Re: expose-event

["richard boaz" <riboaz xs4all nl>]

hmm, not sure if i'm getting the wrong end of the stick, here, but in my  
drawing program i adhere 100% to the following algorithm:

configure_event - responsible for all drawing code, drawing only to an  
internal pixmap buffer.
expose_event - responsible for rendering the pixmap drawn in the configure  
event to the drawing area itself, i.e, the screen.

for my application, the pixmap i draw to is determined by several program  
settings/factors: it is possible for me to be maintaining more than one  
internal pixmap at a time for a certain drawing area, while only one of  
these pixmaps is ever rendered to the screen at any given moment.

the configure event, then, determines which internal pixmap i should draw,  
makes this internal pixmap, and then sets the variable defining the actual  
pixmap to render to the screen.  it is the configure event that is called  
first upon a resize with the expose event following.

the expose event, then, simply renders the pixmap held in this variable to  
the screen.

N.B. i would not recommend managing drawing areas by using only the expose  
event to render the screen, this is incredibly inefficient since there are  
expose events which do not require redrawing the entire drawing area.

cheers,

richard


On Wed, 22 Jun 2005 10:37:27 +0200, Sven Neumann <sven gimp org> wrote:

> Hi,
>
> abent gmx de writes:
>
> > resize my window. i wanna redraw a drawingarea after i resize
> > the window. but in this case my drawing-function do her work,
> > and after that the expose-event delete it.
>
> You must not do any drawing outside the expose event callback.
>
>
> Sven
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--
Richard Boaz
riboaz xs4all nl
+31.(0)648.792.484
http://www.boazconsultancy.com