How do I prevent a gVim server window stealing focus when receiving a remote command?

Question

I'm writing a debugger and when hitting a breakpoint or stepping through code I'm making a system call that instructs a gVim server to jump to the current line of the file being debugged, like this:

system_call("gvim --remote-send +\"%dG" --servername DEBUG --remote-tab-silent %s",
             line_number, file_name);

The problem is each time gVim receives the command the gVim window steals focus and I have to alt-tab or mouse-click back to the debugger window.

How can I prevent the gVim server window stealing focus when it receives at command?

(I've tagged the question with microsoft-windows and linux as I alternate between both operating systems and as such an answer would ideally work on both.)

Answer 1

A solution to this problem is mentioned in Vim's documentation (:h --remote). The following command should open filename to line_number:

gvim --servername DEBUG --remote-send "<C-\><C-N>:tab drop filename<CR>line_numberG"

Note that this seems to neither raise nor focus Vim. And I believe that opening the file using :tab drop filename should work similar to vim --remote-tab-silent filename. Also, note that I tested this using the i3 and awesome window managers.

:h --remote 
   --remote [+{cmd}] {file} ...                                 *--remote*
                                Open the file list in a remote Vim.  When
                                there is no Vim server, execute locally.
                                There is one optional init command: +{cmd}.
                                This must be an Ex command that can be
                                followed by "|". 
                                The rest of the command line is taken as the
                                file list.  Thus any non-file arguments must
                                come before this.
                                You cannot edit stdin this way |--|.
                                The remote Vim is raised.  If you don't want
                                this use
                                 vim --remote-send "<C-\><C-N>:n filename<CR>"

Answer 2

If you are using Linux, here is a bit of a hacky solution. You can augment your gvim command with a shell command that interacts with windows, like xdotool or wmctrl. Here's an example using xdotool:

xdotool getactivewindow > /tmp/gvim_wid.txt && \
gvim --servername DEBUG --remote-tab-silent +line_number file_name && \
gvim --servername DEBUG --remote-expr "system('cat /tmp/gvim_wid.txt | xargs xdotool windowactivate')"

Explanation:

• line 1: use xdotool to get the window ID of the debugger window, and save it to a file (/tmp/gvim_wid.txt)
• line 2: run your gvim command
• line 3: run another gvim command which executes an xdotool command to focus the debugger window (using the window ID from the file)

A similar approach would be to save the window ID to a shell variable instead of a file, and run the final xdotool command directly from the shell. However, I was only able to make that method work by adding a sleep command before the final xdotool command.

Also, I don't know if there is an xdotool alternative in Windows, but I imagine there must be something similar.