1 /////////////////////////////////////////////////////////////////////////////
3 // Purpose: interface of wxDC
4 // Author: wxWidgets team
6 // Licence: wxWindows license
7 /////////////////////////////////////////////////////////////////////////////
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.
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.
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.
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
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.
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.
47 @see @ref overview_dc, wxGraphicsContext, wxDCFontChanger, wxDCTextColourChanger,
48 wxDCPenChanger, wxDCBrushChanger, wxDCClipper
50 @todo Precise definition of default/initial state.
51 @todo Pixelwise definition of operations (e.g. last point of a line not
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.
57 class wxDC
: public wxObject
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
67 Destination device context x position.
69 Destination device context y position.
71 Width of source area to be copied.
73 Height of source area to be copied.
75 Source device context.
77 Source device context x position.
79 Source device context y position.
81 Logical function to use, see SetLogicalFunction().
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
88 <li>Creates a temporary bitmap and copies the destination area into
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
99 <li>ORs the temporary bitmap with the destination area.</li>
100 <li>Deletes the temporary bitmap.</li>
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.
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.
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.
118 @remarks There is partial support for Blit() in wxPostScriptDC, under X.
120 @see StretchBlit(), wxMemoryDC, wxBitmap, wxMask
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
);
128 Adds the specified point to the bounding box which can be retrieved
129 with MinX(), MaxX() and MinY(), MaxY() functions.
131 @see ResetBoundingBox()
133 void CalcBoundingBox(wxCoord x
, wxCoord y
);
136 Clears the device context using the current background brush.
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
145 void CrossHair(wxCoord x
, wxCoord y
);
148 Destroys the current clipping region so that none of the DC is clipped.
150 @see SetClippingRegion()
152 void DestroyClippingRegion();
155 Convert device X coordinate to logical coordinate, using the current
156 mapping mode, user scale factor, device origin and axis orientation.
158 wxCoord
DeviceToLogicalX(wxCoord x
) const;
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.
165 wxCoord
DeviceToLogicalXRel(wxCoord x
) const;
168 Converts device Y coordinate to logical coordinate, using the current
169 mapping mode, user scale factor, device origin and axis orientation.
171 wxCoord
DeviceToLogicalY(wxCoord y
) const;
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.
178 wxCoord
DeviceToLogicalYRel(wxCoord y
) const;
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.
185 The arc is drawn in a counter-clockwise direction from the start point
188 void DrawArc(wxCoord x1
, wxCoord y1
, wxCoord x2
, wxCoord y2
,
189 wxCoord xc
, wxCoord yc
);
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.
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
201 @see SetTextForeground(), SetTextBackground(), wxMemoryDC
203 void DrawBitmap(const wxBitmap
& bitmap
, wxCoord x
, wxCoord y
,
204 bool useMask
= false);
208 Draws a check mark inside the given rectangle.
210 void DrawCheckMark(wxCoord x
, wxCoord y
, wxCoord width
, wxCoord height
);
211 void DrawCheckMark(const wxRect
& rect
);
216 Draws a circle with the given centre and radius.
220 void DrawCircle(wxCoord x
, wxCoord y
, wxCoord radius
);
221 void DrawCircle(const wxPoint
& pt
, wxCoord radius
);
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.
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
);
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.
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.
244 @a width and @a height specify the width and height of the rectangle
245 that contains the ellipse.
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.
253 void DrawEllipticArc(wxCoord x
, wxCoord y
, wxCoord width
, wxCoord height
,
254 double start
, double end
);
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
261 void DrawIcon(const wxIcon
& icon
, wxCoord x
, wxCoord y
);
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.
270 void DrawLabel(const wxString
& text
, const wxBitmap
& image
,
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);
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).
285 void DrawLine(wxCoord x1
, wxCoord y1
, wxCoord x2
, wxCoord y2
);
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.
292 The wxPython version of this method accepts a Python list of wxPoint
296 void DrawLines(int n
, wxPoint points
[], wxCoord xoffset
= 0,
297 wxCoord yoffset
= 0);
299 This method uses a list of wxPoints, adding the optional offset
300 coordinate. The programmer is responsible for deleting the list of
304 The wxPython version of this method accepts a Python list of wxPoint
308 void DrawLines(const wxPointList
* points
,
309 wxCoord xoffset
= 0, wxCoord yoffset
= 0);
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.
315 void DrawPoint(wxCoord x
, wxCoord y
);
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.
322 The last argument specifies the fill rule: @b wxODDEVEN_RULE (the
323 default) or @b wxWINDING_RULE.
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.
328 void DrawPolygon(int n
, wxPoint points
[], wxCoord xoffset
= 0,
330 wxPolygonFillMode fill_style
= wxODDEVEN_RULE
);
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
336 The last argument specifies the fill rule: @b wxODDEVEN_RULE (the
337 default) or @b wxWINDING_RULE.
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.
342 The programmer is responsible for deleting the list of points.
345 The wxPython version of this method accepts a Python list of wxPoint
349 void DrawPolygon(const wxPointList
* points
,
350 wxCoord xoffset
= 0, wxCoord yoffset
= 0,
351 wxPolygonFillMode fill_style
= wxODDEVEN_RULE
);
354 Draws two or more filled polygons using an array of @a points, adding
355 the optional offset coordinates.
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.
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
365 The last argument specifies the fill rule: @b wxODDEVEN_RULE (the
366 default) or @b wxWINDING_RULE.
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.
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.
380 void DrawPolyPolygon(int n
, int count
[], wxPoint points
[],
381 wxCoord xoffset
= 0, wxCoord yoffset
= 0,
382 wxPolygonFillMode fill_style
= wxODDEVEN_RULE
);
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.
389 void DrawRectangle(wxCoord x
, wxCoord y
, wxCoord width
, wxCoord height
);
392 Draws the text rotated by @a angle degrees.
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.
401 void DrawRotatedText(const wxString
& text
, wxCoord x
, wxCoord y
,
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
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.
417 void DrawRoundedRectangle(wxCoord x
, wxCoord y
, wxCoord width
,
418 wxCoord height
, double radius
);
422 Draws a spline between all given points using the current pen.
425 The wxPython version of this method accepts a Python list of wxPoint
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
);
436 Draws a text string at the specified point, using the current text
437 font, and the current text foreground and background colours.
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.
443 @note The current @ref GetLogicalFunction() "logical function" is
444 ignored by this function.
446 void DrawText(const wxString
& text
, wxCoord x
, wxCoord y
);
449 Ends a document (only relevant when outputting to a printer).
454 Ends a document page (only relevant when outputting to a printer).
459 Flood fills the device context starting from the given point, using
460 the current brush colour, and using a style:
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
467 @return @false if the operation failed.
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.
473 bool FloodFill(wxCoord x
, wxCoord y
, const wxColour
& colour
,
474 wxFloodFillStyle style
= wxFLOOD_SURFACE
);
477 Gets the brush used for painting the background.
479 @see wxDC::SetBackground()
481 const wxBrush
& GetBackground() const;
484 Returns the current background mode: @c wxSOLID or @c wxTRANSPARENT.
486 @see SetBackgroundMode()
488 int GetBackgroundMode() const;
491 Gets the current brush.
493 @see wxDC::SetBrush()
495 const wxBrush
& GetBrush() const;
498 Gets the character height of the currently set font.
500 wxCoord
GetCharHeight() const;
503 Gets the average character width of the currently set font.
505 wxCoord
GetCharWidth() const;
508 Gets the rectangle surrounding the current clipping region.
511 No arguments are required and the four values defining the rectangle
512 are returned as a tuple.
515 void GetClippingBox(wxCoord
*x
, wxCoord
*y
, wxCoord
*width
, wxCoord
*height
) const;
518 Returns the depth (number of bits/pixel) of this DC.
520 @see wxDisplayDepth()
522 int GetDepth() const;
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
530 const wxFont
& GetFont() const;
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.
538 @see SetLayoutDirection()
540 wxLayoutDirection
GetLayoutDirection() const;
543 Gets the current logical function.
545 @see SetLogicalFunction()
547 wxRasterOperationMode
GetLogicalFunction() const;
550 Gets the mapping mode for the device context.
554 wxMappingMode
GetMapMode() const;
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.
561 The text extent is set in the given @a w and @a h pointers.
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
567 @note This function works with both single-line and multi-line strings.
569 @see wxFont, SetFont(), GetPartialTextExtents(), GetTextExtent()
571 void GetMultiLineTextExtent(const wxString
& string
, wxCoord
* w
,
573 wxCoord
* heightLine
= NULL
,
574 const wxFont
* font
= NULL
) const;
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.
580 @return The text extent as a wxSize object.
582 @note This function works with both single-line and multi-line strings.
584 @see wxFont, SetFont(), GetPartialTextExtents(), GetTextExtent()
586 wxSize
GetMultiLineTextExtent(const wxString
& string
) const;
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.
597 This method only takes the @a text parameter and returns a Python list
601 @see GetMultiLineTextExtent(), GetTextExtent()
603 bool GetPartialTextExtents(const wxString
& text
,
604 wxArrayInt
& widths
) const;
607 Gets the current pen.
611 const wxPen
& GetPen() const;
614 Gets in @a colour the colour at the specified location. Not available
615 for wxPostScriptDC or wxMetafileDC.
617 @note Setting a pixel can be done using DrawPoint().
620 The wxColour value is returned and is not required as a parameter.
623 bool GetPixel(wxCoord x
, wxCoord y
, wxColour
* colour
) const;
626 Returns the resolution of the device in pixels per inch.
628 wxSize
GetPPI() const;
632 This gets the horizontal and vertical resolution in device units. It
633 can be used to scale graphics to fit the page.
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:
642 double scaleX = (double)(maxX / w);
643 double scaleY = (double)(maxY / h);
644 dc.SetUserScale(min(scaleX, scaleY),min(scaleX, scaleY));
648 In place of a single overloaded method name, wxPython implements the
650 - GetSize() - Returns a wxSize.
651 - GetSizeWH() - Returns a 2-tuple (width, height).
654 void GetSize(wxCoord
* width
, wxCoord
* height
) const;
655 wxSize
GetSize() const;
660 Returns the horizontal and vertical resolution in millimetres.
662 void GetSizeMM(wxCoord
* width
, wxCoord
* height
) const;
663 wxSize
GetSizeMM() const;
667 Gets the current text background colour.
669 @see SetTextBackground()
671 const wxColour
& GetTextBackground() const;
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).
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.
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
688 @note This function only works with single-line strings.
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).
697 @see wxFont, SetFont(), GetPartialTextExtents(),
698 GetMultiLineTextExtent()
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;
708 Gets the current text foreground colour.
710 @see SetTextForeground()
712 const wxColour
& GetTextForeground() const;
715 Gets the current user scale factor.
719 void GetUserScale(double* x
, double* y
) const;
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.
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
731 @note Currently this function is very slow, don't use it for real-time
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
);
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.
750 void GradientFillLinear(const wxRect
& rect
, const wxColour
& initialColour
,
751 const wxColour
& destColour
,
752 wxDirection nDirection
= wxRIGHT
);
755 Returns @true if the DC is ok to use.
760 Converts logical X coordinate to device coordinate, using the current
761 mapping mode, user scale factor, device origin and axis orientation.
763 wxCoord
LogicalToDeviceX(wxCoord x
) const;
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.
770 wxCoord
LogicalToDeviceXRel(wxCoord x
) const;
773 Converts logical Y coordinate to device coordinate, using the current
774 mapping mode, user scale factor, device origin and axis orientation.
776 wxCoord
LogicalToDeviceY(wxCoord y
) const;
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.
783 wxCoord
LogicalToDeviceYRel(wxCoord y
) const;
786 Gets the maximum horizontal extent used in drawing commands so far.
788 wxCoord
MaxX() const;
791 Gets the maximum vertical extent used in drawing commands so far.
793 wxCoord
MaxY() const;
796 Gets the minimum horizontal extent used in drawing commands so far.
798 wxCoord
MinX() const;
801 Gets the minimum vertical extent used in drawing commands so far.
803 wxCoord
MinY() const;
806 Resets the bounding box: after a call to this function, the bounding
807 box doesn't contain anything.
809 @see CalcBoundingBox()
811 void ResetBoundingBox();
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.
819 True to set the x axis orientation to the natural left to right
820 orientation, @false to invert it.
822 True to set the y axis orientation to the natural bottom up
823 orientation, @false to invert it.
825 void SetAxisOrientation(bool xLeftRight
, bool yBottomUp
);
828 Sets the current background brush for the DC.
830 void SetBackground(const wxBrush
& brush
);
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.
836 void SetBackgroundMode(int mode
);
839 Sets the current brush for the DC.
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.
845 @see wxBrush, wxMemoryDC (for the interpretation of colours when
846 drawing into a monochrome bitmap)
848 void SetBrush(const wxBrush
& brush
);
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.
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.
861 @see DestroyClippingRegion(), wxRegion
863 void SetClippingRegion(wxCoord x
, wxCoord y
, wxCoord width
,
865 void SetClippingRegion(const wxPoint
& pt
, const wxSize
& sz
);
866 void SetClippingRegion(const wxRect
& rect
);
870 Sets the clipping region for this device context.
872 Unlike SetClippingRegion(), this function works with physical
873 coordinates and not with the logical ones.
875 void SetDeviceClippingRegion(const wxRegion
& region
);
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.
882 void SetDeviceOrigin(wxCoord x
, wxCoord y
);
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.
890 void SetFont(const wxFont
& font
);
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.
897 @see GetLayoutDirection()
899 void SetLayoutDirection(wxLayoutDirection dir
);
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.
908 The possible values and their meaning in terms of source and
909 destination pixel values are as follows:
913 wxAND_INVERT (NOT src) AND dst
914 wxAND_REVERSE src AND (NOT dst)
917 wxEQUIV (NOT src) XOR dst
919 wxNAND (NOT src) OR (NOT dst)
920 wxNOR (NOT src) AND (NOT dst)
923 wxOR_INVERT (NOT src) OR dst
924 wxOR_REVERSE src OR (NOT dst)
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.
935 void SetLogicalFunction(wxRasterOperationMode function
);
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.
946 The coordinate origin is always at the top left of the screen/printer.
948 Drawing to a Windows printer device context uses the current mapping
949 mode, but mapping mode is currently ignored for PostScript output.
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
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.
959 void SetMapMode(wxMappingMode mode
);
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.
969 void SetPalette(const wxPalette
& palette
);
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.
976 @see wxMemoryDC for the interpretation of colours when drawing into a
979 void SetPen(const wxPen
& pen
);
982 Sets the current text background colour for the DC.
984 void SetTextBackground(const wxColour
& colour
);
987 Sets the current text foreground colour for the DC.
989 @see wxMemoryDC for the interpretation of colours when drawing into a
992 void SetTextForeground(const wxColour
& colour
);
995 Sets the user scaling factor, useful for applications which require
998 void SetUserScale(double xScale
, double yScale
);
1001 Starts a document (only relevant when outputting to a printer).
1002 @a message is a message to show while printing.
1004 bool StartDoc(const wxString
& message
);
1007 Starts a document page (only relevant when outputting to a printer).
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.
1018 Destination device context x position.
1020 Destination device context y position.
1022 Width of destination area.
1024 Height of destination area.
1026 Source device context.
1028 Source device context x position.
1030 Source device context y position.
1032 Width of source area to be copied.
1034 Height of source area to be copied.
1036 Logical function to use, see SetLogicalFunction().
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
1043 <li>Creates a temporary bitmap and copies the destination area into
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
1054 <li>ORs the temporary bitmap with the destination area.</li>
1055 <li>Deletes the temporary bitmap.</li>
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.
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.
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.
1073 There is partial support for Blit() in wxPostScriptDC, under X.
1075 StretchBlit() is only implemented under wxMAC and wxMSW.
1077 See wxMemoryDC for typical usage.
1081 @see Blit(), wxMemoryDC, wxBitmap, wxMask
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
);
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:
1104 void MyFunction(wxDC& dc)
1106 wxDCClipper clip(dc, rect);
1107 // ... drawing functions here are affected by clipping rect ...
1110 void OtherFunction()
1114 // ... drawing functions here are not affected by clipping rect ...
1121 @see wxDC::SetClippingRegion(), wxDCFontChanger, wxDCTextColourChanger, wxDCPenChanger,
1129 Sets the clipping region to the specified region/coordinates.
1131 The clipping region is automatically unset when this object is destroyed.
1133 wxDCClipper(wxDC
& dc
, const wxRegion
& r
);
1134 wxDCClipper(wxDC
& dc
, const wxRect
& rect
);
1135 wxDCClipper(wxDC
& dc
, wxCoord x
, wxCoord y
, wxCoord w
, wxCoord h
);
1139 Destroys the clipping region associated with the DC passed to the ctor.
1146 @class wxDCBrushChanger
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.
1154 @see wxDC::SetBrush(), wxDCFontChanger, wxDCTextColourChanger, wxDCPenChanger,
1157 class wxDCBrushChanger
1161 Sets @a brush on the given @a dc, storing the old one.
1164 The DC where the brush must be temporary set.
1168 wxDCBrushChanger(wxDC
& dc
, const wxBrush
& brush
);
1171 Restores the brush originally selected in the DC passed to the ctor.
1173 ~wxDCBrushChanger();
1178 @class wxDCPenChanger
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.
1186 @see wxDC::SetPen(), wxDCFontChanger, wxDCTextColourChanger, wxDCBrushChanger,
1189 class wxDCPenChanger
1193 Sets @a pen on the given @a dc, storing the old one.
1196 The DC where the pen must be temporary set.
1200 wxDCPenChanger(wxDC
& dc
, const wxPen
& pen
);
1203 Restores the pen originally selected in the DC passed to the ctor.
1211 @class wxDCTextColourChanger
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.
1220 @see wxDC::SetTextForeground(), wxDCFontChanger, wxDCPenChanger, wxDCBrushChanger,
1223 class wxDCTextColourChanger
1227 Sets @a col on the given @a dc, storing the old one.
1230 The DC where the colour must be temporary set.
1234 wxDCTextColourChanger(wxDC
& dc
, const wxColour
& col
);
1237 Restores the colour originally selected in the DC passed to the ctor.
1239 ~wxDCTextColourChanger();
1245 @class wxDCFontChanger
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.
1255 @see wxDC::SetFont(), wxDCTextColourChanger, wxDCPenChanger, wxDCBrushChanger,
1258 class wxDCFontChanger
1262 Sets @a font on the given @a dc, storing the old one.
1265 The DC where the font must be temporary set.
1269 wxDCFontChanger(wxDC
& dc
, const wxFont
& font
);
1272 Restores the colour originally selected in the DC passed to the ctor.