GAI Programmer's FAQ: (Outdated!)
Thanks goes out to Eric W. Eubank derbaff at yahoo dot com for asking
questions!
Q: How is the different size of the Gnome panel handled?
A: The size of the applet is completely handeled by the library. You tell
the library what image you want as background and your applet will become
as small/large as the background image. Or you tell the library how large
you want your applet to be and it'll be of that size.
From the programmers point of view, the applet will always have the
original size, no matter the real size. The library handles the
scaling.
But sometime you want your applet to be say 16x16, no matter the size
of the gnome panel. Then you call the the library what the maximum
size of the applet should be.
Q: How do you correctly use gai_draw() and gai_draw_update() ?
A: First you call gai_draw() as many times as you need in order to
complete all things you wish to draw. gai_draw() draws the given
data into a buffer, which you put on the screen with gai_draw_update().
Q: When shall I use gai_draw_bg() instead of gai_draw()?
A: If you update the graphics of the applet more often than once a
second, use gai_draw(). gai_draw_bg() changes the background of the
applet and is much slower than gai_draw. But the changes on the background
stays there no matter what the window manger does.(For example, laying
a window upon it and then moves it.)
Except from that the orignal background stays until you change it,
gai_draw_bg() only exists after the following gai_draw_update_bg () until
a new gai_draw_update_bg() is called.
Q: How does the background and foreground interact with each other?
A: Foreground pixels can only be drawn upon a non transparent background
pixel. So having a transparent background pixel and then trying
to draw a foreground pixel makes no good. You will never see it.
Having an unanswered question? Mail it to me! Jonas Aaberg, cja at gmx dot net.