many automated ifacecheck fixes
[wxWidgets.git] / interface / wx / dc.h
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, wxDCFontChanger, wxDCTextColourChanger,
48 wxDCPenChanger, wxDCBrushChanger, wxDCClipper
49
50 @todo Precise definition of default/initial state.
51 @todo Pixelwise definition of operations (e.g. last point of a line not
52 drawn).
53 @todo Coordinates: state clearly which type of coordinates are returned by
54 the various Get*Point() or similar functions - often they are client
55 coordinates but not always.
56 */
57 class wxDC : public wxObject
58 {
59 public:
60 /**
61 Copy from a source DC to this DC, specifying the destination
62 coordinates, size of area to copy, source DC, source coordinates,
63 logical function, whether to use a bitmap mask, and mask source
64 position.
65
66 @param xdest
67 Destination device context x position.
68 @param ydest
69 Destination device context y position.
70 @param width
71 Width of source area to be copied.
72 @param height
73 Height of source area to be copied.
74 @param source
75 Source device context.
76 @param xsrc
77 Source device context x position.
78 @param ysrc
79 Source device context y position.
80 @param logicalFunc
81 Logical function to use, see SetLogicalFunction().
82 @param useMask
83 If @true, Blit does a transparent blit using the mask that is
84 associated with the bitmap selected into the source device context.
85 The Windows implementation does the following if MaskBlt cannot be
86 used:
87 <ol>
88 <li>Creates a temporary bitmap and copies the destination area into
89 it.</li>
90 <li>Copies the source area into the temporary bitmap using the
91 specified logical function.</li>
92 <li>Sets the masked area in the temporary bitmap to BLACK by ANDing
93 the mask bitmap with the temp bitmap with the foreground colour
94 set to WHITE and the bg colour set to BLACK.</li>
95 <li>Sets the unmasked area in the destination area to BLACK by
96 ANDing the mask bitmap with the destination area with the
97 foreground colour set to BLACK and the background colour set to
98 WHITE.</li>
99 <li>ORs the temporary bitmap with the destination area.</li>
100 <li>Deletes the temporary bitmap.</li>
101 </ol>
102 This sequence of operations ensures that the source's transparent
103 area need not be black, and logical functions are supported.
104 @n @b Note: on Windows, blitting with masks can be speeded up
105 considerably by compiling wxWidgets with the wxUSE_DC_CACHE option
106 enabled. You can also influence whether MaskBlt or the explicit
107 mask blitting code above is used, by using wxSystemOptions and
108 setting the @c no-maskblt option to 1.
109 @param xsrcMask
110 Source x position on the mask. If both xsrcMask and ysrcMask are
111 @c -1, xsrc and ysrc will be assumed for the mask source position.
112 Currently only implemented on Windows.
113 @param ysrcMask
114 Source y position on the mask. If both xsrcMask and ysrcMask are
115 @c -1, xsrc and ysrc will be assumed for the mask source position.
116 Currently only implemented on Windows.
117
118 @remarks There is partial support for Blit() in wxPostScriptDC, under X.
119
120 @see StretchBlit(), wxMemoryDC, wxBitmap, wxMask
121 */
122 bool Blit(wxCoord xdest, wxCoord ydest, wxCoord width,
123 wxCoord height, wxDC* source, wxCoord xsrc, wxCoord ysrc,
124 wxRasterOperationMode logicalFunc = wxCOPY, bool useMask = false,
125 wxCoord xsrcMask = wxDefaultCoord, wxCoord ysrcMask = wxDefaultCoord);
126
127 /**
128 Adds the specified point to the bounding box which can be retrieved
129 with MinX(), MaxX() and MinY(), MaxY() functions.
130
131 @see ResetBoundingBox()
132 */
133 void CalcBoundingBox(wxCoord x, wxCoord y);
134
135 /**
136 Clears the device context using the current background brush.
137 */
138 void Clear();
139
140 /**
141 Displays a cross hair using the current pen. This is a vertical and
142 horizontal line the height and width of the window, centred on the
143 given point.
144 */
145 void CrossHair(wxCoord x, wxCoord y);
146
147 /**
148 Destroys the current clipping region so that none of the DC is clipped.
149
150 @see SetClippingRegion()
151 */
152 void DestroyClippingRegion();
153
154 /**
155 Convert device X coordinate to logical coordinate, using the current
156 mapping mode, user scale factor, device origin and axis orientation.
157 */
158 wxCoord DeviceToLogicalX(wxCoord x) const;
159
160 /**
161 Convert device X coordinate to relative logical coordinate, using the
162 current mapping mode and user scale factor but ignoring the
163 axis orientation. Use this for converting a width, for example.
164 */
165 wxCoord DeviceToLogicalXRel(wxCoord x) const;
166
167 /**
168 Converts device Y coordinate to logical coordinate, using the current
169 mapping mode, user scale factor, device origin and axis orientation.
170 */
171 wxCoord DeviceToLogicalY(wxCoord y) const;
172
173 /**
174 Convert device Y coordinate to relative logical coordinate, using the
175 current mapping mode and user scale factor but ignoring the
176 axis orientation. Use this for converting a height, for example.
177 */
178 wxCoord DeviceToLogicalYRel(wxCoord y) const;
179
180 /**
181 Draws an arc of a circle, centred on (@a xc, @a yc), with starting
182 point (@a x1, @a y1) and ending at (@a x2, @a y2). The current pen is
183 used for the outline and the current brush for filling the shape.
184
185 The arc is drawn in a counter-clockwise direction from the start point
186 to the end point.
187 */
188 void DrawArc(wxCoord x1, wxCoord y1, wxCoord x2, wxCoord y2,
189 wxCoord xc, wxCoord yc);
190
191 /**
192 Draw a bitmap on the device context at the specified point. If
193 @a transparent is @true and the bitmap has a transparency mask, the
194 bitmap will be drawn transparently.
195
196 When drawing a mono-bitmap, the current text foreground colour will be
197 used to draw the foreground of the bitmap (all bits set to 1), and the
198 current text background colour to draw the background (all bits set to
199 0).
200
201 @see SetTextForeground(), SetTextBackground(), wxMemoryDC
202 */
203 void DrawBitmap(const wxBitmap& bitmap, wxCoord x, wxCoord y,
204 bool useMask = false);
205
206 //@{
207 /**
208 Draws a check mark inside the given rectangle.
209 */
210 void DrawCheckMark(wxCoord x, wxCoord y, wxCoord width, wxCoord height);
211 void DrawCheckMark(const wxRect& rect);
212 //@}
213
214 //@{
215 /**
216 Draws a circle with the given centre and radius.
217
218 @see DrawEllipse()
219 */
220 void DrawCircle(wxCoord x, wxCoord y, wxCoord radius);
221 void DrawCircle(const wxPoint& pt, wxCoord radius);
222 //@}
223
224 //@{
225 /**
226 Draws an ellipse contained in the rectangle specified either with the
227 given top left corner and the given size or directly. The current pen
228 is used for the outline and the current brush for filling the shape.
229
230 @see DrawCircle()
231 */
232 void DrawEllipse(wxCoord x, wxCoord y, wxCoord width, wxCoord height);
233 void DrawEllipse(const wxPoint& pt, const wxSize& size);
234 void DrawEllipse(const wxRect& rect);
235 //@}
236
237 /**
238 Draws an arc of an ellipse. The current pen is used for drawing the arc
239 and the current brush is used for drawing the pie.
240
241 @a x and @a y specify the x and y coordinates of the upper-left corner
242 of the rectangle that contains the ellipse.
243
244 @a width and @a height specify the width and height of the rectangle
245 that contains the ellipse.
246
247 @a start and @a end specify the start and end of the arc relative to
248 the three-o'clock position from the center of the rectangle. Angles are
249 specified in degrees (360 is a complete circle). Positive values mean
250 counter-clockwise motion. If @a start is equal to @e end, a complete
251 ellipse will be drawn.
252 */
253 void DrawEllipticArc(wxCoord x, wxCoord y, wxCoord width, wxCoord height,
254 double start, double end);
255
256 /**
257 Draw an icon on the display (does nothing if the device context is
258 PostScript). This can be the simplest way of drawing bitmaps on a
259 window.
260 */
261 void DrawIcon(const wxIcon& icon, wxCoord x, wxCoord y);
262
263 //@{
264 /**
265 Draw optional bitmap and the text into the given rectangle and aligns
266 it as specified by alignment parameter; it also will emphasize the
267 character with the given index if it is != -1 and return the bounding
268 rectangle if required.
269 */
270 virtual void DrawLabel(const wxString& text, const wxBitmap& image,
271 const wxRect& rect,
272 int alignment = wxALIGN_LEFT | wxALIGN_TOP,
273 int indexAccel = -1, wxRect* rectBounding = NULL);
274 void DrawLabel(const wxString& text, const wxRect& rect,
275 int alignment = wxALIGN_LEFT | wxALIGN_TOP,
276 int indexAccel = -1);
277 //@}
278
279 /**
280 Draws a line from the first point to the second. The current pen is
281 used for drawing the line. Note that the point (@a x2, @a y2) is not
282 part of the line and is not drawn by this function (this is consistent
283 with the behaviour of many other toolkits).
284 */
285 void DrawLine(wxCoord x1, wxCoord y1, wxCoord x2, wxCoord y2);
286
287 /**
288 Draws lines using an array of points of size @a n adding the optional
289 offset coordinate. The current pen is used for drawing the lines.
290
291 @beginWxPythonOnly
292 The wxPython version of this method accepts a Python list of wxPoint
293 objects.
294 @endWxPythonOnly
295 */
296 void DrawLines(int n, wxPoint points[], wxCoord xoffset = 0,
297 wxCoord yoffset = 0);
298 /**
299 This method uses a list of wxPoints, adding the optional offset
300 coordinate. The programmer is responsible for deleting the list of
301 points.
302
303 @beginWxPythonOnly
304 The wxPython version of this method accepts a Python list of wxPoint
305 objects.
306 @endWxPythonOnly
307 */
308 void DrawLines(const wxPointList* points,
309 wxCoord xoffset = 0, wxCoord yoffset = 0);
310
311 /**
312 Draws a point using the color of the current pen. Note that the other
313 properties of the pen are not used, such as width.
314 */
315 void DrawPoint(wxCoord x, wxCoord y);
316
317 /**
318 Draws a filled polygon using an array of points of size @a n, adding
319 the optional offset coordinate. The first and last points are
320 automatically closed.
321
322 The last argument specifies the fill rule: @b wxODDEVEN_RULE (the
323 default) or @b wxWINDING_RULE.
324
325 The current pen is used for drawing the outline, and the current brush
326 for filling the shape. Using a transparent brush suppresses filling.
327 */
328 void DrawPolygon(int n, wxPoint points[], wxCoord xoffset = 0,
329 wxCoord yoffset = 0,
330 wxPolygonFillMode fill_style = wxODDEVEN_RULE);
331 /**
332 This method draws a filled polygon using a list of wxPoints, adding the
333 optional offset coordinate. The first and last points are automatically
334 closed.
335
336 The last argument specifies the fill rule: @b wxODDEVEN_RULE (the
337 default) or @b wxWINDING_RULE.
338
339 The current pen is used for drawing the outline, and the current brush
340 for filling the shape. Using a transparent brush suppresses filling.
341
342 The programmer is responsible for deleting the list of points.
343
344 @beginWxPythonOnly
345 The wxPython version of this method accepts a Python list of wxPoint
346 objects.
347 @endWxPythonOnly
348 */
349 void DrawPolygon(const wxPointList* points,
350 wxCoord xoffset = 0, wxCoord yoffset = 0,
351 wxPolygonFillMode fill_style = wxODDEVEN_RULE);
352
353 /**
354 Draws two or more filled polygons using an array of @a points, adding
355 the optional offset coordinates.
356
357 Notice that for the platforms providing a native implementation of this
358 function (Windows and PostScript-based wxDC currently), this is more
359 efficient than using DrawPolygon() in a loop.
360
361 @a n specifies the number of polygons to draw, the array @e count of
362 size @a n specifies the number of points in each of the polygons in the
363 @a points array.
364
365 The last argument specifies the fill rule: @b wxODDEVEN_RULE (the
366 default) or @b wxWINDING_RULE.
367
368 The current pen is used for drawing the outline, and the current brush
369 for filling the shape. Using a transparent brush suppresses filling.
370
371 The polygons maybe disjoint or overlapping. Each polygon specified in a
372 call to DrawPolyPolygon() must be closed. Unlike polygons created by
373 the DrawPolygon() member function, the polygons created by this
374 method are not closed automatically.
375
376 @beginWxPythonOnly
377 Not implemented yet.
378 @endWxPythonOnly
379 */
380 void DrawPolyPolygon(int n, int count[], wxPoint points[],
381 wxCoord xoffset = 0, wxCoord yoffset = 0,
382 wxPolygonFillMode fill_style = wxODDEVEN_RULE);
383
384 /**
385 Draws a rectangle with the given top left corner, and with the given
386 size. The current pen is used for the outline and the current brush
387 for filling the shape.
388 */
389 void DrawRectangle(wxCoord x, wxCoord y, wxCoord width, wxCoord height);
390
391 /**
392 Draws the text rotated by @a angle degrees.
393
394 @note Under Win9x only TrueType fonts can be drawn by this function. In
395 particular, a font different from @c wxNORMAL_FONT should be used
396 as the latter is not a TrueType font. @c wxSWISS_FONT is an
397 example of a font which is.
398
399 @see DrawText()
400 */
401 void DrawRotatedText(const wxString& text, wxCoord x, wxCoord y,
402 double angle);
403
404 /**
405 Draws a rectangle with the given top left corner, and with the given
406 size. The corners are quarter-circles using the given radius. The
407 current pen is used for the outline and the current brush for filling
408 the shape.
409
410 If @a radius is positive, the value is assumed to be the radius of the
411 rounded corner. If @a radius is negative, the absolute value is assumed
412 to be the @e proportion of the smallest dimension of the rectangle.
413 This means that the corner can be a sensible size relative to the size
414 of the rectangle, and also avoids the strange effects X produces when
415 the corners are too big for the rectangle.
416 */
417 void DrawRoundedRectangle(wxCoord x, wxCoord y, wxCoord width,
418 wxCoord height, double radius);
419
420 //@{
421 /**
422 Draws a spline between all given points using the current pen.
423
424 @beginWxPythonOnly
425 The wxPython version of this method accepts a Python list of wxPoint
426 objects.
427 @endWxPythonOnly
428 */
429 void DrawSpline(int n, wxPoint points[]);
430 void DrawSpline(const wxPointList* points);
431 void DrawSpline(wxCoord x1, wxCoord y1, wxCoord x2, wxCoord y2,
432 wxCoord x3, wxCoord y3);
433 //@}
434
435 /**
436 Draws a text string at the specified point, using the current text
437 font, and the current text foreground and background colours.
438
439 The coordinates refer to the top-left corner of the rectangle bounding
440 the string. See GetTextExtent() for how to get the dimensions of a text
441 string, which can be used to position the text more precisely.
442
443 @note The current @ref GetLogicalFunction() "logical function" is
444 ignored by this function.
445 */
446 void DrawText(const wxString& text, wxCoord x, wxCoord y);
447
448 /**
449 Ends a document (only relevant when outputting to a printer).
450 */
451 void EndDoc();
452
453 /**
454 Ends a document page (only relevant when outputting to a printer).
455 */
456 void EndPage();
457
458 /**
459 Flood fills the device context starting from the given point, using
460 the current brush colour, and using a style:
461
462 - wxFLOOD_SURFACE: The flooding occurs until a colour other than the
463 given colour is encountered.
464 - wxFLOOD_BORDER: The area to be flooded is bounded by the given
465 colour.
466
467 @return @false if the operation failed.
468
469 @note The present implementation for non-Windows platforms may fail to
470 find colour borders if the pixels do not match the colour
471 exactly. However the function will still return @true.
472 */
473 bool FloodFill(wxCoord x, wxCoord y, const wxColour& colour,
474 wxFloodFillStyle style = wxFLOOD_SURFACE);
475
476 /**
477 Gets the brush used for painting the background.
478
479 @see wxDC::SetBackground()
480 */
481 const wxBrush& GetBackground() const;
482
483 /**
484 Returns the current background mode: @c wxSOLID or @c wxTRANSPARENT.
485
486 @see SetBackgroundMode()
487 */
488 int GetBackgroundMode() const;
489
490 /**
491 Gets the current brush.
492
493 @see wxDC::SetBrush()
494 */
495 const wxBrush& GetBrush() const;
496
497 /**
498 Gets the character height of the currently set font.
499 */
500 wxCoord GetCharHeight() const;
501
502 /**
503 Gets the average character width of the currently set font.
504 */
505 wxCoord GetCharWidth() const;
506
507 /**
508 Gets the rectangle surrounding the current clipping region.
509
510 @beginWxPythonOnly
511 No arguments are required and the four values defining the rectangle
512 are returned as a tuple.
513 @endWxPythonOnly
514 */
515 void GetClippingBox(wxCoord *x, wxCoord *y, wxCoord *width, wxCoord *height) const;
516
517 /**
518 Returns the depth (number of bits/pixel) of this DC.
519
520 @see wxDisplayDepth()
521 */
522 int GetDepth() const;
523
524 /**
525 Gets the current font. Notice that even although each device context
526 object has some default font after creation, this method would return a
527 wxNullFont initially and only after calling SetFont() a valid font is
528 returned.
529 */
530 const wxFont& GetFont() const;
531
532 /**
533 Gets the current layout direction of the device context. On platforms
534 where RTL layout is supported, the return value will either be
535 @c wxLayout_LeftToRight or @c wxLayout_RightToLeft. If RTL layout is
536 not supported, the return value will be @c wxLayout_Default.
537
538 @see SetLayoutDirection()
539 */
540 wxLayoutDirection GetLayoutDirection() const;
541
542 /**
543 Gets the current logical function.
544
545 @see SetLogicalFunction()
546 */
547 wxRasterOperationMode GetLogicalFunction() const;
548
549 /**
550 Gets the mapping mode for the device context.
551
552 @see SetMapMode()
553 */
554 wxMappingMode GetMapMode() const;
555
556 /**
557 Gets the dimensions of the string using the currently selected font.
558 @a string is the text string to measure, @e heightLine, if non @NULL,
559 is where to store the height of a single line.
560
561 The text extent is set in the given @a w and @a h pointers.
562
563 If the optional parameter @a font is specified and valid, then it is
564 used for the text extent calculation, otherwise the currently selected
565 font is used.
566
567 @note This function works with both single-line and multi-line strings.
568
569 @see wxFont, SetFont(), GetPartialTextExtents(), GetTextExtent()
570 */
571 void GetMultiLineTextExtent(const wxString& string, wxCoord* w,
572 wxCoord* h,
573 wxCoord* heightLine = NULL,
574 const wxFont* font = NULL) const;
575 /**
576 Gets the dimensions of the string using the currently selected font.
577 @a string is the text string to measure, @e heightLine, if non @NULL,
578 is where to store the height of a single line.
579
580 @return The text extent as a wxSize object.
581
582 @note This function works with both single-line and multi-line strings.
583
584 @see wxFont, SetFont(), GetPartialTextExtents(), GetTextExtent()
585 */
586 wxSize GetMultiLineTextExtent(const wxString& string) const;
587
588 /**
589 Fills the @a widths array with the widths from the beginning of @a text
590 to the corresponding character of @a text. The generic version simply
591 builds a running total of the widths of each character using
592 GetTextExtent(), however if the various platforms have a native API
593 function that is faster or more accurate than the generic
594 implementation then it should be used instead.
595
596 @beginWxPythonOnly
597 This method only takes the @a text parameter and returns a Python list
598 of integers.
599 @endWxPythonOnly
600
601 @see GetMultiLineTextExtent(), GetTextExtent()
602 */
603 bool GetPartialTextExtents(const wxString& text,
604 wxArrayInt& widths) const;
605
606 /**
607 Gets the current pen.
608
609 @see SetPen()
610 */
611 const wxPen& GetPen() const;
612
613 /**
614 Gets in @a colour the colour at the specified location. Not available
615 for wxPostScriptDC or wxMetafileDC.
616
617 @note Setting a pixel can be done using DrawPoint().
618
619 @beginWxPythonOnly
620 The wxColour value is returned and is not required as a parameter.
621 @endWxPythonOnly
622 */
623 bool GetPixel(wxCoord x, wxCoord y, wxColour* colour) const;
624
625 /**
626 Returns the resolution of the device in pixels per inch.
627 */
628 wxSize GetPPI() const;
629
630 //@{
631 /**
632 This gets the horizontal and vertical resolution in device units. It
633 can be used to scale graphics to fit the page.
634
635 For example, if @e maxX and @e maxY represent the maximum horizontal
636 and vertical 'pixel' values used in your application, the following
637 code will scale the graphic to fit on the printer page:
638
639 @code
640 wxCoord w, h;
641 dc.GetSize(&w, &h);
642 double scaleX = (double)(maxX / w);
643 double scaleY = (double)(maxY / h);
644 dc.SetUserScale(min(scaleX, scaleY),min(scaleX, scaleY));
645 @endcode
646
647 @beginWxPythonOnly
648 In place of a single overloaded method name, wxPython implements the
649 following methods:
650 - GetSize() - Returns a wxSize.
651 - GetSizeWH() - Returns a 2-tuple (width, height).
652 @endWxPythonOnly
653 */
654 void GetSize(wxCoord* width, wxCoord* height) const;
655 wxSize GetSize() const;
656 //@}
657
658 //@{
659 /**
660 Returns the horizontal and vertical resolution in millimetres.
661 */
662 void GetSizeMM(wxCoord* width, wxCoord* height) const;
663 wxSize GetSizeMM() const;
664 //@}
665
666 /**
667 Gets the current text background colour.
668
669 @see SetTextBackground()
670 */
671 const wxColour& GetTextBackground() const;
672
673 //@{
674 /**
675 Gets the dimensions of the string using the currently selected font.
676 @a string is the text string to measure, @a descent is the dimension
677 from the baseline of the font to the bottom of the descender, and
678 @a externalLeading is any extra vertical space added to the font by the
679 font designer (usually is zero).
680
681 The text extent is returned in @a w and @a h pointers or as a wxSize
682 object depending on which version of this function is used.
683
684 If the optional parameter @a font is specified and valid, then it is
685 used for the text extent calculation. Otherwise the currently selected
686 font is.
687
688 @note This function only works with single-line strings.
689
690 @beginWxPythonOnly
691 The following methods are implemented in wxPython:
692 - GetTextExtent(string) - Returns a 2-tuple, (width, height).
693 - GetFullTextExtent(string, font=NULL) -
694 Returns a 4-tuple, (width, height, descent, externalLeading).
695 @endWxPythonOnly
696
697 @see wxFont, SetFont(), GetPartialTextExtents(),
698 GetMultiLineTextExtent()
699 */
700 void GetTextExtent(const wxString& string, wxCoord* w, wxCoord* h,
701 wxCoord* descent = NULL,
702 wxCoord* externalLeading = NULL,
703 const wxFont* font = NULL) const;
704 wxSize GetTextExtent(const wxString& string) const;
705 //@}
706
707 /**
708 Gets the current text foreground colour.
709
710 @see SetTextForeground()
711 */
712 const wxColour& GetTextForeground() const;
713
714 /**
715 Gets the current user scale factor.
716
717 @see SetUserScale()
718 */
719 void GetUserScale(double* x, double* y) const;
720
721 //@{
722 /**
723 Fill the area specified by rect with a radial gradient, starting from
724 @a initialColour at the centre of the circle and fading to
725 @a destColour on the circle outside.
726
727 @a circleCenter are the relative coordinates of centre of the circle in
728 the specified @e rect. If not specified, the circle is placed at the
729 centre of rect.
730
731 @note Currently this function is very slow, don't use it for real-time
732 drawing.
733 */
734 void GradientFillConcentric(const wxRect& rect,
735 const wxColour& initialColour,
736 const wxColour& destColour);
737 void GradientFillConcentric(const wxRect& rect,
738 const wxColour& initialColour,
739 const wxColour& destColour,
740 const wxPoint& circleCenter);
741 //@}
742
743 /**
744 Fill the area specified by @a rect with a linear gradient, starting
745 from @a initialColour and eventually fading to @e destColour. The
746 @a nDirection specifies the direction of the colour change, default is
747 to use @a initialColour on the left part of the rectangle and
748 @a destColour on the right one.
749 */
750 void GradientFillLinear(const wxRect& rect, const wxColour& initialColour,
751 const wxColour& destColour,
752 wxDirection nDirection = wxRIGHT);
753
754 /**
755 Returns @true if the DC is ok to use.
756 */
757 bool IsOk() const;
758
759 /**
760 Converts logical X coordinate to device coordinate, using the current
761 mapping mode, user scale factor, device origin and axis orientation.
762 */
763 wxCoord LogicalToDeviceX(wxCoord x) const;
764
765 /**
766 Converts logical X coordinate to relative device coordinate, using the
767 current mapping mode and user scale factor but ignoring the
768 axis orientation. Use this for converting a width, for example.
769 */
770 wxCoord LogicalToDeviceXRel(wxCoord x) const;
771
772 /**
773 Converts logical Y coordinate to device coordinate, using the current
774 mapping mode, user scale factor, device origin and axis orientation.
775 */
776 wxCoord LogicalToDeviceY(wxCoord y) const;
777
778 /**
779 Converts logical Y coordinate to relative device coordinate, using the
780 current mapping mode and user scale factor but ignoring the
781 axis orientation. Use this for converting a height, for example.
782 */
783 wxCoord LogicalToDeviceYRel(wxCoord y) const;
784
785 /**
786 Gets the maximum horizontal extent used in drawing commands so far.
787 */
788 wxCoord MaxX() const;
789
790 /**
791 Gets the maximum vertical extent used in drawing commands so far.
792 */
793 wxCoord MaxY() const;
794
795 /**
796 Gets the minimum horizontal extent used in drawing commands so far.
797 */
798 wxCoord MinX() const;
799
800 /**
801 Gets the minimum vertical extent used in drawing commands so far.
802 */
803 wxCoord MinY() const;
804
805 /**
806 Resets the bounding box: after a call to this function, the bounding
807 box doesn't contain anything.
808
809 @see CalcBoundingBox()
810 */
811 void ResetBoundingBox();
812
813 /**
814 Sets the x and y axis orientation (i.e., the direction from lowest to
815 highest values on the axis). The default orientation is x axis from
816 left to right and y axis from top down.
817
818 @param xLeftRight
819 True to set the x axis orientation to the natural left to right
820 orientation, @false to invert it.
821 @param yBottomUp
822 True to set the y axis orientation to the natural bottom up
823 orientation, @false to invert it.
824 */
825 void SetAxisOrientation(bool xLeftRight, bool yBottomUp);
826
827 /**
828 Sets the current background brush for the DC.
829 */
830 void SetBackground(const wxBrush& brush);
831
832 /**
833 @a mode may be one of wxSOLID and wxTRANSPARENT. This setting
834 determines whether text will be drawn with a background colour or not.
835 */
836 void SetBackgroundMode(int mode);
837
838 /**
839 Sets the current brush for the DC.
840
841 If the argument is wxNullBrush, the current brush is selected out of
842 the device context (leaving wxDC without any valid brush), allowing the
843 current brush to be destroyed safely.
844
845 @see wxBrush, wxMemoryDC (for the interpretation of colours when
846 drawing into a monochrome bitmap)
847 */
848 void SetBrush(const wxBrush& brush);
849
850 //@{
851 /**
852 Sets the clipping region for this device context to the intersection of
853 the given region described by the parameters of this method and the
854 previously set clipping region. You should call DestroyClippingRegion()
855 if you want to set the clipping region exactly to the region specified.
856
857 The clipping region is an area to which drawing is restricted. Possible
858 uses for the clipping region are for clipping text or for speeding up
859 window redraws when only a known area of the screen is damaged.
860
861 @see DestroyClippingRegion(), wxRegion
862 */
863 void SetClippingRegion(wxCoord x, wxCoord y, wxCoord width,
864 wxCoord height);
865 void SetClippingRegion(const wxPoint& pt, const wxSize& sz);
866 void SetClippingRegion(const wxRect& rect);
867 //@}
868
869 /**
870 Sets the clipping region for this device context.
871
872 Unlike SetClippingRegion(), this function works with physical
873 coordinates and not with the logical ones.
874 */
875 void SetDeviceClippingRegion(const wxRegion& region);
876
877 /**
878 Sets the device origin (i.e., the origin in pixels after scaling has
879 been applied). This function may be useful in Windows printing
880 operations for placing a graphic on a page.
881 */
882 void SetDeviceOrigin(wxCoord x, wxCoord y);
883
884 /**
885 Sets the current font for the DC. It must be a valid font, in
886 particular you should not pass wxNullFont to this method.
887
888 @see wxFont
889 */
890 void SetFont(const wxFont& font);
891
892 /**
893 Sets the current layout direction for the device context. @a dir may be
894 either @c wxLayout_Default, @c wxLayout_LeftToRight or
895 @c wxLayout_RightToLeft.
896
897 @see GetLayoutDirection()
898 */
899 void SetLayoutDirection(wxLayoutDirection dir);
900
901 /**
902 Sets the current logical function for the device context. This
903 determines how a source pixel (from a pen or brush colour, or source
904 device context if using Blit()) combines with a destination pixel in
905 the current device context.
906 Text drawing is not affected by this function.
907
908 The possible values and their meaning in terms of source and
909 destination pixel values are as follows:
910
911 @verbatim
912 wxAND src AND dst
913 wxAND_INVERT (NOT src) AND dst
914 wxAND_REVERSE src AND (NOT dst)
915 wxCLEAR 0
916 wxCOPY src
917 wxEQUIV (NOT src) XOR dst
918 wxINVERT NOT dst
919 wxNAND (NOT src) OR (NOT dst)
920 wxNOR (NOT src) AND (NOT dst)
921 wxNO_OP dst
922 wxOR src OR dst
923 wxOR_INVERT (NOT src) OR dst
924 wxOR_REVERSE src OR (NOT dst)
925 wxSET 1
926 wxSRC_INVERT NOT src
927 wxXOR src XOR dst
928 @endverbatim
929
930 The default is wxCOPY, which simply draws with the current colour. The
931 others combine the current colour and the background using a logical
932 operation. wxINVERT is commonly used for drawing rubber bands or moving
933 outlines, since drawing twice reverts to the original colour.
934 */
935 void SetLogicalFunction(wxRasterOperationMode function);
936
937 /**
938 The mapping mode of the device context defines the unit of measurement
939 used to convert logical units to device units. Note that in X, text
940 drawing isn't handled consistently with the mapping mode; a font is
941 always specified in point size. However, setting the user scale (see
942 SetUserScale()) scales the text appropriately. In Windows, scalable
943 TrueType fonts are always used; in X, results depend on availability of
944 fonts, but usually a reasonable match is found.
945
946 The coordinate origin is always at the top left of the screen/printer.
947
948 Drawing to a Windows printer device context uses the current mapping
949 mode, but mapping mode is currently ignored for PostScript output.
950
951 The mapping mode can be one of the following:
952 - wxMM_TWIPS: Each logical unit is 1/20 of a point, or 1/1440 of an
953 inch.
954 - wxMM_POINTS: Each logical unit is a point, or 1/72 of an inch.
955 - wxMM_METRIC: Each logical unit is 1 mm.
956 - wxMM_LOMETRIC: Each logical unit is 1/10 of a mm.
957 - wxMM_TEXT: Each logical unit is 1 device pixel.
958 */
959 void SetMapMode(wxMappingMode mode);
960
961 /**
962 If this is a window DC or memory DC, assigns the given palette to the
963 window or bitmap associated with the DC. If the argument is
964 wxNullPalette, the current palette is selected out of the device
965 context, and the original palette restored.
966
967 @see wxPalette
968 */
969 void SetPalette(const wxPalette& palette);
970
971 /**
972 Sets the current pen for the DC. If the argument is wxNullPen, the
973 current pen is selected out of the device context (leaving wxDC without
974 any valid pen), allowing the current brush to be destroyed safely.
975
976 @see wxMemoryDC for the interpretation of colours when drawing into a
977 monochrome bitmap.
978 */
979 void SetPen(const wxPen& pen);
980
981 /**
982 Sets the current text background colour for the DC.
983 */
984 void SetTextBackground(const wxColour& colour);
985
986 /**
987 Sets the current text foreground colour for the DC.
988
989 @see wxMemoryDC for the interpretation of colours when drawing into a
990 monochrome bitmap.
991 */
992 void SetTextForeground(const wxColour& colour);
993
994 /**
995 Sets the user scaling factor, useful for applications which require
996 'zooming'.
997 */
998 void SetUserScale(double xScale, double yScale);
999
1000 /**
1001 Starts a document (only relevant when outputting to a printer).
1002 @a message is a message to show while printing.
1003 */
1004 bool StartDoc(const wxString& message);
1005
1006 /**
1007 Starts a document page (only relevant when outputting to a printer).
1008 */
1009 void StartPage();
1010
1011 /**
1012 Copy from a source DC to this DC, specifying the destination
1013 coordinates, destination size, source DC, source coordinates, size of
1014 source area to copy, logical function, whether to use a bitmap mask,
1015 and mask source position.
1016
1017 @param xdest
1018 Destination device context x position.
1019 @param ydest
1020 Destination device context y position.
1021 @param dstWidth
1022 Width of destination area.
1023 @param dstHeight
1024 Height of destination area.
1025 @param source
1026 Source device context.
1027 @param xsrc
1028 Source device context x position.
1029 @param ysrc
1030 Source device context y position.
1031 @param srcWidth
1032 Width of source area to be copied.
1033 @param srcHeight
1034 Height of source area to be copied.
1035 @param logicalFunc
1036 Logical function to use, see SetLogicalFunction().
1037 @param useMask
1038 If @true, Blit does a transparent blit using the mask that is
1039 associated with the bitmap selected into the source device context.
1040 The Windows implementation does the following if MaskBlt cannot be
1041 used:
1042 <ol>
1043 <li>Creates a temporary bitmap and copies the destination area into
1044 it.</li>
1045 <li>Copies the source area into the temporary bitmap using the
1046 specified logical function.</li>
1047 <li>Sets the masked area in the temporary bitmap to BLACK by ANDing
1048 the mask bitmap with the temp bitmap with the foreground colour
1049 set to WHITE and the bg colour set to BLACK.</li>
1050 <li>Sets the unmasked area in the destination area to BLACK by
1051 ANDing the mask bitmap with the destination area with the
1052 foreground colour set to BLACK and the background colour set to
1053 WHITE.</li>
1054 <li>ORs the temporary bitmap with the destination area.</li>
1055 <li>Deletes the temporary bitmap.</li>
1056 </ol>
1057 This sequence of operations ensures that the source's transparent
1058 area need not be black, and logical functions are supported.
1059 @n @b Note: on Windows, blitting with masks can be speeded up
1060 considerably by compiling wxWidgets with the wxUSE_DC_CACHE option
1061 enabled. You can also influence whether MaskBlt or the explicit
1062 mask blitting code above is used, by using wxSystemOptions and
1063 setting the @c no-maskblt option to 1.
1064 @param xsrcMask
1065 Source x position on the mask. If both xsrcMask and ysrcMask are
1066 wxDefaultCoord, @a xsrc and @a ysrc will be assumed for the mask
1067 source position. Currently only implemented on Windows.
1068 @param ysrcMask
1069 Source y position on the mask. If both xsrcMask and ysrcMask are
1070 wxDefaultCoord, @a xsrc and @a ysrc will be assumed for the mask
1071 source position. Currently only implemented on Windows.
1072
1073 There is partial support for Blit() in wxPostScriptDC, under X.
1074
1075 StretchBlit() is only implemented under wxMAC and wxMSW.
1076
1077 See wxMemoryDC for typical usage.
1078
1079 @since 2.9.0
1080
1081 @see Blit(), wxMemoryDC, wxBitmap, wxMask
1082 */
1083 bool StretchBlit(wxCoord xdest, wxCoord ydest,
1084 wxCoord dstWidth, wxCoord dstHeight,
1085 wxDC* source, wxCoord xsrc, wxCoord ysrc,
1086 wxCoord srcWidth, wxCoord srcHeight,
1087 wxRasterOperationMode logicalFunc = wxCOPY,
1088 bool useMask = false,
1089 wxCoord xsrcMask = wxDefaultCoord,
1090 wxCoord ysrcMask = wxDefaultCoord);
1091 };
1092
1093
1094
1095 /**
1096 @class wxDCClipper
1097
1098 wxDCClipper is a small helper class for setting a clipping region on a wxDC
1099 and unsetting it automatically. An object of wxDCClipper class is typically
1100 created on the stack so that it is automatically destroyed when the object
1101 goes out of scope. A typical usage example:
1102
1103 @code
1104 void MyFunction(wxDC& dc)
1105 {
1106 wxDCClipper clip(dc, rect);
1107 // ... drawing functions here are affected by clipping rect ...
1108 }
1109
1110 void OtherFunction()
1111 {
1112 wxDC dc;
1113 MyFunction(dc);
1114 // ... drawing functions here are not affected by clipping rect ...
1115 }
1116 @endcode
1117
1118 @library{wxcore}
1119 @category{gdi}
1120
1121 @see wxDC::SetClippingRegion(), wxDCFontChanger, wxDCTextColourChanger, wxDCPenChanger,
1122 wxDCBrushChanger
1123 */
1124 class wxDCClipper
1125 {
1126 public:
1127 //@{
1128 /**
1129 Sets the clipping region to the specified region/coordinates.
1130
1131 The clipping region is automatically unset when this object is destroyed.
1132 */
1133 wxDCClipper(wxDC& dc, const wxRegion& r);
1134 wxDCClipper(wxDC& dc, const wxRect& rect);
1135 wxDCClipper(wxDC& dc, int x, int y, int w, int h);
1136 //@}
1137
1138 /**
1139 Destroys the clipping region associated with the DC passed to the ctor.
1140 */
1141 ~wxDCClipper();
1142 };
1143
1144
1145 /**
1146 @class wxDCBrushChanger
1147
1148 wxDCBrushChanger is a small helper class for setting a brush on a wxDC
1149 and unsetting it automatically in the destructor, restoring the previous one.
1150
1151 @library{wxcore}
1152 @category{gdi}
1153
1154 @see wxDC::SetBrush(), wxDCFontChanger, wxDCTextColourChanger, wxDCPenChanger,
1155 wxDCClipper
1156 */
1157 class wxDCBrushChanger
1158 {
1159 public:
1160 /**
1161 Sets @a brush on the given @a dc, storing the old one.
1162
1163 @param dc
1164 The DC where the brush must be temporary set.
1165 @param brush
1166 The brush to set.
1167 */
1168 wxDCBrushChanger(wxDC& dc, const wxBrush& brush);
1169
1170 /**
1171 Restores the brush originally selected in the DC passed to the ctor.
1172 */
1173 ~wxDCBrushChanger();
1174 };
1175
1176
1177 /**
1178 @class wxDCPenChanger
1179
1180 wxDCPenChanger is a small helper class for setting a pen on a wxDC
1181 and unsetting it automatically in the destructor, restoring the previous one.
1182
1183 @library{wxcore}
1184 @category{gdi}
1185
1186 @see wxDC::SetPen(), wxDCFontChanger, wxDCTextColourChanger, wxDCBrushChanger,
1187 wxDCClipper
1188 */
1189 class wxDCPenChanger
1190 {
1191 public:
1192 /**
1193 Sets @a pen on the given @a dc, storing the old one.
1194
1195 @param dc
1196 The DC where the pen must be temporary set.
1197 @param pen
1198 The pen to set.
1199 */
1200 wxDCPenChanger(wxDC& dc, const wxPen& pen);
1201
1202 /**
1203 Restores the pen originally selected in the DC passed to the ctor.
1204 */
1205 ~wxDCPenChanger();
1206 };
1207
1208
1209
1210 /**
1211 @class wxDCTextColourChanger
1212
1213 wxDCTextColourChanger is a small helper class for setting a foreground
1214 text colour on a wxDC and unsetting it automatically in the destructor,
1215 restoring the previous one.
1216
1217 @library{wxcore}
1218 @category{gdi}
1219
1220 @see wxDC::SetTextForeground(), wxDCFontChanger, wxDCPenChanger, wxDCBrushChanger,
1221 wxDCClipper
1222 */
1223 class wxDCTextColourChanger
1224 {
1225 public:
1226 /**
1227 Sets @a col on the given @a dc, storing the old one.
1228
1229 @param dc
1230 The DC where the colour must be temporary set.
1231 @param col
1232 The colour to set.
1233 */
1234 wxDCTextColourChanger(wxDC& dc, const wxColour& col);
1235
1236 /**
1237 Restores the colour originally selected in the DC passed to the ctor.
1238 */
1239 ~wxDCTextColourChanger();
1240 };
1241
1242
1243
1244 /**
1245 @class wxDCFontChanger
1246
1247 wxDCFontChanger is a small helper class for setting a font on a wxDC and
1248 unsetting it automatically in the destructor, restoring the previous one.
1249
1250 @since 2.9.0
1251
1252 @library{wxcore}
1253 @category{gdi}
1254
1255 @see wxDC::SetFont(), wxDCTextColourChanger, wxDCPenChanger, wxDCBrushChanger,
1256 wxDCClipper
1257 */
1258 class wxDCFontChanger
1259 {
1260 public:
1261 /**
1262 Sets @a font on the given @a dc, storing the old one.
1263
1264 @param dc
1265 The DC where the font must be temporary set.
1266 @param font
1267 The font to set.
1268 */
1269 wxDCFontChanger(wxDC& dc, const wxFont& font);
1270
1271 /**
1272 Restores the colour originally selected in the DC passed to the ctor.
1273 */
1274 ~wxDCFontChanger();
1275 };
1276