Create simple window management in neovim, you can swap buffers in

windows, resize windows and enter a resizing mode. Also add some utility
functionality to support this and update the rest of the config to use
these new utility functions

home/.config/nvim/lua/window_management.lua

@@ -0,0 +1,227 @@
+local utils = require("utils")
+
+local M = {}
+
+local is_in_resizing_mode = false
+local on_resize_mode_enter_event = "ResizeModeEnter"
+local on_resize_mode_exit_event = "ResizeModeExit"
+
+local function is_floating_window(window)
+    assert(window, "Invalid window")
+
+    return vim.api.nvim_win_get_config(window).relative ~= ""
+end
+
+local function is_window_resizable(window)
+    assert(window, "Invalid window")
+
+    local config = vim.api.nvim_win_get_config(window)
+    return not config.winfixwidth and not config.winfixheight
+end
+
+local function get_total_num_windows_open()
+    return #vim.api.nvim_tabpage_list_wins(0)
+end
+
+local function get_adjacent_window(dir_char)
+    assert(dir_char == "h" or dir_char == "j" or dir_char == "k" or dir_char == "l", "Invalid direction character")
+
+    local current_window = vim.api.nvim_get_current_win()
+    if not current_window then
+        return
+    end
+
+    vim.cmd("wincmd " .. dir_char)
+    local new_window = vim.api.nvim_get_current_win()
+    vim.api.nvim_set_current_win(current_window)
+
+    assert(vim.api.nvim_get_current_win() == current_window, "Cursor moved to a different window")
+    return new_window
+end
+
+local function is_current_window_at_edge(dir_char)
+    return vim.api.nvim_get_current_win() == get_adjacent_window(dir_char)
+end
+
+local function swap_buffer_between_windows(window_a, window_b)
+    assert(window_a and window_b, "Invalid window")
+
+    local buffer_a = vim.api.nvim_win_get_buf(window_a)
+    local buffer_b = vim.api.nvim_win_get_buf(window_b)
+    vim.api.nvim_win_set_buf(window_a, buffer_b)
+    vim.api.nvim_win_set_buf(window_b, buffer_a)
+
+    assert(vim.api.nvim_win_get_buf(window_a) == buffer_b and vim.api.nvim_win_get_buf(window_b) == buffer_a,
+        "Failed to swap buffers")
+end
+
+local function swap_window(dir_char)
+    assert(dir_char == "h" or dir_char == "j" or dir_char == "k" or dir_char == "l", "Invalid direction character")
+
+    local required_num_windows = 2
+    if get_total_num_windows_open() < required_num_windows then
+        return
+    end
+
+    local current_window = vim.api.nvim_get_current_win()
+    if not current_window then
+        return
+    end
+
+    if is_floating_window(current_window) then
+        return
+    end
+
+    if is_current_window_at_edge(dir_char) then
+        return
+    end
+
+    if not is_window_resizable(current_window) then
+        return
+    end
+
+    local adjacent_window = get_adjacent_window(dir_char)
+    if not is_window_resizable(adjacent_window) then
+        return
+    end
+
+    swap_buffer_between_windows(current_window, adjacent_window)
+    vim.api.nvim_set_current_win(adjacent_window)
+
+    assert(vim.api.nvim_get_current_win() == adjacent_window, "Failed to swap windows")
+end
+
+local function resize_window(window, dir_char)
+    assert(is_in_resizing_mode, "Not in resizing mode")
+    assert(window, "Invalid window")
+    assert(dir_char == "h" or dir_char == "j" or dir_char == "k" or dir_char == "l", "Invalid direction character")
+
+    local default_resize_units = 5
+    local tot_resize_units = default_resize_units * vim.v.count1
+    if dir_char == "h" then
+        vim.cmd("vertical resize -" .. tot_resize_units)
+    elseif dir_char == "j" then
+        vim.cmd("resize " .. tot_resize_units)
+    elseif dir_char == "k" then
+        vim.cmd("resize -" .. tot_resize_units)
+    elseif dir_char == "l" then
+        vim.cmd("vertical resize " .. tot_resize_units)
+    end
+end
+
+local function exit_resizing_mode()
+    assert(is_in_resizing_mode, "Not in resizing mode")
+
+    is_in_resizing_mode = false
+    utils.broadcast_event(on_resize_mode_exit_event)
+
+    assert(not is_in_resizing_mode, "Failed to exit resizing mode")
+end
+
+local function enter_resizing_mode()
+    assert(not is_in_resizing_mode, "Already in resizing mode")
+
+    local current_window = vim.api.nvim_get_current_win()
+    if not current_window then
+        return
+    end
+
+    if is_floating_window(current_window) then
+        return
+    end
+
+    if not is_window_resizable(current_window) then
+        return
+    end
+
+    is_in_resizing_mode = true
+    utils.broadcast_event(on_resize_mode_enter_event)
+
+    assert(is_in_resizing_mode, "Failed to enter resizing mode")
+end
+
+function M.autosize_windows()
+    vim.api.nvim_command("wincmd =")
+end
+
+function M.is_in_resizing_mode()
+    return is_in_resizing_mode
+end
+
+function M.setup()
+    local resizing_mode_keymaps = {
+        n = {
+            ["<Left>"] = {
+                cmd = function() resize_window(vim.api.nvim_get_current_win(), "h") end
+            },
+            ["<Down>"] = {
+                cmd = function() resize_window(vim.api.nvim_get_current_win(), "j") end
+            },
+            ["<Up>"] = {
+                cmd = function() resize_window(vim.api.nvim_get_current_win(), "k") end
+            },
+            ["<Right>"] = {
+                cmd = function() resize_window(vim.api.nvim_get_current_win(), "l") end
+            },
+            ["<Esc>"] = {
+                cmd = function() exit_resizing_mode() end
+            },
+            ["<Enter>"] = {
+                cmd = function() exit_resizing_mode() end
+            },
+        }
+    }
+    local enter_resizing_mode_keymaps = {
+        n = {
+            ["<C- >"] = {
+                cmd = function() enter_resizing_mode() end
+            }
+        },
+    }
+    local window_shifting_keymaps = {
+        n = {
+            ["<C-S-Left>"] = {
+                cmd = function()
+                    swap_window("h")
+                end
+            },
+            ["<C-S-Down>"] = {
+                cmd = function()
+                    swap_window("j")
+                end
+            },
+            ["<C-S-Up>"] = {
+                cmd = function()
+                    swap_window("k")
+                end
+            },
+            ["<C-S-Right>"] = {
+                cmd = function()
+                    swap_window("l")
+                end
+            },
+        },
+    }
+
+    utils.add_keymaps({
+        window_shifting_keymaps,
+        enter_resizing_mode_keymaps
+    })
+
+    local function on_resize_mode_enter()
+        utils.remove_keymaps(enter_resizing_mode_keymaps)
+        utils.add_keymaps(resizing_mode_keymaps)
+    end
+
+    local function on_resize_mode_exit()
+        utils.remove_keymaps(resizing_mode_keymaps)
+        utils.add_keymaps(enter_resizing_mode_keymaps)
+    end
+
+    local window_management_augroup = "WindowManagementEvents"
+    vim.api.nvim_create_augroup(window_management_augroup, { clear = true })
+    utils.create_user_event_cb(on_resize_mode_enter_event, on_resize_mode_enter, window_management_augroup)
+    utils.create_user_event_cb(on_resize_mode_exit_event, on_resize_mode_exit, window_management_augroup)
+end
+
+return M