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1 | \section{\class{wxDC}}\label{wxdc} | |
2 | ||
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. | |
8 | ||
9 | Derived types of wxDC have documentation for specific features | |
10 | only, 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 | |
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 | |
17 | them. | |
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 | ||
37 | Constructor. | |
38 | ||
39 | \membersection{wxDC::\destruct{wxDC}} | |
40 | ||
41 | \func{}{\destruct{wxDC}}{\void} | |
42 | ||
43 | Destructor. | |
44 | ||
45 | \membersection{wxDC::BeginDrawing}\label{wxdcbegindrawing} | |
46 | ||
47 | \func{void}{BeginDrawing}{\void} | |
48 | ||
49 | Allows optimization of drawing code under MS Windows. Enclose | |
50 | drawing primitives between {\bf BeginDrawing} and {\bf EndDrawing}\rtfsp | |
51 | calls. | |
52 | ||
53 | Drawing to a wxDialog panel device context outside of a | |
54 | system-generated OnPaint event {\it requires} this pair of calls to | |
55 | enclose drawing code. This is because a Windows dialog box does not have | |
56 | a retained device context associated with it, and selections such as pen | |
57 | and brush settings would be lost if the device context were obtained and | |
58 | released 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 | ||
66 | Copy from a source DC to this DC, specifying the destination | |
67 | coordinates, size of area to copy, source DC, source coordinates, and | |
68 | logical 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 | |
89 | selected 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 | |
95 | mask bitmap with the temp bitmap with the foreground colour set to WHITE | |
96 | and the bg colour set to BLACK. | |
97 | \item Sets the unmasked area in the destination area to BLACK by ANDing the | |
98 | mask bitmap with the destination area with the foreground colour set to BLACK | |
99 | and 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 | ||
104 | This sequence of operations ensures that the source's transparent area need not be black, | |
105 | and logical functions are supported. | |
106 | } | |
107 | ||
108 | \wxheading{Remarks} | |
109 | ||
110 | There is partial support for Blit in wxPostScriptDC, under X. | |
111 | ||
112 | See \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 | ||
122 | Adds 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 | ||
134 | Clears 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 | ||
140 | Displays a cross hair using the current pen. This is a vertical | |
141 | and horizontal line the height and width of the window, centred | |
142 | on the given point. | |
143 | ||
144 | \membersection{wxDC::DestroyClippingRegion}\label{wxdcdestroyclippingregion} | |
145 | ||
146 | \func{void}{DestroyClippingRegion}{\void} | |
147 | ||
148 | Destroys the current clipping region so that none of the DC is clipped. | |
149 | See also \helpref{wxDC::SetClippingRegion}{wxdcsetclippingregion}. | |
150 | ||
151 | \membersection{wxDC::DeviceToLogicalX}\label{wxdcdevicetologicalx} | |
152 | ||
153 | \func{wxCoord}{DeviceToLogicalX}{\param{wxCoord}{ x}} | |
154 | ||
155 | Convert device X coordinate to logical coordinate, using the current | |
156 | mapping mode. | |
157 | ||
158 | \membersection{wxDC::DeviceToLogicalXRel}\label{wxdcdevicetologicalxrel} | |
159 | ||
160 | \func{wxCoord}{DeviceToLogicalXRel}{\param{wxCoord}{ x}} | |
161 | ||
162 | Convert device X coordinate to relative logical coordinate, using the current | |
163 | mapping 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 | ||
169 | Converts device Y coordinate to logical coordinate, using the current | |
170 | mapping mode. | |
171 | ||
172 | \membersection{wxDC::DeviceToLogicalYRel}\label{wxdcdevicetologicalyrel} | |
173 | ||
174 | \func{wxCoord}{DeviceToLogicalYRel}{\param{wxCoord}{ y}} | |
175 | ||
176 | Convert device Y coordinate to relative logical coordinate, using the current | |
177 | mapping 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 | ||
183 | Draws an arc of a circle, centred on ({\it xc, yc}), with starting point ({\it x1, y1}) | |
184 | and ending at ({\it x2, y2}). The current pen is used for the outline | |
185 | and the current brush for filling the shape. | |
186 | ||
187 | The 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 | ||
193 | Draw a bitmap on the device context at the specified point. If {\it transparent} is TRUE and the bitmap has | |
194 | a transparency mask, the bitmap will be drawn transparently. | |
195 | ||
196 | When drawing a mono-bitmap, the current text foreground colour will be used to draw the foreground | |
197 | of 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 | ||
207 | Draws 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 | ||
213 | Draws an ellipse contained in the rectangle with the given top left corner, and with the | |
214 | given size. The current pen is used for the outline and the current brush for | |
215 | filling 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 | ||
222 | Draws an arc of an ellipse. The current pen is used for drawing the arc and | |
223 | the 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 | |
226 | the ellipse. | |
227 | ||
228 | {\it width} and {\it height} specify the width and height of the rectangle that contains | |
229 | the ellipse. | |
230 | ||
231 | {\it start} and {\it end} specify the start and end of the arc relative to the three-o'clock | |
232 | position from the center of the rectangle. Angles are specified | |
233 | in degrees (360 is a complete circle). Positive values mean | |
234 | counter-clockwise motion. If {\it start} is equal to {\it end}, a | |
235 | complete 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 | ||
241 | Draw an icon on the display (does nothing if the device context is PostScript). | |
242 | This 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 | ||
248 | Draws a line from the first point to the second. The current pen is used | |
249 | for 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 | ||
257 | Draws lines using an array of {\it points} of size {\it n}, or list of | |
258 | pointers to points, adding the optional offset coordinate. The current | |
259 | pen is used for drawing the lines. The programmer is responsible for | |
260 | deleting the list of points. | |
261 | ||
262 | \pythonnote{The wxPython version of this method accepts a Python list | |
263 | of 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 | ||
277 | Draws a filled polygon using an array of {\it points} of size {\it n}, | |
278 | or list of pointers to points, adding the optional offset coordinate. | |
279 | ||
280 | The last argument specifies the fill rule: {\bf wxODDEVEN\_RULE} (the | |
281 | default) or {\bf wxWINDING\_RULE}. | |
282 | ||
283 | The current pen is used for drawing the outline, and the current brush | |
284 | for filling the shape. Using a transparent brush suppresses filling. | |
285 | The programmer is responsible for deleting the list of points. | |
286 | ||
287 | Note that wxWindows automatically closes the first and last points. | |
288 | ||
289 | \pythonnote{The wxPython version of this method accepts a Python list | |
290 | of 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 | ||
300 | Draws 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 | ||
306 | Draws a rectangle with the given top left corner, and with the given | |
307 | size. The current pen is used for the outline and the current brush | |
308 | for 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 | ||
314 | Draws 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 | ||
324 | Draws a rectangle with the given top left corner, and with the given | |
325 | size. The corners are quarter-circles using the given radius. The | |
326 | current pen is used for the outline and the current brush for filling | |
327 | the shape. | |
328 | ||
329 | If {\it radius} is positive, the value is assumed to be the | |
330 | radius of the rounded corner. If {\it radius} is negative, | |
331 | the absolute value is assumed to be the {\it proportion} of the smallest | |
332 | dimension of the rectangle. This means that the corner can be | |
333 | a sensible size relative to the size of the rectangle, and also avoids | |
334 | the strange effects X produces when the corners are too big for | |
335 | the rectangle. | |
336 | ||
337 | \membersection{wxDC::DrawSpline}\label{wxdcdrawspline} | |
338 | ||
339 | \func{void}{DrawSpline}{\param{wxList *}{points}} | |
340 | ||
341 | Draws a spline between all given control points, using the current | |
342 | pen. Doesn't delete the wxList and contents. The spline is drawn | |
343 | using a series of lines, using an algorithm taken from the X drawing | |
344 | program `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 | ||
348 | Draws a three-point spline using the current pen. | |
349 | ||
350 | \pythonnote{The wxPython version of this method accepts a Python list | |
351 | of 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 | ||
360 | Draws a text string at the specified point, using the current text font, | |
361 | and the current text foreground and background colours. | |
362 | ||
363 | The coordinates refer to the top-left corner of the rectangle bounding | |
364 | the string. See \helpref{wxDC::GetTextExtent}{wxdcgettextextent} for how | |
365 | to get the dimensions of a text string, which can be used to position the | |
366 | text more precisely. | |
367 | ||
368 | {\bf NB:} under wxGTK the current | |
369 | \helpref{logical function}{wxdcgetlogicalfunction} is used by this function | |
370 | but it is ignored by wxMSW. Thus, you should avoid using logical functions | |
371 | with this function in portable programs. | |
372 | ||
373 | \membersection{wxDC::EndDoc}\label{wxdcenddoc} | |
374 | ||
375 | \func{void}{EndDoc}{\void} | |
376 | ||
377 | Ends a document (only relevant when outputting to a printer). | |
378 | ||
379 | \membersection{wxDC::EndDrawing}\label{wxdcenddrawing} | |
380 | ||
381 | \func{void}{EndDrawing}{\void} | |
382 | ||
383 | Allows optimization of drawing code under MS Windows. Enclose | |
384 | drawing primitives between {\bf BeginDrawing} and {\bf EndDrawing}\rtfsp | |
385 | calls. | |
386 | ||
387 | \membersection{wxDC::EndPage}\label{wxdcendpage} | |
388 | ||
389 | \func{void}{EndPage}{\void} | |
390 | ||
391 | Ends 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 | ||
397 | Flood fills the device context starting from the given point, using | |
398 | the {\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 | ||
413 | Gets 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 | ||
419 | Returns 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 | ||
431 | Gets the current brush (see \helpref{wxDC::SetBrush}{wxdcsetbrush}). | |
432 | ||
433 | \membersection{wxDC::GetCharHeight}\label{wxdcgetcharheight} | |
434 | ||
435 | \func{wxCoord}{GetCharHeight}{\void} | |
436 | ||
437 | Gets the character height of the currently set font. | |
438 | ||
439 | \membersection{wxDC::GetCharWidth}\label{wxdcgetcharwidth} | |
440 | ||
441 | \func{wxCoord}{GetCharWidth}{\void} | |
442 | ||
443 | Gets 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 | ||
449 | Gets the rectangle surrounding the current clipping region. | |
450 | ||
451 | \pythonnote{No arguments are required and the four values defining the | |
452 | rectangle 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 | ||
463 | Gets the current font (see \helpref{wxDC::SetFont}{wxdcsetfont}). | |
464 | ||
465 | \membersection{wxDC::GetLogicalFunction}\label{wxdcgetlogicalfunction} | |
466 | ||
467 | \func{int}{GetLogicalFunction}{\void} | |
468 | ||
469 | Gets the current logical function (see \helpref{wxDC::SetLogicalFunction}{wxdcsetlogicalfunction}). | |
470 | ||
471 | \membersection{wxDC::GetMapMode}\label{wxdcgetmapmode} | |
472 | ||
473 | \func{int}{GetMapMode}{\void} | |
474 | ||
475 | Gets 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 | ||
481 | Returns TRUE if device context optimization is on. | |
482 | See \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 | ||
490 | Gets 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 | ||
496 | Sets {\it colour} to the colour at the specified location. Windows only; an X implementation | |
497 | is being worked on. Not available for wxPostScriptDC or wxMetafileDC. | |
498 | ||
499 | \pythonnote{For wxPython the wxColour value is returned and is not | |
500 | required as a parameter.} | |
501 | ||
502 | \perlnote{This method only takes the parameters {\tt x} and {\tt y} and returns | |
503 | a Wx::Colour value} | |
504 | ||
505 | \membersection{wxDC::GetSize}\label{wxdcgetsize} | |
506 | ||
507 | \func{void}{GetSize}{\param{wxCoord *}{width}, \param{wxCoord *}{height}} | |
508 | ||
509 | For a PostScript device context, this gets the maximum size of graphics | |
510 | drawn so far on the device context. | |
511 | ||
512 | For a Windows printer device context, this gets the horizontal and vertical | |
513 | resolution. It can be used to scale graphics to fit the page when using | |
514 | a Windows printer device context. For example, if {\it maxX} and {\it maxY}\rtfsp | |
515 | represent the maximum horizontal and vertical `pixel' values used in your | |
516 | application, the following code will scale the graphic to fit on the | |
517 | printer 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 | |
528 | implements 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 | ||
549 | Gets 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 | ||
556 | Gets 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 | |
558 | the total width and height respectively, {\it descent} is the | |
559 | dimension from the baseline of the font to the bottom of the | |
560 | descender, and {\it externalLeading} is any extra vertical space added | |
561 | to the font by the font designer (usually is zero). | |
562 | ||
563 | The optional parameter {\it font} specifies an alternative | |
564 | to the currently selected font: but note that this does not | |
565 | yet work under Windows, so you need to set a font for | |
566 | the device context first. | |
567 | ||
568 | See 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 | |
574 | 4-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 | ||
589 | Gets 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 | ||
596 | Gets 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 | ||
605 | Converts logical X coordinate to device coordinate, using the current | |
606 | mapping mode. | |
607 | ||
608 | \membersection{wxDC::LogicalToDeviceXRel}\label{wxdclogicaltodevicexrel} | |
609 | ||
610 | \func{wxCoord}{LogicalToDeviceXRel}{\param{wxCoord}{ x}} | |
611 | ||
612 | Converts logical X coordinate to relative device coordinate, using the current | |
613 | mapping 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 | ||
619 | Converts logical Y coordinate to device coordinate, using the current | |
620 | mapping mode. | |
621 | ||
622 | \membersection{wxDC::LogicalToDeviceYRel}\label{wxdclogicaltodeviceyrel} | |
623 | ||
624 | \func{wxCoord}{LogicalToDeviceYRel}{\param{wxCoord}{ y}} | |
625 | ||
626 | Converts logical Y coordinate to relative device coordinate, using the current | |
627 | mapping mode. Use this for converting a height, for example. | |
628 | ||
629 | \membersection{wxDC::MaxX}\label{wxdcmaxx} | |
630 | ||
631 | \func{wxCoord}{MaxX}{\void} | |
632 | ||
633 | Gets the maximum horizontal extent used in drawing commands so far. | |
634 | ||
635 | \membersection{wxDC::MaxY}\label{wxdcmaxy} | |
636 | ||
637 | \func{wxCoord}{MaxY}{\void} | |
638 | ||
639 | Gets the maximum vertical extent used in drawing commands so far. | |
640 | ||
641 | \membersection{wxDC::MinX}\label{wxdcminx} | |
642 | ||
643 | \func{wxCoord}{MinX}{\void} | |
644 | ||
645 | Gets the minimum horizontal extent used in drawing commands so far. | |
646 | ||
647 | \membersection{wxDC::MinY}\label{wxdcminy} | |
648 | ||
649 | \func{wxCoord}{MinY}{\void} | |
650 | ||
651 | Gets the minimum vertical extent used in drawing commands so far. | |
652 | ||
653 | \membersection{wxDC::Ok}\label{wxdcok} | |
654 | ||
655 | \func{bool}{Ok}{\void} | |
656 | ||
657 | Returns TRUE if the DC is ok to use. | |
658 | ||
659 | \membersection{wxDC::ResetBoundingBox}\label{wxdcresetboundingbox} | |
660 | ||
661 | \func{void}{ResetBoundingBox}{\void} | |
662 | ||
663 | Resets the bounding box: after a call to this function, the bounding box | |
664 | doesn'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 | ||
674 | Sets the device origin (i.e., the origin in pixels after scaling has been | |
675 | applied). | |
676 | ||
677 | This function may be useful in Windows printing | |
678 | operations for placing a graphic on a page. | |
679 | ||
680 | \membersection{wxDC::SetBackground}\label{wxdcsetbackground} | |
681 | ||
682 | \func{void}{SetBackground}{\param{const wxBrush\& }{brush}} | |
683 | ||
684 | Sets 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 | |
691 | whether 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 | ||
699 | Sets the clipping region for the DC. The clipping region is an area | |
700 | to which drawing is restricted. Possible uses for the clipping region are for clipping text | |
701 | or 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 | ||
711 | If this is a window DC or memory DC, assigns the given palette to the window | |
712 | or bitmap associated with the DC. If the argument is wxNullPalette, the current | |
713 | palette is selected out of the device context, and the original palette | |
714 | restored. | |
715 | ||
716 | See \helpref{wxPalette}{wxpalette} for further details. | |
717 | ||
718 | \membersection{wxDC::SetBrush}\label{wxdcsetbrush} | |
719 | ||
720 | \func{void}{SetBrush}{\param{const wxBrush\& }{brush}} | |
721 | ||
722 | Sets the current brush for the DC. | |
723 | ||
724 | If the argument is wxNullBrush, the current brush is selected out of the device | |
725 | context, and the original brush restored, allowing the current brush to | |
726 | be destroyed safely. | |
727 | ||
728 | See also \helpref{wxBrush}{wxbrush}. | |
729 | ||
730 | See also \helpref{wxMemoryDC}{wxmemorydc} for the interpretation of colours | |
731 | when drawing into a monochrome bitmap. | |
732 | ||
733 | \membersection{wxDC::SetFont}\label{wxdcsetfont} | |
734 | ||
735 | \func{void}{SetFont}{\param{const wxFont\& }{font}} | |
736 | ||
737 | Sets the current font for the DC. | |
738 | ||
739 | If the argument is wxNullFont, the current font is selected out of the device | |
740 | context, and the original font restored, allowing the current font to | |
741 | be destroyed safely. | |
742 | ||
743 | See also \helpref{wxFont}{wxfont}. | |
744 | ||
745 | \membersection{wxDC::SetLogicalFunction}\label{wxdcsetlogicalfunction} | |
746 | ||
747 | \func{void}{SetLogicalFunction}{\param{int}{ function}} | |
748 | ||
749 | Sets the current logical function for the device context. This determines how | |
750 | a source pixel (from a pen or brush colour, or source device context if | |
751 | using \helpref{wxDC::Blit}{wxdcblit}) combines with a destination pixel in the | |
752 | current device context. | |
753 | ||
754 | The possible values | |
755 | and their meaning in terms of source and destination pixel values are | |
756 | as follows: | |
757 | ||
758 | \begin{verbatim} | |
759 | wxAND src AND dst | |
760 | wxAND_INVERT (NOT src) AND dst | |
761 | wxAND_REVERSE src AND (NOT dst) | |
762 | wxCLEAR 0 | |
763 | wxCOPY src | |
764 | wxEQUIV (NOT src) XOR dst | |
765 | wxINVERT NOT dst | |
766 | wxNAND (NOT src) OR (NOT dst) | |
767 | wxNOR (NOT src) AND (NOT dst) | |
768 | wxNO_OP dst | |
769 | wxOR src OR dst | |
770 | wxOR_INVERT (NOT src) OR dst | |
771 | wxOR_REVERSE src OR (NOT dst) | |
772 | wxSET 1 | |
773 | wxSRC_INVERT NOT src | |
774 | wxXOR src XOR dst | |
775 | \end{verbatim} | |
776 | ||
777 | The default is wxCOPY, which simply draws with the current colour. | |
778 | The others combine the current colour and the background using a | |
779 | logical operation. wxINVERT is commonly used for drawing rubber bands or | |
780 | moving 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 | ||
786 | The {\it mapping mode} of the device context defines the unit of | |
787 | measurement used to convert logical units to device units. Note that | |
788 | in X, text drawing isn't handled consistently with the mapping mode; a | |
789 | font is always specified in point size. However, setting the {\it | |
790 | user scale} (see \helpref{wxDC::SetUserScale}{wxdcsetuserscale}) scales the text appropriately. In | |
791 | Windows, scaleable TrueType fonts are always used; in X, results depend | |
792 | on availability of fonts, but usually a reasonable match is found. | |
793 | ||
794 | Note that the coordinate origin should ideally be selectable, but for | |
795 | now is always at the top left of the screen/printer. | |
796 | ||
797 | Drawing to a Windows printer device context under UNIX | |
798 | uses the current mapping mode, but mapping mode is currently ignored for | |
799 | PostScript output. | |
800 | ||
801 | The 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 | ||
816 | If {\it optimize} is TRUE (the default), this function sets optimization mode on. | |
817 | This currently means that under X, the device context will not try to set a pen or brush | |
818 | property if it is known to be set already. This approach can fall down | |
819 | if non-wxWindows code is using the same device context or window, for example | |
820 | when the window is a panel on which the windowing system draws panel items. | |
821 | The wxWindows device context 'memory' will now be out of step with reality. | |
822 | ||
823 | Setting optimization off, drawing, then setting it back on again, is a trick | |
824 | that must occasionally be employed. | |
825 | ||
826 | \membersection{wxDC::SetPen}\label{wxdcsetpen} | |
827 | ||
828 | \func{void}{SetPen}{\param{const wxPen\& }{pen}} | |
829 | ||
830 | Sets the current pen for the DC. | |
831 | ||
832 | If the argument is wxNullPen, the current pen is selected out of the device | |
833 | context, and the original pen restored. | |
834 | ||
835 | See also \helpref{wxMemoryDC}{wxmemorydc} for the interpretation of colours | |
836 | when drawing into a monochrome bitmap. | |
837 | ||
838 | \membersection{wxDC::SetTextBackground}\label{wxdcsettextbackground} | |
839 | ||
840 | \func{void}{SetTextBackground}{\param{const wxColour\& }{colour}} | |
841 | ||
842 | Sets 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 | ||
848 | Sets the current text foreground colour for the DC. | |
849 | ||
850 | See also \helpref{wxMemoryDC}{wxmemorydc} for the interpretation of colours | |
851 | when drawing into a monochrome bitmap. | |
852 | ||
853 | \membersection{wxDC::SetUserScale}\label{wxdcsetuserscale} | |
854 | ||
855 | \func{void}{SetUserScale}{\param{double}{ xScale}, \param{double}{ yScale}} | |
856 | ||
857 | Sets 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 | ||
864 | Starts a document (only relevant when outputting to a printer). | |
865 | Message is a message to show whilst printing. | |
866 | ||
867 | \membersection{wxDC::StartPage}\label{wxdcstartpage} | |
868 | ||
869 | \func{bool}{StartPage}{\void} | |
870 | ||
871 | Starts a document page (only relevant when outputting to a printer). | |
872 |