tmux: Use move-window for window dragging

Use move-window for window dragging instead of a loop and swap-window.
When using -a or -b (i.e. after or before) the target can be occupied
and the windows are reordered automatically.

.config/tmux/tmux.conf

@@ -80,8 +80,7 @@ bind -r C-p prev
 bind -r N swap-window -d -t :+1
 bind -r P swap-window -d -t :-1
 
-# Reorder windows by dragging on status line. This uses a loop and swap-window
-# as move-window needs the target index to be free.
+# Reorder windows by dragging on status line.
 # NOTE: This breaks the stack and last-used window.
 bind -n MouseDragEnd1Status {
 	# TODO: Can we somehow get the idx of {mouse} without selecting it?
@@ -90,17 +89,14 @@ bind -n MouseDragEnd1Status {
 	set -F @target_idx "#{window_index}"
 	if -F "#{!=:#{@source_idx},#{window_index}}" { select-window -t! }
 
-	# Get the right direction to not mess up the order when wrapping around
-	tmux_move_direction="#{?#{e|<:#{@target_idx},#{@source_idx}},:-1,:+1}"
-	tmux_move_target_idx="#{@target_idx}"
+	# Depending on the direction the window must be placed before or after
+	# the target
+	tmux_move_direction="#{?#{e|<:#{@target_idx},#{@source_idx}},-b,-a}"
 
-	run-shell "\
-		while [ $tmux_move_target_idx -ne $(tmux display -a | grep -Po '(?<=^window_index=)[0-9]*') ]; do \
-			tmux swap-window -d -t $tmux_move_direction; \
-		done"
+	# NOTE: uses run-shell so the flag can be passed through a variable
+	run-shell "tmux move-window -t #{@target_idx} $tmux_move_direction"
 
 	setenv -u tmux_move_direction
-	setenv -u tmux_move_target_idx
 }
 
 # TODO: Move to beginning or end like in MouseDragEnd1Status