1 \section{\class{wxDC
}}\label{wxdc
}
3 A wxDC is a
{\it device context
} onto which graphics and text can be drawn.
4 It is intended to represent a number of output devices in a generic way,
5 so a window can have a device context associated with it, and a printer also has a device context.
6 In this way, the same piece of code may write to a number of different devices,
7 if the device context is used as a parameter.
9 Notice that wxDC is an abstract base class and can't be created directly,
10 please use
\helpref{wxPaintDC
}{wxpaintdc
},
\helpref{wxClientDC
}{wxclientdc
},
11 \helpref{wxWindowDC
}{wxwindowdc
},
\helpref{wxScreenDC
}{wxscreendc
},
12 \helpref{wxMemoryDC
}{wxmemorydc
} or
\helpref{wxPrinterDC
}{wxprinterdc
}.
14 % VZ: we should really document them instead of this lame excuse, but I don't
15 % have time for it now, when it is done please remove this
16 Please note that in addition to the versions of the methods documented here,
17 there are also versions which accept single
{\tt wxPoint
} parameter instead of
18 two
{\tt wxCoord
} ones or
{\tt wxPoint
} and
{\tt wxSize
} instead of four of
21 \wxheading{Support for Transparency / Alpha Channel
}
23 On Mac OS X when using Core Graphics (wx
\_MAC\_USE\_CORE\_GRAPHICS set to
1)
24 colors with alpha are supported, so instances
{\tt wxPen
} or
{\tt wxBrush
} that are built from
{\tt wxColour
} use
25 the
color's alpha values when stroking or filling.
27 Note that beginning with wxWidgets
2.9.0 the entire wxDC code has been
28 reorganized. All platform dependent code (actual all drawing code) has
29 been moved into backend classes which derive from a common wxDCImpl
30 class. The user-visible classes such as wxClientDC and wxPaintDC
31 merely forward all calls to the backend implementation.
33 \wxheading{Derived from
}
35 \helpref{wxObject
}{wxobject
}
37 \wxheading{Include files
}
43 \helpref{wxCore
}{librarieslist
}
47 \helpref{Overview
}{dcoverview
}
49 \latexignore{\rtfignore{\wxheading{Members
}}}
52 \membersection{wxDC::Blit
}\label{wxdcblit
}
54 \func{bool
}{Blit
}{\param{wxCoord
}{ xdest
},
\param{wxCoord
}{ ydest
},
\param{wxCoord
}{ width
},
\param{wxCoord
}{ height
},
55 \param{wxDC*
}{source
},
\param{wxCoord
}{ xsrc
},
\param{wxCoord
}{ ysrc
},
\param{int
}{ logicalFunc = wxCOPY
},
56 \param{bool
}{useMask = false
},
\param{wxCoord
}{ xsrcMask = -
1},
\param{wxCoord
}{ ysrcMask = -
1}}
58 Copy from a source DC to this DC, specifying the destination
59 coordinates, size of area to copy, source DC, source coordinates,
60 logical function, whether to use a bitmap mask, and mask source position.
62 \wxheading{Parameters
}
64 \docparam{xdest
}{Destination device context x position.
}
66 \docparam{ydest
}{Destination device context y position.
}
68 \docparam{width
}{Width of source area to be copied.
}
70 \docparam{height
}{Height of source area to be copied.
}
72 \docparam{source
}{Source device context.
}
74 \docparam{xsrc
}{Source device context x position.
}
76 \docparam{ysrc
}{Source device context y position.
}
78 \docparam{logicalFunc
}{Logical function to use: see
\helpref{wxDC::SetLogicalFunction
}{wxdcsetlogicalfunction
}.
}
80 \docparam{useMask
}{If true, Blit does a transparent blit using the mask that is associated with the bitmap
81 selected into the source device context. The Windows implementation does the following if MaskBlt cannot be used:
84 \item Creates a temporary bitmap and copies the destination area into it.
85 \item Copies the source area into the temporary bitmap using the specified logical function.
86 \item Sets the masked area in the temporary bitmap to BLACK by ANDing the
87 mask bitmap with the temp bitmap with the foreground colour set to WHITE
88 and the bg colour set to BLACK.
89 \item Sets the unmasked area in the destination area to BLACK by ANDing the
90 mask bitmap with the destination area with the foreground colour set to BLACK
91 and the background colour set to WHITE.
92 \item ORs the temporary bitmap with the destination area.
93 \item Deletes the temporary bitmap.
96 This sequence of operations ensures that the source's transparent area need not be black,
97 and logical functions are supported.
99 {\bf Note:
} on Windows, blitting with masks can be speeded up considerably by compiling
100 wxWidgets with the wxUSE
\_DC\_CACHE option enabled. You can also influence whether MaskBlt
101 or the explicit mask blitting code above is used, by using
\helpref{wxSystemOptions
}{wxsystemoptions
} and
102 setting the
{\bf no-maskblt
} option to
1.
106 \docparam{xsrcMask
}{Source x position on the mask. If both xsrcMask and ysrcMask are -
1, xsrc and ysrc
107 will be assumed for the mask source position. Currently only implemented on Windows.
}
109 \docparam{ysrcMask
}{Source y position on the mask. If both xsrcMask and ysrcMask are -
1, xsrc and ysrc
110 will be assumed for the mask source position. Currently only implemented on Windows.
}
115 There is partial support for Blit in wxPostScriptDC, under X.
117 See
\helpref{wxMemoryDC
}{wxmemorydc
} for typical usage.
121 \helpref{wxDC::StretchBlit
}{wxdcstretchblit
},
\helpref{wxMemoryDC
}{wxmemorydc
},
\helpref{wxBitmap
}{wxbitmap
},
\helpref{wxMask
}{wxmask
}
125 \membersection{wxDC::CacheEnabled
}\label{wxdccacheenabled
}
127 \func{static bool
}{CacheEnabled
}{\void}
129 On supported platforms (currently only Windows), returns true
130 if the DC cache is enabled. The DC cache
131 can speed up the
\helpref{Blit
}{wxdcblit
} operation when
132 drawing a large number of masked bitmaps.
134 If using the cache functions in your code, please test for the
135 wxUSE
\_DC\_CACHEING preprocessor symbol for portability.
139 \helpref{wxDC::EnableCache
}{wxdcenablecache
},
\helpref{wxDC::ClearCache
}
143 \membersection{wxDC::CalcBoundingBox
}\label{wxdccalcboundingbox
}
145 \func{void
}{CalcBoundingBox
}{\param{wxCoord
}{x
},
\param{wxCoord
}{y
}}
147 Adds the specified point to the bounding box which can be retrieved with
148 \helpref{MinX
}{wxdcminx
},
\helpref{MaxX
}{wxdcmaxx
} and
149 \helpref{MinY
}{wxdcminy
},
\helpref{MaxY
}{wxdcmaxy
} functions.
153 \helpref{ResetBoundingBox
}{wxdcresetboundingbox
}
156 \membersection{wxDC::Clear
}\label{wxdcclear
}
158 \func{void
}{Clear
}{\void}
160 Clears the device context using the current background brush.
164 \membersection{wxDC::ClearCache
}\label{wxdcclearcache
}
166 \func{static void
}{ClearCache
}{\void}
168 On supported platforms (currently only Windows), clears
169 the contents of the DC cache (one bitmap and two Windows device contexts). The DC cache
170 can speed up the
\helpref{Blit
}{wxdcblit
} operation when
171 drawing a large number of masked bitmaps. You should
172 call ClearCache at the end of length DC operations if you wish to only use
173 the cache transiently; you should also call it as your application exits.
175 If using the cache functions in your code, please test for the
176 wxUSE
\_DC\_CACHEING preprocessor symbol for portability.
180 \helpref{wxDC::EnableCache
}{wxdcenablecache
},
\helpref{wxDC::CacheEnabled
}
184 \membersection{wxDC::ComputeScaleAndOrigin
}\label{wxdccomputescaleandorigin
}
186 \func{virtual void
}{ComputeScaleAndOrigin
}{\void}
188 Performs all necessary computations for given platform and context type
189 after each change of scale and origin parameters. Usually called automatically
190 internally after such changes.
193 \membersection{wxDC::CrossHair
}\label{wxdccrosshair
}
195 \func{void
}{CrossHair
}{\param{wxCoord
}{ x
},
\param{wxCoord
}{ y
}}
197 Displays a cross hair using the current pen. This is a vertical
198 and horizontal line the height and width of the window, centred
202 \membersection{wxDC::DestroyClippingRegion
}\label{wxdcdestroyclippingregion
}
204 \func{void
}{DestroyClippingRegion
}{\void}
206 Destroys the current clipping region so that none of the DC is clipped.
207 See also
\helpref{wxDC::SetClippingRegion
}{wxdcsetclippingregion
}.
210 \membersection{wxDC::DeviceToLogicalX
}\label{wxdcdevicetologicalx
}
212 \func{virtual wxCoord
}{DeviceToLogicalX
}{\param{wxCoord
}{ x
}}
214 Convert device X coordinate to logical coordinate, using the current
218 \membersection{wxDC::DeviceToLogicalXRel
}\label{wxdcdevicetologicalxrel
}
220 \func{virtual wxCoord
}{DeviceToLogicalXRel
}{\param{wxCoord
}{ x
}}
222 Convert device X coordinate to relative logical coordinate, using the current
223 mapping mode but ignoring the x axis orientation.
224 Use this function for converting a width, for example.
227 \membersection{wxDC::DeviceToLogicalY
}\label{wxdcdevicetologicaly
}
229 \func{virtual wxCoord
}{DeviceToLogicalY
}{\param{wxCoord
}{ y
}}
231 Converts device Y coordinate to logical coordinate, using the current
235 \membersection{wxDC::DeviceToLogicalYRel
}\label{wxdcdevicetologicalyrel
}
237 \func{virtual wxCoord
}{DeviceToLogicalYRel
}{\param{wxCoord
}{ y
}}
239 Convert device Y coordinate to relative logical coordinate, using the current
240 mapping mode but ignoring the y axis orientation.
241 Use this function for converting a height, for example.
244 \membersection{wxDC::DrawArc
}\label{wxdcdrawarc
}
246 \func{void
}{DrawArc
}{\param{wxCoord
}{ x1
},
\param{wxCoord
}{ y1
},
\param{wxCoord
}{ x2
},
\param{wxCoord
}{ y2
},
\param{wxCoord
}{ xc
},
\param{wxCoord
}{ yc
}}
248 Draws an arc of a circle, centred on (
{\it xc, yc
}), with starting point (
{\it x1, y1
})
249 and ending at (
{\it x2, y2
}). The current pen is used for the outline
250 and the current brush for filling the shape.
252 The arc is drawn in an anticlockwise direction from the start point to the end point.
255 \membersection{wxDC::DrawBitmap
}\label{wxdcdrawbitmap
}
257 \func{void
}{DrawBitmap
}{\param{const wxBitmap\&
}{ bitmap
},
\param{wxCoord
}{ x
},
\param{wxCoord
}{ y
},
\param{bool
}{ transparent
}}
259 Draw a bitmap on the device context at the specified point. If
{\it transparent
} is true and the bitmap has
260 a transparency mask, the bitmap will be drawn transparently.
262 When drawing a mono-bitmap, the current text foreground colour will be used to draw the foreground
263 of the bitmap (all bits set to
1), and the current text background colour to draw the background
264 (all bits set to
0). See also
\helpref{SetTextForeground
}{wxdcsettextforeground
},
265 \helpref{SetTextBackground
}{wxdcsettextbackground
} and
\helpref{wxMemoryDC
}{wxmemorydc
}.
268 \membersection{wxDC::DrawCheckMark
}\label{wxdcdrawcheckmark
}
270 \func{void
}{DrawCheckMark
}{\param{wxCoord
}{ x
},
\param{wxCoord
}{ y
},
\param{wxCoord
}{ width
},
\param{wxCoord
}{ height
}}
272 \func{void
}{DrawCheckMark
}{\param{const wxRect \&
}{rect
}}
274 Draws a check mark inside the given rectangle.
277 \membersection{wxDC::DrawCircle
}\label{wxdcdrawcircle
}
279 \func{void
}{DrawCircle
}{\param{wxCoord
}{ x
},
\param{wxCoord
}{ y
},
\param{wxCoord
}{ radius
}}
281 \func{void
}{DrawCircle
}{\param{const wxPoint\&
}{ pt
},
\param{wxCoord
}{ radius
}}
283 Draws a circle with the given centre and radius.
287 \helpref{DrawEllipse
}{wxdcdrawellipse
}
290 \membersection{wxDC::DrawEllipse
}\label{wxdcdrawellipse
}
292 \func{void
}{DrawEllipse
}{\param{wxCoord
}{ x
},
\param{wxCoord
}{ y
},
\param{wxCoord
}{ width
},
\param{wxCoord
}{ height
}}
294 \func{void
}{DrawEllipse
}{\param{const wxPoint\&
}{ pt
},
\param{const wxSize\&
}{ size
}}
296 \func{void
}{DrawEllipse
}{\param{const wxRect\&
}{ rect
}}
298 Draws an ellipse contained in the rectangle specified either with the given top
299 left corner and the given size or directly. The current pen is used for the
300 outline and the current brush for filling the shape.
304 \helpref{DrawCircle
}{wxdcdrawcircle
}
307 \membersection{wxDC::DrawEllipticArc
}\label{wxdcdrawellipticarc
}
309 \func{void
}{DrawEllipticArc
}{\param{wxCoord
}{ x
},
\param{wxCoord
}{ y
},
\param{wxCoord
}{ width
},
\param{wxCoord
}{ height
},
310 \param{double
}{ start
},
\param{double
}{ end
}}
312 Draws an arc of an ellipse. The current pen is used for drawing the arc and
313 the current brush is used for drawing the pie.
315 {\it x
} and
{\it y
} specify the x and y coordinates of the upper-left corner of the rectangle that contains
318 {\it width
} and
{\it height
} specify the width and height of the rectangle that contains
321 {\it start
} and
{\it end
} specify the start and end of the arc relative to the three-o'clock
322 position from the center of the rectangle. Angles are specified
323 in degrees (
360 is a complete circle). Positive values mean
324 counter-clockwise motion. If
{\it start
} is equal to
{\it end
}, a
325 complete ellipse will be drawn.
328 \membersection{wxDC::DrawIcon
}\label{wxdcdrawicon
}
330 \func{void
}{DrawIcon
}{\param{const wxIcon\&
}{ icon
},
\param{wxCoord
}{ x
},
\param{wxCoord
}{ y
}}
332 Draw an icon on the display (does nothing if the device context is PostScript).
333 This can be the simplest way of drawing bitmaps on a window.
336 \membersection{wxDC::DrawLabel
}\label{wxdcdrawlabel
}
338 \func{virtual void
}{DrawLabel
}{\param{const wxString\&
}{ text
},
339 \param{const wxBitmap\&
}{ image
},
340 \param{const wxRect\&
}{ rect
},
341 \param{int
}{ alignment = wxALIGN
\_LEFT | wxALIGN
\_TOP},
342 \param{int
}{ indexAccel = -
1},
343 \param{wxRect *
}{rectBounding = NULL
}}
345 \func{void
}{DrawLabel
}{\param{const wxString\&
}{ text
},
\param{const wxRect\&
}{ rect
},
346 \param{int
}{ alignment = wxALIGN
\_LEFT | wxALIGN
\_TOP},
347 \param{int
}{ indexAccel = -
1}}
349 Draw optional bitmap and the text into the given rectangle and aligns it as specified
350 by alignment parameter; it also will emphasize the character with the given index if
351 it is != -
1 and return the bounding rectangle if required.
354 \membersection{wxDC::DrawLine
}\label{wxdcdrawline
}
356 \func{void
}{DrawLine
}{\param{wxCoord
}{ x1
},
\param{wxCoord
}{ y1
},
\param{wxCoord
}{ x2
},
\param{wxCoord
}{ y2
}}
358 Draws a line from the first point to the second. The current pen is used
359 for drawing the line. Note that the point $(x2, y2)$ is
{\emph not
} part of the
360 line and is not drawn by this function (this is consistent with the behaviour
361 of many other toolkits).
364 \membersection{wxDC::DrawLines
}\label{wxdcdrawlines
}
366 \func{void
}{DrawLines
}{\param{int
}{ n
},
\param{wxPoint
}{ points
[]},
\param{wxCoord
}{ xoffset =
0},
\param{wxCoord
}{ yoffset =
0}}
368 Draws lines using an array of
{\it points
} of size
{\it n
}
369 adding the optional offset coordinate. The current pen is
370 used for drawing the lines.
372 \func{void
}{DrawLines
}{\param{const wxPointList *
}{points
},
\param{wxCoord
}{ xoffset =
0},
\param{wxCoord
}{ yoffset =
0}}
374 This method uses a list of wxPoints, adding the optional offset
375 coordinate. The programmer is responsible for deleting the list
378 \pythonnote{The wxPython version of this method accepts a Python list
381 \perlnote{The wxPerl version of this method accepts
382 as its first parameter a reference to an array
386 \membersection{wxDC::DrawPolygon
}\label{wxdcdrawpolygon
}
388 \func{void
}{DrawPolygon
}{\param{int
}{ n
},
\param{wxPoint
}{ points
[]},
\param{wxCoord
}{ xoffset =
0},
\param{wxCoord
}{ yoffset =
0},\\
389 \param{int
}{fill
\_style = wxODDEVEN
\_RULE}}
391 Draws a filled polygon using an array of
{\it points
} of size
{\it n
},
392 adding the optional offset coordinate.
394 \func{void
}{DrawPolygon
}{\param{const wxPointList *
}{points
},
\param{wxCoord
}{ xoffset =
0},
\param{wxCoord
}{ yoffset =
0},\\
395 \param{int
}{fill
\_style = wxODDEVEN
\_RULE}}
397 This method draws a filled polygon using a list of wxPoints,
398 adding the optional offset coordinate.
400 The last argument specifies the fill rule:
{\bf wxODDEVEN
\_RULE} (the
401 default) or
{\bf wxWINDING
\_RULE}.
403 The current pen is used for drawing the outline, and the current brush
404 for filling the shape. Using a transparent brush suppresses filling.
405 The programmer is responsible for deleting the list of points.
407 Note that wxWidgets automatically closes the first and last points.
409 \pythonnote{The wxPython version of this method accepts a Python list
412 \perlnote{The wxPerl version of this method accepts
413 as its first parameter a reference to an array
417 \membersection{wxDC::DrawPolyPolygon
}\label{wxdcdrawpolypolygon
}
419 \func{void
}{DrawPolyPolygon
}{\param{int
}{ n
},
\param{int
}{ count
[]},
\param{wxPoint
}{ points
[]},
\param{wxCoord
}{ xoffset =
0},
\param{wxCoord
}{ yoffset =
0},\\
420 \param{int
}{fill
\_style = wxODDEVEN
\_RULE}}
422 Draws two or more filled polygons using an array of
{\it points
}, adding the
423 optional offset coordinates.
425 Notice that for the platforms providing a native implementation
426 of this function (Windows and PostScript-based wxDC currently), this is more
427 efficient than using
\helpref{DrawPolygon
}{wxdcdrawpolygon
} in a loop.
429 {\it n
} specifies the number of polygons to draw, the array
{\it count
} of size
430 {\it n
} specifies the number of points in each of the polygons in the
433 The last argument specifies the fill rule:
{\bf wxODDEVEN
\_RULE} (the default)
434 or
{\bf wxWINDING
\_RULE}.
436 The current pen is used for drawing the outline, and the current brush for
437 filling the shape. Using a transparent brush suppresses filling.
439 The polygons maybe disjoint or overlapping. Each polygon specified in a call to
440 {\bf DrawPolyPolygon
} must be closed. Unlike polygons created by the
441 \helpref{DrawPolygon
}{wxdcdrawpolygon
} member function, the polygons created by
442 {\bf DrawPolyPolygon
} are not closed automatically.
444 \pythonnote{Not implemented yet
}
446 \perlnote{Not implemented yet
}
449 \membersection{wxDC::DrawPoint
}\label{wxdcdrawpoint
}
451 \func{void
}{DrawPoint
}{\param{wxCoord
}{ x
},
\param{wxCoord
}{ y
}}
453 Draws a point using the
color of the current pen. Note that the other properties of the pen are not used, such as width etc..
456 \membersection{wxDC::DrawRectangle
}\label{wxdcdrawrectangle
}
458 \func{void
}{DrawRectangle
}{\param{wxCoord
}{ x
},
\param{wxCoord
}{ y
},
\param{wxCoord
}{ width
},
\param{wxCoord
}{ height
}}
460 Draws a rectangle with the given top left corner, and with the given
461 size. The current pen is used for the outline and the current brush
462 for filling the shape.
465 \membersection{wxDC::DrawRotatedText
}\label{wxdcdrawrotatedtext
}
467 \func{void
}{DrawRotatedText
}{\param{const wxString\&
}{text
},
\param{wxCoord
}{ x
},
\param{wxCoord
}{ y
},
\param{double
}{ angle
}}
469 Draws the text rotated by
{\it angle
} degrees.
471 {\bf NB:
} Under Win9x only TrueType fonts can be drawn by this function. In
472 particular, a font different from
{\tt wxNORMAL
\_FONT} should be used as the
473 latter is not a TrueType font.
{\tt wxSWISS
\_FONT} is an example of a font
478 \helpref{DrawText
}{wxdcdrawtext
}
481 \membersection{wxDC::DrawRoundedRectangle
}\label{wxdcdrawroundedrectangle
}
483 \func{void
}{DrawRoundedRectangle
}{\param{wxCoord
}{ x
},
\param{wxCoord
}{ y
},
\param{wxCoord
}{ width
},
\param{wxCoord
}{ height
},
\param{double
}{ radius
}}
485 Draws a rectangle with the given top left corner, and with the given
486 size. The corners are quarter-circles using the given radius. The
487 current pen is used for the outline and the current brush for filling
490 If
{\it radius
} is positive, the value is assumed to be the
491 radius of the rounded corner. If
{\it radius
} is negative,
492 the absolute value is assumed to be the
{\it proportion
} of the smallest
493 dimension of the rectangle. This means that the corner can be
494 a sensible size relative to the size of the rectangle, and also avoids
495 the strange effects X produces when the corners are too big for
499 \membersection{wxDC::DrawSpline
}\label{wxdcdrawspline
}
501 \func{void
}{DrawSpline
}{\param{int
}{n
},
\param{wxPoint
}{points
[]}}
503 Draws a spline between all given control points, using the current
506 \func{void
}{DrawSpline
}{\param{const wxPointList *
}{points
}}
508 Draws a spline between all given control points.
510 \func{void
}{DrawSpline
}{\param{wxCoord
}{ x1
},
\param{wxCoord
}{ y1
},
\param{wxCoord
}{ x2
},
\param{wxCoord
}{ y2
},
\param{wxCoord
}{ x3
},
\param{wxCoord
}{ y3
}}
512 Draws a three-point spline using the current pen.
514 \pythonnote{The wxPython version of this method accepts a Python list
517 \perlnote{The wxPerl version of this method accepts a reference to an array
521 \membersection{wxDC::DrawText
}\label{wxdcdrawtext
}
523 \func{void
}{DrawText
}{\param{const wxString\&
}{text
},
\param{wxCoord
}{ x
},
\param{wxCoord
}{ y
}}
525 Draws a text string at the specified point, using the current text font,
526 and the current text foreground and background colours.
528 The coordinates refer to the top-left corner of the rectangle bounding
529 the string. See
\helpref{wxDC::GetTextExtent
}{wxdcgettextextent
} for how
530 to get the dimensions of a text string, which can be used to position the
533 {\bf NB:
} under wxGTK the current
534 \helpref{logical function
}{wxdcgetlogicalfunction
} is used by this function
535 but it is ignored by wxMSW. Thus, you should avoid using logical functions
536 with this function in portable programs.
540 \membersection{wxDC::EnableCache
}\label{wxdcenablecache
}
542 \func{static void
}{EnableCache
}{\param{bool
}{ enableCache
}}
544 On supported platforms (currently only Windows), enables the DC cache
545 which can speed up the
\helpref{Blit
}{wxdcblit
} operation when
546 drawing a large number of masked bitmaps.
548 If using the cache functions in your code, please test for the
549 wxUSE
\_DC\_CACHEING preprocessor symbol for portability.
553 \helpref{wxDC::CacheEnabled
}{wxdccacheenabled
},
\helpref{wxDC::ClearCache
}
557 \membersection{wxDC::EndDoc
}\label{wxdcenddoc
}
559 \func{void
}{EndDoc
}{\void}
561 Ends a
document (only relevant when outputting to a printer).
564 \membersection{wxDC::EndPage
}\label{wxdcendpage
}
566 \func{void
}{EndPage
}{\void}
568 Ends a
document page (only relevant when outputting to a printer).
571 \membersection{wxDC::FloodFill
}\label{wxdcfloodfill
}
573 \func{bool
}{FloodFill
}{\param{wxCoord
}{ x
},
\param{wxCoord
}{ y
},
\param{const wxColour\&
}{ colour
},
\param{int
}{ style=wxFLOOD
\_SURFACE}}
575 Flood fills the device context starting from the given point, using
576 the
{\it current brush colour
}, and using a style:
578 \begin{itemize
}\itemsep=
0pt
579 \item wxFLOOD
\_SURFACE: the flooding occurs until a colour other than the given colour is encountered.
580 \item wxFLOOD
\_BORDER: the area to be flooded is bounded by the given colour.
583 Returns false if the operation failed.
585 {\it Note:
} The present implementation for non-Windows platforms may fail to find
586 colour borders if the pixels do not match the colour exactly. However the
587 function will still return true.
590 \membersection{wxDC::GetBackground
}\label{wxdcgetbackground
}
592 \constfunc{const wxBrush\&
}{GetBackground
}{\void}
594 Gets the brush used for painting the background (see
\helpref{wxDC::SetBackground
}{wxdcsetbackground
}).
597 \membersection{wxDC::GetBackgroundMode
}\label{wxdcgetbackgroundmode
}
599 \constfunc{int
}{GetBackgroundMode
}{\void}
601 Returns the current background mode:
{\tt wxSOLID
} or
{\tt wxTRANSPARENT
}.
605 \helpref{SetBackgroundMode
}{wxdcsetbackgroundmode
}
608 \membersection{wxDC::GetBrush
}\label{wxdcgetbrush
}
610 \constfunc{const wxBrush\&
}{GetBrush
}{\void}
612 Gets the current brush (see
\helpref{wxDC::SetBrush
}{wxdcsetbrush
}).
615 \membersection{wxDC::GetCharHeight
}\label{wxdcgetcharheight
}
617 \func{wxCoord
}{GetCharHeight
}{\void}
619 Gets the character height of the currently set font.
622 \membersection{wxDC::GetCharWidth
}\label{wxdcgetcharwidth
}
624 \func{wxCoord
}{GetCharWidth
}{\void}
626 Gets the average character width of the currently set font.
629 \membersection{wxDC::GetClippingBox
}\label{wxdcgetclippingbox
}
631 \func{void
}{GetClippingBox
}{\param{wxCoord
}{ *x
},
\param{wxCoord
}{ *y
},
\param{wxCoord
}{ *width
},
\param{wxCoord
}{ *height
}}
633 Gets the rectangle surrounding the current clipping region.
635 \pythonnote{No arguments are required and the four values defining the
636 rectangle are returned as a tuple.
}
638 \perlnote{This method takes no arguments and returns a four element list
639 {\tt ( x, y, width, height )
}}
642 \membersection{wxDC::GetDepth
}\label{wxdcgetdepth
}
644 \constfunc{int
}{GetDepth
}{\void}
646 Returns the depth (number of bits/pixel) of this DC.
650 \helpref{wxDisplayDepth
}{wxdisplaydepth
}
653 \membersection{wxDC::GetFont
}\label{wxdcgetfont
}
655 \constfunc{const wxFont\&
}{GetFont
}{\void}
657 Gets the current font. Notice that even although each device context object has
658 some default font after creation, this method would return a
\texttt{wxNullFont
}
659 initially and only after calling
\helpref{wxDC::SetFont
}{wxdcsetfont
} a valid
663 \membersection{wxDC::GetLayoutDirection
}\label{wxdcgetlayoutdirection
}
665 \constfunc{wxLayoutDirection
}{GetLayoutDirection
}{\void}
667 Gets the current layout direction of the device context. On platforms where RTL layout
668 is supported, the return value will either be
\texttt{wxLayout
\_LeftToRight} or
669 \texttt{wxLayout
\_RightToLeft}. If RTL layout is not supported, the return value will
670 be
\texttt{wxLayout
\_Default}.
674 \helpref{SetLayoutDirection
}{wxdcsetlayoutdirection
}
677 \membersection{wxDC::GetLogicalFunction
}\label{wxdcgetlogicalfunction
}
679 \func{int
}{GetLogicalFunction
}{\void}
681 Gets the current logical function (see
\helpref{wxDC::SetLogicalFunction
}{wxdcsetlogicalfunction
}).
684 \membersection{wxDC::GetMapMode
}\label{wxdcgetmapmode
}
686 \func{int
}{GetMapMode
}{\void}
688 Gets the
{\it mapping mode
} for the device context (see
\helpref{wxDC::SetMapMode
}{wxdcsetmapmode
}).
691 \membersection{wxDC::GetMultiLineTextExtent
}\label{wxdcgetmultilinetextextent
}
693 \constfunc{void
}{GetMultiLineTextExtent
}{\param{const wxString\&
}{string
},
\param{wxCoord *
}{w
},\\
694 \param{wxCoord *
}{h
},
\param{wxCoord *
}{heightLine = NULL
},
\param{wxFont *
}{font = NULL
}}
696 \constfunc{wxSize
}{GetMultiLineTextExtent
}{\param{const wxString\&
}{string
}}
698 Gets the dimensions of the string using the currently selected font.
699 \rtfsp{\it string
} is the text string to measure,
{\it heightLine
}, if non NULL,
700 is where to store the height of a single line.
702 The text extent is returned in
{\it w
} and
{\it h
} pointers (first form) or as
703 a
\helpref{wxSize
}{wxsize
} object (second form).
705 If the optional parameter
{\it font
} is specified and valid, then it is used
706 for the text extent calculation. Otherwise the currently selected font is.
708 Note that this function works both with single-line and multi-line strings.
712 \helpref{wxFont
}{wxfont
},
\rtfsp
713 \helpref{wxDC::SetFont
}{wxdcsetfont
},
\rtfsp
714 \helpref{wxDC::GetPartialTextExtents
}{wxdcgetpartialtextextents
},
\rtfsp
715 \helpref{wxDC::GetTextExtent
}{wxdcgettextextent
}
718 \membersection{wxDC::GetPartialTextExtents
}\label{wxdcgetpartialtextextents
}
720 \constfunc{bool
}{GetPartialTextExtents
}{\param{const wxString\&
}{text
},
721 \param{wxArrayInt\&
}{widths
}}
723 Fills the
{\it widths
} array with the widths from the beginning of
724 {\it text
} to the corresponding character of
{\it text
}. The generic
725 version simply builds a running total of the widths of each character
726 using
\helpref{GetTextExtent
}{wxdcgettextextent
}, however if the
727 various platforms have a native API function that is faster or more
728 accurate than the generic implementation then it should be used
733 \helpref{wxDC::GetMultiLineTextExtent
}{wxdcgetmultilinetextextent
},
\rtfsp
734 \helpref{wxDC::GetTextExtent
}{wxdcgettextextent
}
736 \pythonnote{This method only takes the
{\it text
} parameter and
737 returns a Python list of integers.
}
740 \membersection{wxDC::GetPen
}\label{wxdcgetpen
}
742 \constfunc{const wxPen\&
}{GetPen
}{\void}
744 Gets the current pen (see
\helpref{wxDC::SetPen
}{wxdcsetpen
}).
747 \membersection{wxDC::GetPixel
}\label{wxdcgetpixel
}
749 \func{bool
}{GetPixel
}{\param{wxCoord
}{ x
},
\param{wxCoord
}{ y
},
\param{wxColour *
}{colour
}}
751 Gets in
{\it colour
} the colour at the specified location.
752 Not available for wxPostScriptDC or wxMetafileDC.
754 Note that setting a pixel can be done using
\helpref{DrawPoint
}{wxdcdrawpoint
}.
756 \pythonnote{For wxPython the wxColour value is returned and is not
757 required as a parameter.
}
759 \perlnote{This method only takes the parameters
{\tt x
} and
{\tt y
} and returns
762 \membersection{wxDC::GetPPI
}\label{wxdcgetppi
}
764 \constfunc{wxSize
}{GetPPI
}{\void}
766 Returns the resolution of the device in pixels per inch.
768 \membersection{wxDC::GetSize
}\label{wxdcgetsize
}
770 \constfunc{void
}{GetSize
}{\param{wxCoord *
}{width
},
\param{wxCoord *
}{height
}}
772 \constfunc{wxSize
}{GetSize
}{\void}
774 This gets the horizontal and vertical resolution in device units. It can be used to scale graphics to fit the page.
775 For example, if
{\it maxX
} and
{\it maxY
}\rtfsp
776 represent the maximum horizontal and vertical `pixel' values used in your
777 application, the following code will scale the graphic to fit on the
783 double scaleX=(double)(maxX/w);
784 double scaleY=(double)(maxY/h);
785 dc.SetUserScale(min(scaleX,scaleY),min(scaleX,scaleY));
788 \pythonnote{In place of a single overloaded method name, wxPython
789 implements the following methods:
\par
790 \indented{2cm
}{\begin{twocollist
}
791 \twocolitem{{\bf GetSize()
}}{Returns a wxSize
}
792 \twocolitem{{\bf GetSizeTuple()
}}{Returns a
2-tuple (width, height)
}
796 \perlnote{In place of a single overloaded method, wxPerl uses:
\par
797 \indented{2cm
}{\begin{twocollist
}
798 \twocolitem{{\bf GetSize()
}}{Returns a Wx::Size
}
799 \twocolitem{{\bf GetSizeWH()
}}{Returns a
2-element list
800 {\tt ( width, height )
}}
804 \membersection{wxDC::GetSizeMM
}\label{wxdcgetsizemm
}
806 \constfunc{void
}{GetSizeMM
}{\param{wxCoord *
}{width
},
\param{wxCoord *
}{height
}}
808 \constfunc{wxSize
}{GetSizeMM
}{\void}
810 Returns the horizontal and vertical resolution in millimetres.
812 \membersection{wxDC::GetTextBackground
}\label{wxdcgettextbackground
}
814 \constfunc{const wxColour\&
}{GetTextBackground
}{\void}
816 Gets the current text background colour (see
\helpref{wxDC::SetTextBackground
}{wxdcsettextbackground
}).
819 \membersection{wxDC::GetTextExtent
}\label{wxdcgettextextent
}
821 \constfunc{void
}{GetTextExtent
}{\param{const wxString\&
}{string
},
\param{wxCoord *
}{w
},
\param{wxCoord *
}{h
},\\
822 \param{wxCoord *
}{descent = NULL
},
\param{wxCoord *
}{externalLeading = NULL
},
\param{const wxFont *
}{font = NULL
}}
824 \constfunc{wxSize
}{GetTextExtent
}{\param{const wxString\&
}{string
}}
826 Gets the dimensions of the string using the currently selected font.
827 \rtfsp{\it string
} is the text string to measure,
{\it descent
} is the
828 dimension from the baseline of the font to the bottom of the
829 descender, and
{\it externalLeading
} is any extra vertical space added
830 to the font by the font designer (usually is zero).
832 The text extent is returned in
{\it w
} and
{\it h
} pointers (first form) or as
833 a
\helpref{wxSize
}{wxsize
} object (second form).
835 If the optional parameter
{\it font
} is specified and valid, then it is used
836 for the text extent calculation. Otherwise the currently selected font is.
838 Note that this function only works with single-line strings.
842 \helpref{wxFont
}{wxfont
},
\rtfsp
843 \helpref{wxDC::SetFont
}{wxdcsetfont
},
\rtfsp
844 \helpref{wxDC::GetPartialTextExtents
}{wxdcgetpartialtextextents
},
\rtfsp
845 \helpref{wxDC::GetMultiLineTextExtent
}{wxdcgetmultilinetextextent
}
847 \pythonnote{The following methods are implemented in wxPython:
\par
848 \indented{2cm
}{\begin{twocollist
}
849 \twocolitem{{\bf GetTextExtent(string)
}}{Returns a
2-tuple, (width, height)
}
850 \twocolitem{{\bf GetFullTextExtent(string, font=NULL)
}}{Returns a
851 4-tuple, (width, height, descent, externalLeading)
}
855 \perlnote{In wxPerl this method is implemented as
856 {\bf GetTextExtent( string, font = undef )
} returning a four element
857 array
{\tt ( width, height, descent, externalLeading )
}
861 \membersection{wxDC::GetTextForeground
}\label{wxdcgettextforeground
}
863 \constfunc{const wxColour\&
}{GetTextForeground
}{\void}
865 Gets the current text foreground colour (see
\helpref{wxDC::SetTextForeground
}{wxdcsettextforeground
}).
868 \membersection{wxDC::GetUserScale
}\label{wxdcgetuserscale
}
870 \func{void
}{GetUserScale
}{\param{double
}{ *x
},
\param{double
}{ *y
}}
872 Gets the current user scale factor (set by
\helpref{SetUserScale
}{wxdcsetuserscale
}).
874 \perlnote{In wxPerl this method takes no arguments and return a two element
875 array
{\tt ( x, y )
}}
878 \membersection{wxDC::GradientFillConcentric
}\label{wxdcgradientfillconcentric
}
880 \func{void
}{GradientFillConcentric
}{\param{const wxRect\&
}{ rect
},
\param{const wxColour\&
}{ initialColour
},
\param{const wxColour\&
}{ destColour
}}
882 \func{void
}{GradientFillConcentric
}{\param{const wxRect\&
}{ rect
},
\param{const wxColour\&
}{ initialColour
},
\param{const wxColour\&
}{ destColour
},
\param{const wxPoint\&
}{circleCenter
}}
884 Fill the area specified by rect with a radial gradient, starting from
885 \arg{initialColour
} at the centre of the circle and fading to
\arg{destColour
}
886 on the circle outside.
888 \arg{circleCenter
} are the relative coordinates of centre of the circle in
889 the specified
\arg{rect
}. If not specified, the cercle is placed at the
892 \textbf{Note:
} Currently this function is very slow, don't use it for
896 \membersection{wxDC::GradientFillLinear
}\label{wxdcgradientfilllinear
}
898 \func{void
}{GradientFillLinear
}{\param{const wxRect\&
}{ rect
},
\param{const wxColour\&
}{ initialColour
},
\param{const wxColour\&
}{ destColour
},
\param{wxDirection
}{ nDirection = wxEAST
}}
900 Fill the area specified by
\arg{rect
} with a linear gradient, starting from
901 \arg{initialColour
} and eventually fading to
\arg{destColour
}. The
902 \arg{nDirection
} specifies the direction of the colour change, default is to
903 use
\arg{initialColour
} on the left part of the rectangle and
904 \arg{destColour
} on the right one.
907 \membersection{wxDC::LogicalToDeviceX
}\label{wxdclogicaltodevicex
}
909 \func{virtual wxCoord
}{LogicalToDeviceX
}{\param{wxCoord
}{ x
}}
911 Converts logical X coordinate to device coordinate, using the current
915 \membersection{wxDC::LogicalToDeviceXRel
}\label{wxdclogicaltodevicexrel
}
917 \func{virtual wxCoord
}{LogicalToDeviceXRel
}{\param{wxCoord
}{ x
}}
919 Converts logical X coordinate to relative device coordinate, using the current
920 mapping mode but ignoring the x axis orientation.
921 Use this for converting a width, for example.
924 \membersection{wxDC::LogicalToDeviceY
}\label{wxdclogicaltodevicey
}
926 \func{virtual wxCoord
}{LogicalToDeviceY
}{\param{wxCoord
}{ y
}}
928 Converts logical Y coordinate to device coordinate, using the current
932 \membersection{wxDC::LogicalToDeviceYRel
}\label{wxdclogicaltodeviceyrel
}
934 \func{virtual wxCoord
}{LogicalToDeviceYRel
}{\param{wxCoord
}{ y
}}
936 Converts logical Y coordinate to relative device coordinate, using the current
937 mapping mode but ignoring the y axis orientation.
938 Use this for converting a height, for example.
941 \membersection{wxDC::MaxX
}\label{wxdcmaxx
}
943 \func{wxCoord
}{MaxX
}{\void}
945 Gets the maximum horizontal extent used in drawing commands so far.
948 \membersection{wxDC::MaxY
}\label{wxdcmaxy
}
950 \func{wxCoord
}{MaxY
}{\void}
952 Gets the maximum vertical extent used in drawing commands so far.
955 \membersection{wxDC::MinX
}\label{wxdcminx
}
957 \func{wxCoord
}{MinX
}{\void}
959 Gets the minimum horizontal extent used in drawing commands so far.
962 \membersection{wxDC::MinY
}\label{wxdcminy
}
964 \func{wxCoord
}{MinY
}{\void}
966 Gets the minimum vertical extent used in drawing commands so far.
969 \membersection{wxDC::IsOk
}\label{wxdcisok
}
971 \func{bool
}{Ok
}{\void}
973 Returns true if the DC is ok to use.
976 \membersection{wxDC::ResetBoundingBox
}\label{wxdcresetboundingbox
}
978 \func{void
}{ResetBoundingBox
}{\void}
980 Resets the bounding box: after a call to this function, the bounding box
981 doesn't contain anything.
985 \helpref{CalcBoundingBox
}{wxdccalcboundingbox
}
988 \membersection{wxDC::SetAxisOrientation
}\label{wxdcsetaxisorientation
}
990 \func{void
}{SetAxisOrientation
}{\param{bool
}{ xLeftRight
},
991 \param{bool
}{ yBottomUp
}}
993 Sets the x and y axis orientation (i.e., the direction from lowest to
994 highest values on the axis). The default orientation is
995 x axis from left to right and y axis from top down.
997 \wxheading{Parameters
}
999 \docparam{xLeftRight
}{True to set the x axis orientation to the natural
1000 left to right orientation, false to invert it.
}
1002 \docparam{yBottomUp
}{True to set the y axis orientation to the natural
1003 bottom up orientation, false to invert it.
}
1006 \membersection{wxDC::SetBackground
}\label{wxdcsetbackground
}
1008 \func{void
}{SetBackground
}{\param{const wxBrush\&
}{brush
}}
1010 Sets the current background brush for the DC.
1013 \membersection{wxDC::SetBackgroundMode
}\label{wxdcsetbackgroundmode
}
1015 \func{void
}{SetBackgroundMode
}{\param{int
}{ mode
}}
1017 {\it mode
} may be one of wxSOLID and wxTRANSPARENT. This setting determines
1018 whether text will be drawn with a background colour or not.
1021 \membersection{wxDC::SetBrush
}\label{wxdcsetbrush
}
1023 \func{void
}{SetBrush
}{\param{const wxBrush\&
}{brush
}}
1025 Sets the current brush for the DC.
1027 If the argument is wxNullBrush, the current brush is selected out of the device
1028 context (leaving wxDC without any valid brush), allowing the current brush to
1029 be destroyed safely.
1031 See also
\helpref{wxBrush
}{wxbrush
}.
1033 See also
\helpref{wxMemoryDC
}{wxmemorydc
} for the interpretation of colours
1034 when drawing into a monochrome bitmap.
1037 \membersection{wxDC::SetClippingRegion
}\label{wxdcsetclippingregion
}
1039 \func{void
}{SetClippingRegion
}{\param{wxCoord
}{ x
},
\param{wxCoord
}{ y
},
\param{wxCoord
}{ width
},
\param{wxCoord
}{ height
}}
1041 \func{void
}{SetClippingRegion
}{\param{const wxPoint\&
}{pt
},
\param{const wxSize\&
}{sz
}}
1043 \func{void
}{SetClippingRegion
}{\param{const wxRect\&
}{ rect
}}
1045 \func{void
}{SetClippingRegion
}{\param{const wxRegion\&
}{ region
}}
1047 Sets the clipping region for this device context to the intersection of the
1048 given region described by the parameters of this method and the previously set
1049 clipping region. You should call
1050 \helpref{DestroyClippingRegion
}{wxdcdestroyclippingregion
} if you want to set
1051 the clipping region exactly to the region specified.
1053 The clipping region is an area to which drawing is restricted. Possible uses
1054 for the clipping region are for clipping text or for speeding up window redraws
1055 when only a known area of the screen is damaged.
1057 \wxheading{See also
}
1059 \helpref{wxDC::DestroyClippingRegion
}{wxdcdestroyclippingregion
},
\helpref{wxRegion
}{wxregion
}
1062 \membersection{wxDC::SetDeviceOrigin
}\label{wxdcsetdeviceorigin
}
1064 \func{void
}{SetDeviceOrigin
}{\param{wxCoord
}{ x
},
\param{wxCoord
}{ y
}}
1066 Sets the device origin (i.e., the origin in pixels after scaling has been
1069 This function may be useful in Windows printing
1070 operations for placing a graphic on a page.
1073 \membersection{wxDC::SetFont
}\label{wxdcsetfont
}
1075 \func{void
}{SetFont
}{\param{const wxFont\&
}{font
}}
1077 Sets the current font for the DC. It must be a valid font, in particular you
1078 should not pass
{\tt wxNullFont
} to this method.
1080 See also
\helpref{wxFont
}{wxfont
}.
1083 \membersection{wxDC::SetLayoutDirection
}\label{wxdcsetlayoutdirection
}
1085 \func{void
}{SetLayoutDirection
}{\param{wxLayoutDirection
}{ dir
}}
1087 Sets the current layout direction for the device context.
\arg{dir
} may be either
1088 \texttt{wxLayout
\_Default},
\texttt{wxLayout
\_LeftToRight} or
\texttt{wxLayout
\_RightToLeft}.
1090 \wxheading{See also
}
1092 \helpref{GetLayoutDirection
}{wxdcgetlayoutdirection
}
1095 \membersection{wxDC::SetLogicalFunction
}\label{wxdcsetlogicalfunction
}
1097 \func{void
}{SetLogicalFunction
}{\param{int
}{ function
}}
1099 Sets the current logical function for the device context. This determines how
1100 a source pixel (from a pen or brush colour, or source device context if
1101 using
\helpref{wxDC::Blit
}{wxdcblit
}) combines with a destination pixel in the
1102 current device context.
1105 and their meaning in terms of source and destination pixel values are
1110 wxAND_INVERT (NOT src) AND dst
1111 wxAND_REVERSE src AND (NOT dst)
1114 wxEQUIV (NOT src) XOR dst
1116 wxNAND (NOT src) OR (NOT dst)
1117 wxNOR (NOT src) AND (NOT dst)
1120 wxOR_INVERT (NOT src) OR dst
1121 wxOR_REVERSE src OR (NOT dst)
1123 wxSRC_INVERT NOT src
1127 The default is wxCOPY, which simply draws with the current colour.
1128 The others combine the current colour and the background using a
1129 logical operation. wxINVERT is commonly used for drawing rubber bands or
1130 moving outlines, since drawing twice reverts to the original colour.
1133 \membersection{wxDC::SetMapMode
}\label{wxdcsetmapmode
}
1135 \func{void
}{SetMapMode
}{\param{int
}{ int
}}
1137 The
{\it mapping mode
} of the device context defines the unit of
1138 measurement used to convert logical units to device units. Note that
1139 in X, text drawing isn't handled consistently with the mapping mode; a
1140 font is always specified in point size. However, setting the
{\it
1141 user scale
} (see
\helpref{wxDC::SetUserScale
}{wxdcsetuserscale
}) scales the text appropriately. In
1142 Windows, scalable TrueType fonts are always used; in X, results depend
1143 on availability of fonts, but usually a reasonable match is found.
1145 The coordinate origin is always at the top left of the screen/printer.
1147 Drawing to a Windows printer device context uses the current mapping mode,
1148 but mapping mode is currently ignored for PostScript output.
1150 The mapping mode can be one of the following:
1152 \begin{twocollist
}\itemsep=
0pt
1153 \twocolitem{wxMM
\_TWIPS}{Each logical unit is
1/
20 of a point, or
1/
1440 of
1155 \twocolitem{wxMM
\_POINTS}{Each logical unit is a point, or
1/
72 of an inch.
}
1156 \twocolitem{wxMM
\_METRIC}{Each logical unit is
1 mm.
}
1157 \twocolitem{wxMM
\_LOMETRIC}{Each logical unit is
1/
10 of a mm.
}
1158 \twocolitem{wxMM
\_TEXT}{Each logical unit is
1 device pixel.
}
1162 \membersection{wxDC::SetPalette
}\label{wxdcsetpalette
}
1164 \func{void
}{SetPalette
}{\param{const wxPalette\&
}{palette
}}
1166 If this is a window DC or memory DC, assigns the given palette to the window
1167 or bitmap associated with the DC. If the argument is wxNullPalette, the current
1168 palette is selected out of the device context, and the original palette
1171 See
\helpref{wxPalette
}{wxpalette
} for further details.
1174 \membersection{wxDC::SetPen
}\label{wxdcsetpen
}
1176 \func{void
}{SetPen
}{\param{const wxPen\&
}{pen
}}
1178 Sets the current pen for the DC.
1180 If the argument is wxNullPen, the current pen is selected out of the device
1181 context (leaving wxDC without any valid pen), allowing the current brush to
1182 be destroyed safely.
1184 See also
\helpref{wxMemoryDC
}{wxmemorydc
} for the interpretation of colours
1185 when drawing into a monochrome bitmap.
1188 \membersection{wxDC::SetTextBackground
}\label{wxdcsettextbackground
}
1190 \func{void
}{SetTextBackground
}{\param{const wxColour\&
}{colour
}}
1192 Sets the current text background colour for the DC.
1195 \membersection{wxDC::SetTextForeground
}\label{wxdcsettextforeground
}
1197 \func{void
}{SetTextForeground
}{\param{const wxColour\&
}{colour
}}
1199 Sets the current text foreground colour for the DC.
1201 See also
\helpref{wxMemoryDC
}{wxmemorydc
} for the interpretation of colours
1202 when drawing into a monochrome bitmap.
1205 \membersection{wxDC::SetUserScale
}\label{wxdcsetuserscale
}
1207 \func{void
}{SetUserScale
}{\param{double
}{ xScale
},
\param{double
}{ yScale
}}
1209 Sets the user scaling factor, useful for applications which require
1213 \membersection{wxDC::StartDoc
}\label{wxdcstartdoc
}
1215 \func{bool
}{StartDoc
}{\param{const wxString\&
}{message
}}
1217 Starts a
document (only relevant when outputting to a printer).
1218 Message is a message to show while printing.
1221 \membersection{wxDC::StartPage
}\label{wxdcstartpage
}
1223 \func{bool
}{StartPage
}{\void}
1225 Starts a
document page (only relevant when outputting to a printer).
1228 \membersection{wxDC::StretchBlit
}\label{wxdcstretchblit
}
1230 \func{bool
}{StretchBlit
}{\param{wxCoord
}{ xdest
},
\param{wxCoord
}{ ydest
},
\param{wxCoord
}{ dstWidth
},
\param{wxCoord
}{ dstHeight
},
1231 \param{wxDC*
}{source
},
\param{wxCoord
}{ xsrc
},
\param{wxCoord
}{ ysrc
},
\param{wxCoord
}{ srcWidth
},
\param{wxCoord
}{ srcHeight
},
1232 \param{int
}{ logicalFunc = wxCOPY
},
\param{bool
}{useMask = false
},
\param{wxCoord
}{ xsrcMask = -
1},
\param{wxCoord
}{ ysrcMask = -
1}}
1234 Copy from a source DC to this DC, specifying the destination
1235 coordinates, destination size, source DC, source coordinates,
1236 size of source area to copy, logical function, whether to use a bitmap mask,
1237 and mask source position.
1239 \wxheading{Parameters
}
1241 \docparam{xdest
}{Destination device context x position.
}
1243 \docparam{ydest
}{Destination device context y position.
}
1245 \docparam{dstWidth
}{Width of destination area.
}
1247 \docparam{dstHeight
}{Height of destination area.
}
1249 \docparam{source
}{Source device context.
}
1251 \docparam{xsrc
}{Source device context x position.
}
1253 \docparam{ysrc
}{Source device context y position.
}
1255 \docparam{srcWidth
}{Width of source area to be copied.
}
1257 \docparam{srcHeight
}{Height of source area to be copied.
}
1259 \docparam{logicalFunc
}{Logical function to use: see
\helpref{wxDC::SetLogicalFunction
}{wxdcsetlogicalfunction
}.
}
1261 \docparam{useMask
}{If true, Blit does a transparent blit using the mask that is associated with the bitmap
1262 selected into the source device context. The Windows implementation does the following if
\texttt{MaskBlt
} cannot be used:
1265 \item Creates a temporary bitmap and copies the destination area into it.
1266 \item Copies the source area into the temporary bitmap using the specified logical function.
1267 \item Sets the masked area in the temporary bitmap to BLACK by ANDing the
1268 mask bitmap with the temp bitmap with the foreground colour set to WHITE
1269 and the background colour set to BLACK.
1270 \item Sets the unmasked area in the destination area to BLACK by ANDing the
1271 mask bitmap with the destination area with the foreground colour set to BLACK
1272 and the background colour set to WHITE.
1273 \item ORs the temporary bitmap with the destination area.
1274 \item Deletes the temporary bitmap.
1277 This sequence of operations ensures that the source's transparent area need not be black,
1278 and logical functions are supported.
1280 {\bf Note:
} on Windows, blitting with masks can be speeded up considerably by compiling
1281 wxWidgets with the
\texttt{wxUSE
\_DC\_CACHE} option enabled. You can also influence whether
\texttt{MaskBlt
}
1282 or the explicit mask blitting code above is used, by using
\helpref{wxSystemOptions
}{wxsystemoptions
} and
1283 setting the
{\bf no-maskblt
} option to
1.
1287 \docparam{xsrcMask
}{Source x position on the mask. If both xsrcMask and ysrcMask are -
1, xsrc and ysrc
1288 will be assumed for the mask source position. Currently only implemented on Windows.
}
1290 \docparam{ysrcMask
}{Source y position on the mask. If both xsrcMask and ysrcMask are -
1, xsrc and ysrc
1291 will be assumed for the mask source position. Currently only implemented on Windows.
}
1296 There is partial support for Blit in wxPostScriptDC, under X.
1298 wxDC::StretchBlit is only implemented under wxMAC and wxMSW.
1300 See
\helpref{wxMemoryDC
}{wxmemorydc
} for typical usage.
1304 \wxheading{See also
}
1306 \helpref{wxDC::Blit
}{wxdcblit
},
\helpref{wxMemoryDC
}{wxmemorydc
},
\helpref{wxBitmap
}{wxbitmap
},
\helpref{wxMask
}{wxmask
}