In this way, the same piece of code may write to a number of different devices,
if the device context is used as a parameter.
-Derived types of wxDC have documentation for specific features
-only, so refer to this section for most device context information.
+Notice that wxDC is an abstract base class and can't be created directly,
+please use \helpref{wxPaintDC}{wxpaintdc}, \helpref{wxClientDC}{wxclientdc},
+\helpref{wxWindowDC}{wxwindowdc}, \helpref{wxScreenDC}{wxscreendc},
+\helpref{wxMemoryDC}{wxmemorydc} or \helpref{wxPrinterDC}{wxprinterdc}.
% VZ: we should really document them instead of this lame excuse, but I don't
% have time for it now, when it is done please remove this
two {\tt wxCoord} ones or {\tt wxPoint} and {\tt wxSize} instead of four of
them.
+\wxheading{Support for Transparency / Alpha Channel}
+
+On Mac OS X when using Core Graphics (wx\_MAC\_USE\_CORE\_GRAPHICS set to 1)
+colors with alpha are supported, so instances {\tt wxPen} or {\tt wxBrush} that are built from {\tt wxColour} use
+the color's alpha values when stroking or filling.
+
\wxheading{Derived from}
\helpref{wxObject}{wxobject}
\latexignore{\rtfignore{\wxheading{Members}}}
-\membersection{wxDC::wxDC}\label{wxdcctor}
-
-\func{}{wxDC}{\void}
-
-Constructor.
-
-
-\membersection{wxDC::\destruct{wxDC}}\label{wxdcdtor}
-
-\func{}{\destruct{wxDC}}{\void}
-
-Destructor.
-
-
-\membersection{wxDC::BeginDrawing}\label{wxdcbegindrawing}
-
-\func{void}{BeginDrawing}{\void}
-
-Allows optimization of drawing code under MS Windows. Enclose
-drawing primitives between {\bf BeginDrawing} and {\bf EndDrawing}\rtfsp
-calls.
-
-Drawing to a wxDialog panel device context outside of a
-system-generated OnPaint event {\it requires} this pair of calls to
-enclose drawing code. This is because a Windows dialog box does not have
-a retained device context associated with it, and selections such as pen
-and brush settings would be lost if the device context were obtained and
-released for each drawing operation.
-
-
\membersection{wxDC::Blit}\label{wxdcblit}
\func{bool}{Blit}{\param{wxCoord}{ xdest}, \param{wxCoord}{ ydest}, \param{wxCoord}{ width}, \param{wxCoord}{ height},
\wxheading{See also}
-\helpref{wxMemoryDC}{wxmemorydc}, \helpref{wxBitmap}{wxbitmap}, \helpref{wxMask}{wxmask}
+\helpref{wxDC::StretchBlit}{wxdcstretchblit}, \helpref{wxMemoryDC}{wxmemorydc}, \helpref{wxBitmap}{wxbitmap}, \helpref{wxMask}{wxmask}
\begin{comment}
\end{comment}
+\membersection{wxDC::ComputeScaleAndOrigin}\label{wxdccomputescaleandorigin}
+
+\func{virtual void}{ComputeScaleAndOrigin}{\void}
+
+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.
+
+
\membersection{wxDC::CrossHair}\label{wxdccrosshair}
\func{void}{CrossHair}{\param{wxCoord}{ x}, \param{wxCoord}{ y}}
\membersection{wxDC::DeviceToLogicalX}\label{wxdcdevicetologicalx}
-\func{wxCoord}{DeviceToLogicalX}{\param{wxCoord}{ x}}
+\func{virtual wxCoord}{DeviceToLogicalX}{\param{wxCoord}{ x}}
Convert device X coordinate to logical coordinate, using the current
mapping mode.
\membersection{wxDC::DeviceToLogicalXRel}\label{wxdcdevicetologicalxrel}
-\func{wxCoord}{DeviceToLogicalXRel}{\param{wxCoord}{ x}}
+\func{virtual wxCoord}{DeviceToLogicalXRel}{\param{wxCoord}{ x}}
Convert device X coordinate to relative logical coordinate, using the current
mapping mode but ignoring the x axis orientation.
\membersection{wxDC::DeviceToLogicalY}\label{wxdcdevicetologicaly}
-\func{wxCoord}{DeviceToLogicalY}{\param{wxCoord}{ y}}
+\func{virtual wxCoord}{DeviceToLogicalY}{\param{wxCoord}{ y}}
Converts device Y coordinate to logical coordinate, using the current
mapping mode.
\membersection{wxDC::DeviceToLogicalYRel}\label{wxdcdevicetologicalyrel}
-\func{wxCoord}{DeviceToLogicalYRel}{\param{wxCoord}{ y}}
+\func{virtual wxCoord}{DeviceToLogicalYRel}{\param{wxCoord}{ y}}
Convert device Y coordinate to relative logical coordinate, using the current
mapping mode but ignoring the y axis orientation.
\membersection{wxDC::DrawRoundedRectangle}\label{wxdcdrawroundedrectangle}
-\func{void}{DrawRoundedRectangle}{\param{wxCoord}{ x}, \param{wxCoord}{ y}, \param{wxCoord}{ width}, \param{wxCoord}{ height}, \param{double}{ radius = 20}}
+\func{void}{DrawRoundedRectangle}{\param{wxCoord}{ x}, \param{wxCoord}{ y}, \param{wxCoord}{ width}, \param{wxCoord}{ height}, \param{double}{ radius}}
Draws a rectangle with the given top left corner, and with the given
size. The corners are quarter-circles using the given radius. The
\membersection{wxDC::DrawSpline}\label{wxdcdrawspline}
+\func{void}{DrawSpline}{\param{int }{n}, \param{wxPoint }{points[]}}
+
+Draws a spline between all given control points, using the current
+pen.
+
\func{void}{DrawSpline}{\param{wxList *}{points}}
Draws a spline between all given control points, using the current
-pen. Doesn't delete the wxList and contents. The spline is drawn
-using a series of lines, using an algorithm taken from the X drawing
-program `XFIG'.
+pen. Doesn't delete the wxList and contents.
\func{void}{DrawSpline}{\param{wxCoord}{ x1}, \param{wxCoord}{ y1}, \param{wxCoord}{ x2}, \param{wxCoord}{ y2}, \param{wxCoord}{ x3}, \param{wxCoord}{ y3}}
Ends a document (only relevant when outputting to a printer).
-\membersection{wxDC::EndDrawing}\label{wxdcenddrawing}
-
-\func{void}{EndDrawing}{\void}
-
-Allows optimization of drawing code under MS Windows. Enclose
-drawing primitives between {\bf BeginDrawing} and {\bf EndDrawing}\rtfsp
-calls.
-
-
\membersection{wxDC::EndPage}\label{wxdcendpage}
\func{void}{EndPage}{\void}
\constfunc{const wxFont\&}{GetFont}{\void}
-Gets the current font (see \helpref{wxDC::SetFont}{wxdcsetfont}).
+Gets the current font. Notice that even although each device context object has
+some default font after creation, this method would return a \texttt{wxNullFont}
+initially and only after calling \helpref{wxDC::SetFont}{wxdcsetfont} a valid
+font is returned.
+
+
+\membersection{wxDC::GetLayoutDirection}\label{wxdcgetlayoutdirection}
+
+\constfunc{wxLayoutDirection}{GetLayoutDirection}{\void}
+
+Gets the current layout direction of the device context. On platforms where RTL layout
+is supported, the return value will either be \texttt{wxLayout\_LeftToRight} or
+\texttt{wxLayout\_RightToLeft}. If RTL layout is not supported, the return value will
+be \texttt{wxLayout\_Default}.
+
+\wxheading{See also}
+
+\helpref{SetLayoutDirection}{wxdcsetlayoutdirection}
\membersection{wxDC::GetLogicalFunction}\label{wxdcgetlogicalfunction}
Gets the {\it mapping mode} for the device context (see \helpref{wxDC::SetMapMode}{wxdcsetmapmode}).
-\membersection{wxDC::GetOptimization}\label{wxdcgetoptimization}
+\membersection{wxDC::GetMultiLineTextExtent}\label{wxdcgetmultilinetextextent}
+
+\constfunc{void}{GetMultiLineTextExtent}{\param{const wxString\& }{string}, \param{wxCoord *}{w},\\
+ \param{wxCoord *}{h}, \param{wxCoord *}{heightLine = NULL}, \param{wxFont *}{font = NULL}}
+
+\constfunc{wxSize}{GetMultiLineTextExtent}{\param{const wxString\& }{string}}
+
+Gets the dimensions of the string using the currently selected font.
+\rtfsp{\it string} is the text string to measure, {\it heightLine}, if non NULL,
+is where to store the height of a single line.
+
+The text extent is returned in {\it w} and {\it h} pointers (first form) or as
+a \helpref{wxSize}{wxsize} object (second form).
+
+If the optional parameter {\it font} is specified and valid, then it is used
+for the text extent calculation. Otherwise the currently selected font is.
+
+Note that this function works both with single-line and multi-line strings.
-\func{bool}{GetOptimization}{\void}
+\wxheading{See also}
-Returns true if device context optimization is on.
-See \helpref{wxDC::SetOptimization}{wxsetoptimization} for details.
+\helpref{wxFont}{wxfont},\rtfsp
+\helpref{wxDC::SetFont}{wxdcsetfont},\rtfsp
+\helpref{wxDC::GetPartialTextExtents}{wxdcgetpartialtextextents},\rtfsp
+\helpref{wxDC::GetTextExtent}{wxdcgettextextent}
\membersection{wxDC::GetPartialTextExtents}\label{wxdcgetpartialtextextents}
\constfunc{bool}{GetPartialTextExtents}{\param{const wxString\& }{text},
\param{wxArrayInt\& }{widths}}
-Fills the {\it widths} array with the widths from the begining of
-{\it text} to the coresponding character of {\it text}. The generic
+Fills the {\it widths} array with the widths from the beginning of
+{\it text} to the corresponding character of {\it text}. The generic
version simply builds a running total of the widths of each character
using \helpref{GetTextExtent}{wxdcgettextextent}, however if the
various platforms have a native API function that is faster or more
-accurate than the generic implementaiton then it should be used
+accurate than the generic implementation then it should be used
instead.
+\wxheading{See also}
+
+\helpref{wxDC::GetMultiLineTextExtent}{wxdcgetmultilinetextextent},\rtfsp
+\helpref{wxDC::GetTextExtent}{wxdcgettextextent}
+
\pythonnote{This method only takes the {\it text} parameter and
returns a Python list of integers.}
\func{bool}{GetPixel}{\param{wxCoord}{ x}, \param{wxCoord}{ y}, \param{wxColour *}{colour}}
-Sets {\it colour} to the colour at the specified location.
+Gets in {\it colour} the colour at the specified location.
Not available for wxPostScriptDC or wxMetafileDC.
+Note that setting a pixel can be done using \helpref{DrawPoint}{wxdcdrawpoint}.
+
\pythonnote{For wxPython the wxColour value is returned and is not
required as a parameter.}
\membersection{wxDC::GetTextExtent}\label{wxdcgettextextent}
-\func{void}{GetTextExtent}{\param{const wxString\& }{string}, \param{wxCoord *}{w}, \param{wxCoord *}{h},\\
- \param{wxCoord *}{descent = NULL}, \param{wxCoord *}{externalLeading = NULL}, \param{wxFont *}{font = NULL}}
+\constfunc{void}{GetTextExtent}{\param{const wxString\& }{string}, \param{wxCoord *}{w}, \param{wxCoord *}{h},\\
+ \param{wxCoord *}{descent = NULL}, \param{wxCoord *}{externalLeading = NULL}, \param{const wxFont *}{font = NULL}}
+
+\constfunc{wxSize}{GetTextExtent}{\param{const wxString\& }{string}}
Gets the dimensions of the string using the currently selected font.
-\rtfsp{\it string} is the text string to measure, {\it w} and {\it h} are
-the total width and height respectively, {\it descent} is the
+\rtfsp{\it string} is the text string to measure, {\it descent} is the
dimension from the baseline of the font to the bottom of the
descender, and {\it externalLeading} is any extra vertical space added
to the font by the font designer (usually is zero).
-The optional parameter {\it font} specifies an alternative
-to the currently selected font: but note that this does not
-yet work under Windows, so you need to set a font for
-the device context first.
+The text extent is returned in {\it w} and {\it h} pointers (first form) or as
+a \helpref{wxSize}{wxsize} object (second form).
-See also \helpref{wxFont}{wxfont}, \helpref{wxDC::SetFont}{wxdcsetfont}.
+If the optional parameter {\it font} is specified and valid, then it is used
+for the text extent calculation. Otherwise the currently selected font is.
+
+Note that this function only works with single-line strings.
+
+\wxheading{See also}
+
+\helpref{wxFont}{wxfont},\rtfsp
+\helpref{wxDC::SetFont}{wxdcsetfont},\rtfsp
+\helpref{wxDC::GetPartialTextExtents}{wxdcgetpartialtextextents},\rtfsp
+\helpref{wxDC::GetMultiLineTextExtent}{wxdcgetmultilinetextextent}
\pythonnote{The following methods are implemented in wxPython:\par
\indented{2cm}{\begin{twocollist}
array {\tt ( x, y )}}
+\membersection{wxDC::GradientFillConcentric}\label{wxdcgradientfillconcentric}
+
+\func{void}{GradientFillConcentric}{\param{const wxRect\&}{ rect}, \param{const wxColour\&}{ initialColour}, \param{const wxColour\&}{ destColour}}
+
+\func{void}{GradientFillConcentric}{\param{const wxRect\&}{ rect}, \param{const wxColour\&}{ initialColour}, \param{const wxColour\&}{ destColour}, \param{const wxPoint\& }{circleCenter}}
+
+Fill the area specified by rect with a radial gradient, starting from
+\arg{initialColour} at the centre of the circle and fading to \arg{destColour}
+on the circle outside.
+
+\arg{circleCenter} are the relative coordinates of centre of the circle in
+the specified \arg{rect}. If not specified, the cercle is placed at the
+centre of rect.
+
+\textbf{Note: } Currently this function is very slow, don't use it for
+real-time drawing.
+
+
+\membersection{wxDC::GradientFillLinear}\label{wxdcgradientfilllinear}
+
+\func{void}{GradientFillLinear}{\param{const wxRect\&}{ rect}, \param{const wxColour\&}{ initialColour}, \param{const wxColour\&}{ destColour}, \param{wxDirection}{ nDirection = wxEAST}}
+
+Fill the area specified by \arg{rect} with a linear gradient, starting from
+\arg{initialColour} and eventually fading to \arg{destColour}. The
+\arg{nDirection} specifies the direction of the colour change, default is to
+use \arg{initialColour} on the left part of the rectangle and
+\arg{destColour} on the right one.
+
+
\membersection{wxDC::LogicalToDeviceX}\label{wxdclogicaltodevicex}
-\func{wxCoord}{LogicalToDeviceX}{\param{wxCoord}{ x}}
+\func{virtual wxCoord}{LogicalToDeviceX}{\param{wxCoord}{ x}}
Converts logical X coordinate to device coordinate, using the current
mapping mode.
\membersection{wxDC::LogicalToDeviceXRel}\label{wxdclogicaltodevicexrel}
-\func{wxCoord}{LogicalToDeviceXRel}{\param{wxCoord}{ x}}
+\func{virtual wxCoord}{LogicalToDeviceXRel}{\param{wxCoord}{ x}}
Converts logical X coordinate to relative device coordinate, using the current
mapping mode but ignoring the x axis orientation.
\membersection{wxDC::LogicalToDeviceY}\label{wxdclogicaltodevicey}
-\func{wxCoord}{LogicalToDeviceY}{\param{wxCoord}{ y}}
+\func{virtual wxCoord}{LogicalToDeviceY}{\param{wxCoord}{ y}}
Converts logical Y coordinate to device coordinate, using the current
mapping mode.
\membersection{wxDC::LogicalToDeviceYRel}\label{wxdclogicaltodeviceyrel}
-\func{wxCoord}{LogicalToDeviceYRel}{\param{wxCoord}{ y}}
+\func{virtual wxCoord}{LogicalToDeviceYRel}{\param{wxCoord}{ y}}
Converts logical Y coordinate to relative device coordinate, using the current
mapping mode but ignoring the y axis orientation.
Gets the minimum vertical extent used in drawing commands so far.
-\membersection{wxDC::Ok}\label{wxdcok}
+\membersection{wxDC::IsOk}\label{wxdcisok}
\func{bool}{Ok}{\void}
\param{bool}{ yBottomUp}}
Sets the x and y axis orientation (i.e., the direction from lowest to
-highest values on the axis). The default orientation is the natural
-orientation, e.g. x axis from left to right and y axis from bottom up.
+highest values on the axis). The default orientation is
+x axis from left to right and y axis from top down.
\wxheading{Parameters}
Sets the current brush for the DC.
If the argument is wxNullBrush, the current brush is selected out of the device
-context, and the original brush restored, allowing the current brush to
+context (leaving wxDC without any valid brush), allowing the current brush to
be destroyed safely.
See also \helpref{wxBrush}{wxbrush}.
See also \helpref{wxFont}{wxfont}.
+\membersection{wxDC::SetLayoutDirection}\label{wxdcsetlayoutdirection}
+
+\func{void}{SetLayoutDirection}{\param{wxLayoutDirection}{ dir}}
+
+Sets the current layout direction for the device context. \arg{dir} may be either
+\texttt{wxLayout\_Default}, \texttt{wxLayout\_LeftToRight} or \texttt{wxLayout\_RightToLeft}.
+
+\wxheading{See also}
+
+\helpref{GetLayoutDirection}{wxdcgetlayoutdirection}
+
+
\membersection{wxDC::SetLogicalFunction}\label{wxdcsetlogicalfunction}
\func{void}{SetLogicalFunction}{\param{int}{ function}}
\end{twocollist}
-\membersection{wxDC::SetOptimization}\label{wxsetoptimization}
-
-\func{void}{SetOptimization}{\param{bool }{optimize}}
-
-If {\it optimize} is true (the default), this function sets optimization mode on.
-This currently means that under X, the device context will not try to set a pen or brush
-property if it is known to be set already. This approach can fall down
-if non-wxWidgets code is using the same device context or window, for example
-when the window is a panel on which the windowing system draws panel items.
-The wxWidgets device context 'memory' will now be out of step with reality.
-
-Setting optimization off, drawing, then setting it back on again, is a trick
-that must occasionally be employed.
-
-
\membersection{wxDC::SetPalette}\label{wxdcsetpalette}
\func{void}{SetPalette}{\param{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, and the original pen restored.
+context (leaving wxDC without any valid pen), allowing the current brush to
+be destroyed safely.
See also \helpref{wxMemoryDC}{wxmemorydc} for the interpretation of colours
when drawing into a monochrome bitmap.
\func{bool}{StartDoc}{\param{const wxString\& }{message}}
Starts a document (only relevant when outputting to a printer).
-Message is a message to show whilst printing.
+Message is a message to show while printing.
\membersection{wxDC::StartPage}\label{wxdcstartpage}
Starts a document page (only relevant when outputting to a printer).
-\section{\class{wxDCClipper}}\label{wxdcclipper}
-This is a small helper class which sets the specified to its constructor
-clipping region and then automatically destroys it in its destructor. Using
-it ensures that unwanted clipping region is not left set on the DC.
+\membersection{wxDC::StretchBlit}\label{wxdcstretchblit}
-\wxheading{Derived from}
+\func{bool}{StretchBlit}{\param{wxCoord}{ xdest}, \param{wxCoord}{ ydest}, \param{wxCoord}{ dstWidth}, \param{wxCoord}{ dstHeight},
+ \param{wxDC* }{source}, \param{wxCoord}{ xsrc}, \param{wxCoord}{ ysrc}, \param{wxCoord}{ srcWidth}, \param{wxCoord}{ srcHeight},
+ \param{int}{ logicalFunc = wxCOPY}, \param{bool }{useMask = false}, \param{wxCoord}{ xsrcMask = -1}, \param{wxCoord}{ ysrcMask = -1}}
-No base class
+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.
-\wxheading{Include files}
+\wxheading{Parameters}
-<wx/dc.h>
+\docparam{xdest}{Destination device context x position.}
-\wxheading{See also}
+\docparam{ydest}{Destination device context y position.}
-\helpref{wxDC}{wxdc}
+\docparam{dstWidth}{Width of destination area.}
-\latexignore{\rtfignore{\wxheading{Members}}}
+\docparam{dstHeight}{Height of destination area.}
+
+\docparam{source}{Source device context.}
+
+\docparam{xsrc}{Source device context x position.}
+
+\docparam{ysrc}{Source device context y position.}
+
+\docparam{srcWidth}{Width of source area to be copied.}
+
+\docparam{srcHeight}{Height of source area to be copied.}
+
+\docparam{logicalFunc}{Logical function to use: see \helpref{wxDC::SetLogicalFunction}{wxdcsetlogicalfunction}.}
+
+\docparam{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 \texttt{MaskBlt} cannot be used:
+\begin{enumerate}
+\item Creates a temporary bitmap and copies the destination area into it.
+\item Copies the source area into the temporary bitmap using the specified logical function.
+\item 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 background colour set to BLACK.
+\item 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.
+\item ORs the temporary bitmap with the destination area.
+\item Deletes the temporary bitmap.
+\end{enumerate}
-\membersection{wxDCClipper::wxDCClipper}\label{wxdcclipperctor}
+This sequence of operations ensures that the source's transparent area need not be black,
+and logical functions are supported.
-\func{}{wxDCClipper}{\param{wxDC\& }{dc}, \param{wxCoord }{x},\param{wxCoord }{y},\param{wxCoord }{w},\param{wxCoord }{h},}
+{\bf Note:} on Windows, blitting with masks can be speeded up considerably by compiling
+wxWidgets with the \texttt{wxUSE\_DC\_CACHE} option enabled. You can also influence whether \texttt{MaskBlt}
+or the explicit mask blitting code above is used, by using \helpref{wxSystemOptions}{wxsystemoptions} and
+setting the {\bf no-maskblt} option to 1.
+
+}
-\func{}{wxDCClipper}{\param{wxDC\& }{dc}, \param{const wxRect\&}{ rect}}
+\docparam{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.}
-Constructor: sets the the clipping region for the given device context to the
-specified rectangle.
+\docparam{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.}
-\membersection{wxDCClipper::\destruct{wxDCClipper}}\label{wxdcclipperdtor}
+\wxheading{Remarks}
-\func{}{\destruct{wxDCClipper}}{\void}
+There is partial support for Blit in wxPostScriptDC, under X.
+
+wxDC::StretchBlit is only implemented under wxMAC and wxMSW.
+
+See \helpref{wxMemoryDC}{wxmemorydc} for typical usage.
+
+\newsince{2.9.0}
+
+\wxheading{See also}
-Destructor: destroys the clipping region set in the constructor.
+\helpref{wxDC::Blit}{wxdcblit}, \helpref{wxMemoryDC}{wxmemorydc}, \helpref{wxBitmap}{wxbitmap}, \helpref{wxMask}{wxmask}
projects / wxWidgets.git / blobdiff