/////////////////////////////////////////////////////////////////////////////
// Name: dc.h
// Purpose: interface of wxDC
// Author: wxWidgets team
// RCS-ID: $Id$
// Licence: wxWindows license
/////////////////////////////////////////////////////////////////////////////
/**
@class wxDC
@wxheader{dc.h}
A wxDC is a @e "device context" onto which graphics and text can be drawn.
It is intended to represent different output devices and offers a common
abstract API for drawing on any of them.
wxWidgets offers an alternative drawing API based on the modern drawing
backends GDI+, CoreGraphics and Cairo. See wxGraphicsContext, wxGraphicsRenderer
and related classes. There is also a wxGCDC linking the APIs by offering
the wxDC API ontop of a wxGraphicsContext.
wxDC is an abstract base class and cannot be created directly.
Use wxPaintDC, wxClientDC, wxWindowDC, wxScreenDC, wxMemoryDC or
wxPrinterDC.
In addition to the versions of the methods documented below, there
are also versions which accept single wxPoint parameter instead
of the two wxCoord ones or wxPoint and wxSize instead of the four
wxCoord parameters.
Beginning with wxWidgets 2.9.0 the entire wxDC code has been
reorganized. All platform dependent code (actually all drawing code)
has been moved into backend classes which derive from a common
wxDCImpl class. The user-visible classes such as wxClientDC and
wxPaintDC merely forward all calls to the backend implementation.
On Mac OS X colours with alpha channel are supported. Instances wxPen
or wxBrush that are built from wxColour use the colour's alpha values
when stroking or filling.
@library{wxcore}
@category{dc,gdi}
@see @ref overview_dc, wxGraphicsContext
@todo Precise definition of default/initial state.
@todo Pixelwise definition of operations (e.g. last point of a line not
drawn).
@todo Coordinates: state clearly which type of coordinates are returned by
the various Get*Point() or similar functions - often they are client
coordinates but not always.
*/
class wxDC : public wxObject
{
public:
/**
Copy from a source DC to this DC, specifying the destination
coordinates, size of area to copy, source DC, source coordinates,
logical function, whether to use a bitmap mask, and mask source
position.
@param xdest
Destination device context x position.
@param ydest
Destination device context y position.
@param width
Width of source area to be copied.
@param height
Height of source area to be copied.
@param source
Source device context.
@param xsrc
Source device context x position.
@param ysrc
Source device context y position.
@param logicalFunc
Logical function to use, see SetLogicalFunction().
@param useMask
If @true, Blit does a transparent blit using the mask that is
associated with the bitmap selected into the source device context.
The Windows implementation does the following if MaskBlt cannot be
used:
- Creates a temporary bitmap and copies the destination area into
it.
- Copies the source area into the temporary bitmap using the
specified logical function.
- Sets the masked area in the temporary bitmap to BLACK by ANDing
the mask bitmap with the temp bitmap with the foreground colour
set to WHITE and the bg colour set to BLACK.
- Sets the unmasked area in the destination area to BLACK by
ANDing the mask bitmap with the destination area with the
foreground colour set to BLACK and the background colour set to
WHITE.
- ORs the temporary bitmap with the destination area.
- Deletes the temporary bitmap.
This sequence of operations ensures that the source's transparent
area need not be black, and logical functions are supported.
@n @b Note: on Windows, blitting with masks can be speeded up
considerably by compiling wxWidgets with the wxUSE_DC_CACHE option
enabled. You can also influence whether MaskBlt or the explicit
mask blitting code above is used, by using wxSystemOptions and
setting the @c no-maskblt option to 1.
@param xsrcMask
Source x position on the mask. If both xsrcMask and ysrcMask are
-1, xsrc and ysrc will be assumed for the mask source position.
Currently only implemented on Windows.
@param ysrcMask
Source y position on the mask. If both xsrcMask and ysrcMask are
-1, xsrc and ysrc will be assumed for the mask source position.
Currently only implemented on Windows.
@remarks There is partial support for Blit() in wxPostScriptDC, under X.
@see StretchBlit(), wxMemoryDC, wxBitmap, wxMask
*/
bool Blit(wxCoord xdest, wxCoord ydest, wxCoord width,
wxCoord height, wxDC* source, wxCoord xsrc, wxCoord ysrc,
int logicalFunc = wxCOPY, bool useMask = false,
wxCoord xsrcMask = -1, wxCoord ysrcMask = -1);
/**
Adds the specified point to the bounding box which can be retrieved
with MinX(), MaxX() and MinY(), MaxY() functions.
@see ResetBoundingBox()
*/
void CalcBoundingBox(wxCoord x, wxCoord y);
/**
Clears the device context using the current background brush.
*/
void Clear();
/**
Performs all necessary computations for given platform and context type
after each change of scale and origin parameters. Usually called
automatically internally after such changes.
*/
virtual void ComputeScaleAndOrigin();
/**
Displays a cross hair using the current pen. This is a vertical and
horizontal line the height and width of the window, centred on the
given point.
*/
void CrossHair(wxCoord x, wxCoord y);
/**
Destroys the current clipping region so that none of the DC is clipped.
@see SetClippingRegion()
*/
void DestroyClippingRegion();
/**
Convert device X coordinate to logical coordinate, using the current
mapping mode.
*/
virtual wxCoord DeviceToLogicalX(wxCoord x);
/**
Convert device X coordinate to relative logical coordinate, using the
current mapping mode but ignoring the x axis orientation. Use this
function for converting a width, for example.
*/
virtual wxCoord DeviceToLogicalXRel(wxCoord x);
/**
Converts device Y coordinate to logical coordinate, using the current
mapping mode.
*/
virtual wxCoord DeviceToLogicalY(wxCoord y);
/**
Convert device Y coordinate to relative logical coordinate, using the
current mapping mode but ignoring the y axis orientation. Use this
function for converting a height, for example.
*/
virtual wxCoord DeviceToLogicalYRel(wxCoord y);
/**
Draws an arc of a circle, centred on (@a xc, @a yc), with starting
point (@a x1, @a y1) and ending at (@a x2, @a y2). The current pen is
used for the outline and the current brush for filling the shape.
The arc is drawn in a counter-clockwise direction from the start point
to the end point.
*/
void DrawArc(wxCoord x1, wxCoord y1, wxCoord x2, wxCoord y2,
wxCoord xc, wxCoord yc);
/**
Draw a bitmap on the device context at the specified point. If
@a transparent is @true and the bitmap has a transparency mask, the
bitmap will be drawn transparently.
When drawing a mono-bitmap, the current text foreground colour will be
used to draw the foreground of the bitmap (all bits set to 1), and the
current text background colour to draw the background (all bits set to
0).
@see SetTextForeground(), SetTextBackground(), wxMemoryDC
*/
void DrawBitmap(const wxBitmap& bitmap, wxCoord x, wxCoord y,
bool transparent);
//@{
/**
Draws a check mark inside the given rectangle.
*/
void DrawCheckMark(wxCoord x, wxCoord y, wxCoord width, wxCoord height);
void DrawCheckMark(const wxRect& rect);
//@}
//@{
/**
Draws a circle with the given centre and radius.
@see DrawEllipse()
*/
void DrawCircle(wxCoord x, wxCoord y, wxCoord radius);
void DrawCircle(const wxPoint& pt, wxCoord radius);
//@}
//@{
/**
Draws an ellipse contained in the rectangle specified either with the
given top left corner and the given size or directly. The current pen
is used for the outline and the current brush for filling the shape.
@see DrawCircle()
*/
void DrawEllipse(wxCoord x, wxCoord y, wxCoord width, wxCoord height);
void DrawEllipse(const wxPoint& pt, const wxSize& size);
void DrawEllipse(const wxRect& rect);
//@}
/**
Draws an arc of an ellipse. The current pen is used for drawing the arc
and the current brush is used for drawing the pie.
@a x and @a y specify the x and y coordinates of the upper-left corner
of the rectangle that contains the ellipse.
@a width and @a height specify the width and height of the rectangle
that contains the ellipse.
@a start and @a end specify the start and end of the arc relative to
the three-o'clock position from the center of the rectangle. Angles are
specified in degrees (360 is a complete circle). Positive values mean
counter-clockwise motion. If @a start is equal to @e end, a complete
ellipse will be drawn.
*/
void DrawEllipticArc(wxCoord x, wxCoord y, wxCoord width, wxCoord height,
double start, double end);
/**
Draw an icon on the display (does nothing if the device context is
PostScript). This can be the simplest way of drawing bitmaps on a
window.
*/
void DrawIcon(const wxIcon& icon, wxCoord x, wxCoord y);
//@{
/**
Draw optional bitmap and the text into the given rectangle and aligns
it as specified by alignment parameter; it also will emphasize the
character with the given index if it is != -1 and return the bounding
rectangle if required.
*/
virtual void DrawLabel(const wxString& text, const wxBitmap& image,
const wxRect& rect,
int alignment = wxALIGN_LEFT | wxALIGN_TOP,
int indexAccel = -1, wxRect* rectBounding = NULL);
void DrawLabel(const wxString& text, const wxRect& rect,
int alignment = wxALIGN_LEFT | wxALIGN_TOP,
int indexAccel = -1);
//@}
/**
Draws a line from the first point to the second. The current pen is
used for drawing the line. Note that the point (@a x2, @a y2) is not
part of the line and is not drawn by this function (this is consistent
with the behaviour of many other toolkits).
*/
void DrawLine(wxCoord x1, wxCoord y1, wxCoord x2, wxCoord y2);
/**
Draws lines using an array of points of size @a n adding the optional
offset coordinate. The current pen is used for drawing the lines.
@beginWxPythonOnly
The wxPython version of this method accepts a Python list of wxPoint
objects.
@endWxPythonOnly
*/
void DrawLines(int n, wxPoint points[], wxCoord xoffset = 0,
wxCoord yoffset = 0);
/**
This method uses a list of wxPoints, adding the optional offset
coordinate. The programmer is responsible for deleting the list of
points.
@beginWxPythonOnly
The wxPython version of this method accepts a Python list of wxPoint
objects.
@endWxPythonOnly
*/
void DrawLines(const wxPointList* points,
wxCoord xoffset = 0, wxCoord yoffset = 0);
/**
Draws a point using the color of the current pen. Note that the other
properties of the pen are not used, such as width.
*/
void DrawPoint(wxCoord x, wxCoord y);
/**
Draws a filled polygon using an array of points of size @a n, adding
the optional offset coordinate. The first and last points are
automatically closed.
The last argument specifies the fill rule: @b wxODDEVEN_RULE (the
default) or @b wxWINDING_RULE.
The current pen is used for drawing the outline, and the current brush
for filling the shape. Using a transparent brush suppresses filling.
*/
void DrawPolygon(int n, wxPoint points[], wxCoord xoffset = 0,
wxCoord yoffset = 0, int fill_style = wxODDEVEN_RULE);
/**
This method draws a filled polygon using a list of wxPoints, adding the
optional offset coordinate. The first and last points are automatically
closed.
The last argument specifies the fill rule: @b wxODDEVEN_RULE (the
default) or @b wxWINDING_RULE.
The current pen is used for drawing the outline, and the current brush
for filling the shape. Using a transparent brush suppresses filling.
The programmer is responsible for deleting the list of points.
@beginWxPythonOnly
The wxPython version of this method accepts a Python list of wxPoint
objects.
@endWxPythonOnly
*/
void DrawPolygon(const wxPointList* points,
wxCoord xoffset = 0, wxCoord yoffset = 0,
int fill_style = wxODDEVEN_RULE);
/**
Draws two or more filled polygons using an array of @a points, adding
the optional offset coordinates.
Notice that for the platforms providing a native implementation of this
function (Windows and PostScript-based wxDC currently), this is more
efficient than using DrawPolygon() in a loop.
@a n specifies the number of polygons to draw, the array @e count of
size @a n specifies the number of points in each of the polygons in the
@a points array.
The last argument specifies the fill rule: @b wxODDEVEN_RULE (the
default) or @b wxWINDING_RULE.
The current pen is used for drawing the outline, and the current brush
for filling the shape. Using a transparent brush suppresses filling.
The polygons maybe disjoint or overlapping. Each polygon specified in a
call to DrawPolyPolygon() must be closed. Unlike polygons created by
the DrawPolygon() member function, the polygons created by this
method are not closed automatically.
@beginWxPythonOnly
Not implemented yet.
@endWxPythonOnly
*/
void DrawPolyPolygon(int n, int count[], wxPoint points[],
wxCoord xoffset = 0, wxCoord yoffset = 0,
int fill_style = wxODDEVEN_RULE);
/**
Draws a rectangle with the given top left corner, and with the given
size. The current pen is used for the outline and the current brush
for filling the shape.
*/
void DrawRectangle(wxCoord x, wxCoord y, wxCoord width, wxCoord height);
/**
Draws the text rotated by @a angle degrees.
@note Under Win9x only TrueType fonts can be drawn by this function. In
particular, a font different from @c wxNORMAL_FONT should be used
as the latter is not a TrueType font. @c wxSWISS_FONT is an
example of a font which is.
@see DrawText()
*/
void DrawRotatedText(const wxString& text, wxCoord x, wxCoord y,
double angle);
/**
Draws a rectangle with the given top left corner, and with the given
size. The corners are quarter-circles using the given radius. The
current pen is used for the outline and the current brush for filling
the shape.
If @a radius is positive, the value is assumed to be the radius of the
rounded corner. If @a radius is negative, the absolute value is assumed
to be the @e proportion of the smallest dimension of the rectangle.
This means that the corner can be a sensible size relative to the size
of the rectangle, and also avoids the strange effects X produces when
the corners are too big for the rectangle.
*/
void DrawRoundedRectangle(wxCoord x, wxCoord y, wxCoord width,
wxCoord height, double radius);
//@{
/**
Draws a spline between all given points using the current pen.
@beginWxPythonOnly
The wxPython version of this method accepts a Python list of wxPoint
objects.
@endWxPythonOnly
*/
void DrawSpline(int n, wxPoint points[]);
void DrawSpline(const wxPointList* points);
void DrawSpline(wxCoord x1, wxCoord y1, wxCoord x2, wxCoord y2,
wxCoord x3, wxCoord y3);
//@}
/**
Draws a text string at the specified point, using the current text
font, and the current text foreground and background colours.
The coordinates refer to the top-left corner of the rectangle bounding
the string. See GetTextExtent() for how to get the dimensions of a text
string, which can be used to position the text more precisely.
@note Under wxGTK, the current
@ref GetLogicalFunction() "logical function" is used by this
function but it is ignored by wxMSW. Thus, you should avoid using
logical functions with this function in portable programs.
*/
void DrawText(const wxString& text, wxCoord x, wxCoord y);
/**
Ends a document (only relevant when outputting to a printer).
*/
void EndDoc();
/**
Ends a document page (only relevant when outputting to a printer).
*/
void EndPage();
/**
Flood fills the device context starting from the given point, using
the current brush colour, and using a style:
- wxFLOOD_SURFACE: The flooding occurs until a colour other than the
given colour is encountered.
- wxFLOOD_BORDER: The area to be flooded is bounded by the given
colour.
@return @false if the operation failed.
@note The present implementation for non-Windows platforms may fail to
find colour borders if the pixels do not match the colour
exactly. However the function will still return @true.
*/
bool FloodFill(wxCoord x, wxCoord y, const wxColour& colour,
int style = wxFLOOD_SURFACE);
/**
Gets the brush used for painting the background.
@see wxDC::SetBackground()
*/
const wxBrush GetBackground() const;
/**
Returns the current background mode: @c wxSOLID or @c wxTRANSPARENT.
@see SetBackgroundMode()
*/
int GetBackgroundMode() const;
/**
Gets the current brush.
@see wxDC::SetBrush()
*/
const wxBrush GetBrush() const;
/**
Gets the character height of the currently set font.
*/
wxCoord GetCharHeight();
/**
Gets the average character width of the currently set font.
*/
wxCoord GetCharWidth();
/**
Gets the rectangle surrounding the current clipping region.
@beginWxPythonOnly
No arguments are required and the four values defining the rectangle
are returned as a tuple.
@endWxPythonOnly
*/
void GetClippingBox(wxCoord x, wxCoord y, wxCoord width, wxCoord height);
/**
Returns the depth (number of bits/pixel) of this DC.
@see wxDisplayDepth()
*/
int GetDepth() const;
/**
Gets the current font. Notice that even although each device context
object has some default font after creation, this method would return a
wxNullFont initially and only after calling SetFont() a valid font is
returned.
*/
const wxFont GetFont() const;
/**
Gets the current layout direction of the device context. On platforms
where RTL layout is supported, the return value will either be
@c wxLayout_LeftToRight or @c wxLayout_RightToLeft. If RTL layout is
not supported, the return value will be @c wxLayout_Default.
@see SetLayoutDirection()
*/
wxLayoutDirection GetLayoutDirection() const;
/**
Gets the current logical function.
@see SetLogicalFunction()
*/
int GetLogicalFunction();
/**
Gets the mapping mode for the device context.
@see SetMapMode()
*/
int GetMapMode();
/**
Gets the dimensions of the string using the currently selected font.
@a string is the text string to measure, @e heightLine, if non @NULL,
is where to store the height of a single line.
The text extent is set in the given @a w and @a h pointers.
If the optional parameter @a font is specified and valid, then it is
used for the text extent calculation, otherwise the currently selected
font is used.
@note This function works with both single-line and multi-line strings.
@see wxFont, SetFont(), GetPartialTextExtents(), GetTextExtent()
*/
void GetMultiLineTextExtent(const wxString& string, wxCoord* w,
wxCoord* h,
wxCoord* heightLine = NULL,
wxFont* font = NULL) const;
/**
Gets the dimensions of the string using the currently selected font.
@a string is the text string to measure, @e heightLine, if non @NULL,
is where to store the height of a single line.
@return The text extent as a wxSize object.
@note This function works with both single-line and multi-line strings.
@see wxFont, SetFont(), GetPartialTextExtents(), GetTextExtent()
*/
const wxSize GetMultiLineTextExtent(const wxString& string) const;
/**
Fills the @a widths array with the widths from the beginning of @a text
to the corresponding character of @a text. The generic version simply
builds a running total of the widths of each character using
GetTextExtent(), however if the various platforms have a native API
function that is faster or more accurate than the generic
implementation then it should be used instead.
@beginWxPythonOnly
This method only takes the @a text parameter and returns a Python list
of integers.
@endWxPythonOnly
@see GetMultiLineTextExtent(), GetTextExtent()
*/
bool GetPartialTextExtents(const wxString& text,
wxArrayInt& widths) const;
/**
Gets the current pen.
@see SetPen()
*/
const wxPen GetPen() const;
/**
Gets in @a colour the colour at the specified location. Not available
for wxPostScriptDC or wxMetafileDC.
@note Setting a pixel can be done using DrawPoint().
@beginWxPythonOnly
The wxColour value is returned and is not required as a parameter.
@endWxPythonOnly
*/
bool GetPixel(wxCoord x, wxCoord y, wxColour* colour);
/**
Returns the resolution of the device in pixels per inch.
*/
wxSize GetPPI() const;
//@{
/**
This gets the horizontal and vertical resolution in device units. It
can be used to scale graphics to fit the page.
For example, if @e maxX and @e maxY represent the maximum horizontal
and vertical 'pixel' values used in your application, the following
code will scale the graphic to fit on the printer page:
@code
wxCoord w, h;
dc.GetSize(&w, &h);
double scaleX = (double)(maxX / w);
double scaleY = (double)(maxY / h);
dc.SetUserScale(min(scaleX, scaleY),min(scaleX, scaleY));
@endcode
@beginWxPythonOnly
In place of a single overloaded method name, wxPython implements the
following methods:
- GetSize() - Returns a wxSize.
- GetSizeWH() - Returns a 2-tuple (width, height).
@endWxPythonOnly
*/
void GetSize(wxCoord* width, wxCoord* height) const;
const wxSize GetSize() const;
//@}
//@{
/**
Returns the horizontal and vertical resolution in millimetres.
*/
void GetSizeMM(wxCoord* width, wxCoord* height) const;
const wxSize GetSizeMM() const;
//@}
/**
Gets the current text background colour.
@see SetTextBackground()
*/
const wxColour GetTextBackground() const;
//@{
/**
Gets the dimensions of the string using the currently selected font.
@a string is the text string to measure, @a descent is the dimension
from the baseline of the font to the bottom of the descender, and
@a externalLeading is any extra vertical space added to the font by the
font designer (usually is zero).
The text extent is returned in @a w and @a h pointers or as a wxSize
object depending on which version of this function is used.
If the optional parameter @a font is specified and valid, then it is
used for the text extent calculation. Otherwise the currently selected
font is.
@note This function only works with single-line strings.
@beginWxPythonOnly
The following methods are implemented in wxPython:
- GetTextExtent(string) - Returns a 2-tuple, (width, height).
- GetFullTextExtent(string, font=NULL) -
Returns a 4-tuple, (width, height, descent, externalLeading).
@endWxPythonOnly
@see wxFont, SetFont(), GetPartialTextExtents(),
GetMultiLineTextExtent()
*/
void GetTextExtent(const wxString& string, wxCoord* w, wxCoord* h,
wxCoord* descent = NULL,
wxCoord* externalLeading = NULL,
const wxFont* font = NULL) const;
const wxSize GetTextExtent(const wxString& string) const;
//@}
/**
Gets the current text foreground colour.
@see SetTextForeground()
*/
const wxColour GetTextForeground() const;
/**
Gets the current user scale factor.
@see SetUserScale()
*/
void GetUserScale(double x, double y);
//@{
/**
Fill the area specified by rect with a radial gradient, starting from
@a initialColour at the centre of the circle and fading to
@a destColour on the circle outside.
@a circleCenter are the relative coordinates of centre of the circle in
the specified @e rect. If not specified, the circle is placed at the
centre of rect.
@note Currently this function is very slow, don't use it for real-time
drawing.
*/
void GradientFillConcentric(const wxRect& rect,
const wxColour& initialColour,
const wxColour& destColour);
void GradientFillConcentric(const wxRect& rect,
const wxColour& initialColour,
const wxColour& destColour,
const wxPoint& circleCenter);
//@}
/**
Fill the area specified by @a rect with a linear gradient, starting
from @a initialColour and eventually fading to @e destColour. The
@a nDirection specifies the direction of the colour change, default is
to use @a initialColour on the left part of the rectangle and
@a destColour on the right one.
*/
void GradientFillLinear(const wxRect& rect,
const wxColour& initialColour,
const wxColour& destColour,
wxDirection nDirection = wxEAST);
/**
Returns @true if the DC is ok to use.
*/
bool Ok();
/**
Converts logical X coordinate to device coordinate, using the current
mapping mode.
*/
virtual wxCoord LogicalToDeviceX(wxCoord x);
/**
Converts logical X coordinate to relative device coordinate, using the
current mapping mode but ignoring the x axis orientation. Use this for
converting a width, for example.
*/
virtual wxCoord LogicalToDeviceXRel(wxCoord x);
/**
Converts logical Y coordinate to device coordinate, using the current
mapping mode.
*/
virtual wxCoord LogicalToDeviceY(wxCoord y);
/**
Converts logical Y coordinate to relative device coordinate, using the
current mapping mode but ignoring the y axis orientation. Use this for
converting a height, for example.
*/
virtual wxCoord LogicalToDeviceYRel(wxCoord y);
/**
Gets the maximum horizontal extent used in drawing commands so far.
*/
wxCoord MaxX();
/**
Gets the maximum vertical extent used in drawing commands so far.
*/
wxCoord MaxY();
/**
Gets the minimum horizontal extent used in drawing commands so far.
*/
wxCoord MinX();
/**
Gets the minimum vertical extent used in drawing commands so far.
*/
wxCoord MinY();
/**
Resets the bounding box: after a call to this function, the bounding
box doesn't contain anything.
@see CalcBoundingBox()
*/
void ResetBoundingBox();
/**
Sets the x and y axis orientation (i.e., the direction from lowest to
highest values on the axis). The default orientation is x axis from
left to right and y axis from top down.
@param xLeftRight
True to set the x axis orientation to the natural left to right
orientation, @false to invert it.
@param yBottomUp
True to set the y axis orientation to the natural bottom up
orientation, @false to invert it.
*/
void SetAxisOrientation(bool xLeftRight, bool yBottomUp);
/**
Sets the current background brush for the DC.
*/
void SetBackground(const wxBrush& brush);
/**
@a mode may be one of wxSOLID and wxTRANSPARENT. This setting
determines whether text will be drawn with a background colour or not.
*/
void SetBackgroundMode(int mode);
/**
Sets the current brush for the DC.
If the argument is wxNullBrush, the current brush is selected out of
the device context (leaving wxDC without any valid brush), allowing the
current brush to be destroyed safely.
@see wxBrush, wxMemoryDC (for the interpretation of colours when
drawing into a monochrome bitmap)
*/
void SetBrush(const wxBrush& brush);
//@{
/**
Sets the clipping region for this device context to the intersection of
the given region described by the parameters of this method and the
previously set clipping region. You should call DestroyClippingRegion()
if you want to set the clipping region exactly to the region specified.
The clipping region is an area to which drawing is restricted. Possible
uses for the clipping region are for clipping text or for speeding up
window redraws when only a known area of the screen is damaged.
@see DestroyClippingRegion(), wxRegion
*/
void SetClippingRegion(wxCoord x, wxCoord y, wxCoord width,
wxCoord height);
void SetClippingRegion(const wxPoint& pt, const wxSize& sz);
void SetClippingRegion(const wxRect& rect);
//@}
/**
Sets the clipping region for this device context.
Unlike SetClippingRegion(), this function works with physical
coordinates and not with the logical ones.
*/
void SetDeviceClippingRegion(const wxRegion& region);
/**
Sets the device origin (i.e., the origin in pixels after scaling has
been applied). This function may be useful in Windows printing
operations for placing a graphic on a page.
*/
void SetDeviceOrigin(wxCoord x, wxCoord y);
/**
Sets the current font for the DC. It must be a valid font, in
particular you should not pass wxNullFont to this method.
@see wxFont
*/
void SetFont(const wxFont& font);
/**
Sets the current layout direction for the device context. @a dir may be
either @c wxLayout_Default, @c wxLayout_LeftToRight or
@c wxLayout_RightToLeft.
@see GetLayoutDirection()
*/
void SetLayoutDirection(wxLayoutDirection dir);
/**
Sets the current logical function for the device context. This
determines how a source pixel (from a pen or brush colour, or source
device context if using Blit()) combines with a destination pixel in
the current device context.
The possible values and their meaning in terms of source and
destination pixel values are as follows:
@verbatim
wxAND src AND dst
wxAND_INVERT (NOT src) AND dst
wxAND_REVERSE src AND (NOT dst)
wxCLEAR 0
wxCOPY src
wxEQUIV (NOT src) XOR dst
wxINVERT NOT dst
wxNAND (NOT src) OR (NOT dst)
wxNOR (NOT src) AND (NOT dst)
wxNO_OP dst
wxOR src OR dst
wxOR_INVERT (NOT src) OR dst
wxOR_REVERSE src OR (NOT dst)
wxSET 1
wxSRC_INVERT NOT src
wxXOR src XOR dst
@endverbatim
The default is wxCOPY, which simply draws with the current colour. The
others combine the current colour and the background using a logical
operation. wxINVERT is commonly used for drawing rubber bands or moving
outlines, since drawing twice reverts to the original colour.
*/
void SetLogicalFunction(int function);
/**
The mapping mode of the device context defines the unit of measurement
used to convert logical units to device units. Note that in X, text
drawing isn't handled consistently with the mapping mode; a font is
always specified in point size. However, setting the user scale (see
SetUserScale()) scales the text appropriately. In Windows, scalable
TrueType fonts are always used; in X, results depend on availability of
fonts, but usually a reasonable match is found.
The coordinate origin is always at the top left of the screen/printer.
Drawing to a Windows printer device context uses the current mapping
mode, but mapping mode is currently ignored for PostScript output.
The mapping mode can be one of the following:
- wxMM_TWIPS: Each logical unit is 1/20 of a point, or 1/1440 of an
inch.
- wxMM_POINTS: Each logical unit is a point, or 1/72 of an inch.
- wxMM_METRIC: Each logical unit is 1 mm.
- wxMM_LOMETRIC: Each logical unit is 1/10 of a mm.
- wxMM_TEXT: Each logical unit is 1 device pixel.
*/
void SetMapMode(int mode);
/**
If this is a window DC or memory DC, assigns the given palette to the
window or bitmap associated with the DC. If the argument is
wxNullPalette, the current palette is selected out of the device
context, and the original palette restored.
@see wxPalette
*/
void SetPalette(const wxPalette& palette);
/**
Sets the current pen for the DC. If the argument is wxNullPen, the
current pen is selected out of the device context (leaving wxDC without
any valid pen), allowing the current brush to be destroyed safely.
@see wxMemoryDC for the interpretation of colours when drawing into a
monochrome bitmap.
*/
void SetPen(const wxPen& pen);
/**
Sets the current text background colour for the DC.
*/
void SetTextBackground(const wxColour& colour);
/**
Sets the current text foreground colour for the DC.
@see wxMemoryDC for the interpretation of colours when drawing into a
monochrome bitmap.
*/
void SetTextForeground(const wxColour& colour);
/**
Sets the user scaling factor, useful for applications which require
'zooming'.
*/
void SetUserScale(double xScale, double yScale);
/**
Starts a document (only relevant when outputting to a printer).
@a message is a message to show while printing.
*/
bool StartDoc(const wxString& message);
/**
Starts a document page (only relevant when outputting to a printer).
*/
bool StartPage();
/**
Copy from a source DC to this DC, specifying the destination
coordinates, destination size, source DC, source coordinates, size of
source area to copy, logical function, whether to use a bitmap mask,
and mask source position.
@param xdest
Destination device context x position.
@param ydest
Destination device context y position.
@param dstWidth
Width of destination area.
@param dstHeight
Height of destination area.
@param source
Source device context.
@param xsrc
Source device context x position.
@param ysrc
Source device context y position.
@param srcWidth
Width of source area to be copied.
@param srcHeight
Height of source area to be copied.
@param logicalFunc
Logical function to use, see SetLogicalFunction().
@param useMask
If @true, Blit does a transparent blit using the mask that is
associated with the bitmap selected into the source device context.
The Windows implementation does the following if MaskBlt cannot be
used:
- Creates a temporary bitmap and copies the destination area into
it.
- Copies the source area into the temporary bitmap using the
specified logical function.
- Sets the masked area in the temporary bitmap to BLACK by ANDing
the mask bitmap with the temp bitmap with the foreground colour
set to WHITE and the bg colour set to BLACK.
- Sets the unmasked area in the destination area to BLACK by
ANDing the mask bitmap with the destination area with the
foreground colour set to BLACK and the background colour set to
WHITE.
- ORs the temporary bitmap with the destination area.
- Deletes the temporary bitmap.
This sequence of operations ensures that the source's transparent
area need not be black, and logical functions are supported.
@n @b Note: on Windows, blitting with masks can be speeded up
considerably by compiling wxWidgets with the wxUSE_DC_CACHE option
enabled. You can also influence whether MaskBlt or the explicit
mask blitting code above is used, by using wxSystemOptions and
setting the @c no-maskblt option to 1.
@param xsrcMask
Source x position on the mask. If both xsrcMask and ysrcMask are
-1, xsrc and ysrc will be assumed for the mask source position.
Currently only implemented on Windows.
@param ysrcMask
Source y position on the mask. If both xsrcMask and ysrcMask are
-1, xsrc and ysrc will be assumed for the mask source position.
Currently only implemented on Windows.
There is partial support for Blit() in wxPostScriptDC, under X.
StretchBlit() is only implemented under wxMAC and wxMSW.
See wxMemoryDC for typical usage.
@since 2.9.0
@see Blit(), wxMemoryDC, wxBitmap, wxMask
*/
bool StretchBlit(wxCoord xdest, wxCoord ydest,
wxCoord dstWidth, wxCoord dstHeight,
wxDC* source, wxCoord xsrc, wxCoord ysrc,
wxCoord srcWidth, wxCoord srcHeight,
int logicalFunc = wxCOPY,
bool useMask = false,
wxCoord xsrcMask = -1, wxCoord ysrcMask = -1);
};
/**
@class wxDCClipper
@wxheader{dc.h}
wxDCClipper is a small helper class for setting a clipping region on a wxDC
and unsetting it automatically. An object of wxDCClipper class is typically
created on the stack so that it is automatically destroyed when the object
goes out of scope. A typical usage example:
@code
void MyFunction(wxDC& dc)
{
wxDCClipper clip(dc, rect);
// ... drawing functions here are affected by clipping rect ...
}
void OtherFunction()
{
wxDC dc;
MyFunction(dc);
// ... drawing functions here are not affected by clipping rect ...
}
@endcode
@library{wxcore}
@category{gdi}
@see wxDC::SetClippingRegion()
*/
class wxDCClipper
{
public:
//@{
/**
Sets the clipping region to the specified region/coordinates.
The clipping region is automatically unset when this object is destroyed.
*/
wxDCClipper(wxDC& dc, const wxRegion& r);
wxDCClipper(wxDC& dc, const wxRect& rect);
wxDCClipper(wxDC& dc, int x, int y, int w, int h);
//@}
};