a transparent brush suppresses filling.
 481
 482         The programmer is responsible for deleting the list of points.
 483
 484         @beginWxPythonOnly
 485         The wxPython version of this method accepts a Python list of wxPoint
 486         objects.
 487         @endWxPythonOnly
 488
 489         @beginWxPerlOnly
 490         The wxPerl version of this method accepts
 491         as its first parameter a reference to an array
 492         of wxPoint objects.
 493         @endWxPerlOnly
 494     */
 495     void DrawPolygon(const wxPointList* points,
 496                      wxCoord xoffset = 0, wxCoord yoffset = 0,
 497                      wxPolygonFillMode fill_style = wxODDEVEN_RULE);
 498
 499     /**
 500         Draws two or more filled polygons using an array of @a points, adding
 501         the optional offset coordinates.
 502
 503         Notice that for the platforms providing a native implementation of this
 504         function (Windows and PostScript-based wxDC currently), this is more
 505         efficient than using DrawPolygon() in a loop.
 506
 507         @a n specifies the number of polygons to draw, the array @e count of
 508         size @a n specifies the number of points in each of the polygons in the
 509         @a points array.
 510
 511         The last argument specifies the fill rule: @b wxODDEVEN_RULE (the
 512         default) or @b wxWINDING_RULE.
 513
 514         The current pen is used for drawing the outline, and the current brush
 515         for filling the shape. Using a transparent brush suppresses filling.
 516
 517         The polygons maybe disjoint or overlapping. Each polygon specified in a
 518         call to DrawPolyPolygon() must be closed. Unlike polygons created by
 519         the DrawPolygon() member function, the polygons created by this
 520         method are not closed automatically.
 521
 522         @beginWxPythonOnly
 523         Not implemented yet.
 524         @endWxPythonOnly
 525     */
 526     void DrawPolyPolygon(int n, int count[], wxPoint points[],
 527                          wxCoord xoffset = 0, wxCoord yoffset = 0,
 528                          wxPolygonFillMode fill_style = wxODDEVEN_RULE);
 529
 530     /**
 531         Draws a rectangle with the given top left corner, and with the given
 532         size.  The current pen is used for the outline and the current brush
 533         for filling the shape.
 534     */
 535     void DrawRectangle(wxCoord x, wxCoord y, wxCoord width, wxCoord height);
 536
 537     /**
 538         @overload
 539     */
 540     void DrawRectangle(const wxPoint& pt, const wxSize& sz);
 541
 542     /**
 543         @overload
 544     */
 545     void DrawRectangle(const wxRect& rect);
 546
 547     /**
 548         Draws the text rotated by @a angle degrees
 549         (positive angles are counterclockwise; the full angle is 360 degrees).
 550
 551         @note Under Win9x only TrueType fonts can be drawn by this function. In
 552               particular, a font different from @c wxNORMAL_FONT should be used
 553               as the latter is not a TrueType font. @c wxSWISS_FONT is an
 554               example of a font which is.
 555
 556         @see DrawText()
 557     */
 558     void DrawRotatedText(const wxString& text, wxCoord x, wxCoord y,
 559                          double angle);
 560
 561     /**
 562         @overload
 563     */
 564     void DrawRotatedText(const wxString& text, const wxPoint& point,
 565                          double angle);
 566
 567     /**
 568         Draws a rectangle with the given top left corner, and with the given
 569         size. The corners are quarter-circles using the given radius. The
 570         current pen is used for the outline and the current brush for filling
 571         the shape.
 572
 573         If @a radius is positive, the value is assumed to be the radius of the
 574         rounded corner. If @a radius is negative, the absolute value is assumed
 575         to be the @e proportion of the smallest dimension of the rectangle.
 576         This means that the corner can be a sensible size relative to the size
 577         of the rectangle, and also avoids the strange effects X produces when
 578         the corners are too big for the rectangle.
 579     */
 580     void DrawRoundedRectangle(wxCoord x, wxCoord y, wxCoord width,
 581                               wxCoord height, double radius);
 582
 583     /**
 584         @overload
 585     */
 586     void DrawRoundedRectangle(const wxPoint& pt, const wxSize& sz,
 587                               double radius);
 588
 589     /**
 590         @overload
 591     */
 592     void DrawRoundedRectangle(const wxRect& rect, double radius);
 593
 594     /**
 595         Draws a spline between all given points using the current pen.
 596
 597         @beginWxPythonOnly
 598         The wxPython version of this method accepts a Python list of wxPoint
 599         objects.
 600         @endWxPythonOnly
 601
 602         @beginWxPerlOnly
 603         Not supported by wxPerl.
 604         @endWxPerlOnly
 605     */
 606     void DrawSpline(int n, wxPoint points[]);
 607
 608     /**
 609         @overload
 610
 611
 612         @beginWxPerlOnly
 613         The wxPerl version of this method accepts
 614         as its first parameter a reference to an array
 615         of wxPoint objects.
 616         @endWxPerlOnly
 617     */
 618     void DrawSpline(const wxPointList* points);
 619
 620     /**
 621         @overload
 622
 623
 624         @beginWxPerlOnly
 625         Not supported by wxPerl.
 626         @endWxPerlOnly
 627     */
 628     void DrawSpline(wxCoord x1, wxCoord y1, wxCoord x2, wxCoord y2,
 629                     wxCoord x3, wxCoord y3);
 630
 631     /**
 632         Draws a text string at the specified point, using the current text
 633         font, and the current text foreground and background colours.
 634
 635         The coordinates refer to the top-left corner of the rectangle bounding
 636         the string. See GetTextExtent() for how to get the dimensions of a text
 637         string, which can be used to position the text more precisely and
 638         DrawLabel() if you need to align the string differently.
 639
 640         Starting from wxWidgets 2.9.2 @a text parameter can be a multi-line
 641         string, i.e. contain new line characters, and will be rendered
 642         correctly.
 643
 644         @note The current @ref GetLogicalFunction() "logical function" is
 645               ignored by this function.
 646     */
 647     void DrawText(const wxString& text, wxCoord x, wxCoord y);
 648
 649     /**
 650         @overload
 651     */
 652     void DrawText(const wxString& text, const wxPoint& pt);
 653
 654     /**
 655         Fill the area specified by rect with a radial gradient, starting from
 656         @a initialColour at the centre of the circle and fading to
 657         @a destColour on the circle outside.
 658
 659         The circle is placed at the centre of @a rect.
 660
 661         @note Currently this function is very slow, don't use it for real-time
 662               drawing.
 663     */
 664     void GradientFillConcentric(const wxRect& rect,
 665                                 const wxColour& initialColour,
 666                                 const wxColour& destColour);
 667
 668     /**
 669         Fill the area specified by rect with a radial gradient, starting from
 670         @a initialColour at the centre of the circle and fading to
 671         @a destColour on the circle outside.
 672
 673         @a circleCenter are the relative coordinates of centre of the circle in
 674         the specified @a rect.
 675
 676         @note Currently this function is very slow, don't use it for real-time
 677               drawing.
 678     */
 679     void GradientFillConcentric(const wxRect& rect,
 680                                 const wxColour& initialColour,
 681                                 const wxColour& destColour,
 682                                 const wxPoint& circleCenter);
 683
 684     /**
 685         Fill the area specified by @a rect with a linear gradient, starting
 686         from @a initialColour and eventually fading to @e destColour.
 687
 688         The @a nDirection specifies the direction of the colour change, default is
 689         to use @a initialColour on the left part of the rectangle and
 690         @a destColour on the right one.
 691     */
 692     void GradientFillLinear(const wxRect& rect, const wxColour& initialColour,
 693                             const wxColour& destColour,
 694                             wxDirection nDirection = wxRIGHT);
 695
 696     /**
 697         Flood fills the device context starting from the given point, using
 698         the current brush colour, and using a style:
 699
 700         - wxFLOOD_SURFACE: The flooding occurs until a colour other than the
 701           given colour is encountered.
 702         - wxFLOOD_BORDER: The area to be flooded is bounded by the given
 703           colour.
 704
 705         @return @false if the operation failed.
 706
 707         @note The present implementation for non-Windows platforms may fail to
 708               find colour borders if the pixels do not match the colour
 709               exactly. However the function will still return @true.
 710     */
 711     bool FloodFill(wxCoord x, wxCoord y, const wxColour& colour,
 712                    wxFloodFillStyle style = wxFLOOD_SURFACE);
 713
 714     /**
 715         @overload
 716     */
 717     bool FloodFill(const wxPoint& pt, const wxColour& col,
 718                    wxFloodFillStyle style = wxFLOOD_SURFACE);
 719
 720     /**
 721         Displays a cross hair using the current pen. This is a vertical and
 722         horizontal line the height and width of the window, centred on the
 723         given point.
 724     */
 725     void CrossHair(wxCoord x, wxCoord y);
 726
 727     /**
 728         @overload
 729     */
 730     void CrossHair(const wxPoint& pt);
 731
 732     //@}
 733
 734
 735     /**
 736         @name Clipping region functions
 737     */
 738     //@{
 739
 740     /**
 741         Destroys the current clipping region so that none of the DC is clipped.
 742
 743         @see SetClippingRegion()
 744     */
 745     void DestroyClippingRegion();
 746
 747     /**
 748         Gets the rectangle surrounding the current clipping region.
 749
 750         @beginWxPythonOnly
 751         No arguments are required and the four values defining the rectangle
 752         are returned as a tuple.
 753         @endWxPythonOnly
 754     */
 755     void GetClippingBox(wxCoord *x, wxCoord *y, wxCoord *width, wxCoord *height) const;
 756
 757     /**
 758         Sets the clipping region for this device context to the intersection of
 759         the given region described by the parameters of this method and the
 760         previously set clipping region.
 761
 762         The clipping region is an area to which drawing is restricted. Possible
 763         uses for the clipping region are for clipping text or for speeding up
 764         window redraws when only a known area of the screen is damaged.
 765
 766         Notice that you need to call DestroyClippingRegion() if you want to set
 767         the clipping region exactly to the region specified.
 768
 769         Also note that if the clipping region is empty, any previously set
 770         clipping region is destroyed, i.e. it is equivalent to calling
 771         DestroyClippingRegion(), and not to clipping out all drawing on the DC
 772         as might be expected.
 773
 774         @see DestroyClippingRegion(), wxRegion
 775     */
 776     void SetClippingRegion(wxCoord x, wxCoord y, wxCoord width, wxCoord height);
 777
 778     /**
 779         @overload
 780     */
 781     void SetClippingRegion(const wxPoint& pt, const wxSize& sz);
 782
 783     /**
 784         @overload
 785     */
 786     void SetClippingRegion(const wxRect& rect);
 787
 788     /**
 789         Sets the clipping region for this device context.
 790
 791         Unlike SetClippingRegion(), this function works with physical
 792         coordinates and not with the logical ones.
 793      */
 794     void SetDeviceClippingRegion(const wxRegion& region);
 795
 796     //@}
 797
 798
 799     /**
 800         @name Text/character extent functions
 801     */
 802     //@{
 803
 804     /**
 805         Gets the character height of the currently set font.
 806     */
 807     wxCoord GetCharHeight() const;
 808
 809     /**
 810         Gets the average character width of the currently set font.
 811     */
 812     wxCoord GetCharWidth() const;
 813
 814     /**
 815         Returns the various font characteristics.
 816
 817         This method allows to retrieve some of the font characteristics not
 818         returned by GetTextExtent(), notably internal leading and average
 819         character width.
 820
 821         Currently this method returns correct results only under wxMSW, in the
 822         other ports the internal leading will always be 0 and the average
 823         character width will be computed as the width of the character 'x'.
 824
 825         @since 2.9.2
 826      */
 827     wxFontMetrics GetFontMetrics() const;
 828
 829     /**
 830         Gets the dimensions of the string using the currently selected font.
 831         @a string is the text string to measure, @e heightLine, if non @NULL,
 832         is where to store the height of a single line.
 833
 834         The text extent is set in the given @a w and @a h pointers.
 835
 836         If the optional parameter @a font is specified and valid, then it is
 837         used for the text extent calculation, otherwise the currently selected
 838         font is used.
 839
 840         @note This function works with both single-line and multi-line strings.
 841
 842         @beginWxPerlOnly
 843         In wxPerl this method is implemented as
 844         GetMultiLineTextExtent(string, font = undef) returning a
 845         3-element list (width, height, line_height)
 846         @endWxPerlOnly
 847
 848         @see wxFont, SetFont(), GetPartialTextExtents(), GetTextExtent()
 849     */
 850     void GetMultiLineTextExtent(const wxString& string, wxCoord* w,
 851                                 wxCoord* h,
 852                                 wxCoord* heightLine = NULL,
 853                                 const wxFont* font = NULL) const;
 854     /**
 855         Gets the dimensions of the string using the currently selected font.
 856         @a string is the text string to measure, @e heightLine, if non @NULL,
 857         is where to store the height of a single line.
 858
 859         @return The text extent as a wxSize object.
 860
 861         @note This function works with both single-line and multi-line strings.
 862
 863         @beginWxPerlOnly
 864         Not supported by wxPerl.
 865         @endWxPerlOnly
 866
 867         @see wxFont, SetFont(), GetPartialTextExtents(), GetTextExtent()
 868     */
 869     wxSize GetMultiLineTextExtent(const wxString& string) const;
 870
 871     /**
 872         Fills the @a widths array with the widths from the beginning of @a text
 873         to the corresponding character of @a text. The generic version simply
 874         builds a running total of the widths of each character using
 875         GetTextExtent(), however if the various platforms have a native API
 876         function that is faster or more accurate than the generic
 877         implementation then it should be used instead.
 878
 879         @beginWxPythonOnly
 880         This method only takes the @a text parameter and returns a Python list
 881         of integers.
 882         @endWxPythonOnly
 883
 884         @beginWxPerlOnly
 885         In wxPerl this method only takes the @a text parameter and
 886         returns the widths as a list of integers.
 887         @endWxPerlOnly
 888
 889         @see GetMultiLineTextExtent(), GetTextExtent()
 890     */
 891     bool GetPartialTextExtents(const wxString& text,
 892                                wxArrayInt& widths) const;
 893
 894     /**
 895         Gets the dimensions of the string using the currently selected font.
 896         @a string is the text string to measure, @a descent is the dimension
 897         from the baseline of the font to the bottom of the descender, and
 898         @a externalLeading is any extra vertical space added to the font by the
 899         font designer (usually is zero).
 900
 901         The text extent is returned in @a w and @a h pointers or as a wxSize
 902         object depending on which version of this function is used.
 903
 904         If the optional parameter @a font is specified and valid, then it is
 905         used for the text extent calculation. Otherwise the currently selected
 906         font is.
 907
 908         @note This function only works with single-line strings.
 909
 910         @beginWxPythonOnly
 911         The following methods are implemented in wxPython:
 912         - GetTextExtent(string) - Returns a 2-tuple, (width, height).
 913         - GetFullTextExtent(string, font=NULL) -
 914             Returns a 4-tuple, (width, height, descent, externalLeading).
 915         @endWxPythonOnly
 916
 917         @beginWxPerlOnly
 918         In wxPerl this method is implemented as GetTextExtent(string,
 919         font = undef) returning a 4-element list (width, height,
 920         descent, externalLeading)
 921         @endWxPerlOnly
 922
 923         @see wxFont, SetFont(), GetPartialTextExtents(),
 924              GetMultiLineTextExtent()
 925     */
 926     void GetTextExtent(const wxString& string, wxCoord* w, wxCoord* h,
 927                        wxCoord* descent = NULL,
 928                        wxCoord* externalLeading = NULL,
 929                        const wxFont* font = NULL) const;
 930
 931     /**
 932         @overload
 933
 934
 935         @beginWxPerlOnly
 936         Not supported by wxPerl.
 937         @endWxPerlOnly
 938     */
 939     wxSize GetTextExtent(const wxString& string) const;
 940
 941     //@}
 942
 943
 944     /**
 945         @name Text properties functions
 946     */
 947     //@{
 948
 949     /**
 950         Returns the current background mode: @c wxSOLID or @c wxTRANSPARENT.
 951
 952         @see SetBackgroundMode()
 953     */
 954     int GetBackgroundMode() const;
 955
 956     /**
 957         Gets the current font.
 958
 959         Notice that even although each device context object has some default font
 960         after creation, this method would return a ::wxNullFont initially and only
 961         after calling SetFont() a valid font is returned.
 962     */
 963     const wxFont& GetFont() const;
 964
 965     /**
 966         Gets the current layout direction of the device context. On platforms
 967         where RTL layout is supported, the return value will either be
 968         @c wxLayout_LeftToRight or @c wxLayout_RightToLeft. If RTL layout is
 969         not supported, the return value will be @c wxLayout_Default.
 970
 971         @see SetLayoutDirection()
 972     */
 973     wxLayoutDirection GetLayoutDirection() const;
 974
 975     /**
 976         Gets the current text background colour.
 977
 978         @see SetTextBackground()
 979     */
 980     const wxColour& GetTextBackground() const;
 981
 982     /**
 983         Gets the current text foreground colour.
 984
 985         @see SetTextForeground()
 986     */
 987     const wxColour& GetTextForeground() const;
 988
 989     /**
 990         @a mode may be one of @c wxSOLID and @c wxTRANSPARENT.
 991
 992         This setting determines whether text will be drawn with a background
 993         colour or not.
 994     */
 995     void SetBackgroundMode(int mode);
 996
 997     /**
 998         Sets the current font for the DC.
 999
1000         If the argument is ::wxNullFont (or another invalid font; see wxFont::IsOk),
1001         the current font is selected out of the device context (leaving wxDC without
1002         any valid font), allowing the current font to be destroyed safely.
1003
1004         @see wxFont
1005     */
1006     void SetFont(const wxFont& font);
1007
1008     /**
1009         Sets the current text background colour for the DC.
1010     */
1011     void SetTextBackground(const wxColour& colour);
1012
1013     /**
1014         Sets the current text foreground colour for the DC.
1015
1016         @see wxMemoryDC for the interpretation of colours when drawing into a
1017              monochrome bitmap.
1018     */
1019     void SetTextForeground(const wxColour& colour);
1020
1021     /**
1022         Sets the current layout direction for the device context.
1023
1024         @param dir
1025            May be either @c wxLayout_Default, @c wxLayout_LeftToRight or
1026            @c wxLayout_RightToLeft.
1027
1028         @see GetLayoutDirection()
1029     */
1030     void SetLayoutDirection(wxLayoutDirection dir);
1031
1032     //@}
1033
1034
1035     /**
1036         @name Bounding box functions
1037     */
1038     //@{
1039
1040     /**
1041         Adds the specified point to the bounding box which can be retrieved
1042         with MinX(), MaxX() and MinY(), MaxY() functions.
1043
1044         @see ResetBoundingBox()
1045     */
1046     void CalcBoundingBox(wxCoord x, wxCoord y);
1047
1048     /**
1049         Gets the maximum horizontal extent used in drawing commands so far.
1050     */
1051     wxCoord MaxX() const;
1052
1053     /**
1054         Gets the maximum vertical extent used in drawing commands so far.
1055     */
1056     wxCoord MaxY() const;
1057
1058     /**
1059         Gets the minimum horizontal extent used in drawing commands so far.
1060     */
1061     wxCoord MinX() const;
1062
1063     /**
1064         Gets the minimum vertical extent used in drawing commands so far.
1065     */
1066     wxCoord MinY() const;
1067
1068     /**
1069         Resets the bounding box: after a call to this function, the bounding
1070         box doesn't contain anything.
1071
1072         @see CalcBoundingBox()
1073     */
1074     void ResetBoundingBox();
1075
1076     //@}
1077
1078
1079     /**
1080         @name Page and document start/end functions
1081     */
1082     //@{
1083
1084     /**
1085         Starts a document (only relevant when outputting to a printer).
1086         @a message is a message to show while printing.
1087     */
1088     bool StartDoc(const wxString& message);
1089
1090     /**
1091         Starts a document page (only relevant when outputting to a printer).
1092     */
1093     void StartPage();
1094
1095     /**
1096         Ends a document (only relevant when outputting to a printer).
1097     */
1098     void EndDoc();
1099
1100     /**
1101         Ends a document page (only relevant when outputting to a printer).
1102     */
1103     void EndPage();
1104
1105     //@}
1106
1107
1108     /**
1109         @name Bit-Block Transfer operations (blit)
1110     */
1111     //@{
1112
1113     /**
1114         Copy from a source DC to this DC, specifying the destination
1115         coordinates, size of area to copy, source DC, source coordinates,
1116         logical function, whether to use a bitmap mask, and mask source
1117         position.
1118
1119         @param xdest
1120             Destination device context x position.
1121         @param ydest
1122             Destination device context y position.
1123         @param width
1124             Width of source area to be copied.
1125         @param height
1126             Height of source area to be copied.
1127         @param source
1128             Source device context.
1129         @param xsrc
1130             Source device context x position.
1131         @param ysrc
1132             Source device context y position.
1133         @param logicalFunc
1134             Logical function to use, see SetLogicalFunction().
1135         @param useMask
1136             If @true, Blit does a transparent blit using the mask that is
1137             associated with the bitmap selected into the source device context.
1138             The Windows implementation does the following if MaskBlt cannot be
1139             used:
1140             <ol>
1141             <li>Creates a temporary bitmap and copies the destination area into
1142                 it.</li>
1143             <li>Copies the source area into the temporary bitmap using the
1144                 specified logical function.</li>
1145             <li>Sets the masked area in the temporary bitmap to BLACK by ANDing
1146                 the mask bitmap with the temp bitmap with the foreground colour
1147                 set to WHITE and the bg colour set to BLACK.</li>
1148             <li>Sets the unmasked area in the destination area to BLACK by
1149                 ANDing the mask bitmap with the destination area with the
1150                 foreground colour set to BLACK and the background colour set to
1151                 WHITE.</li>
1152             <li>ORs the temporary bitmap with the destination area.</li>
1153             <li>Deletes the temporary bitmap.</li>
1154             </ol>
1155             This sequence of operations ensures that the source's transparent
1156             area need not be black, and logical functions are supported.
1157             @n @b Note: on Windows, blitting with masks can be speeded up
1158             considerably by compiling wxWidgets with the wxUSE_DC_CACHEING option
1159             enabled. You can also influence whether MaskBlt or the explicit
1160             mask blitting code above is used, by using wxSystemOptions and
1161             setting the @c no-maskblt option to 1.
1162         @param xsrcMask
1163             Source x position on the mask. If both xsrcMask and ysrcMask are
1164             @c -1, xsrc and ysrc will be assumed for the mask source position.
1165             Currently only implemented on Windows.
1166         @param ysrcMask
1167             Source y position on the mask. If both xsrcMask and ysrcMask are
1168             @c -1, xsrc and ysrc will be assumed for the mask source position.
1169             Currently only implemented on Windows.
1170
1171         @remarks There is partial support for Blit() in wxPostScriptDC, under X.
1172
1173         @see StretchBlit(), wxMemoryDC, wxBitmap, wxMask
1174     */
1175     bool Blit(wxCoord xdest, wxCoord ydest, wxCoord width,
1176               wxCoord height, wxDC* source, wxCoord xsrc, wxCoord ysrc,
1177               wxRasterOperationMode logicalFunc = wxCOPY, bool useMask = false,
1178               wxCoord xsrcMask = wxDefaultCoord, wxCoord ysrcMask = wxDefaultCoord);
1179
1180     /**
1181         Copy from a source DC to this DC, specifying the destination
1182         coordinates, destination size, source DC, source coordinates, size of
1183         source area to copy, logical function, whether to use a bitmap mask,
1184         and mask source position.
1185
1186         @param xdest
1187             Destination device context x position.
1188         @param ydest
1189             Destination device context y position.
1190         @param dstWidth
1191             Width of destination area.
1192         @param dstHeight
1193             Height of destination area.
1194         @param source
1195             Source device context.
1196         @param xsrc
1197             Source device context x position.
1198         @param ysrc
1199             Source device context y position.
1200         @param srcWidth
1201             Width of source area to be copied.
1202         @param srcHeight
1203             Height of source area to be copied.
1204         @param logicalFunc
1205             Logical function to use, see SetLogicalFunction().
1206         @param useMask
1207             If @true, Blit does a transparent blit using the mask that is
1208             associated with the bitmap selected into the source device context.
1209             The Windows implementation does the following if MaskBlt cannot be
1210             used:
1211             <ol>
1212             <li>Creates a temporary bitmap and copies the destination area into
1213                 it.</li>
1214             <li>Copies the source area into the temporary bitmap using the
1215                 specified logical function.</li>
1216             <li>Sets the masked area in the temporary bitmap to BLACK by ANDing
1217                 the mask bitmap with the temp bitmap with the foreground colour
1218                 set to WHITE and the bg colour set to BLACK.</li>
1219             <li>Sets the unmasked area in the destination area to BLACK by
1220                 ANDing the mask bitmap with the destination area with the
1221                 foreground colour set to BLACK and the background colour set to
1222                 WHITE.</li>
1223             <li>ORs the temporary bitmap with the destination area.</li>
1224             <li>Deletes the temporary bitmap.</li>
1225             </ol>
1226             This sequence of operations ensures that the source's transparent
1227             area need not be black, and logical functions are supported.
1228             @n @b Note: on Windows, blitting with masks can be speeded up
1229             considerably by compiling wxWidgets with the wxUSE_DC_CACHEING option
1230             enabled. You can also influence whether MaskBlt or the explicit
1231             mask blitting code above is used, by using wxSystemOptions and
1232             setting the @c no-maskblt option to 1.
1233         @param xsrcMask
1234             Source x position on the mask. If both xsrcMask and ysrcMask are
1235             wxDefaultCoord, @a xsrc and @a ysrc will be assumed for the mask
1236             source position. Currently only implemented on Windows.
1237         @param ysrcMask
1238             Source y position on the mask. If both xsrcMask and ysrcMask are
1239             wxDefaultCoord, @a xsrc and @a ysrc will be assumed for the mask
1240             source position. Currently only implemented on Windows.
1241
1242         There is partial support for Blit() in wxPostScriptDC, under X.
1243
1244         StretchBlit() is only implemented under wxMAC and wxMSW.
1245
1246         See wxMemoryDC for typical usage.
1247
1248         @since 2.9.0
1249
1250         @see Blit(), wxMemoryDC, wxBitmap, wxMask
1251     */
1252     bool StretchBlit(wxCoord xdest, wxCoord ydest,
1253                      wxCoord dstWidth, wxCoord dstHeight,
1254                      wxDC* source, wxCoord xsrc, wxCoord ysrc,
1255                      wxCoord srcWidth, wxCoord srcHeight,
1256                      wxRasterOperationMode logicalFunc = wxCOPY,
1257                      bool useMask = false,
1258                      wxCoord xsrcMask = wxDefaultCoord,
1259                      wxCoord ysrcMask = wxDefaultCoord);
1260     //@}
1261
1262
1263     /**
1264         @name Background/foreground brush and pen
1265     */
1266     //@{
1267
1268     /**
1269         Gets the brush used for painting the background.
1270
1271         @see wxDC::SetBackground()
1272     */
1273     const wxBrush& GetBackground() const;
1274
1275     /**
1276         Gets the current brush.
1277
1278         @see wxDC::SetBrush()
1279     */
1280     const wxBrush& GetBrush() const;
1281
1282     /**
1283         Gets the current pen.
1284
1285         @see SetPen()
1286     */
1287     const wxPen& GetPen() const;
1288
1289     /**
1290         Sets the current background brush for the DC.
1291     */
1292     void SetBackground(const wxBrush& brush);
1293
1294     /**
1295         Sets the current brush for the DC.
1296
1297         If the argument is ::wxNullBrush (or another invalid brush; see wxBrush::IsOk),
1298         the current brush is selected out of the device context (leaving wxDC without
1299         any valid brush), allowing the current brush to be destroyed safely.
1300
1301         @see wxBrush, wxMemoryDC (for the interpretation of colours when
1302              drawing into a monochrome bitmap)
1303     */
1304     void SetBrush(const wxBrush& brush);
1305
1306     /**
1307         Sets the current pen for the DC.
1308
1309         If the argument is ::wxNullPen (or another invalid pen; see wxPen::IsOk),
1310         the current pen is selected out of the device context (leaving wxDC without any
1311         valid pen), allowing the current pen to be destroyed safely.
1312
1313         @see wxMemoryDC for the interpretation of colours when drawing into a
1314              monochrome bitmap.
1315     */
1316     void SetPen(const wxPen& pen);
1317
1318     //@}
1319
1320
1321     /**
1322         Copy attributes from another DC.
1323
1324         The copied attributes currently are:
1325             - Font
1326             - Text foreground and background colours
1327             - Background brush
1328             - Layout direction
1329
1330         @param dc
1331             A valid (i.e. its IsOk() must return @true) source device context.
1332      */
1333     void CopyAttributes(const wxDC& dc);
1334
1335     /**
1336         Returns the depth (number of bits/pixel) of this DC.
1337
1338         @see wxDisplayDepth()
1339     */
1340     int GetDepth() const;
1341
1342     /**
1343         Returns the current device origin.
1344
1345         @see SetDeviceOrigin()
1346     */
1347     wxPoint GetDeviceOrigin() const;
1348
1349     /**
1350         Gets the current logical function.
1351
1352         @see SetLogicalFunction()
1353     */
1354     wxRasterOperationMode GetLogicalFunction() const;
1355
1356     /**
1357         Gets the current mapping mode for the device context.
1358
1359         @see SetMapMode()
1360     */
1361     wxMappingMode GetMapMode() const;
1362
1363     /**
1364         Gets in @a colour the colour at the specified location. Not available
1365         for wxPostScriptDC or wxMetafileDC.
1366
1367         @note Setting a pixel can be done using DrawPoint().
1368
1369         @beginWxPythonOnly
1370         The wxColour value is returned and is not required as a parameter.
1371         @endWxPythonOnly
1372     */
1373     bool GetPixel(wxCoord x, wxCoord y, wxColour* colour) const;
1374
1375     /**
1376         Returns the resolution of the device in pixels per inch.
1377     */
1378     wxSize GetPPI() const;
1379
1380     /**
1381         Gets the horizontal and vertical extent of this device context in @e device units.
1382         It can be used to scale graphics to fit the page.
1383
1384         For example, if @e maxX and @e maxY represent the maximum horizontal
1385         and vertical 'pixel' values used in your application, the following
1386         code will scale the graphic to fit on the printer page:
1387
1388         @code
1389         wxCoord w, h;
1390         dc.GetSize(&w, &h);
1391         double scaleX = (double)(maxX / w);
1392         double scaleY = (double)(maxY / h);
1393         dc.SetUserScale(min(scaleX, scaleY),min(scaleX, scaleY));
1394         @endcode
1395
1396         @beginWxPythonOnly
1397         In place of a single overloaded method name, wxPython implements the
1398         following methods:
1399         - GetSize() - Returns a wxSize.
1400         - GetSizeWH() - Returns a 2-tuple (width, height).
1401         @endWxPythonOnly
1402
1403         @beginWxPerlOnly
1404         In wxPerl there are two methods instead of a single overloaded
1405         method:
1406         - GetSize(): returns a Wx::Size object.
1407         - GetSizeWH(): returns a 2-element list (width, height).
1408         @endWxPerlOnly
1409     */
1410     void GetSize(wxCoord* width, wxCoord* height) const;
1411
1412     /**
1413         @overload
1414     */
1415     wxSize GetSize() const;
1416
1417     /**
1418         Returns the horizontal and vertical resolution in millimetres.
1419     */
1420     void GetSizeMM(wxCoord* width, wxCoord* height) const;
1421
1422     /**
1423         @overload
1424     */
1425     wxSize GetSizeMM() const;
1426
1427     /**
1428         Gets the current user scale factor.
1429
1430         @beginWxPerlOnly
1431         In wxPerl this method takes no arguments and return a two
1432         element array (x, y).
1433         @endWxPerlOnly
1434
1435         @see SetUserScale()
1436     */
1437     void GetUserScale(double* x, double* y) const;
1438
1439     /**
1440         Returns @true if the DC is ok to use.
1441     */
1442     bool IsOk() const;
1443
1444     /**
1445         Sets the x and y axis orientation (i.e., the direction from lowest to
1446         highest values on the axis). The default orientation is x axis from
1447         left to right and y axis from top down.
1448
1449         @param xLeftRight
1450             True to set the x axis orientation to the natural left to right
1451             orientation, @false to invert it.
1452         @param yBottomUp
1453             True to set the y axis orientation to the natural bottom up
1454             orientation, @false to invert it.
1455     */
1456     void SetAxisOrientation(bool xLeftRight, bool yBottomUp);
1457
1458     /**
1459         Sets the device origin (i.e., the origin in pixels after scaling has
1460         been applied). This function may be useful in Windows printing
1461         operations for placing a graphic on a page.
1462     */
1463     void SetDeviceOrigin(wxCoord x, wxCoord y);
1464
1465     /**
1466         Sets the current logical function for the device context.
1467         It determines how a @e source pixel (from a pen or brush colour, or source
1468         device context if using Blit()) combines with a @e destination pixel in
1469         the current device context.
1470         Text drawing is not affected by this function.
1471
1472         See ::wxRasterOperationMode enumeration values for more info.
1473
1474         The default is @c wxCOPY, which simply draws with the current colour.
1475         The others combine the current colour and the background using a logical
1476         operation. @c wxINVERT is commonly used for drawing rubber bands or moving
1477         outlines, since drawing twice reverts to the original colour.
1478     */
1479     void SetLogicalFunction(wxRasterOperationMode function);
1480
1481     /**
1482         The mapping mode of the device context defines the unit of measurement
1483         used to convert @e logical units to @e device units.
1484
1485         Note that in X, text drawing isn't handled consistently with the mapping mode;
1486         a font is always specified in point size. However, setting the user scale (see
1487         SetUserScale()) scales the text appropriately. In Windows, scalable
1488         TrueType fonts are always used; in X, results depend on availability of
1489         fonts, but usually a reasonable match is found.
1490
1491         The coordinate origin is always at the top left of the screen/printer.
1492
1493         Drawing to a Windows printer device context uses the current mapping
1494         mode, but mapping mode is currently ignored for PostScript output.
1495     */
1496     void SetMapMode(wxMappingMode mode);
1497
1498     /**
1499         If this is a window DC or memory DC, assigns the given palette to the
1500         window or bitmap associated with the DC. If the argument is
1501         ::wxNullPalette, the current palette is selected out of the device
1502         context, and the original palette restored.
1503
1504         @see wxPalette
1505     */
1506     void SetPalette(const wxPalette& palette);
1507
1508     /**
1509         Sets the user scaling factor, useful for applications which require
1510         'zooming'.
1511     */
1512     void SetUserScale(double xScale, double yScale);
1513
1514
1515     /**
1516         @name Transformation matrix
1517
1518         See the notes about the availability of these functions in the class
1519         documentation.
1520     */
1521     //@{
1522
1523     /**
1524         Check if the use of transformation matrix is supported by the current
1525         system.
1526
1527         Currently this function always returns @false for non-MSW platforms and
1528         may return @false for old (Windows 9x/ME) Windows systems. Normally
1529         support for the transformation matrix is always available in any
1530         relatively recent Windows versions.
1531
1532         @since 2.9.2
1533     */
1534     bool CanUseTransformMatrix() const;
1535
1536     /**
1537         Set the transformation matrix.
1538
1539         If transformation matrix is supported on the current system, the
1540         specified @a matrix will be used to transform between wxDC and physical
1541         coordinates. Otherwise the function returns @false and doesn't change
1542         the coordinate mapping.
1543
1544         @since 2.9.2
1545     */
1546     bool SetTransformMatrix(const wxAffineMatrix2D& matrix);
1547
1548     /**
1549         Return the transformation matrix used by this device context.
1550
1551         By default the transformation matrix is the identity matrix.
1552
1553         @since 2.9.2
1554     */
1555     wxAffineMatrix2D GetTransformMatrix() const;
1556
1557     /**
1558         Revert the transformation matrix to identity matrix.
1559
1560         @since 2.9.2
1561     */
1562     void ResetTransformMatrix();
1563
1564     //@}
1565
1566
1567     void SetLogicalScale(double x, double y);
1568     void GetLogicalScale(double *x, double *y) const;
1569     void SetLogicalOrigin(wxCoord x, wxCoord y);
1570     void GetLogicalOrigin(wxCoord *x, wxCoord *y) const;
1571     wxPoint GetLogicalOrigin() const;
1572
1573 };
1574
1575
1576
1577 /**
1578     @class wxDCClipper
1579
1580     wxDCClipper is a small helper class for setting a clipping region on a wxDC
1581     and unsetting it automatically. An object of wxDCClipper class is typically
1582     created on the stack so that it is automatically destroyed when the object
1583     goes out of scope. A typical usage example:
1584
1585     @code
1586     void MyFunction(wxDC& dc)
1587     {
1588         wxDCClipper clip(dc, rect);
1589         // ... drawing functions here are affected by clipping rect ...
1590     }
1591
1592     void OtherFunction()
1593     {
1594         wxDC dc;
1595         MyFunction(dc);
1596         // ... drawing functions here are not affected by clipping rect ...
1597     }
1598     @endcode
1599
1600     @library{wxcore}
1601     @category{gdi}
1602
1603     @see wxDC::SetClippingRegion(), wxDCFontChanger, wxDCTextColourChanger, wxDCPenChanger,
1604          wxDCBrushChanger
1605 */
1606 class wxDCClipper
1607 {
1608 public:
1609     //@{
1610     /**
1611         Sets the clipping region to the specified region/coordinates.
1612
1613         The clipping region is automatically unset when this object is destroyed.
1614     */
1615     wxDCClipper(wxDC& dc, const wxRegion& region);
1616     wxDCClipper(wxDC& dc, const wxRect& rect);
1617     wxDCClipper(wxDC& dc, wxCoord x, wxCoord y, wxCoord w, wxCoord h);
1618     //@}
1619
1620     /**
1621         Destroys the clipping region associated with the DC passed to the ctor.
1622     */
1623     ~wxDCClipper();
1624 };
1625
1626
1627 /**
1628     @class wxDCBrushChanger
1629
1630     wxDCBrushChanger is a small helper class for setting a brush on a wxDC
1631     and unsetting it automatically in the destructor, restoring the previous one.
1632
1633     @library{wxcore}
1634     @category{gdi}
1635
1636     @see wxDC::SetBrush(), wxDCFontChanger, wxDCTextColourChanger, wxDCPenChanger,
1637          wxDCClipper
1638 */
1639 class wxDCBrushChanger
1640 {
1641 public:
1642     /**
1643         Sets @a brush on the given @a dc, storing the old one.
1644
1645         @param dc
1646             The DC where the brush must be temporary set.
1647         @param brush
1648             The brush to set.
1649     */
1650     wxDCBrushChanger(wxDC& dc, const wxBrush& brush);
1651
1652     /**
1653         Restores the brush originally selected in the DC passed to the ctor.
1654     */
1655     ~wxDCBrushChanger();
1656 };
1657
1658
1659 /**
1660     @class wxDCPenChanger
1661
1662     wxDCPenChanger is a small helper class for setting a pen on a wxDC
1663     and unsetting it automatically in the destructor, restoring the previous one.
1664
1665     @library{wxcore}
1666     @category{gdi}
1667
1668     @see wxDC::SetPen(), wxDCFontChanger, wxDCTextColourChanger, wxDCBrushChanger,
1669          wxDCClipper
1670 */
1671 class wxDCPenChanger
1672 {
1673 public:
1674     /**
1675         Sets @a pen on the given @a dc, storing the old one.
1676
1677         @param dc
1678             The DC where the pen must be temporary set.
1679         @param pen
1680             The pen to set.
1681     */
1682     wxDCPenChanger(wxDC& dc, const wxPen& pen);
1683
1684     /**
1685         Restores the pen originally selected in the DC passed to the ctor.
1686     */
1687     ~wxDCPenChanger();
1688 };
1689
1690
1691
1692 /**
1693     @class wxDCTextColourChanger
1694
1695     wxDCTextColourChanger is a small helper class for setting a foreground
1696     text colour on a wxDC and unsetting it automatically in the destructor,
1697     restoring the previous one.
1698
1699     @library{wxcore}
1700     @category{gdi}
1701
1702     @see wxDC::SetTextForeground(), wxDCFontChanger, wxDCPenChanger, wxDCBrushChanger,
1703          wxDCClipper
1704 */
1705 class wxDCTextColourChanger
1706 {
1707 public:
1708     /**
1709         Trivial constructor not changing anything.
1710
1711         This constructor is useful if you don't know beforehand if the colour
1712         needs to be changed or not. It simply creates the object which won't do
1713         anything in its destructor unless Set() is called -- in which case it
1714         would reset the previous colour.
1715      */
1716     wxDCTextColourChanger(wxDC& dc);
1717
1718     /**
1719         Sets @a col on the given @a dc, storing the old one.
1720
1721         @param dc
1722             The DC where the colour must be temporary set.
1723         @param col
1724             The colour to set.
1725     */
1726     wxDCTextColourChanger(wxDC& dc, const wxColour& col);
1727
1728     /**
1729         Set the colour to use.
1730
1731         This method is meant to be called once only and only on the objects
1732         created with the constructor overload not taking wxColour argument and
1733         has the same effect as the other constructor, i.e. sets the colour to
1734         the given @a col and ensures that the old value is restored when this
1735         object is destroyed.
1736      */
1737     void Set(const wxColour& col);
1738
1739     /**
1740         Restores the colour originally selected in the DC passed to the ctor.
1741     */
1742     ~wxDCTextColourChanger();
1743 };
1744
1745
1746
1747 /**
1748     @class wxDCFontChanger
1749
1750     wxDCFontChanger is a small helper class for setting a font on a wxDC and
1751     unsetting it automatically in the destructor, restoring the previous one.
1752
1753     @since 2.9.0
1754
1755     @library{wxcore}
1756     @category{gdi}
1757
1758     @see wxDC::SetFont(), wxDCTextColourChanger, wxDCPenChanger, wxDCBrushChanger,
1759          wxDCClipper
1760 */
1761 class wxDCFontChanger
1762 {
1763 public:
1764     /**
1765         Trivial constructor not changing anything.
1766
1767         This constructor is useful if you don't know beforehand if the font
1768         needs to be changed or not. It simply creates the object which won't do
1769         anything in its destructor unless Set() is called -- in which case it
1770         would reset the previous font.
1771
1772         @since 2.9.1
1773      */
1774     wxDCFontChanger(wxDC& dc);
1775
1776     /**
1777         Sets @a font on the given @a dc, storing the old one.
1778
1779         @param dc
1780             The DC where the font must be temporary set.
1781         @param font
1782             The font to set.
1783     */
1784     wxDCFontChanger(wxDC& dc, const wxFont& font);
1785
1786     /**
1787         Set the font to use.
1788
1789         This method is meant to be called once only and only on the objects
1790         created with the constructor overload not taking wxColour argument and
1791         has the same effect as the other constructor, i.e. sets the font to
1792         the given @a font and ensures that the old value is restored when this
1793         object is destroyed.
1794      */
1795     void Set(const wxFont& font);
1796
1797     /**
1798         Restores the font originally selected in the DC passed to the ctor.
1799     */
1800     ~wxDCFontChanger();
1801 };
1802