feat(ui): add support for 'current' position in UI configuration (#146)

* feat(ui): add support for 'current' position in UI configuration
- allow 'current' as a valid position option for UI placement
- update position handling in dimensions and window closing logic
- ensure compatibility with existing configurations

* fix(ui): disable winfixbuf in 'current' mode and auto-close on buffer switch

When 'ui.position' is set to 'current', disabling 'winfixbuf' prevents E1513
errors when external pickers (like Snacks) try to switch buffers. Added a
BufEnter autocmd to automatically close the Opencode UI when a non-Opencode
buffer enters an Opencode window in this mode.

* docs(readme): update UI position options in configuration
- clarify that UI position can now be 'current' alongside 'right' and 'left'
- improve documentation for better user understanding of options

Author: aweis89

README.md

@@ -175,7 +175,7 @@ require('opencode').setup({
     }
   },
   ui = {
-    position = 'right', -- 'right' (default) or 'left'. Position of the UI split
+    position = 'right', -- 'right' (default), 'left' or 'current'. Position of the UI split. 'current' uses the current window for the output.
     input_position = 'bottom', -- 'bottom' (default) or 'top'. Position of the input window
     window_width = 0.40, -- Width as percentage of editor width
     zoom_width = 0.8, -- Zoom width as percentage of editor width

lua/opencode/health.lua

@@ -113,7 +113,7 @@ local function check_configuration()
 
   ---@cast config OpencodeConfig
 
-  local valid_positions = { 'left', 'right', 'top', 'bottom' }
+  local valid_positions = { 'left', 'right', 'top', 'bottom', 'current' }
   if not vim.tbl_contains(valid_positions, config.ui.position) then
     health.warn(
       string.format('Invalid UI position: %s', config.ui.position),

lua/opencode/types.lua

@@ -114,7 +114,7 @@
 ---@field frames string[]
 
 ---@class OpencodeUIConfig
----@field position 'right'|'left' # Position of the UI (default: 'right')
+---@field position 'right'|'left'|'current' # Position of the UI (default: 'right')
 ---@field input_position 'bottom'|'top' # Position of the input window (default: 'bottom')
 ---@field window_width number
 ---@field zoom_width number

lua/opencode/ui/autocmds.lua

@@ -42,6 +42,32 @@ function M.setup_autocmds(windows)
       require('opencode.state').is_opencode_focused = require('opencode.ui.ui').is_opencode_focused()
     end,
   })
+
+  if require('opencode.config').ui.position == 'current' then
+    vim.api.nvim_create_autocmd('BufEnter', {
+      group = group,
+      callback = function()
+        local current_win = vim.api.nvim_get_current_win()
+        local current_buf = vim.api.nvim_get_current_buf()
+
+        if current_win ~= windows.output_win and current_win ~= windows.input_win then
+          return
+        end
+
+        local is_opencode_buf = (
+          current_buf == windows.output_buf
+          or current_buf == windows.input_buf
+          or (windows.footer_buf and current_buf == windows.footer_buf)
+        )
+
+        if not is_opencode_buf then
+          vim.schedule(function()
+            require('opencode.ui.ui').close_windows(windows)
+          end)
+        end
+      end,
+    })
+  end
 end
 
 function M.setup_resize_handler(windows)

lua/opencode/ui/input_window.lua

@@ -107,7 +107,9 @@ function M.setup(windows)
   vim.api.nvim_set_option_value('buftype', 'nofile', { buf = windows.input_buf })
   vim.api.nvim_set_option_value('swapfile', false, { buf = windows.input_buf })
   -- vim.b[windows.input_buf].completion = false
-  vim.api.nvim_set_option_value('winfixbuf', true, { win = windows.input_win })
+  if config.ui.position ~= 'current' then
+    vim.api.nvim_set_option_value('winfixbuf', true, { win = windows.input_win })
+  end
   vim.api.nvim_set_option_value('winfixheight', true, { win = windows.input_win })
   vim.api.nvim_set_option_value('winfixwidth', true, { win = windows.input_win })
 
@@ -124,11 +126,17 @@ function M.update_dimensions(windows)
     return
   end
 
-  local total_width = vim.api.nvim_get_option_value('columns', {})
   local total_height = vim.api.nvim_get_option_value('lines', {})
-  local width = math.floor(total_width * config.ui.window_width)
   local height = math.floor(total_height * config.ui.input_height)
 
+  if config.ui.position == 'current' then
+    pcall(vim.api.nvim_win_set_height, windows.input_win, height)
+    return
+  end
+
+  local total_width = vim.api.nvim_get_option_value('columns', {})
+  local width = math.floor(total_width * config.ui.window_width)
+
   vim.api.nvim_win_set_config(windows.input_win, { width = width, height = height })
 end
 

lua/opencode/ui/output_window.lua

@@ -66,7 +66,9 @@ function M.setup(windows)
   vim.api.nvim_set_option_value('modifiable', false, { buf = windows.output_buf })
   vim.api.nvim_set_option_value('buftype', 'nofile', { buf = windows.output_buf })
   vim.api.nvim_set_option_value('swapfile', false, { buf = windows.output_buf })
-  vim.api.nvim_set_option_value('winfixbuf', true, { win = windows.output_win })
+  if config.ui.position ~= 'current' then
+    vim.api.nvim_set_option_value('winfixbuf', true, { win = windows.output_win })
+  end
   vim.api.nvim_set_option_value('winfixheight', true, { win = windows.output_win })
   vim.api.nvim_set_option_value('winfixwidth', true, { win = windows.output_win })
   vim.api.nvim_set_option_value('signcolumn', 'yes', { scope = 'local', win = windows.output_win })
@@ -78,6 +80,9 @@ function M.setup(windows)
 end
 
 function M.update_dimensions(windows)
+  if config.ui.position == 'current' then
+    return
+  end
   local total_width = vim.api.nvim_get_option_value('columns', {})
   local width = math.floor(total_width * config.ui.window_width)
 

lua/opencode/ui/ui.lua

@@ -26,7 +26,14 @@ function M.close_windows(windows)
 
   ---@cast windows { input_win: integer, output_win: integer, input_buf: integer, output_buf: integer }
   pcall(vim.api.nvim_win_close, windows.input_win, true)
-  pcall(vim.api.nvim_win_close, windows.output_win, true)
+  if config.ui.position == 'current' then
+    pcall(vim.api.nvim_set_option_value, 'winfixbuf', false, { win = windows.output_win })
+    if state.current_code_buf and vim.api.nvim_buf_is_valid(state.current_code_buf) then
+      pcall(vim.api.nvim_win_set_buf, windows.output_win, state.current_code_buf)
+    end
+  else
+    pcall(vim.api.nvim_win_close, windows.output_win, true)
+  end
   pcall(vim.api.nvim_buf_delete, windows.input_buf, { force = true })
   pcall(vim.api.nvim_buf_delete, windows.output_buf, { force = true })
   footer.close()
@@ -67,7 +74,12 @@ function M.create_split_windows(input_buf, output_buf)
   end
   local ui_conf = config.ui
 
-  local main_win = open_split(ui_conf.position, 'vertical')
+  local main_win
+  if ui_conf.position == 'current' then
+    main_win = vim.api.nvim_get_current_win()
+  else
+    main_win = open_split(ui_conf.position, 'vertical')
+  end
   vim.api.nvim_set_current_win(main_win)
 
   local input_win = open_split(ui_conf.input_position, 'horizontal')