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1 /////////////////////////////////////////////////////////////////////////////
2 // Name: dc.h
3 // Purpose: interface of wxDC
4 // Author: wxWidgets team
5 // RCS-ID: $Id$
6 // Licence: wxWindows license
7 /////////////////////////////////////////////////////////////////////////////
8
9 /**
10 @class wxDC
11
12 A wxDC is a @e "device context" onto which graphics and text can be drawn.
13 It is intended to represent different output devices and offers a common
14 abstract API for drawing on any of them.
15
16 wxWidgets offers an alternative drawing API based on the modern drawing
17 backends GDI+, CoreGraphics and Cairo. See wxGraphicsContext, wxGraphicsRenderer
18 and related classes. There is also a wxGCDC linking the APIs by offering
19 the wxDC API ontop of a wxGraphicsContext.
20
21 wxDC is an abstract base class and cannot be created directly.
22 Use wxPaintDC, wxClientDC, wxWindowDC, wxScreenDC, wxMemoryDC or
23 wxPrinterDC. Notice that device contexts which are associated with windows
24 (i.e. wxClientDC, wxWindowDC and wxPaintDC) use the window font and colours
25 by default (starting with wxWidgets 2.9.0) but the other device context
26 classes use system-default values so you always must set the appropriate
27 fonts and colours before using them.
28
29 In addition to the versions of the methods documented below, there
30 are also versions which accept single wxPoint parameter instead
31 of the two wxCoord ones or wxPoint and wxSize instead of the four
32 wxCoord parameters.
33
34 Beginning with wxWidgets 2.9.0 the entire wxDC code has been
35 reorganized. All platform dependent code (actually all drawing code)
36 has been moved into backend classes which derive from a common
37 wxDCImpl class. The user-visible classes such as wxClientDC and
38 wxPaintDC merely forward all calls to the backend implementation.
39
40 On Mac OS X colours with alpha channel are supported. Instances wxPen
41 or wxBrush that are built from wxColour use the colour's alpha values
42 when stroking or filling.
43
44 @library{wxcore}
45 @category{dc,gdi}
46
47 @see @ref overview_dc, wxGraphicsContext
48
49 @todo Precise definition of default/initial state.
50 @todo Pixelwise definition of operations (e.g. last point of a line not
51 drawn).
52 @todo Coordinates: state clearly which type of coordinates are returned by
53 the various Get*Point() or similar functions - often they are client
54 coordinates but not always.
55 */
56 class wxDC : public wxObject
57 {
58 public:
59 /**
60 Copy from a source DC to this DC, specifying the destination
61 coordinates, size of area to copy, source DC, source coordinates,
62 logical function, whether to use a bitmap mask, and mask source
63 position.
64
65 @param xdest
66 Destination device context x position.
67 @param ydest
68 Destination device context y position.
69 @param width
70 Width of source area to be copied.
71 @param height
72 Height of source area to be copied.
73 @param source
74 Source device context.
75 @param xsrc
76 Source device context x position.
77 @param ysrc
78 Source device context y position.
79 @param logicalFunc
80 Logical function to use, see SetLogicalFunction().
81 @param useMask
82 If @true, Blit does a transparent blit using the mask that is
83 associated with the bitmap selected into the source device context.
84 The Windows implementation does the following if MaskBlt cannot be
85 used:
86 <ol>
87 <li>Creates a temporary bitmap and copies the destination area into
88 it.</li>
89 <li>Copies the source area into the temporary bitmap using the
90 specified logical function.</li>
91 <li>Sets the masked area in the temporary bitmap to BLACK by ANDing
92 the mask bitmap with the temp bitmap with the foreground colour
93 set to WHITE and the bg colour set to BLACK.</li>
94 <li>Sets the unmasked area in the destination area to BLACK by
95 ANDing the mask bitmap with the destination area with the
96 foreground colour set to BLACK and the background colour set to
97 WHITE.</li>
98 <li>ORs the temporary bitmap with the destination area.</li>
99 <li>Deletes the temporary bitmap.</li>
100 </ol>
101 This sequence of operations ensures that the source's transparent
102 area need not be black, and logical functions are supported.
103 @n @b Note: on Windows, blitting with masks can be speeded up
104 considerably by compiling wxWidgets with the wxUSE_DC_CACHE option
105 enabled. You can also influence whether MaskBlt or the explicit
106 mask blitting code above is used, by using wxSystemOptions and
107 setting the @c no-maskblt option to 1.
108 @param xsrcMask
109 Source x position on the mask. If both xsrcMask and ysrcMask are
110 @c -1, xsrc and ysrc will be assumed for the mask source position.
111 Currently only implemented on Windows.
112 @param ysrcMask
113 Source y position on the mask. If both xsrcMask and ysrcMask are
114 @c -1, xsrc and ysrc will be assumed for the mask source position.
115 Currently only implemented on Windows.
116
117 @remarks There is partial support for Blit() in wxPostScriptDC, under X.
118
119 @see StretchBlit(), wxMemoryDC, wxBitmap, wxMask
120 */
121 bool Blit(wxCoord xdest, wxCoord ydest, wxCoord width,
122 wxCoord height, wxDC* source, wxCoord xsrc, wxCoord ysrc,
123 wxRasterOperationMode logicalFunc = wxCOPY, bool useMask = false,
124 wxCoord xsrcMask = wxDefaultCoord, wxCoord ysrcMask = wxDefaultCoord);
125
126 /**
127 Adds the specified point to the bounding box which can be retrieved
128 with MinX(), MaxX() and MinY(), MaxY() functions.
129
130 @see ResetBoundingBox()
131 */
132 void CalcBoundingBox(wxCoord x, wxCoord y);
133
134 /**
135 Clears the device context using the current background brush.
136 */
137 void Clear();
138
139 /**
140 Displays a cross hair using the current pen. This is a vertical and
141 horizontal line the height and width of the window, centred on the
142 given point.
143 */
144 void CrossHair(wxCoord x, wxCoord y);
145
146 /**
147 Destroys the current clipping region so that none of the DC is clipped.
148
149 @see SetClippingRegion()
150 */
151 void DestroyClippingRegion();
152
153 /**
154 Convert device X coordinate to logical coordinate, using the current
155 mapping mode, user scale factor, device origin and axis orientation.
156 */
157 wxCoord DeviceToLogicalX(wxCoord x) const;
158
159 /**
160 Convert device X coordinate to relative logical coordinate, using the
161 current mapping mode and user scale factor but ignoring the
162 axis orientation. Use this for converting a width, for example.
163 */
164 wxCoord DeviceToLogicalXRel(wxCoord x) const;
165
166 /**
167 Converts device Y coordinate to logical coordinate, using the current
168 mapping mode, user scale factor, device origin and axis orientation.
169 */
170 wxCoord DeviceToLogicalY(wxCoord y) const;
171
172 /**
173 Convert device Y coordinate to relative logical coordinate, using the
174 current mapping mode and user scale factor but ignoring the
175 axis orientation. Use this for converting a height, for example.
176 */
177 wxCoord DeviceToLogicalYRel(wxCoord y) const;
178
179 /**
180 Draws an arc of a circle, centred on (@a xc, @a yc), with starting
181 point (@a x1, @a y1) and ending at (@a x2, @a y2). The current pen is
182 used for the outline and the current brush for filling the shape.
183
184 The arc is drawn in a counter-clockwise direction from the start point
185 to the end point.
186 */
187 void DrawArc(wxCoord x1, wxCoord y1, wxCoord x2, wxCoord y2,
188 wxCoord xc, wxCoord yc);
189
190 /**
191 Draw a bitmap on the device context at the specified point. If
192 @a transparent is @true and the bitmap has a transparency mask, the
193 bitmap will be drawn transparently.
194
195 When drawing a mono-bitmap, the current text foreground colour will be
196 used to draw the foreground of the bitmap (all bits set to 1), and the
197 current text background colour to draw the background (all bits set to
198 0).
199
200 @see SetTextForeground(), SetTextBackground(), wxMemoryDC
201 */
202 void DrawBitmap(const wxBitmap& bitmap, wxCoord x, wxCoord y,
203 bool useMask = false);
204
205 //@{
206 /**
207 Draws a check mark inside the given rectangle.
208 */
209 void DrawCheckMark(wxCoord x, wxCoord y, wxCoord width, wxCoord height);
210 void DrawCheckMark(const wxRect& rect);
211 //@}
212
213 //@{
214 /**
215 Draws a circle with the given centre and radius.
216
217 @see DrawEllipse()
218 */
219 void DrawCircle(wxCoord x, wxCoord y, wxCoord radius);
220 void DrawCircle(const wxPoint& pt, wxCoord radius);
221 //@}
222
223 //@{
224 /**
225 Draws an ellipse contained in the rectangle specified either with the
226 given top left corner and the given size or directly. The current pen
227 is used for the outline and the current brush for filling the shape.
228
229 @see DrawCircle()
230 */
231 void DrawEllipse(wxCoord x, wxCoord y, wxCoord width, wxCoord height);
232 void DrawEllipse(const wxPoint& pt, const wxSize& size);
233 void DrawEllipse(const wxRect& rect);
234 //@}
235
236 /**
237 Draws an arc of an ellipse. The current pen is used for drawing the arc
238 and the current brush is used for drawing the pie.
239
240 @a x and @a y specify the x and y coordinates of the upper-left corner
241 of the rectangle that contains the ellipse.
242
243 @a width and @a height specify the width and height of the rectangle
244 that contains the ellipse.
245
246 @a start and @a end specify the start and end of the arc relative to
247 the three-o'clock position from the center of the rectangle. Angles are
248 specified in degrees (360 is a complete circle). Positive values mean
249 counter-clockwise motion. If @a start is equal to @e end, a complete
250 ellipse will be drawn.
251 */
252 void DrawEllipticArc(wxCoord x, wxCoord y, wxCoord width, wxCoord height,
253 double start, double end);
254
255 /**
256 Draw an icon on the display (does nothing if the device context is
257 PostScript). This can be the simplest way of drawing bitmaps on a
258 window.
259 */
260 void DrawIcon(const wxIcon& icon, wxCoord x, wxCoord y);
261
262 //@{
263 /**
264 Draw optional bitmap and the text into the given rectangle and aligns
265 it as specified by alignment parameter; it also will emphasize the
266 character with the given index if it is != -1 and return the bounding
267 rectangle if required.
268 */
269 virtual void DrawLabel(const wxString& text, const wxBitmap& image,
270 const wxRect& rect,
271 int alignment = wxALIGN_LEFT | wxALIGN_TOP,
272 int indexAccel = -1, wxRect* rectBounding = NULL);
273 void DrawLabel(const wxString& text, const wxRect& rect,
274 int alignment = wxALIGN_LEFT | wxALIGN_TOP,
275 int indexAccel = -1);
276 //@}
277
278 /**
279 Draws a line from the first point to the second. The current pen is
280 used for drawing the line. Note that the point (@a x2, @a y2) is not
281 part of the line and is not drawn by this function (this is consistent
282 with the behaviour of many other toolkits).
283 */
284 void DrawLine(wxCoord x1, wxCoord y1, wxCoord x2, wxCoord y2);
285
286 /**
287 Draws lines using an array of points of size @a n adding the optional
288 offset coordinate. The current pen is used for drawing the lines.
289
290 @beginWxPythonOnly
291 The wxPython version of this method accepts a Python list of wxPoint
292 objects.
293 @endWxPythonOnly
294 */
295 void DrawLines(int n, wxPoint points[], wxCoord xoffset = 0,
296 wxCoord yoffset = 0);
297 /**
298 This method uses a list of wxPoints, adding the optional offset
299 coordinate. The programmer is responsible for deleting the list of
300 points.
301
302 @beginWxPythonOnly
303 The wxPython version of this method accepts a Python list of wxPoint
304 objects.
305 @endWxPythonOnly
306 */
307 void DrawLines(const wxPointList* points,
308 wxCoord xoffset = 0, wxCoord yoffset = 0);
309
310 /**
311 Draws a point using the color of the current pen. Note that the other
312 properties of the pen are not used, such as width.
313 */
314 void DrawPoint(wxCoord x, wxCoord y);
315
316 /**
317 Draws a filled polygon using an array of points of size @a n, adding
318 the optional offset coordinate. The first and last points are
319 automatically closed.
320
321 The last argument specifies the fill rule: @b wxODDEVEN_RULE (the
322 default) or @b wxWINDING_RULE.
323
324 The current pen is used for drawing the outline, and the current brush
325 for filling the shape. Using a transparent brush suppresses filling.
326 */
327 void DrawPolygon(int n, wxPoint points[], wxCoord xoffset = 0,
328 wxCoord yoffset = 0,
329 wxPolygonFillMode fill_style = wxODDEVEN_RULE);
330 /**
331 This method draws a filled polygon using a list of wxPoints, adding the
332 optional offset coordinate. The first and last points are automatically
333 closed.
334
335 The last argument specifies the fill rule: @b wxODDEVEN_RULE (the
336 default) or @b wxWINDING_RULE.
337
338 The current pen is used for drawing the outline, and the current brush
339 for filling the shape. Using a transparent brush suppresses filling.
340
341 The programmer is responsible for deleting the list of points.
342
343 @beginWxPythonOnly
344 The wxPython version of this method accepts a Python list of wxPoint
345 objects.
346 @endWxPythonOnly
347 */
348 void DrawPolygon(const wxPointList* points,
349 wxCoord xoffset = 0, wxCoord yoffset = 0,
350 wxPolygonFillMode fill_style = wxODDEVEN_RULE);
351
352 /**
353 Draws two or more filled polygons using an array of @a points, adding
354 the optional offset coordinates.
355
356 Notice that for the platforms providing a native implementation of this
357 function (Windows and PostScript-based wxDC currently), this is more
358 efficient than using DrawPolygon() in a loop.
359
360 @a n specifies the number of polygons to draw, the array @e count of
361 size @a n specifies the number of points in each of the polygons in the
362 @a points array.
363
364 The last argument specifies the fill rule: @b wxODDEVEN_RULE (the
365 default) or @b wxWINDING_RULE.
366
367 The current pen is used for drawing the outline, and the current brush
368 for filling the shape. Using a transparent brush suppresses filling.
369
370 The polygons maybe disjoint or overlapping. Each polygon specified in a
371 call to DrawPolyPolygon() must be closed. Unlike polygons created by
372 the DrawPolygon() member function, the polygons created by this
373 method are not closed automatically.
374
375 @beginWxPythonOnly
376 Not implemented yet.
377 @endWxPythonOnly
378 */
379 void DrawPolyPolygon(int n, int count[], wxPoint points[],
380 wxCoord xoffset = 0, wxCoord yoffset = 0,
381 wxPolygonFillMode fill_style = wxODDEVEN_RULE);
382
383 /**
384 Draws a rectangle with the given top left corner, and with the given
385 size. The current pen is used for the outline and the current brush
386 for filling the shape.
387 */
388 void DrawRectangle(wxCoord x, wxCoord y, wxCoord width, wxCoord height);
389
390 /**
391 Draws the text rotated by @a angle degrees.
392
393 @note Under Win9x only TrueType fonts can be drawn by this function. In
394 particular, a font different from @c wxNORMAL_FONT should be used
395 as the latter is not a TrueType font. @c wxSWISS_FONT is an
396 example of a font which is.
397
398 @see DrawText()
399 */
400 void DrawRotatedText(const wxString& text, wxCoord x, wxCoord y,
401 double angle);
402
403 /**
404 Draws a rectangle with the given top left corner, and with the given
405 size. The corners are quarter-circles using the given radius. The
406 current pen is used for the outline and the current brush for filling
407 the shape.
408
409 If @a radius is positive, the value is assumed to be the radius of the
410 rounded corner. If @a radius is negative, the absolute value is assumed
411 to be the @e proportion of the smallest dimension of the rectangle.
412 This means that the corner can be a sensible size relative to the size
413 of the rectangle, and also avoids the strange effects X produces when
414 the corners are too big for the rectangle.
415 */
416 void DrawRoundedRectangle(wxCoord x, wxCoord y, wxCoord width,
417 wxCoord height, double radius);
418
419 //@{
420 /**
421 Draws a spline between all given points using the current pen.
422
423 @beginWxPythonOnly
424 The wxPython version of this method accepts a Python list of wxPoint
425 objects.
426 @endWxPythonOnly
427 */
428 void DrawSpline(int n, wxPoint points[]);
429 void DrawSpline(const wxPointList* points);
430 void DrawSpline(wxCoord x1, wxCoord y1, wxCoord x2, wxCoord y2,
431 wxCoord x3, wxCoord y3);
432 //@}
433
434 /**
435 Draws a text string at the specified point, using the current text
436 font, and the current text foreground and background colours.
437
438 The coordinates refer to the top-left corner of the rectangle bounding
439 the string. See GetTextExtent() for how to get the dimensions of a text
440 string, which can be used to position the text more precisely.
441
442 @note The current @ref GetLogicalFunction() "logical function" is
443 ignored by this function.
444 */
445 void DrawText(const wxString& text, wxCoord x, wxCoord y);
446
447 /**
448 Ends a document (only relevant when outputting to a printer).
449 */
450 void EndDoc();
451
452 /**
453 Ends a document page (only relevant when outputting to a printer).
454 */
455 void EndPage();
456
457 /**
458 Flood fills the device context starting from the given point, using
459 the current brush colour, and using a style:
460
461 - wxFLOOD_SURFACE: The flooding occurs until a colour other than the
462 given colour is encountered.
463 - wxFLOOD_BORDER: The area to be flooded is bounded by the given
464 colour.
465
466 @return @false if the operation failed.
467
468 @note The present implementation for non-Windows platforms may fail to
469 find colour borders if the pixels do not match the colour
470 exactly. However the function will still return @true.
471 */
472 bool FloodFill(wxCoord x, wxCoord y, const wxColour& colour,
473 wxFloodFillStyle style = wxFLOOD_SURFACE);
474
475 /**
476 Gets the brush used for painting the background.
477
478 @see wxDC::SetBackground()
479 */
480 const wxBrush& GetBackground() const;
481
482 /**
483 Returns the current background mode: @c wxSOLID or @c wxTRANSPARENT.
484
485 @see SetBackgroundMode()
486 */
487 int GetBackgroundMode() const;
488
489 /**
490 Gets the current brush.
491
492 @see wxDC::SetBrush()
493 */
494 const wxBrush& GetBrush() const;
495
496 /**
497 Gets the character height of the currently set font.
498 */
499 wxCoord GetCharHeight() const;
500
501 /**
502 Gets the average character width of the currently set font.
503 */
504 wxCoord GetCharWidth() const;
505
506 /**
507 Gets the rectangle surrounding the current clipping region.
508
509 @beginWxPythonOnly
510 No arguments are required and the four values defining the rectangle
511 are returned as a tuple.
512 @endWxPythonOnly
513 */
514 void GetClippingBox(wxCoord *x, wxCoord *y, wxCoord *width, wxCoord *height) const;
515
516 /**
517 Returns the depth (number of bits/pixel) of this DC.
518
519 @see wxDisplayDepth()
520 */
521 int GetDepth() const;
522
523 /**
524 Gets the current font. Notice that even although each device context
525 object has some default font after creation, this method would return a
526 wxNullFont initially and only after calling SetFont() a valid font is
527 returned.
528 */
529 const wxFont& GetFont() const;
530
531 /**
532 Gets the current layout direction of the device context. On platforms
533 where RTL layout is supported, the return value will either be
534 @c wxLayout_LeftToRight or @c wxLayout_RightToLeft. If RTL layout is
535 not supported, the return value will be @c wxLayout_Default.
536
537 @see SetLayoutDirection()
538 */
539 wxLayoutDirection GetLayoutDirection() const;
540
541 /**
542 Gets the current logical function.
543
544 @see SetLogicalFunction()
545 */
546 wxRasterOperationMode GetLogicalFunction() const;
547
548 /**
549 Gets the mapping mode for the device context.
550
551 @see SetMapMode()
552 */
553 wxMappingMode GetMapMode() const;
554
555 /**
556 Gets the dimensions of the string using the currently selected font.
557 @a string is the text string to measure, @e heightLine, if non @NULL,
558 is where to store the height of a single line.
559
560 The text extent is set in the given @a w and @a h pointers.
561
562 If the optional parameter @a font is specified and valid, then it is
563 used for the text extent calculation, otherwise the currently selected
564 font is used.
565
566 @note This function works with both single-line and multi-line strings.
567
568 @see wxFont, SetFont(), GetPartialTextExtents(), GetTextExtent()
569 */
570 void GetMultiLineTextExtent(const wxString& string, wxCoord* w,
571 wxCoord* h,
572 wxCoord* heightLine = NULL,
573 const wxFont* font = NULL) const;
574 /**
575 Gets the dimensions of the string using the currently selected font.
576 @a string is the text string to measure, @e heightLine, if non @NULL,
577 is where to store the height of a single line.
578
579 @return The text extent as a wxSize object.
580
581 @note This function works with both single-line and multi-line strings.
582
583 @see wxFont, SetFont(), GetPartialTextExtents(), GetTextExtent()
584 */
585 wxSize GetMultiLineTextExtent(const wxString& string) const;
586
587 /**
588 Fills the @a widths array with the widths from the beginning of @a text
589 to the corresponding character of @a text. The generic version simply
590 builds a running total of the widths of each character using
591 GetTextExtent(), however if the various platforms have a native API
592 function that is faster or more accurate than the generic
593 implementation then it should be used instead.
594
595 @beginWxPythonOnly
596 This method only takes the @a text parameter and returns a Python list
597 of integers.
598 @endWxPythonOnly
599
600 @see GetMultiLineTextExtent(), GetTextExtent()
601 */
602 bool GetPartialTextExtents(const wxString& text,
603 wxArrayInt& widths) const;
604
605 /**
606 Gets the current pen.
607
608 @see SetPen()
609 */
610 const wxPen& GetPen() const;
611
612 /**
613 Gets in @a colour the colour at the specified location. Not available
614 for wxPostScriptDC or wxMetafileDC.
615
616 @note Setting a pixel can be done using DrawPoint().
617
618 @beginWxPythonOnly
619 The wxColour value is returned and is not required as a parameter.
620 @endWxPythonOnly
621 */
622 bool GetPixel(wxCoord x, wxCoord y, wxColour* colour) const;
623
624 /**
625 Returns the resolution of the device in pixels per inch.
626 */
627 wxSize GetPPI() const;
628
629 //@{
630 /**
631 This gets the horizontal and vertical resolution in device units. It
632 can be used to scale graphics to fit the page.
633
634 For example, if @e maxX and @e maxY represent the maximum horizontal
635 and vertical 'pixel' values used in your application, the following
636 code will scale the graphic to fit on the printer page:
637
638 @code
639 wxCoord w, h;
640 dc.GetSize(&w, &h);
641 double scaleX = (double)(maxX / w);
642 double scaleY = (double)(maxY / h);
643 dc.SetUserScale(min(scaleX, scaleY),min(scaleX, scaleY));
644 @endcode
645
646 @beginWxPythonOnly
647 In place of a single overloaded method name, wxPython implements the
648 following methods:
649 - GetSize() - Returns a wxSize.
650 - GetSizeWH() - Returns a 2-tuple (width, height).
651 @endWxPythonOnly
652 */
653 void GetSize(wxCoord* width, wxCoord* height) const;
654 const wxSize GetSize() const;
655 //@}
656
657 //@{
658 /**
659 Returns the horizontal and vertical resolution in millimetres.
660 */
661 void GetSizeMM(wxCoord* width, wxCoord* height) const;
662 const wxSize GetSizeMM() const;
663 //@}
664
665 /**
666 Gets the current text background colour.
667
668 @see SetTextBackground()
669 */
670 const wxColour& GetTextBackground() const;
671
672 //@{
673 /**
674 Gets the dimensions of the string using the currently selected font.
675 @a string is the text string to measure, @a descent is the dimension
676 from the baseline of the font to the bottom of the descender, and
677 @a externalLeading is any extra vertical space added to the font by the
678 font designer (usually is zero).
679
680 The text extent is returned in @a w and @a h pointers or as a wxSize
681 object depending on which version of this function is used.
682
683 If the optional parameter @a font is specified and valid, then it is
684 used for the text extent calculation. Otherwise the currently selected
685 font is.
686
687 @note This function only works with single-line strings.
688
689 @beginWxPythonOnly
690 The following methods are implemented in wxPython:
691 - GetTextExtent(string) - Returns a 2-tuple, (width, height).
692 - GetFullTextExtent(string, font=NULL) -
693 Returns a 4-tuple, (width, height, descent, externalLeading).
694 @endWxPythonOnly
695
696 @see wxFont, SetFont(), GetPartialTextExtents(),
697 GetMultiLineTextExtent()
698 */
699 void GetTextExtent(const wxString& string, wxCoord* w, wxCoord* h,
700 wxCoord* descent = NULL,
701 wxCoord* externalLeading = NULL,
702 const wxFont* font = NULL) const;
703 const wxSize GetTextExtent(const wxString& string) const;
704 //@}
705
706 /**
707 Gets the current text foreground colour.
708
709 @see SetTextForeground()
710 */
711 const wxColour& GetTextForeground() const;
712
713 /**
714 Gets the current user scale factor.
715
716 @see SetUserScale()
717 */
718 void GetUserScale(double* x, double* y) const;
719
720 //@{
721 /**
722 Fill the area specified by rect with a radial gradient, starting from
723 @a initialColour at the centre of the circle and fading to
724 @a destColour on the circle outside.
725
726 @a circleCenter are the relative coordinates of centre of the circle in
727 the specified @e rect. If not specified, the circle is placed at the
728 centre of rect.
729
730 @note Currently this function is very slow, don't use it for real-time
731 drawing.
732 */
733 void GradientFillConcentric(const wxRect& rect,
734 const wxColour& initialColour,
735 const wxColour& destColour);
736 void GradientFillConcentric(const wxRect& rect,
737 const wxColour& initialColour,
738 const wxColour& destColour,
739 const wxPoint& circleCenter);
740 //@}
741
742 /**
743 Fill the area specified by @a rect with a linear gradient, starting
744 from @a initialColour and eventually fading to @e destColour. The
745 @a nDirection specifies the direction of the colour change, default is
746 to use @a initialColour on the left part of the rectangle and
747 @a destColour on the right one.
748 */
749 void GradientFillLinear(const wxRect& rect, const wxColour& initialColour,
750 const wxColour& destColour,
751 wxDirection nDirection = wxRIGHT);
752
753 /**
754 Returns @true if the DC is ok to use.
755 */
756 bool IsOk() const;
757
758 /**
759 Converts logical X coordinate to device coordinate, using the current
760 mapping mode, user scale factor, device origin and axis orientation.
761 */
762 wxCoord LogicalToDeviceX(wxCoord x) const;
763
764 /**
765 Converts logical X coordinate to relative device coordinate, using the
766 current mapping mode and user scale factor but ignoring the
767 axis orientation. Use this for converting a width, for example.
768 */
769 wxCoord LogicalToDeviceXRel(wxCoord x) const;
770
771 /**
772 Converts logical Y coordinate to device coordinate, using the current
773 mapping mode, user scale factor, device origin and axis orientation.
774 */
775 wxCoord LogicalToDeviceY(wxCoord y) const;
776
777 /**
778 Converts logical Y coordinate to relative device coordinate, using the
779 current mapping mode and user scale factor but ignoring the
780 axis orientation. Use this for converting a height, for example.
781 */
782 wxCoord LogicalToDeviceYRel(wxCoord y) const;
783
784 /**
785 Gets the maximum horizontal extent used in drawing commands so far.
786 */
787 wxCoord MaxX() const;
788
789 /**
790 Gets the maximum vertical extent used in drawing commands so far.
791 */
792 wxCoord MaxY() const;
793
794 /**
795 Gets the minimum horizontal extent used in drawing commands so far.
796 */
797 wxCoord MinX() const;
798
799 /**
800 Gets the minimum vertical extent used in drawing commands so far.
801 */
802 wxCoord MinY() const;
803
804 /**
805 Resets the bounding box: after a call to this function, the bounding
806 box doesn't contain anything.
807
808 @see CalcBoundingBox()
809 */
810 void ResetBoundingBox();
811
812 /**
813 Sets the x and y axis orientation (i.e., the direction from lowest to
814 highest values on the axis). The default orientation is x axis from
815 left to right and y axis from top down.
816
817 @param xLeftRight
818 True to set the x axis orientation to the natural left to right
819 orientation, @false to invert it.
820 @param yBottomUp
821 True to set the y axis orientation to the natural bottom up
822 orientation, @false to invert it.
823 */
824 void SetAxisOrientation(bool xLeftRight, bool yBottomUp);
825
826 /**
827 Sets the current background brush for the DC.
828 */
829 void SetBackground(const wxBrush& brush);
830
831 /**
832 @a mode may be one of wxSOLID and wxTRANSPARENT. This setting
833 determines whether text will be drawn with a background colour or not.
834 */
835 void SetBackgroundMode(int mode);
836
837 /**
838 Sets the current brush for the DC.
839
840 If the argument is wxNullBrush, the current brush is selected out of
841 the device context (leaving wxDC without any valid brush), allowing the
842 current brush to be destroyed safely.
843
844 @see wxBrush, wxMemoryDC (for the interpretation of colours when
845 drawing into a monochrome bitmap)
846 */
847 void SetBrush(const wxBrush& brush);
848
849 //@{
850 /**
851 Sets the clipping region for this device context to the intersection of
852 the given region described by the parameters of this method and the
853 previously set clipping region. You should call DestroyClippingRegion()
854 if you want to set the clipping region exactly to the region specified.
855
856 The clipping region is an area to which drawing is restricted. Possible
857 uses for the clipping region are for clipping text or for speeding up
858 window redraws when only a known area of the screen is damaged.
859
860 @see DestroyClippingRegion(), wxRegion
861 */
862 void SetClippingRegion(wxCoord x, wxCoord y, wxCoord width,
863 wxCoord height);
864 void SetClippingRegion(const wxPoint& pt, const wxSize& sz);
865 void SetClippingRegion(const wxRect& rect);
866 //@}
867
868 /**
869 Sets the clipping region for this device context.
870
871 Unlike SetClippingRegion(), this function works with physical
872 coordinates and not with the logical ones.
873 */
874 void SetDeviceClippingRegion(const wxRegion& region);
875
876 /**
877 Sets the device origin (i.e., the origin in pixels after scaling has
878 been applied). This function may be useful in Windows printing
879 operations for placing a graphic on a page.
880 */
881 void SetDeviceOrigin(wxCoord x, wxCoord y);
882
883 /**
884 Sets the current font for the DC. It must be a valid font, in
885 particular you should not pass wxNullFont to this method.
886
887 @see wxFont
888 */
889 void SetFont(const wxFont& font);
890
891 /**
892 Sets the current layout direction for the device context. @a dir may be
893 either @c wxLayout_Default, @c wxLayout_LeftToRight or
894 @c wxLayout_RightToLeft.
895
896 @see GetLayoutDirection()
897 */
898 void SetLayoutDirection(wxLayoutDirection dir);
899
900 /**
901 Sets the current logical function for the device context. This
902 determines how a source pixel (from a pen or brush colour, or source
903 device context if using Blit()) combines with a destination pixel in
904 the current device context.
905 Text drawing is not affected by this function.
906
907 The possible values and their meaning in terms of source and
908 destination pixel values are as follows:
909
910 @verbatim
911 wxAND src AND dst
912 wxAND_INVERT (NOT src) AND dst
913 wxAND_REVERSE src AND (NOT dst)
914 wxCLEAR 0
915 wxCOPY src
916 wxEQUIV (NOT src) XOR dst
917 wxINVERT NOT dst
918 wxNAND (NOT src) OR (NOT dst)
919 wxNOR (NOT src) AND (NOT dst)
920 wxNO_OP dst
921 wxOR src OR dst
922 wxOR_INVERT (NOT src) OR dst
923 wxOR_REVERSE src OR (NOT dst)
924 wxSET 1
925 wxSRC_INVERT NOT src
926 wxXOR src XOR dst
927 @endverbatim
928
929 The default is wxCOPY, which simply draws with the current colour. The
930 others combine the current colour and the background using a logical
931 operation. wxINVERT is commonly used for drawing rubber bands or moving
932 outlines, since drawing twice reverts to the original colour.
933 */
934 void SetLogicalFunction(wxRasterOperationMode function);
935
936 /**
937 The mapping mode of the device context defines the unit of measurement
938 used to convert logical units to device units. Note that in X, text
939 drawing isn't handled consistently with the mapping mode; a font is
940 always specified in point size. However, setting the user scale (see
941 SetUserScale()) scales the text appropriately. In Windows, scalable
942 TrueType fonts are always used; in X, results depend on availability of
943 fonts, but usually a reasonable match is found.
944
945 The coordinate origin is always at the top left of the screen/printer.
946
947 Drawing to a Windows printer device context uses the current mapping
948 mode, but mapping mode is currently ignored for PostScript output.
949
950 The mapping mode can be one of the following:
951 - wxMM_TWIPS: Each logical unit is 1/20 of a point, or 1/1440 of an
952 inch.
953 - wxMM_POINTS: Each logical unit is a point, or 1/72 of an inch.
954 - wxMM_METRIC: Each logical unit is 1 mm.
955 - wxMM_LOMETRIC: Each logical unit is 1/10 of a mm.
956 - wxMM_TEXT: Each logical unit is 1 device pixel.
957 */
958 void SetMapMode(wxMappingMode mode);
959
960 /**
961 If this is a window DC or memory DC, assigns the given palette to the
962 window or bitmap associated with the DC. If the argument is
963 wxNullPalette, the current palette is selected out of the device
964 context, and the original palette restored.
965
966 @see wxPalette
967 */
968 void SetPalette(const wxPalette& palette);
969
970 /**
971 Sets the current pen for the DC. If the argument is wxNullPen, the
972 current pen is selected out of the device context (leaving wxDC without
973 any valid pen), allowing the current brush to be destroyed safely.
974
975 @see wxMemoryDC for the interpretation of colours when drawing into a
976 monochrome bitmap.
977 */
978 void SetPen(const wxPen& pen);
979
980 /**
981 Sets the current text background colour for the DC.
982 */
983 void SetTextBackground(const wxColour& colour);
984
985 /**
986 Sets the current text foreground colour for the DC.
987
988 @see wxMemoryDC for the interpretation of colours when drawing into a
989 monochrome bitmap.
990 */
991 void SetTextForeground(const wxColour& colour);
992
993 /**
994 Sets the user scaling factor, useful for applications which require
995 'zooming'.
996 */
997 void SetUserScale(double xScale, double yScale);
998
999 /**
1000 Starts a document (only relevant when outputting to a printer).
1001 @a message is a message to show while printing.
1002 */
1003 bool StartDoc(const wxString& message);
1004
1005 /**
1006 Starts a document page (only relevant when outputting to a printer).
1007 */
1008 void StartPage();
1009
1010 /**
1011 Copy from a source DC to this DC, specifying the destination
1012 coordinates, destination size, source DC, source coordinates, size of
1013 source area to copy, logical function, whether to use a bitmap mask,
1014 and mask source position.
1015
1016 @param xdest
1017 Destination device context x position.
1018 @param ydest
1019 Destination device context y position.
1020 @param dstWidth
1021 Width of destination area.
1022 @param dstHeight
1023 Height of destination area.
1024 @param source
1025 Source device context.
1026 @param xsrc
1027 Source device context x position.
1028 @param ysrc
1029 Source device context y position.
1030 @param srcWidth
1031 Width of source area to be copied.
1032 @param srcHeight
1033 Height of source area to be copied.
1034 @param logicalFunc
1035 Logical function to use, see SetLogicalFunction().
1036 @param useMask
1037 If @true, Blit does a transparent blit using the mask that is
1038 associated with the bitmap selected into the source device context.
1039 The Windows implementation does the following if MaskBlt cannot be
1040 used:
1041 <ol>
1042 <li>Creates a temporary bitmap and copies the destination area into
1043 it.</li>
1044 <li>Copies the source area into the temporary bitmap using the
1045 specified logical function.</li>
1046 <li>Sets the masked area in the temporary bitmap to BLACK by ANDing
1047 the mask bitmap with the temp bitmap with the foreground colour
1048 set to WHITE and the bg colour set to BLACK.</li>
1049 <li>Sets the unmasked area in the destination area to BLACK by
1050 ANDing the mask bitmap with the destination area with the
1051 foreground colour set to BLACK and the background colour set to
1052 WHITE.</li>
1053 <li>ORs the temporary bitmap with the destination area.</li>
1054 <li>Deletes the temporary bitmap.</li>
1055 </ol>
1056 This sequence of operations ensures that the source's transparent
1057 area need not be black, and logical functions are supported.
1058 @n @b Note: on Windows, blitting with masks can be speeded up
1059 considerably by compiling wxWidgets with the wxUSE_DC_CACHE option
1060 enabled. You can also influence whether MaskBlt or the explicit
1061 mask blitting code above is used, by using wxSystemOptions and
1062 setting the @c no-maskblt option to 1.
1063 @param xsrcMask
1064 Source x position on the mask. If both xsrcMask and ysrcMask are
1065 wxDefaultCoord, @a xsrc and @a ysrc will be assumed for the mask
1066 source position. Currently only implemented on Windows.
1067 @param ysrcMask
1068 Source y position on the mask. If both xsrcMask and ysrcMask are
1069 wxDefaultCoord, @a xsrc and @a ysrc will be assumed for the mask
1070 source position. Currently only implemented on Windows.
1071
1072 There is partial support for Blit() in wxPostScriptDC, under X.
1073
1074 StretchBlit() is only implemented under wxMAC and wxMSW.
1075
1076 See wxMemoryDC for typical usage.
1077
1078 @since 2.9.0
1079
1080 @see Blit(), wxMemoryDC, wxBitmap, wxMask
1081 */
1082 bool StretchBlit(wxCoord xdest, wxCoord ydest,
1083 wxCoord dstWidth, wxCoord dstHeight,
1084 wxDC* source, wxCoord xsrc, wxCoord ysrc,
1085 wxCoord srcWidth, wxCoord srcHeight,
1086 wxRasterOperationMode logicalFunc = wxCOPY,
1087 bool useMask = false,
1088 wxCoord xsrcMask = wxDefaultCoord,
1089 wxCoord ysrcMask = wxDefaultCoord);
1090 };
1091
1092
1093
1094 /**
1095 @class wxDCClipper
1096
1097 wxDCClipper is a small helper class for setting a clipping region on a wxDC
1098 and unsetting it automatically. An object of wxDCClipper class is typically
1099 created on the stack so that it is automatically destroyed when the object
1100 goes out of scope. A typical usage example:
1101
1102 @code
1103 void MyFunction(wxDC& dc)
1104 {
1105 wxDCClipper clip(dc, rect);
1106 // ... drawing functions here are affected by clipping rect ...
1107 }
1108
1109 void OtherFunction()
1110 {
1111 wxDC dc;
1112 MyFunction(dc);
1113 // ... drawing functions here are not affected by clipping rect ...
1114 }
1115 @endcode
1116
1117 @library{wxcore}
1118 @category{gdi}
1119
1120 @see wxDC::SetClippingRegion()
1121 */
1122 class wxDCClipper
1123 {
1124 public:
1125 //@{
1126 /**
1127 Sets the clipping region to the specified region/coordinates.
1128
1129 The clipping region is automatically unset when this object is destroyed.
1130 */
1131 wxDCClipper(wxDC& dc, const wxRegion& r);
1132 wxDCClipper(wxDC& dc, const wxRect& rect);
1133 wxDCClipper(wxDC& dc, int x, int y, int w, int h);
1134 //@}
1135
1136 /**
1137 Destroys the clipping region associated with the DC passed to the ctor.
1138 */
1139 ~wxDCClipper();
1140 };
1141
1142
1143 /**
1144 @class wxDCBrushChanger
1145
1146 wxDCBrushChanger is a small helper class for setting a brush on a wxDC
1147 and unsetting it automatically in the destructor, restoring the previous one.
1148
1149 @library{wxcore}
1150 @category{gdi}
1151
1152 @see wxDC::SetBrush()
1153 */
1154 class wxDCBrushChanger
1155 {
1156 public:
1157 /**
1158 Sets @a brush on the given @a dc, storing the old one.
1159
1160 @param dc
1161 The DC where the brush must be temporary set.
1162 @param brush
1163 The brush to set.
1164 */
1165 wxDCBrushChanger(wxDC& dc, const wxBrush& brush);
1166
1167 /**
1168 Restores the brush originally selected in the DC passed to the ctor.
1169 */
1170 ~wxDCBrushChanger();
1171 };
1172
1173
1174 /**
1175 @class wxDCPenChanger
1176
1177 wxDCPenChanger is a small helper class for setting a pen on a wxDC
1178 and unsetting it automatically in the destructor, restoring the previous one.
1179
1180 @library{wxcore}
1181 @category{gdi}
1182
1183 @see wxDC::SetPen()
1184 */
1185 class wxDCPenChanger
1186 {
1187 public:
1188 /**
1189 Sets @a pen on the given @a dc, storing the old one.
1190
1191 @param dc
1192 The DC where the pen must be temporary set.
1193 @param pen
1194 The pen to set.
1195 */
1196 wxDCPenChanger(wxDC& dc, const wxPen& pen);
1197
1198 /**
1199 Restores the pen originally selected in the DC passed to the ctor.
1200 */
1201 ~wxDCPenChanger();
1202 };
1203
1204
1205
1206 /**
1207 @class wxDCTextColourChanger
1208
1209 wxDCTextColourChanger is a small helper class for setting a foreground
1210 text colour on a wxDC and unsetting it automatically in the destructor,
1211 restoring the previous one.
1212
1213 @library{wxcore}
1214 @category{gdi}
1215
1216 @see wxDC::SetTextForeground()
1217 */
1218 class wxDCTextColourChanger
1219 {
1220 public:
1221 /**
1222 Sets @a col on the given @a dc, storing the old one.
1223
1224 @param dc
1225 The DC where the colour must be temporary set.
1226 @param col
1227 The colour to set.
1228 */
1229 wxDCTextColourChanger(wxDC& dc, const wxColour& col);
1230
1231 /**
1232 Restores the colour originally selected in the DC passed to the ctor.
1233 */
1234 ~wxDCTextColourChanger();
1235 };
1236
1237
1238
1239 /**
1240 @class wxDCFontChanger
1241
1242 wxDCFontChanger is a small helper class for setting a font on a wxDC and
1243 unsetting it automatically in the destructor, restoring the previous one.
1244
1245 @since 2.9.0
1246
1247 @library{wxcore}
1248 @category{gdi}
1249
1250 @see wxDC::SetFont()
1251 */
1252 class wxDCFontChanger
1253 {
1254 public:
1255 /**
1256 Sets @a font on the given @a dc, storing the old one.
1257
1258 @param dc
1259 The DC where the font must be temporary set.
1260 @param font
1261 The font to set.
1262 */
1263 wxDCFontChanger(wxDC& dc, const wxFont& font);
1264
1265 /**
1266 Restores the colour originally selected in the DC passed to the ctor.
1267 */
1268 ~wxDCFontChanger();
1269 };
1270