Shared tag across monitors

[gitbxf4]

Hello,
I like Sway/i3 and Xmonad's one set of tags (e.g., 1-9) being shared across multiple monitors. That is, for example, tag 3 is on DP-1 and I can move it with its contents over to DP-2. I thought perhaps Issue #263 was about this, but I'm not sure. And I couldn't figure out the mmsg code identified as the answer:
mmsg -d focusmon,HEADLESS-1 && mmsg -d view,4
Is this possible and if so, can someone tell me how?
Thank you for your time and help.

[MLuc24]

The reason that command didn't make sense is that mango's tags aren't the same kind of object as i3/Sway workspaces, so there's nothing to "move over" in the way you're picturing.

In mango each monitor carries its own tagset, and a window's visibility is tested against its own monitor's tags:

uint32_t tagset[2];                                  // per-monitor, in struct Monitor

if (!(c->tags & c->mon->tagset[c->mon->seltags]))    // src/fetch/client.h

So "tag 3" isn't one thing living on DP-1 — DP-1 and DP-2 each have their own tag 3, and every window is bound to a monitor (c->mon) as well as to tags. That's the dwm lineage rather than the i3 one, where a workspace is a global object assigned to an output and can be reassigned wholesale.

The command you found is doing two steps because view acts on the focused monitor: focus HEADLESS-1, then switch that monitor to tag 4. There's a one-shot version you'll like better:

mmsg -d viewcrossmon,4,DP-2

viewcrossmon mask,monitor_spec views the given tag(s) on the given monitor without focusing it first. Its sibling tagcrossmon mask,monitor_spec sends the focused window to a tag on a specific monitor, and tagmon left/right/…,keeptag moves a window monitor-wise with keeptag=1 preserving its tag numbers.

For moving a tag's contents across, there's no single command, and that follows from the model above — the windows are each bound to a monitor, so it's per-window (tagcrossmon or tagmon) rather than one operation on the tag.

The closest thing to the "one shared set of tags" feel is the synctag argument, which most of the view commands take:

mmsg -d view,4,1

The trailing 1 syncs the switch to all monitors, so both screens move to tag 4 together instead of tracking tags independently. viewtoleft/viewtoright take it too. That gives you a single conceptual tagset across the setup, which I suspect is most of what you're after from the Xmonad habit — just arrived at from the other direction, since it's the monitors following one tag rather than one tag being relocated.

[rogervn]

I'm also interested on this question as mangowc seems to tick all the boxes I have with the exception of this one.

I have a 2-monitor + laptop setup that I constantly organise in a way that I have a set of windows on each and when I dock/undock I want that set to continue to behave like a set and eventually come back to the correct monitors when I dock again.

i3/sway/hyprland do this by having unique workspaces and then assigning workspaces per monitor
niri does this by having the workspaces continue to be a set, but the indexes vary per monitor and can be named to prefer monitors and move between them in case that doesn't work.

Is there any other way mango can map that behaviour? Because moving all windows to a single tag and then having to manually pick them up each is definitely a deal-breaker for this type of workload.