I'd like to be able to draw on the root window in Linux.
I.e. make an OSD.
I'm using Gnome.
Code samples or links to them would be appreciated.
It is possible, but you will not see anything in GNOME. Nautilus, GNOME's file manager, opens its own window on top of root X window to display icons. Because of that the root X window is fully covered... so there is no point in drawing on it.
If you want to make OSD, either you should use a library like XOSD, or open your own X window and make it translucent. In fact, XOSD's source code should be a good example of how to do this.
Whole library seems to be implemented in one file: xosd.c.
use X11::Protocol;
my $x = X11::Protocol->new();
my $desktop;
my ($root,undef,#kids)=$x->QueryTree($x->{'root'});
printf "%10x:\tRoot\n", $root;
foreach (#kids){
my $gdkw = Gtk2::Gdk::Window->foreign_new($_);
printf ("%10x:\tDesktop\n",$gdkw->get_xid),$desktop=$gdkw,last if $gdkw->get_type_hint eq 'desktop';
}
$desktop=Gtk2::Gdk::Window->foreign_new($root) if ! $desktop;
#------------------------------------------
I can find desktop, verified by xwininfo.
But, I lost the code which can draw desktop, seems used "set_back_pixmap".
Now cairo can draw on any windows very simply, just use
$cr = Gtk2::Gdk::Cairo::Context->create ($drawable);
But, this does not work on desktop.
Perhaps due to kernel update? Or I messed up now on Ubuntu 10.04-3.
Related
Could someone share how can i create tui like this one with input boxex and search ?
What do i need?
Normally programmers use a ready to use library like ncurses.
You can also do it by hand if you really have to much time. To get for example the border lines of a dialog window you have to take a look at the current code page your terminal is emulating, for example: Code Page 850. As you can see, you will find single and double line boarders and also crossings and so on. Now you have to move your cursor to a given position, print that char from the code page and ... lots of work. Moving cursors itself can also be done by simple chars from your emulated terminal by using escape codes.
As said: Instead of doing it all by hand, simply use a lib like ncurses.
You can use some python libraries like pyTermTk or textual, there is wide selection of
libraries to choose from.
I am having trouble with using the python curses module for windows. I have used the wheel found here to get a script I had written on my mac to run on my desktop. For now, the script just displays a border around the window using the screen.border() method and another line across the whole width of the display. I displayed the bar across the screen using this:
dimensions = screen.getmaxyx()
screen.addstr(dimensions[0]/2, 0, "-"*dimensions[1])
I ran this in a loop, resetting dimensions each time and using getch to check for a curses.KEY_RRESIZE and then running screen.erase() to allow me to resize the window and the script will still work. When I ran this on windows after installing the wheel for python 3.7 (win32 because the amd64 one gave an error) I found that screen.getmaxyx() always returned the same value: the initial screen size, and never changed when I resized the window. I appreciate any help if anyone knows a way to fix this issue, or if I simply cannot use curses on windows, an alternative library for windows. Thank you!
Call resize_term(0, 0) after you get a KEY_RESIZE. (I’m not sure of the exact Python mapping.)
That ("on windows") is probably using PDCurses, which doesn't have a way to automatically update the screensize (e.g., as done with POSIX-based ncurses's SIGWINCH handler). Rather, it detects the window-size change and the application can call is_termresized to decide whether to tell the library to change the data structures to match using resize_term.
The python wrapper doesn't use that.
I want to write an extension that does the opposite of the "focus-follows mouse" setting in GNOME Shell: I want to make my pointer move to the center of the currently focused window.
Can this be done in a GNOME Shell extension? I see some GNOME code that wraps xfixes cursor, but I can't find any references to programmatic pointer updates in either the core Javascript or any existing extensions. (Am I just bad at Google?)
Valid answers include (1) example code that does it or (2) citation of a canonical source that says it can't be done.
Found this code in overview.js
Gdk = imports.gi.Gdk
let display = Gdk.Display.get_default();
let deviceManager = display.get_device_manager();
let pointer = deviceManager.get_client_pointer();
let [screen, pointerX, pointerY] = pointer.get_position();
pointer.warp(screen, 10, 10);
Are you willing to write your own script? If you are, I have found three tools, which, if used together, can get the job done for you.
First, use xprop to get the PID of the window you have clicked on.
Next, use xwininfo to get the dimensions and position information of the window based on its process ID.
Finally, use xdotool to calculate the center position of said window and move the cursor to that exact position.
Hope this helps. I don't have enough time write now to write the script (sorry), but this should be enough to get you started.
EDIT: Based on your comment, you want to stay in GNOME js. Totally understandable. You can call xdotool (which is the most efficient way of changing the position of the cursor on screen) from within GNOME js by use of something like:
const Util = imports.misc.util;
Util.spawn(['/bin/bash', '-c', "xrandr --query | awk 'something'"]) # replace the code here wih your own
This code was found at this thread.
Currently, I use print -dpng foo.png to print a plot to file in Octave 3.0.1 on Ubuntu.
Sometimes, I generate thousands of images in a loop.
Whenever a new image pops up, it grabs the mouse control precluding me from multitasking.
Is there anyway to print silently or quietly?
It would be easier to answer your question with a little more information about what you are doing. But with a little guessing maybe this is what you need:
f = figure
set(f, "visible", "off")
plot([1,2,3,4])
print("MyPNG.png", "-dpng")
I done lots of googling but I am still unsure on how to proceed.
What's the most common way of reading/write to the clipboard under Linux? I want both support for Gnome & KDE desktops.
Updated: do I take there isn't an easy solution and one must "aggregate" together multiple sources (gnome, kde) in order to craft a solution?
Maybe you can look at xclip and see how they have done it.
It provides an interface to X
selections ("the clipboard") from the
command line. It can read data from
standard in or a file and place it in
an X selection for pasting into other
X applications. xclip can also print
an X selection to standard out, which
can then be redirected to a file or
another program.
I might be shooting myself in the foot, but this could give you a hint on how to do the clipboard for kde, not sure about Gnome myself but try it, the script is in python and demonstrates how to get/set stuff on the clipboard, via using dcop and klipper, it is on this site here.
Hope this helps,
Best regards,
Tom.