Linux.Desktop.Hacks [Electronic resources] نسخه متنی

Hack 34. Give Your Desktop X-Ray Vision

This hack won't let you see through
anyone's
clothes, but it will make your applications translucent so that
anything behind the applications shows through, as if you have X-ray
vision. You simply issue a command, and then click a window.
Poof!the window suddenly becomes as translucent as you want.

If you want to use this hack you need to have a recent version of the
Xorg X Window System, and you need to install
xcompmgr, as covered in [Hack #33] . If you
can't get xcompmgr to work, you
won't be able to get this hack to work, because this
hack needs to have xcompmgr running in the
background.

Once xcompmgr is working and running in the
background, you need the transset program. Once
again, this is an experimental program, so you probably
won't find it in the regular package repositories
for your Linux distribution. You might find that an RPM package for
xcompmgr includes transset,
or you might have to find a separate transset
package. If all else fails, you can always download the program and
compile it yourself. Here's how (no password is
required, so just press Enter when prompted for a password):

# cvs -d :pserver:anoncvs@cvs.freedesktop.org:/cvs/xorg login
CVS password: (press Enter)
# cvs -d :pserver:anoncvs@pdx.freedesktop.org:/cvs/xapps co transset
# cd transset
# make
# chmod +x transset
# cp transset /usr/bin

Let's assume you have a window manager or desktop
environment running, and you have already launched
xcompmgr (see the previous hack for a sample
xcompmgr command). Now, all you have to do is
issue the transset command, followed by the degree
of opacity you want. For example, open an X terminal and type this
command:

# transset 0.7
got arg 0.7
d is 0.7

You should see the cursor change to a crosshair (or something like
one). Click the window you want to make translucent. It is probably
best to click the window's titlebar. Now you should
be able to see the wallpaper or even other windows behind the window
you just clicked. See Figure 4-4 for an example of
xterm with a degree of transparency. In case
you're not aware of this fact, the
xterm program has no built-in capability to
emulate transparency, so you cannot get this affect with an
xterm without using
transset.

Figure 4-4. An xterm with true transparency

Something such as the following text should also appear in the X
terminal where you typed the transset command:

opacity 0xb3333332
Set Property to 0.7

If you want a real thrill (and your window manager has the ability to
display the contents of windows while moving, instead of just
outlines), move the see-through window around. This is not
"fake" translucency, where the
window manager has to wait until you have finished repositioning the
window for it to redraw the background through the window. It changes
in real time, even as you move windows over the wallpaper or other
windows.

The transset program is at an even more
experimental stage than the xcompmgr program on
which it relies. No fancy features are available for making your
window manager know which windows should be transparent, and to what
degree. If you want transparent windows, you're
going to have to go through the process of making them transparent
manually every time you start your desktop.

No doubt this will be made user-friendly in the future. In the
meantime, it's not all that difficult to streamline
the process of making windows transparent. You can add a menu entry
or create an icon on the desktop that executes the
transset 0.7 command.
When you want to make a window transparent, just click the icon (or
select the menu entry) and then click the target window.