Drawing gradients in X11 and transparent windows

llothar · External Since: Jul 02, 2007 Posts: 9

I would like to improve the appearence of my application.

For the gradient: Is there any fast way other then doing it myself in
a client side image.

And transparent windows - well how at all can i do it and how portable
is it?

ShieldsOnTour · External Since: Jul 16, 2007 Posts: 3

Hi there,

I can't answer the questions about the gradient fills, but I can offer
some help on transparent windows - depending upon what it is you are
trying to achieve.

First of all, you will need to be running a composite window manager -
such as beryl.... These window managers allow access to and obey the
alpha byte if you create you windows as ARGB 32-bit. You can then
directly manipulate the alpha channel (Using XGetImage/XPutImage to
access the data --- or shared memory extensions).

If you are wanting to set the transparency of your entire window, you
simply need to set a window property that the composite window manager
will honor --- its a really simply 2 line process. I'm not at work
right now so I can't remember what the property is called. When I get
to work tomorrow, I will post some code to do this ( and also a
function to tell you if you are even running a composite window
manager).

Hope this helps some --- I will try and be more helpful tomorrow Smile

Regards,

Tim

On 22 Jul, 14:01, llothar <llot....TakeThisOut@web.de> wrote:
> I would like to improve the appearence of my application.
>
> For the gradient: Is there any fast way other then doing it myself in
> a client side image.
>
> And transparent windows - well how at all can i do it and how portable
> is it?

Jasen Betts · External Since: Jul 10, 2005 Posts: 27

On 2007-07-22, llothar <llothar.RemoveThis@web.de> wrote:
> I would like to improve the appearence of my application.
>
> For the gradient: Is there any fast way other then doing it myself in
> a client side image.
>
> And transparent windows - well how at all can i do it and how portable
> is it?

shaped windows have been around since atleast the early 90s (eg: xeyes uses a
shaped window) another example, of more recent origin, would be xosd

Bye.
Jasen

llothar · External Since: Jul 02, 2007 Posts: 9

On 23 Jul., 16:28, Jasen Betts <ja... DeleteThis @free.net.nz> wrote:

> shaped windows have been around since atleast the early 90s (eg: xeyes uses a
> shaped window) another example, of more recent origin, would be xosd

I know about shaped windows. But i'm asking about alpha transparent
ones say 50% opaque. Sorry thought that this is clear from the wording.

llothar · External Since: Jul 02, 2007 Posts: 9

Sorry for the delayed response, was very busy with something else.

> If you are wanting to set the transparency of your entire window, you
> simply need to set a window property that the composite window manager
> will honor --- its a really simply 2 line process. I'm not at work
> right now so I can't remember what the property is called. When I get
> to work tomorrow, I will post some code to do this ( and also a
> function to tell you if you are even running a composite window
> manager).

Yes this is exactly what i want. I have done this on windows and there
it is also a 2 lines code. Would be very nice from you if would help
me here. It seems i can't come up with the right google words to find
the answer.

By the way, how can i find out if the window manager is a composite
window manager?
Is there same property i can check.

llothar · External Since: Jul 02, 2007 Posts: 9

> A way to find the code is to download the GTK/GDK source and look
> through it -- have a look at the function gdk_window_set_opacity
> (http://developer.gnome.org/doc/API/2.0/gdk/gdk-Windows.html#gdk-windo...)
> as a start. Trace that through the code and it will show you how to
> set the opacity of the window --- and also how to tell if the user is
> running a composite window manager. Remember - GDK is your friend -
> its just a wrapper ( a good one ) around native X code.

Thanks i think i can find it now.

I will be able to work again with Linux in about 10 days, btw. never
buy ASROCK mainboards if you live in a country with high air humidity.

And one more question: Does the Beryl WM work with old Matrox G450
cards? I never needed more then this but now i want to add some nice
transparent shaped windows for Drag operations to my application. Pure
eye candy but who don't like candies?

ShieldsOnTour · External Since: Jul 16, 2007 Posts: 3

I really, really sorry --- have been snowed under at work and no time
to post the functions.

A way to find the code is to download the GTK/GDK source and look
through it -- have a look at the function gdk_window_set_opacity
( http://developer.gnome.org/doc/API/2.0/gdk/gdk-Windows.html#gdk-window...t-opaci)
as a start. Trace that through the code and it will show you how to
set the opacity of the window --- and also how to tell if the user is
running a composite window manager. Remember - GDK is your friend -
its just a wrapper ( a good one ) around native X code.

If you cant find the relevant code, I promise I will post it on Monday
when I get back into work Smile

regards,

Tim

On 27 Jul, 20:16, llothar <llot... RemoveThis @web.de> wrote:
> Sorry for the delayed response, was very busy with something else.
>
> > If you are wanting to set the transparency of your entire window, you
> > simply need to set a window property that the composite window manager
> > will honor --- its a really simply 2 line process. I'm not at work
> > right now so I can't remember what the property is called. When I get
> > to work tomorrow, I will post some code to do this ( and also a
> > function to tell you if you are even running a composite window
> > manager).
>
> Yes this is exactly what i want. I have done this on windows and there
> it is also a 2 lines code. Would be very nice from you if would help
> me here. It seems i can't come up with the right google words to find
> the answer.
>
> By the way, how can i find out if the window manager is a composite
> window manager?
> Is there same property i can check.