How to spawn graphical program with gtkmm

0
votes

I am trying to spawn process with gtkmm but am faced with a problem. Here is the specific snippet of my code:

std::vector<std::string> args, envp;

args.push_back("/usr/libexec/mc/ext.d/doc.sh");
args.push_back("open");
args.push_back("pdf");

envp.push_back("MC_EXT_FILENAME="DATADIR"/bsbguide.pdf");
Glib::spawn_async("", args, envp, Glib::SPAWN_SEARCH_PATH);`

Task is to open a pdf file that is installed in DATADIR (this var is defined with automake). This variable pushed in envp is essential for opening file using Midnight Commander's stuff. The command

MC_EXT_FILENAME="some_file" /usr/libexec/mc/ext.d/doc.sh open pdf

will exactly open some_file with a PDF viewer.

The program compiles and works, but when I try to invoke programs with these functions I get this:

(zathura:3014): Gtk-WARNING **: cannot open display:

and nothing happens. Same command from console results in opened pdf file with my PDF viewer (Zathura). I found this in Devhelp:

If you are writing a GTK+ application, and the program you are spawning is a graphical application, too, then you may want to use gdk_spawn_on_screen() instead to ensure that the spawned program opens its windows on the right screen.

But no such function I found. Maybe there is a more elegant and correct way to open a file with the user's default PDF, viewer without MC parts? If not, how can I make this works? Even better if it will be in C++ style without gdk_spawn_on_screen.

1
c++gtkgtkmm
"But no such function I found". That's because gdk_spawn_on_screen() was deprecated in GTK+/GDK version 2 and removed outright in version 3. The GLib documentation that you quoted is extremely outdated and needs to be fixed; there is an existing bug report for this. The real replacement now is to use GAppInfoContext, GdkAppInfoContext, or at least set the DISPLAY env var before spawning if you find that it is required (which might be OS-dependent). - underscore_d

1 Answers

0
votes

So, as a simple workaround I've found is such code

setenv("MC_EXT_FILENAME", DATADIR"/bsbguide.pdf", true);
Glib::spawn_command_line_async("/usr/libexec/mc/ext.d/doc.sh open pdf");