@wxheader{dc.h}
A wxDC is a @e "device context" onto which graphics and text can be drawn.
- It is intended to represent a number of output devices in a generic way, so
- a window can have a device context associated with it, and a printer also
- has a device context. 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.
+ It is intended to represent different output devices and offers a common
+ abstract API for drawing on any of them.
- wxWidgets offers alternative drawing classes based on the modern drawing
+ wxWidgets offers an alternative drawing API based on the modern drawing
backends GDI+, CoreGraphics and Cairo. See wxGraphicsContext, wxGraphicsRenderer
- and related classes.
+ and related classes. There is also a wxGCDC linking the APIs by offering
+ the wxDC API ontop of a wxGraphicsContext.
- Notice that wxDC is an abstract base class and can't be created directly,
- please use wxPaintDC, wxClientDC, wxWindowDC, wxScreenDC, wxMemoryDC or
+ wxDC is an abstract base class and cannot be created directly.
+ Use wxPaintDC, wxClientDC, wxWindowDC, wxScreenDC, wxMemoryDC or
wxPrinterDC.
- Please note that in addition to the versions of the methods documented
- here, there are also versions which accept single wxPoint parameter instead
- of two wxCoord ones or wxPoint and wxSize instead of four of them.
+ 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.
- @note Beginning with wxWidgets 2.9.0 the entire wxDC code has been
- reorganized. All platform dependent code (actual 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.
+ 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.
- @section dc_alpha Support for Transparency / Alpha Channel
-
- On Mac OS X colors with alpha are supported. Instances wxPen or wxBrush
- that are built from wxColour use the color's alpha values when stroking or filling.
+ 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
+ @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
- wxFLOOD_BORDER: The area to be flooded is bounded by the given
colour.
- @returns @false if the operation failed.
+ @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
@a string is the text string to measure, @e heightLine, if non @NULL,
is where to store the height of a single line.
- @returns The text extent as a wxSize object.
+ @return The text extent as a wxSize object.
@note This function works with both single-line and multi-line strings.
projects / wxWidgets.git / blobdiff