X-Git-Url: https://git.saurik.com/wxWidgets.git/blobdiff_plain/b1263dcfa3fb318e9a48bdbdfe548eb474ae5fde..9c72cf7619064969b5c7f59cece74013789db4cf:/docs/latex/wx/dc.tex?ds=inline diff --git a/docs/latex/wx/dc.tex b/docs/latex/wx/dc.tex index febf46d150..e0f3256f49 100644 --- a/docs/latex/wx/dc.tex +++ b/docs/latex/wx/dc.tex @@ -6,8 +6,10 @@ so a window can have a device context associated with it, and a printer also has 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 @@ -16,6 +18,12 @@ there are also versions which accept single {\tt wxPoint} parameter instead of 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} @@ -31,36 +39,6 @@ them. \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}, @@ -486,7 +464,7 @@ which is. \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 @@ -504,12 +482,15 @@ the rectangle. \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}} @@ -565,15 +546,6 @@ wxUSE\_DC\_CACHEING preprocessor symbol for portability. 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} @@ -656,7 +628,10 @@ rectangle are returned as a tuple.} \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::GetLogicalFunction}\label{wxdcgetlogicalfunction} @@ -678,12 +653,12 @@ Gets the {\it mapping mode} for the device context (see \helpref{wxDC::SetMapMod \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. \pythonnote{This method only takes the {\it text} parameter and @@ -701,9 +676,11 @@ Gets the current pen (see \helpref{wxDC::SetPen}{wxdcsetpen}). \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.} @@ -779,10 +756,8 @@ 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. +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. See also \helpref{wxFont}{wxfont}, \helpref{wxDC::SetFont}{wxdcsetfont}. @@ -817,6 +792,35 @@ Gets the current user scale factor (set by \helpref{SetUserScale}{wxdcsetusersca 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}} @@ -904,8 +908,8 @@ doesn't contain anything. \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} @@ -1115,7 +1119,7 @@ Sets the user scaling factor, useful for applications which require \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} @@ -1123,41 +1127,3 @@ Message is a message to show whilst printing. \func{bool}{StartPage}{\void} 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 DC to its constructor -clipping region and then automatically destroys it in its destructor. Using -it ensures that an unwanted clipping region is not left set on the DC. - -\wxheading{Derived from} - -No base class - -\wxheading{Include files} - - - -\wxheading{See also} - -\helpref{wxDC}{wxdc} - -\latexignore{\rtfignore{\wxheading{Members}}} - - -\membersection{wxDCClipper::wxDCClipper}\label{wxdcclipperctor} - -\func{}{wxDCClipper}{\param{wxDC\& }{dc}, \param{wxCoord }{x},\param{wxCoord }{y},\param{wxCoord }{w},\param{wxCoord }{h},} - -\func{}{wxDCClipper}{\param{wxDC\& }{dc}, \param{const wxRect\&}{ rect}} - -Constructor: sets the the clipping region for the given device context to the -specified rectangle. - - -\membersection{wxDCClipper::\destruct{wxDCClipper}}\label{wxdcclipperdtor} - -\func{}{\destruct{wxDCClipper}}{\void} - -Destructor: destroys the clipping region set in the constructor. -