allow terminal setup to preserve backend focus

README.md

@@ -157,8 +157,9 @@ local snacks_terminal_opts = {
     position = 'right',
     enter = false,
     on_win = function(win)
-      -- Set up keymaps and cleanup for an arbitrary terminal
-      require('opencode.terminal').setup(win.win)
+      -- Set up keymaps and cleanup for an arbitrary terminal.
+      -- `restore_focus = false` preserves the terminal backend's focus choice.
+      require('opencode.terminal').setup(win.win, { restore_focus = false })
     end,
   },
 }

lua/opencode/terminal.lua

@@ -1,6 +1,8 @@
 local M = {}
 
 ---@class opencode.terminal.Opts : vim.api.keyset.win_config
+---@class opencode.terminal.SetupOpts
+---@field restore_focus? boolean Return focus to the previously focused window after the initial redraw workaround. Defaults to true.
 
 local winid
 local bufnr
@@ -142,7 +144,12 @@ end
 --- - Keymaps for Neovim-like message navigation.
 --- - Properly clean up `opencode` process on close.
 ---@param win integer
-function M.setup(win)
+---@param opts? opencode.terminal.SetupOpts
+function M.setup(win, opts)
+  opts = vim.tbl_extend("keep", opts or {}, {
+    restore_focus = true,
+  })
+
   local buf = vim.api.nvim_win_get_buf(win)
   ---@type integer|nil
   local pid
@@ -161,6 +168,24 @@ function M.setup(win)
     end,
   })
 
+  -- Redraw terminal buffer on initial render.
+  -- Fixes empty columns on the right side.
+  local auid
+  auid = vim.api.nvim_create_autocmd("TermRequest", {
+    buffer = buf,
+    callback = function(ev)
+      if ev.data.cursor[1] > 1 then
+        vim.api.nvim_del_autocmd(auid)
+        vim.api.nvim_set_current_win(win)
+        if opts.restore_focus then
+          vim.cmd([[startinsert | call feedkeys("\<C-\>\<C-n>\<C-w>p", "n")]])
+        else
+          vim.cmd("startinsert")
+        end
+      end
+    end,
+  })
+
   -- When the terminal's job stops normally
   vim.api.nvim_create_autocmd("TermClose", {
     buffer = buf,