feat: add swap windows feature (#130)

* feat: add swap windows feature
* refactor: remove utils

Author: devsunb

README.md

@@ -109,6 +109,13 @@ The following defaults are given:
 
         -- sets resize steps for y axis
         resize_step_y = 1,
+    },
+    swap = {
+        -- cycles to opposite pane while navigating into the border
+        cycle_navigation = false,
+
+        -- enables default keybindings (C-A-hjkl) for normal mode
+        enable_default_keybindings = true,
     }
 }
 ```
@@ -207,6 +214,37 @@ To run custom bindings in nvim, make sure to not set `enable_default_keybindings
 }
 ```
 
+### swap
+
+Add the following bindings to your `~/.tmux.conf`:
+
+> It is important to note, that your bindings in nvim must match the defined bindings in tmux! Otherwise the pass through will not have the seamless effect!
+
+```tmux
+is_vim="ps -o state= -o comm= -t '#{pane_tty}' | grep -iqE '^[^TXZ ]+ +(\\S+\\/)?g?(view|n?vim?x?)(diff)?$'"
+
+bind -n 'C-M-h' if-shell "$is_vim" 'send-keys C-M-h' 'swap-pane -s "{left-of}"'
+bind -n 'C-M-j' if-shell "$is_vim" 'send-keys C-M-j' 'swap-pane -s "{down-of}"'
+bind -n 'C-M-k' if-shell "$is_vim" 'send-keys C-M-k' 'swap-pane -s "{up-of}"'
+bind -n 'C-M-l' if-shell "$is_vim" 'send-keys C-M-l' 'swap-pane -s "{right-of}"'
+
+bind-key -T copy-mode-vi C-M-h swap-pane -s "{left-of}"
+bind-key -T copy-mode-vi C-M-j swap-pane -s "{down-of}"
+bind-key -T copy-mode-vi C-M-k swap-pane -s "{up-of}"
+bind-key -T copy-mode-vi C-M-l swap-pane -s "{right-of}"
+```
+
+To run custom bindings in nvim, make sure to not set `enable_default_keybindings` to `true`. The following functions are used to resize windows:
+
+```lua
+{
+    [[<cmd>lua require("tmux").swap_left()<cr>]],
+    [[<cmd>lua require("tmux").swap_bottom()<cr>]],
+    [[<cmd>lua require("tmux").swap_top()<cr>]],
+    [[<cmd>lua require("tmux").swap_right()<cr>]],
+}
+```
+
 ## tpm
 
 If you are using [tmux plugin manager](https://github.com/tmux-plugins/tpm), you can add the following plugin.

lua/tmux/configuration/options.lua

@@ -77,6 +77,13 @@ local M = {
         -- sets resize steps for y axis
         resize_step_y = 1,
     },
+    swap = {
+        -- cycles to opposite pane while navigating into the border
+        cycle_navigation = false,
+
+        -- enables default keybindings (C-M-hjkl) for normal mode
+        enable_default_keybindings = false,
+    },
 }
 
 function M.set(options)

lua/tmux/init.lua

@@ -3,6 +3,7 @@ local copy = require("tmux.copy")
 local log = require("tmux.log")
 local navigation = require("tmux.navigation")
 local resize = require("tmux.resize")
+local swap = require("tmux.swap")
 local tmux = require("tmux.wrapper.tmux")
 
 local options = {
@@ -15,6 +16,9 @@ local options = {
     resize = {
         enable_default_keybindings = true,
     },
+    swap = {
+        enable_default_keybindings = true,
+    },
 }
 
 local M = {
@@ -30,6 +34,11 @@ local M = {
     resize_bottom = resize.to_bottom,
     resize_top = resize.to_top,
     resize_right = resize.to_right,
+
+    swap_left = swap.to_left,
+    swap_bottom = swap.to_bottom,
+    swap_top = swap.to_top,
+    swap_right = swap.to_right,
 }
 
 function M.setup(options_, logging)
@@ -55,6 +64,9 @@ function M.setup(options_, logging)
 
     log.debug("setup resize")
     resize.setup()
+
+    log.debug("setup swap")
+    swap.setup()
 end
 
 return M

lua/tmux/layout/init.lua

@@ -1,5 +1,6 @@
 local log = require("tmux.log")
 local parse = require("tmux.layout.parse")
+local nvim = require("tmux.wrapper.nvim")
 local tmux = require("tmux.wrapper.tmux")
 
 local direction_checks = {
@@ -53,6 +54,17 @@ local function check_is_border(display, id, direction)
     return nil
 end
 
+--return true if there is no other nvim window in the direction of @border
+local function is_only_window(border)
+    if border == "h" or border == "l" then
+        --check for other horizontal window
+        return (nvim.winnr("1h") == nvim.winnr("1l"))
+    else
+        --check for other vertical window
+        return (nvim.winnr("1j") == nvim.winnr("1k"))
+    end
+end
+
 local M = {}
 
 function M.is_border(direction)
@@ -67,4 +79,25 @@ function M.is_border(direction)
     return result
 end
 
+function M.is_tmux_target(border)
+    if not tmux.is_tmux then
+        return false
+    end
+
+    return not M.is_border(border) or is_only_window(border)
+end
+
+function M.has_tmux_target(direction, persist_zoom, cycle_navigation)
+    if not tmux.is_tmux then
+        return false
+    end
+    if tmux.is_zoomed() and persist_zoom then
+        return false
+    end
+    if not M.is_border(direction) then
+        return true
+    end
+    return cycle_navigation and not M.is_border(nvim.opposite_direction(direction))
+end
+
 return M

lua/tmux/navigation/init.lua

@@ -3,6 +3,7 @@ local navigate = require("tmux.navigation.navigate")
 local options = require("tmux.configuration.options")
 
 local M = {}
+
 function M.setup()
     if options.navigation.enable_default_keybindings then
         keymaps.register("n", {

lua/tmux/navigation/navigate.lua

@@ -4,35 +4,18 @@ local nvim = require("tmux.wrapper.nvim")
 local options = require("tmux.configuration.options")
 local tmux = require("tmux.wrapper.tmux")
 
-local opposite_directions = {
-    h = "l",
-    j = "k",
-    k = "j",
-    l = "h",
-}
-
 local M = {}
-function M.has_tmux_target(direction)
-    if not tmux.is_tmux then
-        return false
-    end
-    if tmux.is_zoomed() and options.navigation.persist_zoom then
-        return false
-    end
-    if not layout.is_border(direction) then
-        return true
-    end
-    return options.navigation.cycle_navigation and not layout.is_border(opposite_directions[direction])
-end
 
 function M.to(direction)
     log.debug("navigate_to: " .. direction)
 
     local is_nvim_border = nvim.is_nvim_border(direction)
-    if (nvim.is_nvim_float() or is_nvim_border) and M.has_tmux_target(direction) then
+    local has_tmux_target =
+        layout.has_tmux_target(direction, options.navigation.persist_zoom, options.navigation.cycle_navigation)
+    if (nvim.is_nvim_float() or is_nvim_border) and has_tmux_target then
         tmux.change_pane(direction)
     elseif is_nvim_border and options.navigation.cycle_navigation then
-        nvim.wincmd(opposite_directions[direction], 999)
+        nvim.wincmd(nvim.opposite_direction(direction), 999)
     elseif not is_nvim_border then
         nvim.wincmd(direction, vim.v.count)
     end

lua/tmux/resize.lua

@@ -4,26 +4,8 @@ local nvim = require("tmux.wrapper.nvim")
 local options = require("tmux.configuration.options")
 local tmux = require("tmux.wrapper.tmux")
 
---return true if there is no other nvim window in the direction of @border
-local function is_only_window(border)
-    if border == "h" or border == "l" then
-        --check for other horizontal window
-        return (nvim.winnr("1h") == nvim.winnr("1l"))
-    else
-        --check for other vertical window
-        return (nvim.winnr("1j") == nvim.winnr("1k"))
-    end
-end
-
-local function is_tmux_target(border)
-    if not tmux.is_tmux then
-        return false
-    end
-
-    return not layout.is_border(border) or is_only_window(border)
-end
-
 local M = {}
+
 function M.setup()
     if options.resize.enable_default_keybindings then
         keymaps.register("n", {
@@ -38,7 +20,7 @@ end
 function M.to_left(step)
     step = step or options.resize.resize_step_x
     local is_border = nvim.is_nvim_border("l")
-    if (nvim.is_nvim_float() or is_border) and is_tmux_target("l") then
+    if (nvim.is_nvim_float() or is_border) and layout.is_tmux_target("l") then
         tmux.resize("h", step)
     elseif is_border then
         nvim.resize("x", "+", step)
@@ -50,7 +32,7 @@ end
 function M.to_bottom(step)
     step = step or options.resize.resize_step_y
     local is_border = nvim.is_nvim_border("j")
-    if (nvim.is_nvim_float() or is_border) and is_tmux_target("j") then
+    if (nvim.is_nvim_float() or is_border) and layout.is_tmux_target("j") then
         tmux.resize("j", step)
     elseif is_border then
         nvim.resize("y", "-", step)
@@ -62,7 +44,7 @@ end
 function M.to_top(step)
     step = step or options.resize.resize_step_y
     local is_border = nvim.is_nvim_border("j")
-    if (nvim.is_nvim_float() or is_border) and is_tmux_target("j") then
+    if (nvim.is_nvim_float() or is_border) and layout.is_tmux_target("j") then
         tmux.resize("k", step)
     elseif is_border then
         nvim.resize("y", "+", step)
@@ -74,7 +56,7 @@ end
 function M.to_right(step)
     step = step or options.resize.resize_step_x
     local is_border = nvim.is_nvim_border("l")
-    if (nvim.is_nvim_float() or is_border) and is_tmux_target("l") then
+    if (nvim.is_nvim_float() or is_border) and layout.is_tmux_target("l") then
         tmux.resize("l", step)
     elseif is_border then
         nvim.resize("x", "-", step)

lua/tmux/swap.lua

@@ -0,0 +1,49 @@
+local keymaps = require("tmux.keymaps")
+local options = require("tmux.configuration.options")
+local layout = require("tmux.layout")
+local nvim = require("tmux.wrapper.nvim")
+local tmux = require("tmux.wrapper.tmux")
+
+local M = {}
+
+function M.setup()
+    if options.swap.enable_default_keybindings then
+        keymaps.register("n", {
+            ["<C-A-h>"] = [[<cmd>lua require'tmux'.swap_left()<cr>]],
+            ["<C-A-j>"] = [[<cmd>lua require'tmux'.swap_bottom()<cr>]],
+            ["<C-A-k>"] = [[<cmd>lua require'tmux'.swap_top()<cr>]],
+            ["<C-A-l>"] = [[<cmd>lua require'tmux'.swap_right()<cr>]],
+        })
+    end
+end
+
+function M.to(direction)
+    local is_nvim_border = nvim.is_nvim_border(direction)
+    local persist_zoom = true -- tmux swap-pane when zoomed causes error
+    local has_tmux_target = layout.has_tmux_target(direction, persist_zoom, options.swap.cycle_navigation)
+    if (nvim.is_nvim_float() or is_nvim_border) and has_tmux_target then
+        tmux.swap(direction)
+    elseif is_nvim_border and options.swap.cycle_navigation then
+        nvim.swap(nvim.opposite_direction(direction), 999)
+    elseif not is_nvim_border then
+        nvim.swap(direction, vim.v.count)
+    end
+end
+
+function M.to_left()
+    M.to("h")
+end
+
+function M.to_bottom()
+    M.to("j")
+end
+
+function M.to_top()
+    M.to("k")
+end
+
+function M.to_right()
+    M.to("l")
+end
+
+return M

lua/tmux/wrapper/nvim.lua

@@ -1,4 +1,7 @@
+local opposite_directions = { h = "l", j = "k", k = "j", l = "h" }
+
 local M = {}
+
 function M.is_nvim_border(border)
     return M.winnr() == M.winnr("1" .. border)
 end
@@ -16,6 +19,17 @@ function M.resize(axis, direction, step_size)
     return vim.api.nvim_command(command .. direction .. step_size)
 end
 
+function M.swap(direction, count)
+    local current_win = vim.api.nvim_get_current_win()
+    local current_buf = vim.api.nvim_win_get_buf(current_win)
+    local target_winnr = M.winnr(count .. direction)
+    local target_win = vim.api.nvim_call_function("win_getid", { target_winnr })
+    local target_buf = vim.api.nvim_win_get_buf(target_win)
+    vim.api.nvim_win_set_buf(current_win, target_buf)
+    vim.api.nvim_win_set_buf(target_win, current_buf)
+    M.wincmd(direction, count)
+end
+
 function M.wincmd(direction, count)
     return vim.api.nvim_command((count or 1) .. "wincmd " .. direction)
 end
@@ -24,4 +38,8 @@ function M.winnr(direction)
     return vim.api.nvim_call_function("winnr", { direction })
 end
 
+function M.opposite_direction(direction)
+    return opposite_directions[direction]
+end
+
 return M

lua/tmux/wrapper/tmux.lua

@@ -2,12 +2,8 @@ local vim = vim
 
 local log = require("tmux.log")
 
-local tmux_directions = {
-    h = "L",
-    j = "D",
-    k = "U",
-    l = "R",
-}
+local tmux_directions = { h = "L", j = "D", k = "U", l = "R" }
+local tmux_swap_directions = { h = "left", j = "down", k = "up", l = "right" }
 
 local function get_tmux()
     return os.getenv("TMUX")
@@ -94,6 +90,10 @@ function M.resize(direction, step)
     execute(string.format("resize-pane -t '%s' -%s %d", get_tmux_pane(), tmux_directions[direction], step))
 end
 
+function M.swap(direction)
+    execute(string.format("swap-pane -t '%s' -s '{%s-of}'", get_tmux_pane(), tmux_swap_directions[direction]))
+end
+
 function M.set_buffer(content, sync_clipboard)
     content = content:gsub("\\", "\\\\")
     content = content:gsub('"', '\\"')