1 /////////////////////////////////////////////////////////////////////////////
3 // Purpose: interface of wxDC
4 // Author: wxWidgets team
6 // Licence: wxWindows license
7 /////////////////////////////////////////////////////////////////////////////
11 Logical raster operations which can be used with wxDC::SetLogicalFunction
12 and some other wxDC functions (e.g. wxDC::Blit and wxDC::StretchBlit).
14 The description of the values below refer to how a generic @e src source pixel
15 and the corresponding @e dst destination pixel gets combined together to produce
16 the final pixel. E.g. @c wxCLEAR and @c wxSET completely ignore the source
17 and the destination pixel and always put zeroes or ones in the final surface.
19 enum wxRasterOperationMode
22 wxXOR
, //!< @e src XOR @e dst
23 wxINVERT
, //!< NOT @e dst
24 wxOR_REVERSE
, //!< @e src OR (NOT @e dst)
25 wxAND_REVERSE
, //!< @e src AND (NOT @e dst)
27 wxAND
, //!< @e src AND @e dst
28 wxAND_INVERT
, //!< (NOT @e src) AND @e dst
30 wxNOR
, //!< (NOT @e src) AND (NOT @e dst)
31 wxEQUIV
, //!< (NOT @e src) XOR @e dst
32 wxSRC_INVERT
, //!< (NOT @e src)
33 wxOR_INVERT
, //!< (NOT @e src) OR @e dst
34 wxNAND
, //!< (NOT @e src) OR (NOT @e dst)
35 wxOR
, //!< @e src OR @e dst
40 Flood styles used by wxDC::FloodFill.
44 /** The flooding occurs until a colour other than the given colour is encountered. */
47 /** The area to be flooded is bounded by the given colour. */
52 The mapping used to transform @e logical units to @e device units.
58 Each logical unit is 1 device pixel.
59 This is the default mapping mode for all wxDC-derived classes.
63 /** Each logical unit is 1 millimeter. */
66 /** Each logical unit is 1/10 of a millimeter. */
70 Each logical unit is 1/20 of a @e "printer point", or 1/1440 of an inch
71 (also known as "twip"). Equivalent to about 17.64 micrometers.
76 Each logical unit is a @e "printer point" i.e. 1/72 of an inch.
77 Equivalent to about 353 micrometers.
87 A wxDC is a @e "device context" onto which graphics and text can be drawn.
88 It is intended to represent different output devices and offers a common
89 abstract API for drawing on any of them.
91 wxWidgets offers an alternative drawing API based on the modern drawing
92 backends GDI+, CoreGraphics and Cairo. See wxGraphicsContext, wxGraphicsRenderer
93 and related classes. There is also a wxGCDC linking the APIs by offering
94 the wxDC API ontop of a wxGraphicsContext.
96 wxDC is an abstract base class and cannot be created directly.
97 Use wxPaintDC, wxClientDC, wxWindowDC, wxScreenDC, wxMemoryDC or
98 wxPrinterDC. Notice that device contexts which are associated with windows
99 (i.e. wxClientDC, wxWindowDC and wxPaintDC) use the window font and colours
100 by default (starting with wxWidgets 2.9.0) but the other device context
101 classes use system-default values so you always must set the appropriate
102 fonts and colours before using them.
104 In addition to the versions of the methods documented below, there
105 are also versions which accept single wxPoint parameter instead
106 of the two wxCoord ones or wxPoint and wxSize instead of the four
109 Beginning with wxWidgets 2.9.0 the entire wxDC code has been
110 reorganized. All platform dependent code (actually all drawing code)
111 has been moved into backend classes which derive from a common
112 wxDCImpl class. The user-visible classes such as wxClientDC and
113 wxPaintDC merely forward all calls to the backend implementation.
116 @section dc_units Device and logical units
118 In the wxDC context there is a distinction between @e logical units and @e device units.
120 @b Device units are the units native to the particular device; e.g. for a screen,
121 a device unit is a @e pixel. For a printer, the device unit is defined by the
122 resolution of the printer (usually given in @c DPI: dot-per-inch).
124 All wxDC functions use instead @b logical units, unless where explicitely
125 stated. Logical units are arbitrary units mapped to device units using
126 the current mapping mode (see wxDC::SetMapMode).
128 This mechanism allows to reuse the same code which prints on e.g. a window
129 on the screen to print on e.g. a paper.
132 @section dc_alpha_support Support for Transparency / Alpha Channel
134 On Mac OS X colours with alpha channel are supported. Instances of wxPen
135 or wxBrush that are built from wxColour use the colour's alpha values
136 when stroking or filling.
142 @see @ref overview_dc, wxGraphicsContext, wxDCFontChanger, wxDCTextColourChanger,
143 wxDCPenChanger, wxDCBrushChanger, wxDCClipper
145 @todo Precise definition of default/initial state.
146 @todo Pixelwise definition of operations (e.g. last point of a line not
149 class wxDC
: public wxObject
153 @name Coordinate conversion functions
158 Convert @e device X coordinate to logical coordinate, using the current
159 mapping mode, user scale factor, device origin and axis orientation.
161 wxCoord
DeviceToLogicalX(wxCoord x
) const;
164 Convert @e device X coordinate to relative logical coordinate, using the
165 current mapping mode and user scale factor but ignoring the
166 axis orientation. Use this for converting a width, for example.
168 wxCoord
DeviceToLogicalXRel(wxCoord x
) const;
171 Converts @e device Y coordinate to logical coordinate, using the current
172 mapping mode, user scale factor, device origin and axis orientation.
174 wxCoord
DeviceToLogicalY(wxCoord y
) const;
177 Convert @e device Y coordinate to relative logical coordinate, using the
178 current mapping mode and user scale factor but ignoring the
179 axis orientation. Use this for converting a height, for example.
181 wxCoord
DeviceToLogicalYRel(wxCoord y
) const;
184 Converts logical X coordinate to device coordinate, using the current
185 mapping mode, user scale factor, device origin and axis orientation.
187 wxCoord
LogicalToDeviceX(wxCoord x
) const;
190 Converts logical X coordinate to relative device coordinate, using the
191 current mapping mode and user scale factor but ignoring the
192 axis orientation. Use this for converting a width, for example.
194 wxCoord
LogicalToDeviceXRel(wxCoord x
) const;
197 Converts logical Y coordinate to device coordinate, using the current
198 mapping mode, user scale factor, device origin and axis orientation.
200 wxCoord
LogicalToDeviceY(wxCoord y
) const;
203 Converts logical Y coordinate to relative device coordinate, using the
204 current mapping mode and user scale factor but ignoring the
205 axis orientation. Use this for converting a height, for example.
207 wxCoord
LogicalToDeviceYRel(wxCoord y
) const;
214 @name Drawing functions
219 Clears the device context using the current background brush.
224 Draws an arc of a circle, centred on (@a xc, @a yc), with starting
225 point (@a xStart, @a yStart) and ending at (@a xEnd, @a yEnd).
226 The current pen is used for the outline and the current brush for
229 The arc is drawn in a counter-clockwise direction from the start point
232 void DrawArc(wxCoord xStart
, wxCoord yStart
, wxCoord xEnd
, wxCoord yEnd
,
233 wxCoord xc
, wxCoord yc
);
238 void DrawArc(const wxPoint
& ptStart
, const wxPoint
& ptEnd
, const wxPoint
& centre
);
241 Draw a bitmap on the device context at the specified point. If
242 @a transparent is @true and the bitmap has a transparency mask, the
243 bitmap will be drawn transparently.
245 When drawing a mono-bitmap, the current text foreground colour will be
246 used to draw the foreground of the bitmap (all bits set to 1), and the
247 current text background colour to draw the background (all bits set to
250 @see SetTextForeground(), SetTextBackground(), wxMemoryDC
252 void DrawBitmap(const wxBitmap
& bitmap
, wxCoord x
, wxCoord y
,
253 bool useMask
= false);
258 void DrawBitmap(const wxBitmap
&bmp
, const wxPoint
& pt
,
259 bool useMask
= false);
262 Draws a check mark inside the given rectangle.
264 void DrawCheckMark(wxCoord x
, wxCoord y
, wxCoord width
, wxCoord height
);
269 void DrawCheckMark(const wxRect
& rect
);
272 Draws a circle with the given centre and radius.
276 void DrawCircle(wxCoord x
, wxCoord y
, wxCoord radius
);
281 void DrawCircle(const wxPoint
& pt
, wxCoord radius
);
284 Draws an ellipse contained in the rectangle specified either with the
285 given top left corner and the given size or directly. The current pen
286 is used for the outline and the current brush for filling the shape.
290 void DrawEllipse(wxCoord x
, wxCoord y
, wxCoord width
, wxCoord height
);
295 void DrawEllipse(const wxPoint
& pt
, const wxSize
& size
);
300 void DrawEllipse(const wxRect
& rect
);
303 Draws an arc of an ellipse. The current pen is used for drawing the arc
304 and the current brush is used for drawing the pie.
306 @a x and @a y specify the x and y coordinates of the upper-left corner
307 of the rectangle that contains the ellipse.
309 @a width and @a height specify the width and height of the rectangle
310 that contains the ellipse.
312 @a start and @a end specify the start and end of the arc relative to
313 the three-o'clock position from the center of the rectangle. Angles are
314 specified in degrees (360 is a complete circle). Positive values mean
315 counter-clockwise motion. If @a start is equal to @e end, a complete
316 ellipse will be drawn.
318 void DrawEllipticArc(wxCoord x
, wxCoord y
, wxCoord width
, wxCoord height
,
319 double start
, double end
);
324 void DrawEllipticArc(const wxPoint
& pt
, const wxSize
& sz
,
325 double sa
, double ea
);
328 Draw an icon on the display (does nothing if the device context is
329 PostScript). This can be the simplest way of drawing bitmaps on a
332 void DrawIcon(const wxIcon
& icon
, wxCoord x
, wxCoord y
);
337 void DrawIcon(const wxIcon
& icon
, const wxPoint
& pt
);
340 Draw optional bitmap and the text into the given rectangle and aligns
341 it as specified by alignment parameter; it also will emphasize the
342 character with the given index if it is != -1 and return the bounding
343 rectangle if required.
345 void DrawLabel(const wxString
& text
, const wxBitmap
& image
,
347 int alignment
= wxALIGN_LEFT
| wxALIGN_TOP
,
348 int indexAccel
= -1, wxRect
* rectBounding
= NULL
);
353 void DrawLabel(const wxString
& text
, const wxRect
& rect
,
354 int alignment
= wxALIGN_LEFT
| wxALIGN_TOP
,
355 int indexAccel
= -1);
358 Draws a line from the first point to the second. The current pen is
359 used for drawing the line. Note that the point (@a x2, @a y2) is not
360 part of the line and is not drawn by this function (this is consistent
361 with the behaviour of many other toolkits).
363 void DrawLine(wxCoord x1
, wxCoord y1
, wxCoord x2
, wxCoord y2
);
368 void DrawLine(const wxPoint
& pt1
, const wxPoint
& pt2
);
371 Draws lines using an array of points of size @a n adding the optional
372 offset coordinate. The current pen is used for drawing the lines.
375 The wxPython version of this method accepts a Python list of wxPoint
380 Not supported by wxPerl.
383 void DrawLines(int n
, wxPoint points
[], wxCoord xoffset
= 0,
384 wxCoord yoffset
= 0);
386 This method uses a list of wxPoints, adding the optional offset
387 coordinate. The programmer is responsible for deleting the list of
391 The wxPython version of this method accepts a Python list of wxPoint
396 The wxPerl version of this method accepts
397 as its first parameter a reference to an array
401 void DrawLines(const wxPointList
* points
,
402 wxCoord xoffset
= 0, wxCoord yoffset
= 0);
405 Draws a point using the color of the current pen. Note that the other
406 properties of the pen are not used, such as width.
408 void DrawPoint(wxCoord x
, wxCoord y
);
413 void DrawPoint(const wxPoint
& pt
);
416 Draws a filled polygon using an array of points of size @a n, adding
417 the optional offset coordinate. The first and last points are
418 automatically closed.
420 The last argument specifies the fill rule: @b wxODDEVEN_RULE (the
421 default) or @b wxWINDING_RULE.
423 The current pen is used for drawing the outline, and the current brush
424 for filling the shape. Using a transparent brush suppresses filling.
427 Not supported by wxPerl.
430 void DrawPolygon(int n
, wxPoint points
[], wxCoord xoffset
= 0,
432 wxPolygonFillMode fill_style
= wxODDEVEN_RULE
);
434 This method draws a filled polygon using a list of wxPoints, adding the
435 optional offset coordinate. The first and last points are automatically
438 The last argument specifies the fill rule: @b wxODDEVEN_RULE (the
439 default) or @b wxWINDING_RULE.
441 The current pen is used for drawing the outline, and the current brush
442 for filling the shape. Using a transparent brush suppresses filling.
444 The programmer is responsible for deleting the list of points.
447 The wxPython version of this method accepts a Python list of wxPoint
452 The wxPerl version of this method accepts
453 as its first parameter a reference to an array
457 void DrawPolygon(const wxPointList
* points
,
458 wxCoord xoffset
= 0, wxCoord yoffset
= 0,
459 wxPolygonFillMode fill_style
= wxODDEVEN_RULE
);
462 Draws two or more filled polygons using an array of @a points, adding
463 the optional offset coordinates.
465 Notice that for the platforms providing a native implementation of this
466 function (Windows and PostScript-based wxDC currently), this is more
467 efficient than using DrawPolygon() in a loop.
469 @a n specifies the number of polygons to draw, the array @e count of
470 size @a n specifies the number of points in each of the polygons in the
473 The last argument specifies the fill rule: @b wxODDEVEN_RULE (the
474 default) or @b wxWINDING_RULE.
476 The current pen is used for drawing the outline, and the current brush
477 for filling the shape. Using a transparent brush suppresses filling.
479 The polygons maybe disjoint or overlapping. Each polygon specified in a
480 call to DrawPolyPolygon() must be closed. Unlike polygons created by
481 the DrawPolygon() member function, the polygons created by this
482 method are not closed automatically.
488 void DrawPolyPolygon(int n
, int count
[], wxPoint points
[],
489 wxCoord xoffset
= 0, wxCoord yoffset
= 0,
490 wxPolygonFillMode fill_style
= wxODDEVEN_RULE
);
493 Draws a rectangle with the given top left corner, and with the given
494 size. The current pen is used for the outline and the current brush
495 for filling the shape.
497 void DrawRectangle(wxCoord x
, wxCoord y
, wxCoord width
, wxCoord height
);
502 void DrawRectangle(const wxPoint
& pt
, const wxSize
& sz
);
507 void DrawRectangle(const wxRect
& rect
);
510 Draws the text rotated by @a angle degrees
511 (positive angles are counterclockwise; the full angle is 360 degrees).
513 @note Under Win9x only TrueType fonts can be drawn by this function. In
514 particular, a font different from @c wxNORMAL_FONT should be used
515 as the latter is not a TrueType font. @c wxSWISS_FONT is an
516 example of a font which is.
520 void DrawRotatedText(const wxString
& text
, wxCoord x
, wxCoord y
,
526 void DrawRotatedText(const wxString
& text
, const wxPoint
&,
530 Draws a rectangle with the given top left corner, and with the given
531 size. The corners are quarter-circles using the given radius. The
532 current pen is used for the outline and the current brush for filling
535 If @a radius is positive, the value is assumed to be the radius of the
536 rounded corner. If @a radius is negative, the absolute value is assumed
537 to be the @e proportion of the smallest dimension of the rectangle.
538 This means that the corner can be a sensible size relative to the size
539 of the rectangle, and also avoids the strange effects X produces when
540 the corners are too big for the rectangle.
542 void DrawRoundedRectangle(wxCoord x
, wxCoord y
, wxCoord width
,
543 wxCoord height
, double radius
);
548 void DrawRoundedRectangle(const wxPoint
& pt
, const wxSize
& sz
,
554 void DrawRoundedRectangle(const wxRect
& rect
, double radius
);
557 Draws a spline between all given points using the current pen.
560 The wxPython version of this method accepts a Python list of wxPoint
565 Not supported by wxPerl.
568 void DrawSpline(int n
, wxPoint points
[]);
575 The wxPerl version of this method accepts
576 as its first parameter a reference to an array
580 void DrawSpline(const wxPointList
* points
);
587 Not supported by wxPerl.
590 void DrawSpline(wxCoord x1
, wxCoord y1
, wxCoord x2
, wxCoord y2
,
591 wxCoord x3
, wxCoord y3
);
594 Draws a text string at the specified point, using the current text
595 font, and the current text foreground and background colours.
597 The coordinates refer to the top-left corner of the rectangle bounding
598 the string. See GetTextExtent() for how to get the dimensions of a text
599 string, which can be used to position the text more precisely.
601 @note The current @ref GetLogicalFunction() "logical function" is
602 ignored by this function.
604 void DrawText(const wxString
& text
, wxCoord x
, wxCoord y
);
609 void DrawText(const wxString
& text
, const wxPoint
& pt
);
612 Fill the area specified by rect with a radial gradient, starting from
613 @a initialColour at the centre of the circle and fading to
614 @a destColour on the circle outside.
616 The circle is placed at the centre of @a rect.
618 @note Currently this function is very slow, don't use it for real-time
621 void GradientFillConcentric(const wxRect
& rect
,
622 const wxColour
& initialColour
,
623 const wxColour
& destColour
);
626 Fill the area specified by rect with a radial gradient, starting from
627 @a initialColour at the centre of the circle and fading to
628 @a destColour on the circle outside.
630 @a circleCenter are the relative coordinates of centre of the circle in
631 the specified @a rect.
633 @note Currently this function is very slow, don't use it for real-time
636 void GradientFillConcentric(const wxRect
& rect
,
637 const wxColour
& initialColour
,
638 const wxColour
& destColour
,
639 const wxPoint
& circleCenter
);
642 Fill the area specified by @a rect with a linear gradient, starting
643 from @a initialColour and eventually fading to @e destColour.
645 The @a nDirection specifies the direction of the colour change, default is
646 to use @a initialColour on the left part of the rectangle and
647 @a destColour on the right one.
649 void GradientFillLinear(const wxRect
& rect
, const wxColour
& initialColour
,
650 const wxColour
& destColour
,
651 wxDirection nDirection
= wxRIGHT
);
654 Flood fills the device context starting from the given point, using
655 the current brush colour, and using a style:
657 - wxFLOOD_SURFACE: The flooding occurs until a colour other than the
658 given colour is encountered.
659 - wxFLOOD_BORDER: The area to be flooded is bounded by the given
662 @return @false if the operation failed.
664 @note The present implementation for non-Windows platforms may fail to
665 find colour borders if the pixels do not match the colour
666 exactly. However the function will still return @true.
668 bool FloodFill(wxCoord x
, wxCoord y
, const wxColour
& colour
,
669 wxFloodFillStyle style
= wxFLOOD_SURFACE
);
674 bool FloodFill(const wxPoint
& pt
, const wxColour
& col
,
675 int style
= wxFLOOD_SURFACE
);
678 Displays a cross hair using the current pen. This is a vertical and
679 horizontal line the height and width of the window, centred on the
682 void CrossHair(wxCoord x
, wxCoord y
);
687 void CrossHair(const wxPoint
& pt
);
693 @name Clipping region functions
698 Destroys the current clipping region so that none of the DC is clipped.
700 @see SetClippingRegion()
702 void DestroyClippingRegion();
705 Gets the rectangle surrounding the current clipping region.
708 No arguments are required and the four values defining the rectangle
709 are returned as a tuple.
712 void GetClippingBox(wxCoord
*x
, wxCoord
*y
, wxCoord
*width
, wxCoord
*height
) const;
715 Sets the clipping region for this device context to the intersection of
716 the given region described by the parameters of this method and the
717 previously set clipping region.
719 The clipping region is an area to which drawing is restricted. Possible
720 uses for the clipping region are for clipping text or for speeding up
721 window redraws when only a known area of the screen is damaged.
723 Notice that you need to call DestroyClippingRegion() if you want to set
724 the clipping region exactly to the region specified.
726 Also note that if the clipping region is empty, any previously set
727 clipping region is destroyed, i.e. it is equivalent to calling
728 DestroyClippingRegion(), and not to clipping out all drawing on the DC
729 as might be expected.
731 @see DestroyClippingRegion(), wxRegion
733 void SetClippingRegion(wxCoord x
, wxCoord y
, wxCoord width
, wxCoord height
);
738 void SetClippingRegion(const wxPoint
& pt
, const wxSize
& sz
);
743 void SetClippingRegion(const wxRect
& rect
);
746 Sets the clipping region for this device context.
748 Unlike SetClippingRegion(), this function works with physical
749 coordinates and not with the logical ones.
751 void SetDeviceClippingRegion(const wxRegion
& region
);
757 @name Text/character extent functions
762 Gets the character height of the currently set font.
764 wxCoord
GetCharHeight() const;
767 Gets the average character width of the currently set font.
769 wxCoord
GetCharWidth() const;
772 Gets the dimensions of the string using the currently selected font.
773 @a string is the text string to measure, @e heightLine, if non @NULL,
774 is where to store the height of a single line.
776 The text extent is set in the given @a w and @a h pointers.
778 If the optional parameter @a font is specified and valid, then it is
779 used for the text extent calculation, otherwise the currently selected
782 @note This function works with both single-line and multi-line strings.
785 In wxPerl this method is implemented as
786 GetMultiLineTextExtent(string, font = undef) returning a
787 3-element list (width, height, line_height)
790 @see wxFont, SetFont(), GetPartialTextExtents(), GetTextExtent()
792 void GetMultiLineTextExtent(const wxString
& string
, wxCoord
* w
,
794 wxCoord
* heightLine
= NULL
,
795 const wxFont
* font
= NULL
) const;
797 Gets the dimensions of the string using the currently selected font.
798 @a string is the text string to measure, @e heightLine, if non @NULL,
799 is where to store the height of a single line.
801 @return The text extent as a wxSize object.
803 @note This function works with both single-line and multi-line strings.
806 Not supported by wxPerl.
809 @see wxFont, SetFont(), GetPartialTextExtents(), GetTextExtent()
811 wxSize
GetMultiLineTextExtent(const wxString
& string
) const;
814 Fills the @a widths array with the widths from the beginning of @a text
815 to the corresponding character of @a text. The generic version simply
816 builds a running total of the widths of each character using
817 GetTextExtent(), however if the various platforms have a native API
818 function that is faster or more accurate than the generic
819 implementation then it should be used instead.
822 This method only takes the @a text parameter and returns a Python list
827 In wxPerl this method only takes the @a text parameter and
828 returns the widths as a list of integers.
831 @see GetMultiLineTextExtent(), GetTextExtent()
833 bool GetPartialTextExtents(const wxString
& text
,
834 wxArrayInt
& widths
) const;
837 Gets the dimensions of the string using the currently selected font.
838 @a string is the text string to measure, @a descent is the dimension
839 from the baseline of the font to the bottom of the descender, and
840 @a externalLeading is any extra vertical space added to the font by the
841 font designer (usually is zero).
843 The text extent is returned in @a w and @a h pointers or as a wxSize
844 object depending on which version of this function is used.
846 If the optional parameter @a font is specified and valid, then it is
847 used for the text extent calculation. Otherwise the currently selected
850 @note This function only works with single-line strings.
853 The following methods are implemented in wxPython:
854 - GetTextExtent(string) - Returns a 2-tuple, (width, height).
855 - GetFullTextExtent(string, font=NULL) -
856 Returns a 4-tuple, (width, height, descent, externalLeading).
860 In wxPerl this method is implemented as GetTextExtent(string,
861 font = undef) returning a 4-element list (width, height,
862 descent, externalLeading)
865 @see wxFont, SetFont(), GetPartialTextExtents(),
866 GetMultiLineTextExtent()
868 void GetTextExtent(const wxString
& string
, wxCoord
* w
, wxCoord
* h
,
869 wxCoord
* descent
= NULL
,
870 wxCoord
* externalLeading
= NULL
,
871 const wxFont
* font
= NULL
) const;
878 Not supported by wxPerl.
881 wxSize
GetTextExtent(const wxString
& string
) const;
887 @name Text properties functions
892 Returns the current background mode: @c wxSOLID or @c wxTRANSPARENT.
894 @see SetBackgroundMode()
896 int GetBackgroundMode() const;
899 Gets the current font.
901 Notice that even although each device context object has some default font
902 after creation, this method would return a ::wxNullFont initially and only
903 after calling SetFont() a valid font is returned.
905 const wxFont
& GetFont() const;
908 Gets the current layout direction of the device context. On platforms
909 where RTL layout is supported, the return value will either be
910 @c wxLayout_LeftToRight or @c wxLayout_RightToLeft. If RTL layout is
911 not supported, the return value will be @c wxLayout_Default.
913 @see SetLayoutDirection()
915 wxLayoutDirection
GetLayoutDirection() const;
918 Gets the current text background colour.
920 @see SetTextBackground()
922 const wxColour
& GetTextBackground() const;
925 Gets the current text foreground colour.
927 @see SetTextForeground()
929 const wxColour
& GetTextForeground() const;
932 @a mode may be one of @c wxSOLID and @c wxTRANSPARENT.
934 This setting determines whether text will be drawn with a background
937 void SetBackgroundMode(int mode
);
940 Sets the current font for the DC.
942 If the argument is ::wxNullFont (or another invalid font; see wxFont::IsOk),
943 the current font is selected out of the device context (leaving wxDC without
944 any valid font), allowing the current font to be destroyed safely.
948 void SetFont(const wxFont
& font
);
951 Sets the current text background colour for the DC.
953 void SetTextBackground(const wxColour
& colour
);
956 Sets the current text foreground colour for the DC.
958 @see wxMemoryDC for the interpretation of colours when drawing into a
961 void SetTextForeground(const wxColour
& colour
);
964 Sets the current layout direction for the device context.
967 May be either @c wxLayout_Default, @c wxLayout_LeftToRight or
968 @c wxLayout_RightToLeft.
970 @see GetLayoutDirection()
972 void SetLayoutDirection(wxLayoutDirection dir
);
978 @name Bounding box functions
983 Adds the specified point to the bounding box which can be retrieved
984 with MinX(), MaxX() and MinY(), MaxY() functions.
986 @see ResetBoundingBox()
988 void CalcBoundingBox(wxCoord x
, wxCoord y
);
991 Gets the maximum horizontal extent used in drawing commands so far.
993 wxCoord
MaxX() const;
996 Gets the maximum vertical extent used in drawing commands so far.
998 wxCoord
MaxY() const;
1001 Gets the minimum horizontal extent used in drawing commands so far.
1003 wxCoord
MinX() const;
1006 Gets the minimum vertical extent used in drawing commands so far.
1008 wxCoord
MinY() const;
1011 Resets the bounding box: after a call to this function, the bounding
1012 box doesn't contain anything.
1014 @see CalcBoundingBox()
1016 void ResetBoundingBox();
1022 @name Page and document start/end functions
1027 Starts a document (only relevant when outputting to a printer).
1028 @a message is a message to show while printing.
1030 bool StartDoc(const wxString
& message
);
1033 Starts a document page (only relevant when outputting to a printer).
1038 Ends a document (only relevant when outputting to a printer).
1043 Ends a document page (only relevant when outputting to a printer).
1051 @name Bit-Block Transfer operations (blit)
1056 Copy from a source DC to this DC, specifying the destination
1057 coordinates, size of area to copy, source DC, source coordinates,
1058 logical function, whether to use a bitmap mask, and mask source
1062 Destination device context x position.
1064 Destination device context y position.
1066 Width of source area to be copied.
1068 Height of source area to be copied.
1070 Source device context.
1072 Source device context x position.
1074 Source device context y position.
1076 Logical function to use, see SetLogicalFunction().
1078 If @true, Blit does a transparent blit using the mask that is
1079 associated with the bitmap selected into the source device context.
1080 The Windows implementation does the following if MaskBlt cannot be
1083 <li>Creates a temporary bitmap and copies the destination area into
1085 <li>Copies the source area into the temporary bitmap using the
1086 specified logical function.</li>
1087 <li>Sets the masked area in the temporary bitmap to BLACK by ANDing
1088 the mask bitmap with the temp bitmap with the foreground colour
1089 set to WHITE and the bg colour set to BLACK.</li>
1090 <li>Sets the unmasked area in the destination area to BLACK by
1091 ANDing the mask bitmap with the destination area with the
1092 foreground colour set to BLACK and the background colour set to
1094 <li>ORs the temporary bitmap with the destination area.</li>
1095 <li>Deletes the temporary bitmap.</li>
1097 This sequence of operations ensures that the source's transparent
1098 area need not be black, and logical functions are supported.
1099 @n @b Note: on Windows, blitting with masks can be speeded up
1100 considerably by compiling wxWidgets with the wxUSE_DC_CACHE option
1101 enabled. You can also influence whether MaskBlt or the explicit
1102 mask blitting code above is used, by using wxSystemOptions and
1103 setting the @c no-maskblt option to 1.
1105 Source x position on the mask. If both xsrcMask and ysrcMask are
1106 @c -1, xsrc and ysrc will be assumed for the mask source position.
1107 Currently only implemented on Windows.
1109 Source y position on the mask. If both xsrcMask and ysrcMask are
1110 @c -1, xsrc and ysrc will be assumed for the mask source position.
1111 Currently only implemented on Windows.
1113 @remarks There is partial support for Blit() in wxPostScriptDC, under X.
1115 @see StretchBlit(), wxMemoryDC, wxBitmap, wxMask
1117 bool Blit(wxCoord xdest
, wxCoord ydest
, wxCoord width
,
1118 wxCoord height
, wxDC
* source
, wxCoord xsrc
, wxCoord ysrc
,
1119 wxRasterOperationMode logicalFunc
= wxCOPY
, bool useMask
= false,
1120 wxCoord xsrcMask
= wxDefaultCoord
, wxCoord ysrcMask
= wxDefaultCoord
);
1123 Copy from a source DC to this DC, specifying the destination
1124 coordinates, destination size, source DC, source coordinates, size of
1125 source area to copy, logical function, whether to use a bitmap mask,
1126 and mask source position.
1129 Destination device context x position.
1131 Destination device context y position.
1133 Width of destination area.
1135 Height of destination area.
1137 Source device context.
1139 Source device context x position.
1141 Source device context y position.
1143 Width of source area to be copied.
1145 Height of source area to be copied.
1147 Logical function to use, see SetLogicalFunction().
1149 If @true, Blit does a transparent blit using the mask that is
1150 associated with the bitmap selected into the source device context.
1151 The Windows implementation does the following if MaskBlt cannot be
1154 <li>Creates a temporary bitmap and copies the destination area into
1156 <li>Copies the source area into the temporary bitmap using the
1157 specified logical function.</li>
1158 <li>Sets the masked area in the temporary bitmap to BLACK by ANDing
1159 the mask bitmap with the temp bitmap with the foreground colour
1160 set to WHITE and the bg colour set to BLACK.</li>
1161 <li>Sets the unmasked area in the destination area to BLACK by
1162 ANDing the mask bitmap with the destination area with the
1163 foreground colour set to BLACK and the background colour set to
1165 <li>ORs the temporary bitmap with the destination area.</li>
1166 <li>Deletes the temporary bitmap.</li>
1168 This sequence of operations ensures that the source's transparent
1169 area need not be black, and logical functions are supported.
1170 @n @b Note: on Windows, blitting with masks can be speeded up
1171 considerably by compiling wxWidgets with the wxUSE_DC_CACHE option
1172 enabled. You can also influence whether MaskBlt or the explicit
1173 mask blitting code above is used, by using wxSystemOptions and
1174 setting the @c no-maskblt option to 1.
1176 Source x position on the mask. If both xsrcMask and ysrcMask are
1177 wxDefaultCoord, @a xsrc and @a ysrc will be assumed for the mask
1178 source position. Currently only implemented on Windows.
1180 Source y position on the mask. If both xsrcMask and ysrcMask are
1181 wxDefaultCoord, @a xsrc and @a ysrc will be assumed for the mask
1182 source position. Currently only implemented on Windows.
1184 There is partial support for Blit() in wxPostScriptDC, under X.
1186 StretchBlit() is only implemented under wxMAC and wxMSW.
1188 See wxMemoryDC for typical usage.
1192 @see Blit(), wxMemoryDC, wxBitmap, wxMask
1194 bool StretchBlit(wxCoord xdest
, wxCoord ydest
,
1195 wxCoord dstWidth
, wxCoord dstHeight
,
1196 wxDC
* source
, wxCoord xsrc
, wxCoord ysrc
,
1197 wxCoord srcWidth
, wxCoord srcHeight
,
1198 wxRasterOperationMode logicalFunc
= wxCOPY
,
1199 bool useMask
= false,
1200 wxCoord xsrcMask
= wxDefaultCoord
,
1201 wxCoord ysrcMask
= wxDefaultCoord
);
1206 @name Background/foreground brush and pen
1211 Gets the brush used for painting the background.
1213 @see wxDC::SetBackground()
1215 const wxBrush
& GetBackground() const;
1218 Gets the current brush.
1220 @see wxDC::SetBrush()
1222 const wxBrush
& GetBrush() const;
1225 Gets the current pen.
1229 const wxPen
& GetPen() const;
1232 Sets the current background brush for the DC.
1234 void SetBackground(const wxBrush
& brush
);
1237 Sets the current brush for the DC.
1239 If the argument is ::wxNullBrush (or another invalid brush; see wxBrush::IsOk),
1240 the current brush is selected out of the device context (leaving wxDC without
1241 any valid brush), allowing the current brush to be destroyed safely.
1243 @see wxBrush, wxMemoryDC (for the interpretation of colours when
1244 drawing into a monochrome bitmap)
1246 void SetBrush(const wxBrush
& brush
);
1249 Sets the current pen for the DC.
1251 If the argument is ::wxNullPen (or another invalid pen; see wxPen::IsOk),
1252 the current pen is selected out of the device context (leaving wxDC without any
1253 valid pen), allowing the current pen to be destroyed safely.
1255 @see wxMemoryDC for the interpretation of colours when drawing into a
1258 void SetPen(const wxPen
& pen
);
1264 Copy attributes from another DC.
1266 The copied attributes currently are:
1268 - Text foreground and background colours
1273 A valid (i.e. its IsOk() must return @true) source device context.
1275 void CopyAttributes(const wxDC
& dc
);
1278 Returns the depth (number of bits/pixel) of this DC.
1280 @see wxDisplayDepth()
1282 int GetDepth() const;
1285 Returns the current device origin.
1287 @see SetDeviceOrigin()
1289 wxPoint
GetDeviceOrigin() const;
1292 Gets the current logical function.
1294 @see SetLogicalFunction()
1296 wxRasterOperationMode
GetLogicalFunction() const;
1299 Gets the current mapping mode for the device context.
1303 wxMappingMode
GetMapMode() const;
1306 Gets in @a colour the colour at the specified location. Not available
1307 for wxPostScriptDC or wxMetafileDC.
1309 @note Setting a pixel can be done using DrawPoint().
1312 The wxColour value is returned and is not required as a parameter.
1315 bool GetPixel(wxCoord x
, wxCoord y
, wxColour
* colour
) const;
1318 Returns the resolution of the device in pixels per inch.
1320 wxSize
GetPPI() const;
1323 Gets the horizontal and vertical extent of this device context in @e device units.
1324 It can be used to scale graphics to fit the page.
1326 For example, if @e maxX and @e maxY represent the maximum horizontal
1327 and vertical 'pixel' values used in your application, the following
1328 code will scale the graphic to fit on the printer page:
1333 double scaleX = (double)(maxX / w);
1334 double scaleY = (double)(maxY / h);
1335 dc.SetUserScale(min(scaleX, scaleY),min(scaleX, scaleY));
1339 In place of a single overloaded method name, wxPython implements the
1341 - GetSize() - Returns a wxSize.
1342 - GetSizeWH() - Returns a 2-tuple (width, height).
1346 In wxPerl there are two methods instead of a single overloaded
1348 - GetSize(): returns a Wx::Size object.
1349 - GetSizeWH(): returns a 2-element list (width, height).
1352 void GetSize(wxCoord
* width
, wxCoord
* height
) const;
1357 wxSize
GetSize() const;
1360 Returns the horizontal and vertical resolution in millimetres.
1362 void GetSizeMM(wxCoord
* width
, wxCoord
* height
) const;
1367 wxSize
GetSizeMM() const;
1370 Gets the current user scale factor.
1373 In wxPerl this method takes no arguments and return a two
1374 element array (x, y).
1379 void GetUserScale(double* x
, double* y
) const;
1382 Returns @true if the DC is ok to use.
1387 Sets the x and y axis orientation (i.e., the direction from lowest to
1388 highest values on the axis). The default orientation is x axis from
1389 left to right and y axis from top down.
1392 True to set the x axis orientation to the natural left to right
1393 orientation, @false to invert it.
1395 True to set the y axis orientation to the natural bottom up
1396 orientation, @false to invert it.
1398 void SetAxisOrientation(bool xLeftRight
, bool yBottomUp
);
1401 Sets the device origin (i.e., the origin in pixels after scaling has
1402 been applied). This function may be useful in Windows printing
1403 operations for placing a graphic on a page.
1405 void SetDeviceOrigin(wxCoord x
, wxCoord y
);
1408 Sets the current logical function for the device context.
1409 It determines how a @e source pixel (from a pen or brush colour, or source
1410 device context if using Blit()) combines with a @e destination pixel in
1411 the current device context.
1412 Text drawing is not affected by this function.
1414 See ::wxRasterOperationMode enumeration values for more info.
1416 The default is @c wxCOPY, which simply draws with the current colour.
1417 The others combine the current colour and the background using a logical
1418 operation. @c wxINVERT is commonly used for drawing rubber bands or moving
1419 outlines, since drawing twice reverts to the original colour.
1421 void SetLogicalFunction(wxRasterOperationMode function
);
1424 The mapping mode of the device context defines the unit of measurement
1425 used to convert @e logical units to @e device units.
1427 Note that in X, text drawing isn't handled consistently with the mapping mode;
1428 a font is always specified in point size. However, setting the user scale (see
1429 SetUserScale()) scales the text appropriately. In Windows, scalable
1430 TrueType fonts are always used; in X, results depend on availability of
1431 fonts, but usually a reasonable match is found.
1433 The coordinate origin is always at the top left of the screen/printer.
1435 Drawing to a Windows printer device context uses the current mapping
1436 mode, but mapping mode is currently ignored for PostScript output.
1438 void SetMapMode(wxMappingMode mode
);
1441 If this is a window DC or memory DC, assigns the given palette to the
1442 window or bitmap associated with the DC. If the argument is
1443 ::wxNullPalette, the current palette is selected out of the device
1444 context, and the original palette restored.
1448 void SetPalette(const wxPalette
& palette
);
1451 Sets the user scaling factor, useful for applications which require
1454 void SetUserScale(double xScale
, double yScale
);
1462 wxDCClipper is a small helper class for setting a clipping region on a wxDC
1463 and unsetting it automatically. An object of wxDCClipper class is typically
1464 created on the stack so that it is automatically destroyed when the object
1465 goes out of scope. A typical usage example:
1468 void MyFunction(wxDC& dc)
1470 wxDCClipper clip(dc, rect);
1471 // ... drawing functions here are affected by clipping rect ...
1474 void OtherFunction()
1478 // ... drawing functions here are not affected by clipping rect ...
1485 @see wxDC::SetClippingRegion(), wxDCFontChanger, wxDCTextColourChanger, wxDCPenChanger,
1493 Sets the clipping region to the specified region/coordinates.
1495 The clipping region is automatically unset when this object is destroyed.
1497 wxDCClipper(wxDC
& dc
, const wxRegion
& r
);
1498 wxDCClipper(wxDC
& dc
, const wxRect
& rect
);
1499 wxDCClipper(wxDC
& dc
, wxCoord x
, wxCoord y
, wxCoord w
, wxCoord h
);
1503 Destroys the clipping region associated with the DC passed to the ctor.
1510 @class wxDCBrushChanger
1512 wxDCBrushChanger is a small helper class for setting a brush on a wxDC
1513 and unsetting it automatically in the destructor, restoring the previous one.
1518 @see wxDC::SetBrush(), wxDCFontChanger, wxDCTextColourChanger, wxDCPenChanger,
1521 class wxDCBrushChanger
1525 Sets @a brush on the given @a dc, storing the old one.
1528 The DC where the brush must be temporary set.
1532 wxDCBrushChanger(wxDC
& dc
, const wxBrush
& brush
);
1535 Restores the brush originally selected in the DC passed to the ctor.
1537 ~wxDCBrushChanger();
1542 @class wxDCPenChanger
1544 wxDCPenChanger is a small helper class for setting a pen on a wxDC
1545 and unsetting it automatically in the destructor, restoring the previous one.
1550 @see wxDC::SetPen(), wxDCFontChanger, wxDCTextColourChanger, wxDCBrushChanger,
1553 class wxDCPenChanger
1557 Sets @a pen on the given @a dc, storing the old one.
1560 The DC where the pen must be temporary set.
1564 wxDCPenChanger(wxDC
& dc
, const wxPen
& pen
);
1567 Restores the pen originally selected in the DC passed to the ctor.
1575 @class wxDCTextColourChanger
1577 wxDCTextColourChanger is a small helper class for setting a foreground
1578 text colour on a wxDC and unsetting it automatically in the destructor,
1579 restoring the previous one.
1584 @see wxDC::SetTextForeground(), wxDCFontChanger, wxDCPenChanger, wxDCBrushChanger,
1587 class wxDCTextColourChanger
1591 Trivial constructor not changing anything.
1593 This constructor is useful if you don't know beforehand if the colour
1594 needs to be changed or not. It simply creates the object which won't do
1595 anything in its destructor unless Set() is called -- in which case it
1596 would reset the previous colour.
1598 wxDCTextColourChanger(wxDC
& dc
);
1601 Sets @a col on the given @a dc, storing the old one.
1604 The DC where the colour must be temporary set.
1608 wxDCTextColourChanger(wxDC
& dc
, const wxColour
& col
);
1611 Set the colour to use.
1613 This method is meant to be called once only and only on the objects
1614 created with the constructor overload not taking wxColour argument and
1615 has the same effect as the other constructor, i.e. sets the colour to
1616 the given @a col and ensures that the old value is restored when this
1617 object is destroyed.
1619 void Set(const wxColour
& col
);
1622 Restores the colour originally selected in the DC passed to the ctor.
1624 ~wxDCTextColourChanger();
1630 @class wxDCFontChanger
1632 wxDCFontChanger is a small helper class for setting a font on a wxDC and
1633 unsetting it automatically in the destructor, restoring the previous one.
1640 @see wxDC::SetFont(), wxDCTextColourChanger, wxDCPenChanger, wxDCBrushChanger,
1643 class wxDCFontChanger
1647 Trivial constructor not changing anything.
1649 This constructor is useful if you don't know beforehand if the font
1650 needs to be changed or not. It simply creates the object which won't do
1651 anything in its destructor unless Set() is called -- in which case it
1652 would reset the previous font.
1656 wxDCFontChanger(wxDC
& dc
);
1659 Sets @a font on the given @a dc, storing the old one.
1662 The DC where the font must be temporary set.
1666 wxDCFontChanger(wxDC
& dc
, const wxFont
& font
);
1669 Set the font to use.
1671 This method is meant to be called once only and only on the objects
1672 created with the constructor overload not taking wxColour argument and
1673 has the same effect as the other constructor, i.e. sets the font to
1674 the given @a font and ensures that the old value is restored when this
1675 object is destroyed.
1677 void Set(const wxFont
& font
);
1680 Restores the font originally selected in the DC passed to the ctor.