In Linux, Which component decides to open a new window in gedit? - linux

Question

Let's consider that I open a file with the command gedit toto1.txt, a new window shows up with the content of toto1.txt. This sound familiar and usual, however the two following cases are not that straight to undertand: (1) a new command (let's says gedit toto2.txt) open a new tab in the previous window and (2) a new command (let's says gedit toto3.txt) will open a new tab in a new window.
My question is : which component decide to open the new window in case (2) and what are the condition to do so ? Why It did not opened a new window in case (1) ?
Any idea ?

Answer 1

It's gedit itself that makes that decision. Let's take a look at the source code. The function open_files will open a new window when it cannot find an active window (or when the flag --new-window was explicitly specified).
static void
open_files (GApplication *application,
gboolean new_window,
...)
{
GeditWindow *window = NULL;
if (!new_window)
{
window = get_active_window (GTK_APPLICATION (application));
}
if (window == NULL)
{
gedit_debug_message (DEBUG_APP, "Create main window");
window = gedit_app_create_window (GEDIT_APP (application), NULL);
gedit_debug_message (DEBUG_APP, "Show window");
gtk_widget_show (GTK_WIDGET (window));
}
...
}
So what's an "active window"? Let's look at get_active_window:
static GeditWindow *
get_active_window (GtkApplication *app)
{
GdkScreen *screen;
guint workspace;
gint viewport_x, viewport_y;
GList *windows, *l;
screen = gdk_screen_get_default ();
workspace = gedit_utils_get_current_workspace (screen);
gedit_utils_get_current_viewport (screen, &viewport_x, &viewport_y);
/* Gtk documentation says the window list is always in MRU order */
windows = gtk_application_get_windows (app);
for (l = windows; l != NULL; l = l->next)
{
GtkWindow *window = l->data;
if (GEDIT_IS_WINDOW (window) && is_in_viewport (window, screen, workspace, viewport_x, viewport_y))
{
return GEDIT_WINDOW (window);
}
}
return NULL;
}
So, the answer is: gedit will open a new window if there's not already a gedit window on screen.
(Well, there could of course be bugs here. I haven't looked very closely. That viewport_x/y stuff looks a bit suspect, as a viewport should have four coordinates: top/bottom/left/right. The code might be confused by multi-monitor setups).

Answer 2

Looks like this is done by gedit itself :)
But, if you want to open document in new window you can use --new-window switch. Try to call gedit with --help from command line.
If you need an straight answer on question "How gedit determine is it can use existing window or must open a new one?" i think you must see the gedit source code at https://github.com/GNOME/gedit