From bc5af8e053fa06af43f2e4c4919223a6fcc107b4 Mon Sep 17 00:00:00 2001
From: Ryan Miller <ryan@devopsmachine.com>
Date: Sun, 19 Apr 2020 21:01:23 -0400
Subject: [PATCH] Better Vim -> tmux Forwarding (#6)

* Comment out unused function

* Specify test socket name in Makefile

* Refactor vim/tmux resize determination method

* Uncomment process list; maybe useful for debugging

* Add separate make vim for testing only vim

* Update plugin header

* Clean up unused code and add comments
---
 Makefile                           |  7 ++--
 plugin/better_vim_tmux_resizer.vim | 52 ++++++++++++------------------
 2 files changed, 26 insertions(+), 33 deletions(-)

diff --git a/Makefile b/Makefile
index 836755e..cbc702a 100644
--- a/Makefile
+++ b/Makefile
@@ -1,4 +1,7 @@
-.PHONY: test
+.PHONY: test vim
 
 test:
-	tmux -f test/.tmux.conf new-session "nvim -u test/.vimrc"
+	tmux -L tmux-testing -f test/.tmux.conf new-session "make vim"
+
+vim:
+	nvim -u test/.vimrc
diff --git a/plugin/better_vim_tmux_resizer.vim b/plugin/better_vim_tmux_resizer.vim
index b17bb28..790f3c3 100644
--- a/plugin/better_vim_tmux_resizer.vim
+++ b/plugin/better_vim_tmux_resizer.vim
@@ -1,5 +1,6 @@
-" Maps <M-h/j/k/l> to resize vim splits in the given direction. If there
-" are no more windows in that direction, forwards the operation to tmux.
+" Maps <M-h/j/k/l> to resize vim splits in the given direction.
+" If the movement operation has no effect in Vim, it forwards the operation to
+" Tmux.
 
 if exists("g:loaded_tmux_resizer") || &cp || v:version < 700
   finish
@@ -22,7 +23,7 @@ if !exists("g:tmux_resizer_no_mappings")
 endif
 
 function! s:VimResize(direction)
-  " Resize toward given direction, like tmux
+  " Resize Vim window toward given direction, like tmux
   let l:current_window_is_last_window = (winnr() == winnr('$'))
   if (a:direction == 'h' || a:direction == 'k')
     let l:modifier = l:current_window_is_last_window ? '+' : '-'
@@ -37,6 +38,7 @@ function! s:VimResize(direction)
     let l:command = 'resize'
     let l:window_resize_count = g:tmux_resizer_resize_count
   endif
+
   execute l:command . ' ' . l:modifier . l:window_resize_count . '<CR>'
 endfunction
 
@@ -67,48 +69,36 @@ function! s:TmuxCommand(args)
   return system(cmd)
 endfunction
 
-function! s:TmuxResizerProcessList()
-  echo s:TmuxCommand("run-shell 'ps -o state= -o comm= -t ''''#{pane_tty}'''''")
-endfunction
-command! TmuxResizerProcessList call s:TmuxResizerProcessList()
-
-let s:tmux_is_last_pane = 0
-augroup tmux_resizer
-  au!
-  autocmd WinEnter * let s:tmux_is_last_pane = 0
-augroup END
-
 function! s:NeedsVitalityRedraw()
   return exists('g:loaded_vitality') && v:version < 704 && !has("patch481")
 endfunction
 
-function! s:ShouldForwardResizeBackToTmux(tmux_last_pane, at_tab_page_edge)
-  return a:tmux_last_pane || a:at_tab_page_edge
-endfunction
-
 function! s:TmuxAwareResize(direction)
-  let nr = winnr()
-  let tmux_last_pane = (a:direction == 'p' && s:tmux_is_last_pane)
-  if !tmux_last_pane
-    call s:VimResize(a:direction)
-  endif
-  let at_tab_page_edge = (nr == winnr())
-  " Forward the resize panes command to tmux if:
-  " a) we're toggling between the last tmux pane;
-  " b) we tried resizing windows in vim but it didn't have effect.
-  if s:ShouldForwardResizeBackToTmux(tmux_last_pane, at_tab_page_edge)
+  let l:previous_window_width = winwidth(0)
+  let l:previous_window_height = winheight(0)
+
+  " Attempt to resize Vim window
+  call s:VimResize(a:direction)
+
+  " Call tmux if Vim window dimentions did not change
+  if (l:previous_window_height == winheight(0) && l:previous_window_width == winwidth(0))
     if (a:direction == 'h' || a:direction == 'l')
       let l:resize_count = g:tmux_resizer_vertical_resize_count
     else
       let l:resize_count = g:tmux_resizer_resize_count
     endif
     let args = 'resize-pane -' . tr(a:direction, 'hjkl', 'LDUR') . ' ' . l:resize_count
+
     silent call s:TmuxCommand(args)
+
     if s:NeedsVitalityRedraw()
       redraw!
     endif
-    let s:tmux_is_last_pane = 1
-  else
-    let s:tmux_is_last_pane = 0
   endif
 endfunction
+
+" For debugging
+function! s:TmuxResizerProcessList()
+  echo s:TmuxCommand("run-shell 'ps -o state= -o comm= -t ''''#{pane_tty}'''''")
+endfunction
+command! TmuxResizerProcessList call s:TmuxResizerProcessList()