]> git.saurik.com Git - wxWidgets.git/blame_incremental - docs/latex/wx/dc.tex
Added EVT_GRID_EDITOR_CREATED and wxGridEditorCreatedEvent so the user
[wxWidgets.git] / docs / latex / wx / dc.tex
... / ...
CommitLineData
1\section{\class{wxDC}}\label{wxdc}
2
3A wxDC is a {\it device context} onto which graphics and text can be drawn.
4It is intended to represent a number of output devices in a generic way,
5so a window can have a device context associated with it, and a printer also has a device context.
6In this way, the same piece of code may write to a number of different devices,
7if the device context is used as a parameter.
8
9Derived types of wxDC have documentation for specific features
10only, so refer to this section for most device context information.
11
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
14Please note that in addition to the versions of the methods documented here,
15there are also versions which accept single {\tt wxPoint} parameter instead of
16two {\tt wxCoord} ones or {\tt wxPoint} and {\tt wxSize} instead of four of
17them.
18
19\wxheading{Derived from}
20
21\helpref{wxObject}{wxobject}
22
23\wxheading{Include files}
24
25<wx/dc.h>
26
27\wxheading{See also}
28
29\helpref{Overview}{dcoverview}
30
31\latexignore{\rtfignore{\wxheading{Members}}}
32
33\membersection{wxDC::wxDC}
34
35\func{}{wxDC}{\void}
36
37Constructor.
38
39\membersection{wxDC::\destruct{wxDC}}
40
41\func{}{\destruct{wxDC}}{\void}
42
43Destructor.
44
45\membersection{wxDC::BeginDrawing}\label{wxdcbegindrawing}
46
47\func{void}{BeginDrawing}{\void}
48
49Allows optimization of drawing code under MS Windows. Enclose
50drawing primitives between {\bf BeginDrawing} and {\bf EndDrawing}\rtfsp
51calls.
52
53Drawing to a wxDialog panel device context outside of a
54system-generated OnPaint event {\it requires} this pair of calls to
55enclose drawing code. This is because a Windows dialog box does not have
56a retained device context associated with it, and selections such as pen
57and brush settings would be lost if the device context were obtained and
58released for each drawing operation.
59
60\membersection{wxDC::Blit}\label{wxdcblit}
61
62\func{bool}{Blit}{\param{wxCoord}{ xdest}, \param{wxCoord}{ ydest}, \param{wxCoord}{ width}, \param{wxCoord}{ height},
63 \param{wxDC* }{source}, \param{wxCoord}{ xsrc}, \param{wxCoord}{ ysrc}, \param{int}{ logicalFunc = wxCOPY},
64 \param{bool }{useMask = FALSE}}
65
66Copy from a source DC to this DC, specifying the destination
67coordinates, size of area to copy, source DC, source coordinates, and
68logical function.
69
70\wxheading{Parameters}
71
72\docparam{xdest}{Destination device context x position.}
73
74\docparam{ydest}{Destination device context y position.}
75
76\docparam{width}{Width of source area to be copied.}
77
78\docparam{height}{Height of source area to be copied.}
79
80\docparam{source}{Source device context.}
81
82\docparam{xsrc}{Source device context x position.}
83
84\docparam{ysrc}{Source device context y position.}
85
86\docparam{logicalFunc}{Logical function to use: see \helpref{wxDC::SetLogicalFunction}{wxdcsetlogicalfunction}.}
87
88\docparam{useMask}{If TRUE, Blit does a transparent blit using the mask that is associated with the bitmap
89selected into the source device context. The Windows implementation does the following:
90
91\begin{enumerate}
92\item Creates a temporary bitmap and copies the destination area into it.
93\item Copies the source area into the temporary bitmap using the specified logical function.
94\item Sets the masked area in the temporary bitmap to BLACK by ANDing the
95mask bitmap with the temp bitmap with the foreground colour set to WHITE
96and the bg colour set to BLACK.
97\item Sets the unmasked area in the destination area to BLACK by ANDing the
98mask bitmap with the destination area with the foreground colour set to BLACK
99and the background colour set to WHITE.
100\item ORs the temporary bitmap with the destination area.
101\item Deletes the temporary bitmap.
102\end{enumerate}
103
104This sequence of operations ensures that the source's transparent area need not be black,
105and logical functions are supported.
106}
107
108\wxheading{Remarks}
109
110There is partial support for Blit in wxPostScriptDC, under X.
111
112See \helpref{wxMemoryDC}{wxmemorydc} for typical usage.
113
114\wxheading{See also}
115
116\helpref{wxMemoryDC}{wxmemorydc}, \helpref{wxBitmap}{wxbitmap}, \helpref{wxMask}{wxmask}
117
118\membersection{wxDC::CalcBoundingBox}\label{wxdccalcboundingbox}
119
120\func{void}{CalcBoundingBox}{\param{wxCoord }{x}, \param{wxCoord }{y}}
121
122Adds the specified point to the bounding box which can be retrieved with
123\helpref{MinX}{wxdcminx}, \helpref{MaxX}{wxdcmaxx} and
124\helpref{MinY}{wxdcminy}, \helpref{MaxY}{wxdcmaxy} functions.
125
126\wxheading{See also}
127
128\helpref{ResetBoundingBox}{wxdcresetboundingbox}
129
130\membersection{wxDC::Clear}\label{wxdcclear}
131
132\func{void}{Clear}{\void}
133
134Clears the device context using the current background brush.
135
136\membersection{wxDC::CrossHair}\label{wxdccrosshair}
137
138\func{void}{CrossHair}{\param{wxCoord}{ x}, \param{wxCoord}{ y}}
139
140Displays a cross hair using the current pen. This is a vertical
141and horizontal line the height and width of the window, centred
142on the given point.
143
144\membersection{wxDC::DestroyClippingRegion}\label{wxdcdestroyclippingregion}
145
146\func{void}{DestroyClippingRegion}{\void}
147
148Destroys the current clipping region so that none of the DC is clipped.
149See also \helpref{wxDC::SetClippingRegion}{wxdcsetclippingregion}.
150
151\membersection{wxDC::DeviceToLogicalX}\label{wxdcdevicetologicalx}
152
153\func{wxCoord}{DeviceToLogicalX}{\param{wxCoord}{ x}}
154
155Convert device X coordinate to logical coordinate, using the current
156mapping mode.
157
158\membersection{wxDC::DeviceToLogicalXRel}\label{wxdcdevicetologicalxrel}
159
160\func{wxCoord}{DeviceToLogicalXRel}{\param{wxCoord}{ x}}
161
162Convert device X coordinate to relative logical coordinate, using the current
163mapping mode. Use this function for converting a width, for example.
164
165\membersection{wxDC::DeviceToLogicalY}\label{wxdcdevicetologicaly}
166
167\func{wxCoord}{DeviceToLogicalY}{\param{wxCoord}{ y}}
168
169Converts device Y coordinate to logical coordinate, using the current
170mapping mode.
171
172\membersection{wxDC::DeviceToLogicalYRel}\label{wxdcdevicetologicalyrel}
173
174\func{wxCoord}{DeviceToLogicalYRel}{\param{wxCoord}{ y}}
175
176Convert device Y coordinate to relative logical coordinate, using the current
177mapping mode. Use this function for converting a height, for example.
178
179\membersection{wxDC::DrawArc}\label{wxdcdrawarc}
180
181\func{void}{DrawArc}{\param{wxCoord}{ x1}, \param{wxCoord}{ y1}, \param{wxCoord}{ x2}, \param{wxCoord}{ y2}, \param{double}{ xc}, \param{double}{ yc}}
182
183Draws an arc of a circle, centred on ({\it xc, yc}), with starting point ({\it x1, y1})
184and ending at ({\it x2, y2}). The current pen is used for the outline
185and the current brush for filling the shape.
186
187The arc is drawn in an anticlockwise direction from the start point to the end point.
188
189\membersection{wxDC::DrawBitmap}\label{wxdcdrawbitmap}
190
191\func{void}{DrawBitmap}{\param{const wxBitmap\&}{ bitmap}, \param{wxCoord}{ x}, \param{wxCoord}{ y}, \param{bool}{ transparent}}
192
193Draw a bitmap on the device context at the specified point. If {\it transparent} is TRUE and the bitmap has
194a transparency mask, the bitmap will be drawn transparently.
195
196When drawing a mono-bitmap, the current text foreground colour will be used to draw the foreground
197of the bitmap (all bits set to 1), and the current text background colour to draw the background
198(all bits set to 0). See also \helpref{SetTextForeground}{wxdcsettextforeground},
199\helpref{SetTextBackground}{wxdcsettextbackground} and \helpref{wxMemoryDC}{wxmemorydc}.
200
201\membersection{wxDC::DrawCheckMark}\label{wxdcdrawcheckmark}
202
203\func{void}{DrawCheckMark}{\param{wxCoord}{ x}, \param{wxCoord}{ y}, \param{wxCoord}{ width}, \param{wxCoord}{ height}}
204
205\func{void}{DrawCheckMark}{\param{const wxRect \&}{rect}}
206
207Draws a check mark inside the given rectangle.
208
209\membersection{wxDC::DrawEllipse}\label{wxdcdrawellipse}
210
211\func{void}{DrawEllipse}{\param{wxCoord}{ x}, \param{wxCoord}{ y}, \param{wxCoord}{ width}, \param{wxCoord}{ height}}
212
213Draws an ellipse contained in the rectangle with the given top left corner, and with the
214given size. The current pen is used for the outline and the current brush for
215filling the shape.
216
217\membersection{wxDC::DrawEllipticArc}\label{wxdcdrawellipticarc}
218
219\func{void}{DrawEllipticArc}{\param{wxCoord}{ x}, \param{wxCoord}{ y}, \param{wxCoord}{ width}, \param{wxCoord}{ height},
220 \param{double}{ start}, \param{double}{ end}}
221
222Draws an arc of an ellipse. The current pen is used for drawing the arc and
223the current brush is used for drawing the pie.
224
225{\it x} and {\it y} specify the x and y coordinates of the upper-left corner of the rectangle that contains
226the ellipse.
227
228{\it width} and {\it height} specify the width and height of the rectangle that contains
229the ellipse.
230
231{\it start} and {\it end} specify the start and end of the arc relative to the three-o'clock
232position from the center of the rectangle. Angles are specified
233in degrees (360 is a complete circle). Positive values mean
234counter-clockwise motion. If {\it start} is equal to {\it end}, a
235complete ellipse will be drawn.
236
237\membersection{wxDC::DrawIcon}\label{wxdcdrawicon}
238
239\func{void}{DrawIcon}{\param{const wxIcon\&}{ icon}, \param{wxCoord}{ x}, \param{wxCoord}{ y}}
240
241Draw an icon on the display (does nothing if the device context is PostScript).
242This can be the simplest way of drawing bitmaps on a window.
243
244\membersection{wxDC::DrawLine}\label{wxdcdrawline}
245
246\func{void}{DrawLine}{\param{wxCoord}{ x1}, \param{wxCoord}{ y1}, \param{wxCoord}{ x2}, \param{wxCoord}{ y2}}
247
248Draws a line from the first point to the second. The current pen is used
249for drawing the line.
250
251\membersection{wxDC::DrawLines}\label{wxdcdrawlines}
252
253\func{void}{DrawLines}{\param{int}{ n}, \param{wxPoint}{ points[]}, \param{wxCoord}{ xoffset = 0}, \param{wxCoord}{ yoffset = 0}}
254
255\func{void}{DrawLines}{\param{wxList *}{points}, \param{wxCoord}{ xoffset = 0}, \param{wxCoord}{ yoffset = 0}}
256
257Draws lines using an array of {\it points} of size {\it n}, or list of
258pointers to points, adding the optional offset coordinate. The current
259pen is used for drawing the lines. The programmer is responsible for
260deleting the list of points.
261
262\pythonnote{The wxPython version of this method accepts a Python list
263of wxPoint objects.}
264
265\perlnote{The wxPerl version of this method accepts
266 as its first parameter a reference to an array
267 of wxPoint objects.}
268
269\membersection{wxDC::DrawPolygon}\label{wxdcdrawpolygon}
270
271\func{void}{DrawPolygon}{\param{int}{ n}, \param{wxPoint}{ points[]}, \param{wxCoord}{ xoffset = 0}, \param{wxCoord}{ yoffset = 0},\\
272 \param{int }{fill\_style = wxODDEVEN\_RULE}}
273
274\func{void}{DrawPolygon}{\param{wxList *}{points}, \param{wxCoord}{ xoffset = 0}, \param{wxCoord}{ yoffset = 0},\\
275 \param{int }{fill\_style = wxODDEVEN\_RULE}}
276
277Draws a filled polygon using an array of {\it points} of size {\it n},
278or list of pointers to points, adding the optional offset coordinate.
279
280The last argument specifies the fill rule: {\bf wxODDEVEN\_RULE} (the
281default) or {\bf wxWINDING\_RULE}.
282
283The current pen is used for drawing the outline, and the current brush
284for filling the shape. Using a transparent brush suppresses filling.
285The programmer is responsible for deleting the list of points.
286
287Note that wxWindows automatically closes the first and last points.
288
289\pythonnote{The wxPython version of this method accepts a Python list
290of wxPoint objects.}
291
292\perlnote{The wxPerl version of this method accepts
293 as its first parameter a reference to an array
294 of wxPoint objects.}
295
296\membersection{wxDC::DrawPoint}\label{wxdcdrawpoint}
297
298\func{void}{DrawPoint}{\param{wxCoord}{ x}, \param{wxCoord}{ y}}
299
300Draws a point using the current pen.
301
302\membersection{wxDC::DrawRectangle}\label{wxdcdrawrectangle}
303
304\func{void}{DrawRectangle}{\param{wxCoord}{ x}, \param{wxCoord}{ y}, \param{wxCoord}{ width}, \param{wxCoord}{ height}}
305
306Draws a rectangle with the given top left corner, and with the given
307size. The current pen is used for the outline and the current brush
308for filling the shape.
309
310\membersection{wxDC::DrawRotatedText}\label{wxdcdrawrotatedtext}
311
312\func{void}{DrawRotatedText}{\param{const wxString\& }{text}, \param{wxCoord}{ x}, \param{wxCoord}{ y}, \param{double}{ angle}}
313
314Draws the text rotated by {\it angle} degrees.
315
316\wxheading{See also}
317
318\helpref{DrawText}{wxdcdrawtext}
319
320\membersection{wxDC::DrawRoundedRectangle}\label{wxdcdrawroundedrectangle}
321
322\func{void}{DrawRoundedRectangle}{\param{wxCoord}{ x}, \param{wxCoord}{ y}, \param{wxCoord}{ width}, \param{wxCoord}{ height}, \param{double}{ radius = 20}}
323
324Draws a rectangle with the given top left corner, and with the given
325size. The corners are quarter-circles using the given radius. The
326current pen is used for the outline and the current brush for filling
327the shape.
328
329If {\it radius} is positive, the value is assumed to be the
330radius of the rounded corner. If {\it radius} is negative,
331the absolute value is assumed to be the {\it proportion} of the smallest
332dimension of the rectangle. This means that the corner can be
333a sensible size relative to the size of the rectangle, and also avoids
334the strange effects X produces when the corners are too big for
335the rectangle.
336
337\membersection{wxDC::DrawSpline}\label{wxdcdrawspline}
338
339\func{void}{DrawSpline}{\param{wxList *}{points}}
340
341Draws a spline between all given control points, using the current
342pen. Doesn't delete the wxList and contents. The spline is drawn
343using a series of lines, using an algorithm taken from the X drawing
344program `XFIG'.
345
346\func{void}{DrawSpline}{\param{wxCoord}{ x1}, \param{wxCoord}{ y1}, \param{wxCoord}{ x2}, \param{wxCoord}{ y2}, \param{wxCoord}{ x3}, \param{wxCoord}{ y3}}
347
348Draws a three-point spline using the current pen.
349
350\pythonnote{The wxPython version of this method accepts a Python list
351of wxPoint objects.}
352
353\perlnote{The wxPerl version of this method accepts a reference to an array
354 of wxPoint objects.}
355
356\membersection{wxDC::DrawText}\label{wxdcdrawtext}
357
358\func{void}{DrawText}{\param{const wxString\& }{text}, \param{wxCoord}{ x}, \param{wxCoord}{ y}}
359
360Draws a text string at the specified point, using the current text font,
361and the current text foreground and background colours.
362
363The coordinates refer to the top-left corner of the rectangle bounding
364the string. See \helpref{wxDC::GetTextExtent}{wxdcgettextextent} for how
365to get the dimensions of a text string, which can be used to position the
366text more precisely.
367
368{\bf NB:} under wxGTK the current
369\helpref{logical function}{wxdcgetlogicalfunction} is used by this function
370but it is ignored by wxMSW. Thus, you should avoid using logical functions
371with this function in portable programs.
372
373\membersection{wxDC::EndDoc}\label{wxdcenddoc}
374
375\func{void}{EndDoc}{\void}
376
377Ends a document (only relevant when outputting to a printer).
378
379\membersection{wxDC::EndDrawing}\label{wxdcenddrawing}
380
381\func{void}{EndDrawing}{\void}
382
383Allows optimization of drawing code under MS Windows. Enclose
384drawing primitives between {\bf BeginDrawing} and {\bf EndDrawing}\rtfsp
385calls.
386
387\membersection{wxDC::EndPage}\label{wxdcendpage}
388
389\func{void}{EndPage}{\void}
390
391Ends a document page (only relevant when outputting to a printer).
392
393\membersection{wxDC::FloodFill}\label{wxdcfloodfill}
394
395\func{void}{FloodFill}{\param{wxCoord}{ x}, \param{wxCoord}{ y}, \param{const wxColour\&}{ colour}, \param{int}{ style=wxFLOOD\_SURFACE}}
396
397Flood fills the device context starting from the given point, using
398the {\it current brush colour}, and using a style:
399
400\begin{itemize}\itemsep=0pt
401\item wxFLOOD\_SURFACE: the flooding occurs until a colour other than the given colour is encountered.
402\item wxFLOOD\_BORDER: the area to be flooded is bounded by the given colour.
403\end{itemize}
404
405{\it Note:} this function is available in MS Windows only.
406
407\membersection{wxDC::GetBackground}\label{wxdcgetbackground}
408
409\func{wxBrush\&}{GetBackground}{\void}
410
411\constfunc{const wxBrush\&}{GetBackground}{\void}
412
413Gets the brush used for painting the background (see \helpref{wxDC::SetBackground}{wxdcsetbackground}).
414
415\membersection{wxDC::GetBackgroundMode}\label{wxdcgetbackgroundmode}
416
417\constfunc{int}{GetBackgroundMode}{\void}
418
419Returns the current background mode: {\tt wxSOLID} or {\tt wxTRANSPARENT}.
420
421\wxheading{See also}
422
423\helpref{SetBackgroundMode}{wxdcsetbackgroundmode}
424
425\membersection{wxDC::GetBrush}\label{wxdcgetbrush}
426
427\func{wxBrush\&}{GetBrush}{\void}
428
429\constfunc{const wxBrush\&}{GetBrush}{\void}
430
431Gets the current brush (see \helpref{wxDC::SetBrush}{wxdcsetbrush}).
432
433\membersection{wxDC::GetCharHeight}\label{wxdcgetcharheight}
434
435\func{wxCoord}{GetCharHeight}{\void}
436
437Gets the character height of the currently set font.
438
439\membersection{wxDC::GetCharWidth}\label{wxdcgetcharwidth}
440
441\func{wxCoord}{GetCharWidth}{\void}
442
443Gets the average character width of the currently set font.
444
445\membersection{wxDC::GetClippingBox}\label{wxdcgetclippingbox}
446
447\func{void}{GetClippingBox}{\param{wxCoord}{ *x}, \param{wxCoord}{ *y}, \param{wxCoord}{ *width}, \param{wxCoord}{ *height}}
448
449Gets the rectangle surrounding the current clipping region.
450
451\pythonnote{No arguments are required and the four values defining the
452rectangle are returned as a tuple.}
453
454\perlnote{This method takes no arguments and returns a four element list
455{\tt ( \$x, \$y, \$width, \$height )}}
456
457\membersection{wxDC::GetFont}\label{wxdcgetfont}
458
459\func{wxFont\&}{GetFont}{\void}
460
461\constfunc{const wxFont\&}{GetFont}{\void}
462
463Gets the current font (see \helpref{wxDC::SetFont}{wxdcsetfont}).
464
465\membersection{wxDC::GetLogicalFunction}\label{wxdcgetlogicalfunction}
466
467\func{int}{GetLogicalFunction}{\void}
468
469Gets the current logical function (see \helpref{wxDC::SetLogicalFunction}{wxdcsetlogicalfunction}).
470
471\membersection{wxDC::GetMapMode}\label{wxdcgetmapmode}
472
473\func{int}{GetMapMode}{\void}
474
475Gets the {\it mapping mode} for the device context (see \helpref{wxDC::SetMapMode}{wxdcsetmapmode}).
476
477\membersection{wxDC::GetOptimization}\label{wxdcgetoptimization}
478
479\func{bool}{GetOptimization}{\void}
480
481Returns TRUE if device context optimization is on.
482See \helpref{wxDC::SetOptimization}{wxsetoptimization} for details.
483
484\membersection{wxDC::GetPen}\label{wxdcgetpen}
485
486\func{wxPen\&}{GetPen}{\void}
487
488\constfunc{const wxPen\&}{GetPen}{\void}
489
490Gets the current pen (see \helpref{wxDC::SetPen}{wxdcsetpen}).
491
492\membersection{wxDC::GetPixel}\label{wxdcgetpixel}
493
494\func{bool}{GetPixel}{\param{wxCoord}{ x}, \param{wxCoord}{ y}, \param{wxColour *}{colour}}
495
496Sets {\it colour} to the colour at the specified location. Windows only; an X implementation
497is being worked on. Not available for wxPostScriptDC or wxMetafileDC.
498
499\pythonnote{For wxPython the wxColour value is returned and is not
500required as a parameter.}
501
502\perlnote{This method only takes the parameters {\tt x} and {\tt y} and returns
503a Wx::Colour value}
504
505\membersection{wxDC::GetSize}\label{wxdcgetsize}
506
507\func{void}{GetSize}{\param{wxCoord *}{width}, \param{wxCoord *}{height}}
508
509For a PostScript device context, this gets the maximum size of graphics
510drawn so far on the device context.
511
512For a Windows printer device context, this gets the horizontal and vertical
513resolution. It can be used to scale graphics to fit the page when using
514a Windows printer device context. For example, if {\it maxX} and {\it maxY}\rtfsp
515represent the maximum horizontal and vertical `pixel' values used in your
516application, the following code will scale the graphic to fit on the
517printer page:
518
519\begin{verbatim}
520 wxCoord w, h;
521 dc.GetSize(&w, &h);
522 double scaleX=(double)(maxX/w);
523 double scaleY=(double)(maxY/h);
524 dc.SetUserScale(min(scaleX,scaleY),min(scaleX,scaleY));
525\end{verbatim}
526
527\pythonnote{In place of a single overloaded method name, wxPython
528implements the following methods:\par
529\indented{2cm}{\begin{twocollist}
530\twocolitem{{\bf GetSize()}}{Returns a wxSize}
531\twocolitem{{\bf GetSizeTuple()}}{Returns a 2-tuple (width, height)}
532\end{twocollist}}
533}
534
535\perlnote{In place of a single overloaded method, wxPerl uses:\par
536\indented{2cm}{\begin{twocollist}
537\twocolitem{{\bf GetSize()}}{Returns a Wx::Size}
538\twocolitem{{\bf GetSizeWH()}}{Returns a 2-element list
539 {\tt ( \$width, \$height )}}
540\end{twocollist}
541}}
542
543\membersection{wxDC::GetTextBackground}\label{wxdcgettextbackground}
544
545\func{wxColour\&}{GetTextBackground}{\void}
546
547\constfunc{const wxColour\&}{GetTextBackground}{\void}
548
549Gets the current text background colour (see \helpref{wxDC::SetTextBackground}{wxdcsettextbackground}).
550
551\membersection{wxDC::GetTextExtent}\label{wxdcgettextextent}
552
553\func{void}{GetTextExtent}{\param{const wxString\& }{string}, \param{wxCoord *}{w}, \param{wxCoord *}{h},\\
554 \param{wxCoord *}{descent = NULL}, \param{wxCoord *}{externalLeading = NULL}, \param{wxFont *}{font = NULL}}
555
556Gets the dimensions of the string using the currently selected font.
557\rtfsp{\it string} is the text string to measure, {\it w} and {\it h} are
558the total width and height respectively, {\it descent} is the
559dimension from the baseline of the font to the bottom of the
560descender, and {\it externalLeading} is any extra vertical space added
561to the font by the font designer (usually is zero).
562
563The optional parameter {\it font} specifies an alternative
564to the currently selected font: but note that this does not
565yet work under Windows, so you need to set a font for
566the device context first.
567
568See also \helpref{wxFont}{wxfont}, \helpref{wxDC::SetFont}{wxdcsetfont}.
569
570\pythonnote{The following methods are implemented in wxPython:\par
571\indented{2cm}{\begin{twocollist}
572\twocolitem{{\bf GetTextExtent(string)}}{Returns a 2-tuple, (width, height)}
573\twocolitem{{\bf GetFullTextExtent(string, font=NULL)}}{Returns a
5744-tuple, (width, height, descent, externalLeading) }
575\end{twocollist}}
576}
577
578\perlnote{In wxPerl this method is implemented as
579 {\bf GetTextExtent( string, font = undef )} returning a four element
580 array {\tt ( \$width, \$height, \$descent, \$externalLeading )}
581}
582
583\membersection{wxDC::GetTextForeground}\label{wxdcgettextforeground}
584
585\func{wxColour\&}{GetTextForeground}{\void}
586
587\constfunc{const wxColour\&}{GetTextForeground}{\void}
588
589Gets the current text foreground colour (see \helpref{wxDC::SetTextForeground}{wxdcsettextforeground}).
590
591
592\membersection{wxDC::GetUserScale}\label{wxdcgetuserscale}
593
594\func{void}{GetUserScale}{\param{double}{ *x}, \param{double}{ *y}}
595
596Gets the current user scale factor (set by \helpref{SetUserScale}{wxdcsetuserscale}).
597
598\perlnote{In wxPerl this method takes no arguments and returna a two element
599 array {\tt ( \$x, \$y )}}
600
601\membersection{wxDC::LogicalToDeviceX}\label{wxdclogicaltodevicex}
602
603\func{wxCoord}{LogicalToDeviceX}{\param{wxCoord}{ x}}
604
605Converts logical X coordinate to device coordinate, using the current
606mapping mode.
607
608\membersection{wxDC::LogicalToDeviceXRel}\label{wxdclogicaltodevicexrel}
609
610\func{wxCoord}{LogicalToDeviceXRel}{\param{wxCoord}{ x}}
611
612Converts logical X coordinate to relative device coordinate, using the current
613mapping mode. Use this for converting a width, for example.
614
615\membersection{wxDC::LogicalToDeviceY}\label{wxdclogicaltodevicey}
616
617\func{wxCoord}{LogicalToDeviceY}{\param{wxCoord}{ y}}
618
619Converts logical Y coordinate to device coordinate, using the current
620mapping mode.
621
622\membersection{wxDC::LogicalToDeviceYRel}\label{wxdclogicaltodeviceyrel}
623
624\func{wxCoord}{LogicalToDeviceYRel}{\param{wxCoord}{ y}}
625
626Converts logical Y coordinate to relative device coordinate, using the current
627mapping mode. Use this for converting a height, for example.
628
629\membersection{wxDC::MaxX}\label{wxdcmaxx}
630
631\func{wxCoord}{MaxX}{\void}
632
633Gets the maximum horizontal extent used in drawing commands so far.
634
635\membersection{wxDC::MaxY}\label{wxdcmaxy}
636
637\func{wxCoord}{MaxY}{\void}
638
639Gets the maximum vertical extent used in drawing commands so far.
640
641\membersection{wxDC::MinX}\label{wxdcminx}
642
643\func{wxCoord}{MinX}{\void}
644
645Gets the minimum horizontal extent used in drawing commands so far.
646
647\membersection{wxDC::MinY}\label{wxdcminy}
648
649\func{wxCoord}{MinY}{\void}
650
651Gets the minimum vertical extent used in drawing commands so far.
652
653\membersection{wxDC::Ok}\label{wxdcok}
654
655\func{bool}{Ok}{\void}
656
657Returns TRUE if the DC is ok to use.
658
659\membersection{wxDC::ResetBoundingBox}\label{wxdcresetboundingbox}
660
661\func{void}{ResetBoundingBox}{\void}
662
663Resets the bounding box: after a call to this function, the bounding box
664doesn't contain anything.
665
666\wxheading{See also}
667
668\helpref{CalcBoundingBox}{wxdccalcboundingbox}
669
670\membersection{wxDC::SetDeviceOrigin}\label{wxdcsetdeviceorigin}
671
672\func{void}{SetDeviceOrigin}{\param{wxCoord}{ x}, \param{wxCoord}{ y}}
673
674Sets the device origin (i.e., the origin in pixels after scaling has been
675applied).
676
677This function may be useful in Windows printing
678operations for placing a graphic on a page.
679
680\membersection{wxDC::SetBackground}\label{wxdcsetbackground}
681
682\func{void}{SetBackground}{\param{const wxBrush\& }{brush}}
683
684Sets the current background brush for the DC.
685
686\membersection{wxDC::SetBackgroundMode}\label{wxdcsetbackgroundmode}
687
688\func{void}{SetBackgroundMode}{\param{int}{ mode}}
689
690{\it mode} may be one of wxSOLID and wxTRANSPARENT. This setting determines
691whether text will be drawn with a background colour or not.
692
693\membersection{wxDC::SetClippingRegion}\label{wxdcsetclippingregion}
694
695\func{void}{SetClippingRegion}{\param{wxCoord}{ x}, \param{wxCoord}{ y}, \param{wxCoord}{ width}, \param{wxCoord}{ height}}
696
697\func{void}{SetClippingRegion}{\param{const wxRegion\&}{ region}}
698
699Sets the clipping region for the DC. The clipping region is an area
700to which drawing is restricted. Possible uses for the clipping region are for clipping text
701or for speeding up window redraws when only a known area of the screen is damaged.
702
703\wxheading{See also}
704
705\helpref{wxDC::DestroyClippingRegion}{wxdcdestroyclippingregion}, \helpref{wxRegion}{wxregion}
706
707\membersection{wxDC::SetPalette}\label{wxdcsetpalette}
708
709\func{void}{SetPalette}{\param{const wxPalette\& }{palette}}
710
711If this is a window DC or memory DC, assigns the given palette to the window
712or bitmap associated with the DC. If the argument is wxNullPalette, the current
713palette is selected out of the device context, and the original palette
714restored.
715
716See \helpref{wxPalette}{wxpalette} for further details.
717
718\membersection{wxDC::SetBrush}\label{wxdcsetbrush}
719
720\func{void}{SetBrush}{\param{const wxBrush\& }{brush}}
721
722Sets the current brush for the DC.
723
724If the argument is wxNullBrush, the current brush is selected out of the device
725context, and the original brush restored, allowing the current brush to
726be destroyed safely.
727
728See also \helpref{wxBrush}{wxbrush}.
729
730See also \helpref{wxMemoryDC}{wxmemorydc} for the interpretation of colours
731when drawing into a monochrome bitmap.
732
733\membersection{wxDC::SetFont}\label{wxdcsetfont}
734
735\func{void}{SetFont}{\param{const wxFont\& }{font}}
736
737Sets the current font for the DC.
738
739If the argument is wxNullFont, the current font is selected out of the device
740context, and the original font restored, allowing the current font to
741be destroyed safely.
742
743See also \helpref{wxFont}{wxfont}.
744
745\membersection{wxDC::SetLogicalFunction}\label{wxdcsetlogicalfunction}
746
747\func{void}{SetLogicalFunction}{\param{int}{ function}}
748
749Sets the current logical function for the device context. This determines how
750a source pixel (from a pen or brush colour, or source device context if
751using \helpref{wxDC::Blit}{wxdcblit}) combines with a destination pixel in the
752current device context.
753
754The possible values
755and their meaning in terms of source and destination pixel values are
756as follows:
757
758\begin{verbatim}
759wxAND src AND dst
760wxAND_INVERT (NOT src) AND dst
761wxAND_REVERSE src AND (NOT dst)
762wxCLEAR 0
763wxCOPY src
764wxEQUIV (NOT src) XOR dst
765wxINVERT NOT dst
766wxNAND (NOT src) OR (NOT dst)
767wxNOR (NOT src) AND (NOT dst)
768wxNO_OP dst
769wxOR src OR dst
770wxOR_INVERT (NOT src) OR dst
771wxOR_REVERSE src OR (NOT dst)
772wxSET 1
773wxSRC_INVERT NOT src
774wxXOR src XOR dst
775\end{verbatim}
776
777The default is wxCOPY, which simply draws with the current colour.
778The others combine the current colour and the background using a
779logical operation. wxINVERT is commonly used for drawing rubber bands or
780moving outlines, since drawing twice reverts to the original colour.
781
782\membersection{wxDC::SetMapMode}\label{wxdcsetmapmode}
783
784\func{void}{SetMapMode}{\param{int}{ int}}
785
786The {\it mapping mode} of the device context defines the unit of
787measurement used to convert logical units to device units. Note that
788in X, text drawing isn't handled consistently with the mapping mode; a
789font is always specified in point size. However, setting the {\it
790user scale} (see \helpref{wxDC::SetUserScale}{wxdcsetuserscale}) scales the text appropriately. In
791Windows, scaleable TrueType fonts are always used; in X, results depend
792on availability of fonts, but usually a reasonable match is found.
793
794Note that the coordinate origin should ideally be selectable, but for
795now is always at the top left of the screen/printer.
796
797Drawing to a Windows printer device context under UNIX
798uses the current mapping mode, but mapping mode is currently ignored for
799PostScript output.
800
801The mapping mode can be one of the following:
802
803\begin{twocollist}\itemsep=0pt
804\twocolitem{wxMM\_TWIPS}{Each logical unit is 1/20 of a point, or 1/1440 of
805 an inch.}
806\twocolitem{wxMM\_POINTS}{Each logical unit is a point, or 1/72 of an inch.}
807\twocolitem{wxMM\_METRIC}{Each logical unit is 1 mm.}
808\twocolitem{wxMM\_LOMETRIC}{Each logical unit is 1/10 of a mm.}
809\twocolitem{wxMM\_TEXT}{Each logical unit is 1 pixel.}
810\end{twocollist}
811
812\membersection{wxDC::SetOptimization}\label{wxsetoptimization}
813
814\func{void}{SetOptimization}{\param{bool }{optimize}}
815
816If {\it optimize} is TRUE (the default), this function sets optimization mode on.
817This currently means that under X, the device context will not try to set a pen or brush
818property if it is known to be set already. This approach can fall down
819if non-wxWindows code is using the same device context or window, for example
820when the window is a panel on which the windowing system draws panel items.
821The wxWindows device context 'memory' will now be out of step with reality.
822
823Setting optimization off, drawing, then setting it back on again, is a trick
824that must occasionally be employed.
825
826\membersection{wxDC::SetPen}\label{wxdcsetpen}
827
828\func{void}{SetPen}{\param{const wxPen\& }{pen}}
829
830Sets the current pen for the DC.
831
832If the argument is wxNullPen, the current pen is selected out of the device
833context, and the original pen restored.
834
835See also \helpref{wxMemoryDC}{wxmemorydc} for the interpretation of colours
836when drawing into a monochrome bitmap.
837
838\membersection{wxDC::SetTextBackground}\label{wxdcsettextbackground}
839
840\func{void}{SetTextBackground}{\param{const wxColour\& }{colour}}
841
842Sets the current text background colour for the DC.
843
844\membersection{wxDC::SetTextForeground}\label{wxdcsettextforeground}
845
846\func{void}{SetTextForeground}{\param{const wxColour\& }{colour}}
847
848Sets the current text foreground colour for the DC.
849
850See also \helpref{wxMemoryDC}{wxmemorydc} for the interpretation of colours
851when drawing into a monochrome bitmap.
852
853\membersection{wxDC::SetUserScale}\label{wxdcsetuserscale}
854
855\func{void}{SetUserScale}{\param{double}{ xScale}, \param{double}{ yScale}}
856
857Sets the user scaling factor, useful for applications which require
858`zooming'.
859
860\membersection{wxDC::StartDoc}\label{wxdcstartdoc}
861
862\func{bool}{StartDoc}{\param{const wxString\& }{message}}
863
864Starts a document (only relevant when outputting to a printer).
865Message is a message to show whilst printing.
866
867\membersection{wxDC::StartPage}\label{wxdcstartpage}
868
869\func{bool}{StartPage}{\void}
870
871Starts a document page (only relevant when outputting to a printer).
872