SwayWM synchronize workspaces on outputs

README.md

This will monitor workspace changes and update the current workspace on other monitors. The idea is that workspace number 1 is paired with workspace 11 on second monitor, workspace 21 on 3rd monitor...

Usage:

run it in background along your sway session

Problem: Sway does not allow switching workspaces without focusing it, and focusing a workspaces moves the mouse cursor. So it's impossible to change the current workspace on the secondary output without disrupting the user.

As a consequence, the implementation - for now - will only update the workspace when the moves moves to the output, but this is far from ideal.

swaywm/sway#7507

sync-workspaces.sh

#!/bin/bash
# <https://gist.github.com/mildred/8c6983295fe5ff8522028e7a2c7c7a0b>

subscribe_workspaces(){
  swaymsg -t subscribe -m '["workspace"]' \
    | jq --unbuffered -r '[ .old.num, .old.output, .current.num, .current.output, .current.focused ] | join(";")'
}

index_of(){
  local i=0
  local resval="$1"
  local needle="$2"
  shift 2

  for item in "$@"; do
    if [[ $item == $needle ]]; then
      eval "${resval}=\$i"
      return 0
    fi
    let i++
  done
  eval "${resval}="
  return 1
}

log(){
  ( set -x
    "$@"
  )
}

update_other_workspaces(){
  local num="$1"
  local current_output="$2"
  local current_output_index="$3"

  local group_index
  let group_index=num%10
  local json_workspaces="$(swaymsg -r -t get_workspaces)"
  local need_move_back=false

  local i=-1
  for target_output in "${outputs[@]}"; do
    let i++
    local target_num
    let target_num=i*10+group_index

    if [[ $target_output = $current_output ]]; then
      continue
    fi

    #echo "Workspace $num on $current_output_index:$current_output maps to $target_num on $i:$target_output"

    target_workspace_output="$(<<<"$json_workspaces" \
      jq -r --arg num "$target_num" \
      '.[] | select(.num == ($num|tonumber)) | .output')"

    target_workspace_visible="$(<<<"$json_workspaces" \
      jq -r --arg num "$target_num" \
      '.[] | select(.num == ($num|tonumber)) | .visible')"

    if [[ $target_workspace_visible = true ]]; then
      # Target workspace already visible, do nothing
      true
    elif [[ -z "$target_workspace_output" ]]; then
      echo "$num on $current_output_index:$current_output -> (new) $target_num on $i:$target_output"
      # The workspace does not exists, create it and switch to it
      log swaymsg workspace $target_num output $target_output
      log swaymsg workspace $target_num
      ignore+=($target_num)
      need_move_back=true
    elif [[ $target_workspace_output = $target_output ]]; then
      echo "$num on $current_output_index:$current_output -> (existing) $target_num on $i:$target_output"
      # The workspace exists and is already on correct output, switch to it
      log swaymsg workspace $target_num
      ignore+=($target_num)
      need_move_back=true
    else
      echo "Workspace $target_num is already on output $target_workspace_output, not moving to $target_output"
    fi
  done

  if $need_move_back; then
    # Switch back to current workspace if needed
    echo "$num on $current_output_index:$current_output (move back)"
    log swaymsg workspace $num
    ignore+=($num)
    need_move_back=false
  fi
}

update_workspace_on_output_change(){
  local ws="$1"
  local target_num

  let target_num=current_output_index*10+ws

  target_workspace_output="$(<<<"$json_workspaces" \
    jq -r --arg num "$target_num" \
    '.[] | select(.num == ($num|tonumber)) | .output')"

  target_workspace_visible="$(<<<"$json_workspaces" \
    jq -r --arg num "$target_num" \
    '.[] | select(.num == ($num|tonumber)) | .visible')"

  if [[ $target_workspace_visible = true ]]; then
    # Target workspace already visible, do nothing
    echo "$target_num visible on $target_workspace_output"
    true
  elif [[ $num != $target_num ]] && [[ -z "$target_workspace_output" ]]; then
    echo "=> (new) $target_num on $current_output_index:$current_output"
    # The workspace does not exists, create it and switch to it
    log swaymsg workspace $target_num output $current_output
    log swaymsg workspace $target_num
    # ignore+=($target_num)
  elif [[ $num != $target_num ]] && [[ $target_workspace_output = $current_output ]]; then
    # The workspace exists and is already on correct output, switch to it
    echo "=> (existing) $target_num on $current_output_index:$current_output"
    log swaymsg workspace $target_num
    # ignore+=($target_num)
  else
    echo "$target_num already on $current_output_index:$current_output"
  fi
}

ignore=()

subscribe_workspaces | while IFS=';' read last_num last_output num current_output focused; do
  if [[ ${ignore[0]} == $num ]]; then
    echo "ignore event"
    ignore=("${ignore[@]:1}")
    continue
  #elif [[ -n "${ignore[0]}" ]]; then
  #  echo "Ignore event: $num $current_output (not in list, expect ${ignore[0]})"
  #  continue
  fi

  outputs=($(swaymsg -r -t get_outputs | jq -r '.[] | .name'))

  if ! index_of current_output_index "$current_output" "${outputs[@]}"; then
    echo -n "[$last_num on $last_output_index:$last_output -> $num on $current_output_index:$current_output] "
    >&2 echo "Failed to recognize current workspace $num output $current_output in (${outputs[@]})"
    continue
  fi

  if ! index_of last_output_index "$last_output" "${outputs[@]}"; then
    echo -n "[$last_num on $last_output_index:$last_output -> $num on $current_output_index:$current_output] "
    >&2 echo "Failed to recognize last workspace $num output $last_output in (${outputs[@]})"
    continue
  fi

  # echo "detect workspace change $num on $current_output_index:$current_output (focused: $focused)"
  echo -n "[$last_num on $last_output_index:$last_output -> $num on $current_output_index:$current_output] "


  let expected_output_index=num/10
  if [[ $expected_output_index != $current_output_index ]]; then
    echo "Workspace $num should be on output ${outputs[$expected_output_index]} and not ${outputs[$current_output_index]}"
    last_num="$num"
    last_output="$current_output"
    last_output_index=
    continue
  fi

  if [[ -z "$ws" ]]; then
    let ws=last_num%10
  fi

  if [[ $last_output = $current_output ]]; then
    let ws=num%10
    echo "ws=$ws"
  else
    update_workspace_on_output_change "$ws"
  fi

  # update_other_workspaces "$num" "$current_output" "$current_output_index"

done