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 Derived types of wxDC have documentation for specific features
10 only, so refer to this section for most device context information.
12 % VZ: we should really document them instead of this lame excuse, but I don't
13 % have time for it now, when it is done please remove this
14 Please note that in addition to the versions of the methods documented here,
15 there are also versions which accept single
{\tt wxPoint
} parameter instead of
16 two
{\tt wxCoord
} ones or
{\tt wxPoint
} and
{\tt wxSize
} instead of four of
19 \wxheading{Derived from
}
21 \helpref{wxObject
}{wxobject
}
23 \wxheading{Include files
}
29 \helpref{Overview
}{dcoverview
}
31 \latexignore{\rtfignore{\wxheading{Members
}}}
34 \membersection{wxDC::wxDC
}\label{wxdcctor
}
41 \membersection{wxDC::
\destruct{wxDC
}}\label{wxdcdtor
}
43 \func{}{\destruct{wxDC
}}{\void}
48 \membersection{wxDC::BeginDrawing
}\label{wxdcbegindrawing
}
50 \func{void
}{BeginDrawing
}{\void}
52 Allows optimization of drawing code under MS Windows. Enclose
53 drawing primitives between
{\bf BeginDrawing
} and
{\bf EndDrawing
}\rtfsp
56 Drawing to a wxDialog panel device context outside of a
57 system-generated OnPaint event
{\it requires
} this pair of calls to
58 enclose drawing code. This is because a Windows dialog box does not have
59 a retained device context associated with it, and selections such as pen
60 and brush settings would be lost if the device context were obtained and
61 released for each drawing operation.
64 \membersection{wxDC::Blit
}\label{wxdcblit
}
66 \func{bool
}{Blit
}{\param{wxCoord
}{ xdest
},
\param{wxCoord
}{ ydest
},
\param{wxCoord
}{ width
},
\param{wxCoord
}{ height
},
67 \param{wxDC*
}{source
},
\param{wxCoord
}{ xsrc
},
\param{wxCoord
}{ ysrc
},
\param{int
}{ logicalFunc = wxCOPY
},
68 \param{bool
}{useMask = false
},
\param{wxCoord
}{ xsrcMask = -
1},
\param{wxCoord
}{ ysrcMask = -
1}}
70 Copy from a source DC to this DC, specifying the destination
71 coordinates, size of area to copy, source DC, source coordinates,
72 logical function, whether to use a bitmap mask, and mask source position.
74 \wxheading{Parameters
}
76 \docparam{xdest
}{Destination device context x position.
}
78 \docparam{ydest
}{Destination device context y position.
}
80 \docparam{width
}{Width of source area to be copied.
}
82 \docparam{height
}{Height of source area to be copied.
}
84 \docparam{source
}{Source device context.
}
86 \docparam{xsrc
}{Source device context x position.
}
88 \docparam{ysrc
}{Source device context y position.
}
90 \docparam{logicalFunc
}{Logical function to use: see
\helpref{wxDC::SetLogicalFunction
}{wxdcsetlogicalfunction
}.
}
92 \docparam{useMask
}{If true, Blit does a transparent blit using the mask that is associated with the bitmap
93 selected into the source device context. The Windows implementation does the following if MaskBlt cannot be used:
96 \item Creates a temporary bitmap and copies the destination area into it.
97 \item Copies the source area into the temporary bitmap using the specified logical function.
98 \item Sets the masked area in the temporary bitmap to BLACK by ANDing the
99 mask bitmap with the temp bitmap with the foreground colour set to WHITE
100 and the bg colour set to BLACK.
101 \item Sets the unmasked area in the destination area to BLACK by ANDing the
102 mask bitmap with the destination area with the foreground colour set to BLACK
103 and the background colour set to WHITE.
104 \item ORs the temporary bitmap with the destination area.
105 \item Deletes the temporary bitmap.
108 This sequence of operations ensures that the source's transparent area need not be black,
109 and logical functions are supported.
111 {\bf Note:
} on Windows, blitting with masks can be speeded up considerably by compiling
112 wxWidgets with the wxUSE
\_DC\_CACHE option enabled. You can also influence whether MaskBlt
113 or the explicit mask blitting code above is used, by using
\helpref{wxSystemOptions
}{wxsystemoptions
} and
114 setting the
{\bf no-maskblt
} option to
1.
118 \docparam{xsrcMask
}{Source x position on the mask. If both xsrcMask and ysrcMask are -
1, xsrc and ysrc
119 will be assumed for the mask source position. Currently only implemented on Windows.
}
121 \docparam{ysrcMask
}{Source y position on the mask. If both xsrcMask and ysrcMask are -
1, xsrc and ysrc
122 will be assumed for the mask source position. Currently only implemented on Windows.
}
127 There is partial support for Blit in wxPostScriptDC, under X.
129 See
\helpref{wxMemoryDC
}{wxmemorydc
} for typical usage.
133 \helpref{wxMemoryDC
}{wxmemorydc
},
\helpref{wxBitmap
}{wxbitmap
},
\helpref{wxMask
}{wxmask
}
137 \membersection{wxDC::CacheEnabled
}\label{wxdccacheenabled
}
139 \func{static bool
}{CacheEnabled
}{\void}
141 On supported platforms (currently only Windows), returns true
142 if the DC cache is enabled. The DC cache
143 can speed up the
\helpref{Blit
}{wxdcblit
} operation when
144 drawing a large number of masked bitmaps.
146 If using the cache functions in your code, please test for the
147 wxUSE
\_DC\_CACHEING preprocessor symbol for portability.
151 \helpref{wxDC::EnableCache
}{wxdcenablecache
},
\helpref{wxDC::ClearCache
}
155 \membersection{wxDC::CalcBoundingBox
}\label{wxdccalcboundingbox
}
157 \func{void
}{CalcBoundingBox
}{\param{wxCoord
}{x
},
\param{wxCoord
}{y
}}
159 Adds the specified point to the bounding box which can be retrieved with
160 \helpref{MinX
}{wxdcminx
},
\helpref{MaxX
}{wxdcmaxx
} and
161 \helpref{MinY
}{wxdcminy
},
\helpref{MaxY
}{wxdcmaxy
} functions.
165 \helpref{ResetBoundingBox
}{wxdcresetboundingbox
}
168 \membersection{wxDC::Clear
}\label{wxdcclear
}
170 \func{void
}{Clear
}{\void}
172 Clears the device context using the current background brush.
176 \membersection{wxDC::ClearCache
}\label{wxdcclearcache
}
178 \func{static void
}{ClearCache
}{\void}
180 On supported platforms (currently only Windows), clears
181 the contents of the DC cache (one bitmap and two Windows device contexts). The DC cache
182 can speed up the
\helpref{Blit
}{wxdcblit
} operation when
183 drawing a large number of masked bitmaps. You should
184 call ClearCache at the end of length DC operations if you wish to only use
185 the cache transiently; you should also call it as your application exits.
187 If using the cache functions in your code, please test for the
188 wxUSE
\_DC\_CACHEING preprocessor symbol for portability.
192 \helpref{wxDC::EnableCache
}{wxdcenablecache
},
\helpref{wxDC::CacheEnabled
}
196 \membersection{wxDC::ComputeScaleAndOrigin
}\label{wxdccomputescaleandorigin
}
198 \func{virtual void
}{ComputeScaleAndOrigin
}{\void}
200 Performs all necessary computations for given platform and context type
201 after each change of scale and origin parameters. Usually called automatically
202 internally after such changes.
205 \membersection{wxDC::CrossHair
}\label{wxdccrosshair
}
207 \func{void
}{CrossHair
}{\param{wxCoord
}{ x
},
\param{wxCoord
}{ y
}}
209 Displays a cross hair using the current pen. This is a vertical
210 and horizontal line the height and width of the window, centred
214 \membersection{wxDC::DestroyClippingRegion
}\label{wxdcdestroyclippingregion
}
216 \func{void
}{DestroyClippingRegion
}{\void}
218 Destroys the current clipping region so that none of the DC is clipped.
219 See also
\helpref{wxDC::SetClippingRegion
}{wxdcsetclippingregion
}.
222 \membersection{wxDC::DeviceToLogicalX
}\label{wxdcdevicetologicalx
}
224 \func{wxCoord
}{DeviceToLogicalX
}{\param{wxCoord
}{ x
}}
226 Convert device X coordinate to logical coordinate, using the current
230 \membersection{wxDC::DeviceToLogicalXRel
}\label{wxdcdevicetologicalxrel
}
232 \func{wxCoord
}{DeviceToLogicalXRel
}{\param{wxCoord
}{ x
}}
234 Convert device X coordinate to relative logical coordinate, using the current
235 mapping mode but ignoring the x axis orientation.
236 Use this function for converting a width, for example.
239 \membersection{wxDC::DeviceToLogicalY
}\label{wxdcdevicetologicaly
}
241 \func{wxCoord
}{DeviceToLogicalY
}{\param{wxCoord
}{ y
}}
243 Converts device Y coordinate to logical coordinate, using the current
247 \membersection{wxDC::DeviceToLogicalYRel
}\label{wxdcdevicetologicalyrel
}
249 \func{wxCoord
}{DeviceToLogicalYRel
}{\param{wxCoord
}{ y
}}
251 Convert device Y coordinate to relative logical coordinate, using the current
252 mapping mode but ignoring the y axis orientation.
253 Use this function for converting a height, for example.
256 \membersection{wxDC::DrawArc
}\label{wxdcdrawarc
}
258 \func{void
}{DrawArc
}{\param{wxCoord
}{ x1
},
\param{wxCoord
}{ y1
},
\param{wxCoord
}{ x2
},
\param{wxCoord
}{ y2
},
\param{wxCoord
}{ xc
},
\param{wxCoord
}{ yc
}}
260 Draws an arc of a circle, centred on (
{\it xc, yc
}), with starting point (
{\it x1, y1
})
261 and ending at (
{\it x2, y2
}). The current pen is used for the outline
262 and the current brush for filling the shape.
264 The arc is drawn in an anticlockwise direction from the start point to the end point.
267 \membersection{wxDC::DrawBitmap
}\label{wxdcdrawbitmap
}
269 \func{void
}{DrawBitmap
}{\param{const wxBitmap\&
}{ bitmap
},
\param{wxCoord
}{ x
},
\param{wxCoord
}{ y
},
\param{bool
}{ transparent
}}
271 Draw a bitmap on the device context at the specified point. If
{\it transparent
} is true and the bitmap has
272 a transparency mask, the bitmap will be drawn transparently.
274 When drawing a mono-bitmap, the current text foreground colour will be used to draw the foreground
275 of the bitmap (all bits set to
1), and the current text background colour to draw the background
276 (all bits set to
0). See also
\helpref{SetTextForeground
}{wxdcsettextforeground
},
277 \helpref{SetTextBackground
}{wxdcsettextbackground
} and
\helpref{wxMemoryDC
}{wxmemorydc
}.
280 \membersection{wxDC::DrawCheckMark
}\label{wxdcdrawcheckmark
}
282 \func{void
}{DrawCheckMark
}{\param{wxCoord
}{ x
},
\param{wxCoord
}{ y
},
\param{wxCoord
}{ width
},
\param{wxCoord
}{ height
}}
284 \func{void
}{DrawCheckMark
}{\param{const wxRect \&
}{rect
}}
286 Draws a check mark inside the given rectangle.
289 \membersection{wxDC::DrawCircle
}\label{wxdcdrawcircle
}
291 \func{void
}{DrawCircle
}{\param{wxCoord
}{ x
},
\param{wxCoord
}{ y
},
\param{wxCoord
}{ radius
}}
293 \func{void
}{DrawCircle
}{\param{const wxPoint\&
}{ pt
},
\param{wxCoord
}{ radius
}}
295 Draws a circle with the given centre and radius.
299 \helpref{DrawEllipse
}{wxdcdrawellipse
}
302 \membersection{wxDC::DrawEllipse
}\label{wxdcdrawellipse
}
304 \func{void
}{DrawEllipse
}{\param{wxCoord
}{ x
},
\param{wxCoord
}{ y
},
\param{wxCoord
}{ width
},
\param{wxCoord
}{ height
}}
306 \func{void
}{DrawEllipse
}{\param{const wxPoint\&
}{ pt
},
\param{const wxSize\&
}{ size
}}
308 \func{void
}{DrawEllipse
}{\param{const wxRect\&
}{ rect
}}
310 Draws an ellipse contained in the rectangle specified either with the given top
311 left corner and the given size or directly. The current pen is used for the
312 outline and the current brush for filling the shape.
316 \helpref{DrawCircle
}{wxdcdrawcircle
}
319 \membersection{wxDC::DrawEllipticArc
}\label{wxdcdrawellipticarc
}
321 \func{void
}{DrawEllipticArc
}{\param{wxCoord
}{ x
},
\param{wxCoord
}{ y
},
\param{wxCoord
}{ width
},
\param{wxCoord
}{ height
},
322 \param{double
}{ start
},
\param{double
}{ end
}}
324 Draws an arc of an ellipse. The current pen is used for drawing the arc and
325 the current brush is used for drawing the pie.
327 {\it x
} and
{\it y
} specify the x and y coordinates of the upper-left corner of the rectangle that contains
330 {\it width
} and
{\it height
} specify the width and height of the rectangle that contains
333 {\it start
} and
{\it end
} specify the start and end of the arc relative to the three-o'clock
334 position from the center of the rectangle. Angles are specified
335 in degrees (
360 is a complete circle). Positive values mean
336 counter-clockwise motion. If
{\it start
} is equal to
{\it end
}, a
337 complete ellipse will be drawn.
340 \membersection{wxDC::DrawIcon
}\label{wxdcdrawicon
}
342 \func{void
}{DrawIcon
}{\param{const wxIcon\&
}{ icon
},
\param{wxCoord
}{ x
},
\param{wxCoord
}{ y
}}
344 Draw an icon on the display (does nothing if the device context is PostScript).
345 This can be the simplest way of drawing bitmaps on a window.
348 \membersection{wxDC::DrawLabel
}\label{wxdcdrawlabel
}
350 \func{virtual void
}{DrawLabel
}{\param{const wxString\&
}{ text
},
351 \param{const wxBitmap\&
}{ image
},
352 \param{const wxRect\&
}{ rect
},
353 \param{int
}{ alignment = wxALIGN
\_LEFT | wxALIGN
\_TOP},
354 \param{int
}{ indexAccel = -
1},
355 \param{wxRect *
}{rectBounding = NULL
}}
357 \func{void
}{DrawLabel
}{\param{const wxString\&
}{ text
},
\param{const wxRect\&
}{ rect
},
358 \param{int
}{ alignment = wxALIGN
\_LEFT | wxALIGN
\_TOP},
359 \param{int
}{ indexAccel = -
1}}
361 Draw optional bitmap and the text into the given rectangle and aligns it as specified
362 by alignment parameter; it also will emphasize the character with the given index if
363 it is != -
1 and return the bounding rectangle if required.
366 \membersection{wxDC::DrawLine
}\label{wxdcdrawline
}
368 \func{void
}{DrawLine
}{\param{wxCoord
}{ x1
},
\param{wxCoord
}{ y1
},
\param{wxCoord
}{ x2
},
\param{wxCoord
}{ y2
}}
370 Draws a line from the first point to the second. The current pen is used
371 for drawing the line. Note that the point $(x2, y2)$ is
{\emph not
} part of the
372 line and is not drawn by this function (this is consistent with the behaviour
373 of many other toolkits).
376 \membersection{wxDC::DrawLines
}\label{wxdcdrawlines
}
378 \func{void
}{DrawLines
}{\param{int
}{ n
},
\param{wxPoint
}{ points
[]},
\param{wxCoord
}{ xoffset =
0},
\param{wxCoord
}{ yoffset =
0}}
380 \func{void
}{DrawLines
}{\param{wxList *
}{points
},
\param{wxCoord
}{ xoffset =
0},
\param{wxCoord
}{ yoffset =
0}}
382 Draws lines using an array of
{\it points
} of size
{\it n
}, or list of
383 pointers to points, adding the optional offset coordinate. The current
384 pen is used for drawing the lines. The programmer is responsible for
385 deleting the list of points.
387 \pythonnote{The wxPython version of this method accepts a Python list
390 \perlnote{The wxPerl version of this method accepts
391 as its first parameter a reference to an array
395 \membersection{wxDC::DrawPolygon
}\label{wxdcdrawpolygon
}
397 \func{void
}{DrawPolygon
}{\param{int
}{ n
},
\param{wxPoint
}{ points
[]},
\param{wxCoord
}{ xoffset =
0},
\param{wxCoord
}{ yoffset =
0},\\
398 \param{int
}{fill
\_style = wxODDEVEN
\_RULE}}
400 \func{void
}{DrawPolygon
}{\param{wxList *
}{points
},
\param{wxCoord
}{ xoffset =
0},
\param{wxCoord
}{ yoffset =
0},\\
401 \param{int
}{fill
\_style = wxODDEVEN
\_RULE}}
403 Draws a filled polygon using an array of
{\it points
} of size
{\it n
},
404 or list of pointers to points, adding the optional offset coordinate.
406 The last argument specifies the fill rule:
{\bf wxODDEVEN
\_RULE} (the
407 default) or
{\bf wxWINDING
\_RULE}.
409 The current pen is used for drawing the outline, and the current brush
410 for filling the shape. Using a transparent brush suppresses filling.
411 The programmer is responsible for deleting the list of points.
413 Note that wxWidgets automatically closes the first and last points.
415 \pythonnote{The wxPython version of this method accepts a Python list
418 \perlnote{The wxPerl version of this method accepts
419 as its first parameter a reference to an array
423 \membersection{wxDC::DrawPolyPolygon
}\label{wxdcdrawpolypolygon
}
425 \func{void
}{DrawPolyPolygon
}{\param{int
}{ n
},
\param{int
}{ count
[]},
\param{wxPoint
}{ points
[]},
\param{wxCoord
}{ xoffset =
0},
\param{wxCoord
}{ yoffset =
0},\\
426 \param{int
}{fill
\_style = wxODDEVEN
\_RULE}}
428 Draws two or more filled polygons using an array of
{\it points
}, adding the
429 optional offset coordinates.
431 Notice that for the platforms providing a native implementation
432 of this function (Windows and PostScript-based wxDC currently), this is more
433 efficient than using
\helpref{DrawPolygon
}{wxdcdrawpolygon
} in a loop.
435 {\it n
} specifies the number of polygons to draw, the array
{\it count
} of size
436 {\it n
} specifies the number of points in each of the polygons in the
439 The last argument specifies the fill rule:
{\bf wxODDEVEN
\_RULE} (the default)
440 or
{\bf wxWINDING
\_RULE}.
442 The current pen is used for drawing the outline, and the current brush for
443 filling the shape. Using a transparent brush suppresses filling.
445 The polygons maybe disjoint or overlapping. Each polygon specified in a call to
446 {\bf DrawPolyPolygon
} must be closed. Unlike polygons created by the
447 \helpref{DrawPolygon
}{wxdcdrawpolygon
} member function, the polygons created by
448 {\bf DrawPolyPolygon
} are not closed automatically.
450 \pythonnote{Not implemented yet
}
452 \perlnote{Not implemented yet
}
455 \membersection{wxDC::DrawPoint
}\label{wxdcdrawpoint
}
457 \func{void
}{DrawPoint
}{\param{wxCoord
}{ x
},
\param{wxCoord
}{ y
}}
459 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..
462 \membersection{wxDC::DrawRectangle
}\label{wxdcdrawrectangle
}
464 \func{void
}{DrawRectangle
}{\param{wxCoord
}{ x
},
\param{wxCoord
}{ y
},
\param{wxCoord
}{ width
},
\param{wxCoord
}{ height
}}
466 Draws a rectangle with the given top left corner, and with the given
467 size. The current pen is used for the outline and the current brush
468 for filling the shape.
471 \membersection{wxDC::DrawRotatedText
}\label{wxdcdrawrotatedtext
}
473 \func{void
}{DrawRotatedText
}{\param{const wxString\&
}{text
},
\param{wxCoord
}{ x
},
\param{wxCoord
}{ y
},
\param{double
}{ angle
}}
475 Draws the text rotated by
{\it angle
} degrees.
477 {\bf NB:
} Under Win9x only TrueType fonts can be drawn by this function. In
478 particular, a font different from
{\tt wxNORMAL
\_FONT} should be used as the
479 latter is not a TrueType font.
{\tt wxSWISS
\_FONT} is an example of a font
484 \helpref{DrawText
}{wxdcdrawtext
}
487 \membersection{wxDC::DrawRoundedRectangle
}\label{wxdcdrawroundedrectangle
}
489 \func{void
}{DrawRoundedRectangle
}{\param{wxCoord
}{ x
},
\param{wxCoord
}{ y
},
\param{wxCoord
}{ width
},
\param{wxCoord
}{ height
},
\param{double
}{ radius =
20}}
491 Draws a rectangle with the given top left corner, and with the given
492 size. The corners are quarter-circles using the given radius. The
493 current pen is used for the outline and the current brush for filling
496 If
{\it radius
} is positive, the value is assumed to be the
497 radius of the rounded corner. If
{\it radius
} is negative,
498 the absolute value is assumed to be the
{\it proportion
} of the smallest
499 dimension of the rectangle. This means that the corner can be
500 a sensible size relative to the size of the rectangle, and also avoids
501 the strange effects X produces when the corners are too big for
505 \membersection{wxDC::DrawSpline
}\label{wxdcdrawspline
}
507 \func{void
}{DrawSpline
}{\param{int
}{n
},
\param{wxPoint
}{points
[]}}
509 Draws a spline between all given control points, using the current
512 \func{void
}{DrawSpline
}{\param{wxList *
}{points
}}
514 Draws a spline between all given control points, using the current
515 pen. Doesn't delete the wxList and contents.
517 \func{void
}{DrawSpline
}{\param{wxCoord
}{ x1
},
\param{wxCoord
}{ y1
},
\param{wxCoord
}{ x2
},
\param{wxCoord
}{ y2
},
\param{wxCoord
}{ x3
},
\param{wxCoord
}{ y3
}}
519 Draws a three-point spline using the current pen.
521 \pythonnote{The wxPython version of this method accepts a Python list
524 \perlnote{The wxPerl version of this method accepts a reference to an array
528 \membersection{wxDC::DrawText
}\label{wxdcdrawtext
}
530 \func{void
}{DrawText
}{\param{const wxString\&
}{text
},
\param{wxCoord
}{ x
},
\param{wxCoord
}{ y
}}
532 Draws a text string at the specified point, using the current text font,
533 and the current text foreground and background colours.
535 The coordinates refer to the top-left corner of the rectangle bounding
536 the string. See
\helpref{wxDC::GetTextExtent
}{wxdcgettextextent
} for how
537 to get the dimensions of a text string, which can be used to position the
540 {\bf NB:
} under wxGTK the current
541 \helpref{logical function
}{wxdcgetlogicalfunction
} is used by this function
542 but it is ignored by wxMSW. Thus, you should avoid using logical functions
543 with this function in portable programs.
547 \membersection{wxDC::EnableCache
}\label{wxdcenablecache
}
549 \func{static void
}{EnableCache
}{\param{bool
}{ enableCache
}}
551 On supported platforms (currently only Windows), enables the DC cache
552 which can speed up the
\helpref{Blit
}{wxdcblit
} operation when
553 drawing a large number of masked bitmaps.
555 If using the cache functions in your code, please test for the
556 wxUSE
\_DC\_CACHEING preprocessor symbol for portability.
560 \helpref{wxDC::CacheEnabled
}{wxdccacheenabled
},
\helpref{wxDC::ClearCache
}
564 \membersection{wxDC::EndDoc
}\label{wxdcenddoc
}
566 \func{void
}{EndDoc
}{\void}
568 Ends a
document (only relevant when outputting to a printer).
571 \membersection{wxDC::EndDrawing
}\label{wxdcenddrawing
}
573 \func{void
}{EndDrawing
}{\void}
575 Allows optimization of drawing code under MS Windows. Enclose
576 drawing primitives between
{\bf BeginDrawing
} and
{\bf EndDrawing
}\rtfsp
580 \membersection{wxDC::EndPage
}\label{wxdcendpage
}
582 \func{void
}{EndPage
}{\void}
584 Ends a
document page (only relevant when outputting to a printer).
587 \membersection{wxDC::FloodFill
}\label{wxdcfloodfill
}
589 \func{bool
}{FloodFill
}{\param{wxCoord
}{ x
},
\param{wxCoord
}{ y
},
\param{const wxColour\&
}{ colour
},
\param{int
}{ style=wxFLOOD
\_SURFACE}}
591 Flood fills the device context starting from the given point, using
592 the
{\it current brush colour
}, and using a style:
594 \begin{itemize
}\itemsep=
0pt
595 \item wxFLOOD
\_SURFACE: the flooding occurs until a colour other than the given colour is encountered.
596 \item wxFLOOD
\_BORDER: the area to be flooded is bounded by the given colour.
599 Returns false if the operation failed.
601 {\it Note:
} The present implementation for non-Windows platforms may fail to find
602 colour borders if the pixels do not match the colour exactly. However the
603 function will still return true.
606 \membersection{wxDC::GetBackground
}\label{wxdcgetbackground
}
608 \constfunc{const wxBrush\&
}{GetBackground
}{\void}
610 Gets the brush used for painting the background (see
\helpref{wxDC::SetBackground
}{wxdcsetbackground
}).
613 \membersection{wxDC::GetBackgroundMode
}\label{wxdcgetbackgroundmode
}
615 \constfunc{int
}{GetBackgroundMode
}{\void}
617 Returns the current background mode:
{\tt wxSOLID
} or
{\tt wxTRANSPARENT
}.
621 \helpref{SetBackgroundMode
}{wxdcsetbackgroundmode
}
624 \membersection{wxDC::GetBrush
}\label{wxdcgetbrush
}
626 \constfunc{const wxBrush\&
}{GetBrush
}{\void}
628 Gets the current brush (see
\helpref{wxDC::SetBrush
}{wxdcsetbrush
}).
631 \membersection{wxDC::GetCharHeight
}\label{wxdcgetcharheight
}
633 \func{wxCoord
}{GetCharHeight
}{\void}
635 Gets the character height of the currently set font.
638 \membersection{wxDC::GetCharWidth
}\label{wxdcgetcharwidth
}
640 \func{wxCoord
}{GetCharWidth
}{\void}
642 Gets the average character width of the currently set font.
645 \membersection{wxDC::GetClippingBox
}\label{wxdcgetclippingbox
}
647 \func{void
}{GetClippingBox
}{\param{wxCoord
}{ *x
},
\param{wxCoord
}{ *y
},
\param{wxCoord
}{ *width
},
\param{wxCoord
}{ *height
}}
649 Gets the rectangle surrounding the current clipping region.
651 \pythonnote{No arguments are required and the four values defining the
652 rectangle are returned as a tuple.
}
654 \perlnote{This method takes no arguments and returns a four element list
655 {\tt ( x, y, width, height )
}}
658 \membersection{wxDC::GetFont
}\label{wxdcgetfont
}
660 \constfunc{const wxFont\&
}{GetFont
}{\void}
662 Gets the current font (see
\helpref{wxDC::SetFont
}{wxdcsetfont
}).
665 \membersection{wxDC::GetLogicalFunction
}\label{wxdcgetlogicalfunction
}
667 \func{int
}{GetLogicalFunction
}{\void}
669 Gets the current logical function (see
\helpref{wxDC::SetLogicalFunction
}{wxdcsetlogicalfunction
}).
672 \membersection{wxDC::GetMapMode
}\label{wxdcgetmapmode
}
674 \func{int
}{GetMapMode
}{\void}
676 Gets the
{\it mapping mode
} for the device context (see
\helpref{wxDC::SetMapMode
}{wxdcsetmapmode
}).
679 \membersection{wxDC::GetPartialTextExtents
}\label{wxdcgetpartialtextextents
}
681 \constfunc{bool
}{GetPartialTextExtents
}{\param{const wxString\&
}{text
},
682 \param{wxArrayInt\&
}{widths
}}
684 Fills the
{\it widths
} array with the widths from the beginning of
685 {\it text
} to the corresponding character of
{\it text
}. The generic
686 version simply builds a running total of the widths of each character
687 using
\helpref{GetTextExtent
}{wxdcgettextextent
}, however if the
688 various platforms have a native API function that is faster or more
689 accurate than the generic implementation then it should be used
692 \pythonnote{This method only takes the
{\it text
} parameter and
693 returns a Python list of integers.
}
696 \membersection{wxDC::GetPen
}\label{wxdcgetpen
}
698 \constfunc{const wxPen\&
}{GetPen
}{\void}
700 Gets the current pen (see
\helpref{wxDC::SetPen
}{wxdcsetpen
}).
703 \membersection{wxDC::GetPixel
}\label{wxdcgetpixel
}
705 \func{bool
}{GetPixel
}{\param{wxCoord
}{ x
},
\param{wxCoord
}{ y
},
\param{wxColour *
}{colour
}}
707 Gets in
{\it colour
} the colour at the specified location.
708 Not available for wxPostScriptDC or wxMetafileDC.
710 Note that setting a pixel can be done using
\helpref{DrawPoint
}{wxdcdrawpoint
}.
712 \pythonnote{For wxPython the wxColour value is returned and is not
713 required as a parameter.
}
715 \perlnote{This method only takes the parameters
{\tt x
} and
{\tt y
} and returns
718 \membersection{wxDC::GetPPI
}\label{wxdcgetppi
}
720 \constfunc{wxSize
}{GetPPI
}{\void}
722 Returns the resolution of the device in pixels per inch.
724 \membersection{wxDC::GetSize
}\label{wxdcgetsize
}
726 \constfunc{void
}{GetSize
}{\param{wxCoord *
}{width
},
\param{wxCoord *
}{height
}}
728 \constfunc{wxSize
}{GetSize
}{\void}
730 This gets the horizontal and vertical resolution in device units. It can be used to scale graphics to fit the page.
731 For example, if
{\it maxX
} and
{\it maxY
}\rtfsp
732 represent the maximum horizontal and vertical `pixel' values used in your
733 application, the following code will scale the graphic to fit on the
739 double scaleX=(double)(maxX/w);
740 double scaleY=(double)(maxY/h);
741 dc.SetUserScale(min(scaleX,scaleY),min(scaleX,scaleY));
744 \pythonnote{In place of a single overloaded method name, wxPython
745 implements the following methods:
\par
746 \indented{2cm
}{\begin{twocollist
}
747 \twocolitem{{\bf GetSize()
}}{Returns a wxSize
}
748 \twocolitem{{\bf GetSizeTuple()
}}{Returns a
2-tuple (width, height)
}
752 \perlnote{In place of a single overloaded method, wxPerl uses:
\par
753 \indented{2cm
}{\begin{twocollist
}
754 \twocolitem{{\bf GetSize()
}}{Returns a Wx::Size
}
755 \twocolitem{{\bf GetSizeWH()
}}{Returns a
2-element list
756 {\tt ( width, height )
}}
760 \membersection{wxDC::GetSizeMM
}\label{wxdcgetsizemm
}
762 \constfunc{void
}{GetSizeMM
}{\param{wxCoord *
}{width
},
\param{wxCoord *
}{height
}}
764 \constfunc{wxSize
}{GetSizeMM
}{\void}
766 Returns the horizontal and vertical resolution in millimetres.
768 \membersection{wxDC::GetTextBackground
}\label{wxdcgettextbackground
}
770 \constfunc{const wxColour\&
}{GetTextBackground
}{\void}
772 Gets the current text background colour (see
\helpref{wxDC::SetTextBackground
}{wxdcsettextbackground
}).
775 \membersection{wxDC::GetTextExtent
}\label{wxdcgettextextent
}
777 \func{void
}{GetTextExtent
}{\param{const wxString\&
}{string
},
\param{wxCoord *
}{w
},
\param{wxCoord *
}{h
},\\
778 \param{wxCoord *
}{descent = NULL
},
\param{wxCoord *
}{externalLeading = NULL
},
\param{wxFont *
}{font = NULL
}}
780 Gets the dimensions of the string using the currently selected font.
781 \rtfsp{\it string
} is the text string to measure,
{\it w
} and
{\it h
} are
782 the total width and height respectively,
{\it descent
} is the
783 dimension from the baseline of the font to the bottom of the
784 descender, and
{\it externalLeading
} is any extra vertical space added
785 to the font by the font designer (usually is zero).
787 The optional parameter
{\it font
} specifies an alternative
788 to the currently selected font: but note that this does not
789 yet work under Windows, so you need to set a font for
790 the device context first.
792 See also
\helpref{wxFont
}{wxfont
},
\helpref{wxDC::SetFont
}{wxdcsetfont
}.
794 \pythonnote{The following methods are implemented in wxPython:
\par
795 \indented{2cm
}{\begin{twocollist
}
796 \twocolitem{{\bf GetTextExtent(string)
}}{Returns a
2-tuple, (width, height)
}
797 \twocolitem{{\bf GetFullTextExtent(string, font=NULL)
}}{Returns a
798 4-tuple, (width, height, descent, externalLeading)
}
802 \perlnote{In wxPerl this method is implemented as
803 {\bf GetTextExtent( string, font = undef )
} returning a four element
804 array
{\tt ( width, height, descent, externalLeading )
}
808 \membersection{wxDC::GetTextForeground
}\label{wxdcgettextforeground
}
810 \constfunc{const wxColour\&
}{GetTextForeground
}{\void}
812 Gets the current text foreground colour (see
\helpref{wxDC::SetTextForeground
}{wxdcsettextforeground
}).
815 \membersection{wxDC::GetUserScale
}\label{wxdcgetuserscale
}
817 \func{void
}{GetUserScale
}{\param{double
}{ *x
},
\param{double
}{ *y
}}
819 Gets the current user scale factor (set by
\helpref{SetUserScale
}{wxdcsetuserscale
}).
821 \perlnote{In wxPerl this method takes no arguments and return a two element
822 array
{\tt ( x, y )
}}
825 \membersection{wxDC::LogicalToDeviceX
}\label{wxdclogicaltodevicex
}
827 \func{wxCoord
}{LogicalToDeviceX
}{\param{wxCoord
}{ x
}}
829 Converts logical X coordinate to device coordinate, using the current
833 \membersection{wxDC::LogicalToDeviceXRel
}\label{wxdclogicaltodevicexrel
}
835 \func{wxCoord
}{LogicalToDeviceXRel
}{\param{wxCoord
}{ x
}}
837 Converts logical X coordinate to relative device coordinate, using the current
838 mapping mode but ignoring the x axis orientation.
839 Use this for converting a width, for example.
842 \membersection{wxDC::LogicalToDeviceY
}\label{wxdclogicaltodevicey
}
844 \func{wxCoord
}{LogicalToDeviceY
}{\param{wxCoord
}{ y
}}
846 Converts logical Y coordinate to device coordinate, using the current
850 \membersection{wxDC::LogicalToDeviceYRel
}\label{wxdclogicaltodeviceyrel
}
852 \func{wxCoord
}{LogicalToDeviceYRel
}{\param{wxCoord
}{ y
}}
854 Converts logical Y coordinate to relative device coordinate, using the current
855 mapping mode but ignoring the y axis orientation.
856 Use this for converting a height, for example.
859 \membersection{wxDC::MaxX
}\label{wxdcmaxx
}
861 \func{wxCoord
}{MaxX
}{\void}
863 Gets the maximum horizontal extent used in drawing commands so far.
866 \membersection{wxDC::MaxY
}\label{wxdcmaxy
}
868 \func{wxCoord
}{MaxY
}{\void}
870 Gets the maximum vertical extent used in drawing commands so far.
873 \membersection{wxDC::MinX
}\label{wxdcminx
}
875 \func{wxCoord
}{MinX
}{\void}
877 Gets the minimum horizontal extent used in drawing commands so far.
880 \membersection{wxDC::MinY
}\label{wxdcminy
}
882 \func{wxCoord
}{MinY
}{\void}
884 Gets the minimum vertical extent used in drawing commands so far.
887 \membersection{wxDC::Ok
}\label{wxdcok
}
889 \func{bool
}{Ok
}{\void}
891 Returns true if the DC is ok to use.
894 \membersection{wxDC::ResetBoundingBox
}\label{wxdcresetboundingbox
}
896 \func{void
}{ResetBoundingBox
}{\void}
898 Resets the bounding box: after a call to this function, the bounding box
899 doesn't contain anything.
903 \helpref{CalcBoundingBox
}{wxdccalcboundingbox
}
906 \membersection{wxDC::SetAxisOrientation
}\label{wxdcsetaxisorientation
}
908 \func{void
}{SetAxisOrientation
}{\param{bool
}{ xLeftRight
},
909 \param{bool
}{ yBottomUp
}}
911 Sets the x and y axis orientation (i.e., the direction from lowest to
912 highest values on the axis). The default orientation is
913 x axis from left to right and y axis from top down.
915 \wxheading{Parameters
}
917 \docparam{xLeftRight
}{True to set the x axis orientation to the natural
918 left to right orientation, false to invert it.
}
920 \docparam{yBottomUp
}{True to set the y axis orientation to the natural
921 bottom up orientation, false to invert it.
}
924 \membersection{wxDC::SetBackground
}\label{wxdcsetbackground
}
926 \func{void
}{SetBackground
}{\param{const wxBrush\&
}{brush
}}
928 Sets the current background brush for the DC.
931 \membersection{wxDC::SetBackgroundMode
}\label{wxdcsetbackgroundmode
}
933 \func{void
}{SetBackgroundMode
}{\param{int
}{ mode
}}
935 {\it mode
} may be one of wxSOLID and wxTRANSPARENT. This setting determines
936 whether text will be drawn with a background colour or not.
939 \membersection{wxDC::SetBrush
}\label{wxdcsetbrush
}
941 \func{void
}{SetBrush
}{\param{const wxBrush\&
}{brush
}}
943 Sets the current brush for the DC.
945 If the argument is wxNullBrush, the current brush is selected out of the device
946 context, and the original brush restored, allowing the current brush to
949 See also
\helpref{wxBrush
}{wxbrush
}.
951 See also
\helpref{wxMemoryDC
}{wxmemorydc
} for the interpretation of colours
952 when drawing into a monochrome bitmap.
955 \membersection{wxDC::SetClippingRegion
}\label{wxdcsetclippingregion
}
957 \func{void
}{SetClippingRegion
}{\param{wxCoord
}{ x
},
\param{wxCoord
}{ y
},
\param{wxCoord
}{ width
},
\param{wxCoord
}{ height
}}
959 \func{void
}{SetClippingRegion
}{\param{const wxPoint\&
}{pt
},
\param{const wxSize\&
}{sz
}}
961 \func{void
}{SetClippingRegion
}{\param{const wxRect\&
}{ rect
}}
963 \func{void
}{SetClippingRegion
}{\param{const wxRegion\&
}{ region
}}
965 Sets the clipping region for this device context to the intersection of the
966 given region described by the parameters of this method and the previously set
967 clipping region. You should call
968 \helpref{DestroyClippingRegion
}{wxdcdestroyclippingregion
} if you want to set
969 the clipping region exactly to the region specified.
971 The clipping region is an area to which drawing is restricted. Possible uses
972 for the clipping region are for clipping text or for speeding up window redraws
973 when only a known area of the screen is damaged.
977 \helpref{wxDC::DestroyClippingRegion
}{wxdcdestroyclippingregion
},
\helpref{wxRegion
}{wxregion
}
980 \membersection{wxDC::SetDeviceOrigin
}\label{wxdcsetdeviceorigin
}
982 \func{void
}{SetDeviceOrigin
}{\param{wxCoord
}{ x
},
\param{wxCoord
}{ y
}}
984 Sets the device origin (i.e., the origin in pixels after scaling has been
987 This function may be useful in Windows printing
988 operations for placing a graphic on a page.
991 \membersection{wxDC::SetFont
}\label{wxdcsetfont
}
993 \func{void
}{SetFont
}{\param{const wxFont\&
}{font
}}
995 Sets the current font for the DC. It must be a valid font, in particular you
996 should not pass
{\tt wxNullFont
} to this method.
998 See also
\helpref{wxFont
}{wxfont
}.
1001 \membersection{wxDC::SetLogicalFunction
}\label{wxdcsetlogicalfunction
}
1003 \func{void
}{SetLogicalFunction
}{\param{int
}{ function
}}
1005 Sets the current logical function for the device context. This determines how
1006 a source pixel (from a pen or brush colour, or source device context if
1007 using
\helpref{wxDC::Blit
}{wxdcblit
}) combines with a destination pixel in the
1008 current device context.
1011 and their meaning in terms of source and destination pixel values are
1016 wxAND_INVERT (NOT src) AND dst
1017 wxAND_REVERSE src AND (NOT dst)
1020 wxEQUIV (NOT src) XOR dst
1022 wxNAND (NOT src) OR (NOT dst)
1023 wxNOR (NOT src) AND (NOT dst)
1026 wxOR_INVERT (NOT src) OR dst
1027 wxOR_REVERSE src OR (NOT dst)
1029 wxSRC_INVERT NOT src
1033 The default is wxCOPY, which simply draws with the current colour.
1034 The others combine the current colour and the background using a
1035 logical operation. wxINVERT is commonly used for drawing rubber bands or
1036 moving outlines, since drawing twice reverts to the original colour.
1039 \membersection{wxDC::SetMapMode
}\label{wxdcsetmapmode
}
1041 \func{void
}{SetMapMode
}{\param{int
}{ int
}}
1043 The
{\it mapping mode
} of the device context defines the unit of
1044 measurement used to convert logical units to device units. Note that
1045 in X, text drawing isn't handled consistently with the mapping mode; a
1046 font is always specified in point size. However, setting the
{\it
1047 user scale
} (see
\helpref{wxDC::SetUserScale
}{wxdcsetuserscale
}) scales the text appropriately. In
1048 Windows, scalable TrueType fonts are always used; in X, results depend
1049 on availability of fonts, but usually a reasonable match is found.
1051 The coordinate origin is always at the top left of the screen/printer.
1053 Drawing to a Windows printer device context uses the current mapping mode,
1054 but mapping mode is currently ignored for PostScript output.
1056 The mapping mode can be one of the following:
1058 \begin{twocollist
}\itemsep=
0pt
1059 \twocolitem{wxMM
\_TWIPS}{Each logical unit is
1/
20 of a point, or
1/
1440 of
1061 \twocolitem{wxMM
\_POINTS}{Each logical unit is a point, or
1/
72 of an inch.
}
1062 \twocolitem{wxMM
\_METRIC}{Each logical unit is
1 mm.
}
1063 \twocolitem{wxMM
\_LOMETRIC}{Each logical unit is
1/
10 of a mm.
}
1064 \twocolitem{wxMM
\_TEXT}{Each logical unit is
1 pixel.
}
1068 \membersection{wxDC::SetPalette
}\label{wxdcsetpalette
}
1070 \func{void
}{SetPalette
}{\param{const wxPalette\&
}{palette
}}
1072 If this is a window DC or memory DC, assigns the given palette to the window
1073 or bitmap associated with the DC. If the argument is wxNullPalette, the current
1074 palette is selected out of the device context, and the original palette
1077 See
\helpref{wxPalette
}{wxpalette
} for further details.
1080 \membersection{wxDC::SetPen
}\label{wxdcsetpen
}
1082 \func{void
}{SetPen
}{\param{const wxPen\&
}{pen
}}
1084 Sets the current pen for the DC.
1086 If the argument is wxNullPen, the current pen is selected out of the device
1087 context, and the original pen restored.
1089 See also
\helpref{wxMemoryDC
}{wxmemorydc
} for the interpretation of colours
1090 when drawing into a monochrome bitmap.
1093 \membersection{wxDC::SetTextBackground
}\label{wxdcsettextbackground
}
1095 \func{void
}{SetTextBackground
}{\param{const wxColour\&
}{colour
}}
1097 Sets the current text background colour for the DC.
1100 \membersection{wxDC::SetTextForeground
}\label{wxdcsettextforeground
}
1102 \func{void
}{SetTextForeground
}{\param{const wxColour\&
}{colour
}}
1104 Sets the current text foreground colour for the DC.
1106 See also
\helpref{wxMemoryDC
}{wxmemorydc
} for the interpretation of colours
1107 when drawing into a monochrome bitmap.
1110 \membersection{wxDC::SetUserScale
}\label{wxdcsetuserscale
}
1112 \func{void
}{SetUserScale
}{\param{double
}{ xScale
},
\param{double
}{ yScale
}}
1114 Sets the user scaling factor, useful for applications which require
1118 \membersection{wxDC::StartDoc
}\label{wxdcstartdoc
}
1120 \func{bool
}{StartDoc
}{\param{const wxString\&
}{message
}}
1122 Starts a
document (only relevant when outputting to a printer).
1123 Message is a message to show while printing.
1126 \membersection{wxDC::StartPage
}\label{wxdcstartpage
}
1128 \func{bool
}{StartPage
}{\void}
1130 Starts a
document page (only relevant when outputting to a printer).
1132 \section{\class{wxDCClipper
}}\label{wxdcclipper
}
1134 This is a small helper class which sets the specified DC to its constructor
1135 clipping region and then automatically destroys it in its destructor. Using
1136 it ensures that an unwanted clipping region is not left set on the DC.
1138 \wxheading{Derived from
}
1142 \wxheading{Include files
}
1146 \wxheading{See also
}
1148 \helpref{wxDC
}{wxdc
}
1150 \latexignore{\rtfignore{\wxheading{Members
}}}
1153 \membersection{wxDCClipper::wxDCClipper
}\label{wxdcclipperctor
}
1155 \func{}{wxDCClipper
}{\param{wxDC\&
}{dc
},
\param{wxCoord
}{x
},
\param{wxCoord
}{y
},
\param{wxCoord
}{w
},
\param{wxCoord
}{h
},
}
1157 \func{}{wxDCClipper
}{\param{wxDC\&
}{dc
},
\param{const wxRect\&
}{ rect
}}
1159 Constructor: sets the clipping region for the given device context to the
1160 specified rectangle.
1163 \membersection{wxDCClipper::
\destruct{wxDCClipper
}}\label{wxdcclipperdtor
}
1165 \func{}{\destruct{wxDCClipper
}}{\void}
1167 Destructor: destroys the clipping region set in the constructor.