feat(ui): add configurable window position (#26)

Adds `ui.position` option to control where the marks window appears.
Defaults to 'center'. Supported values:
- top_center: positions the window near the top, centered horizontally
- bottom_center: positions it near the bottom
- center: keeps the existing centered behavior

Author: alexekdahl

README.md

@@ -61,6 +61,9 @@ Vim's built-in marks are great, but they're global and get messy fast. Marksman
     silent = false,
     disable_default_keymaps = false,
     debounce_ms = 500,
+    ui = {
+      position = "center",  -- "center", "top_center", or "bottom_center"
+    },
   },
 }
 ```
@@ -129,6 +132,9 @@ require("marksman").setup({
   silent = false,            -- Suppress notifications
   disable_default_keymaps = false,
   debounce_ms = 500,         -- Save debounce (100-5000ms)
+  ui = {
+    position = "center",     -- Window position: "center", "top_center", or "bottom_center"
+  },
   highlights = {
     ProjectMarksTitle = { fg = "#61AFEF", bold = true },
     ProjectMarksNumber = { fg = "#C678DD" },

lua/marksman/init.lua

@@ -34,22 +34,36 @@ local default_config = {
 	},
 	auto_save = true,
 	max_marks = 100,
-	search_in_ui = true,
 	silent = false,
 	minimal = false,
 	disable_default_keymaps = false,
 	debounce_ms = 500, -- Debounce save operations
+	ui = {
+		-- Position of the marks window.
+		-- "center" positions the window in the middle of the editor (default).
+		-- "top_center" aligns the window at the top of the screen, centered horizontally.
+		-- "bottom_center" aligns the window at the bottom of the screen, centered horizontally.
+		position = "center",
+	},
 }
 
 -- Configuration validation schema
 local config_schema = {
 	auto_save = { type = "boolean" },
 	max_marks = { type = "number", min = 1, max = 1000 },
-	search_in_ui = { type = "boolean" },
 	silent = { type = "boolean" },
 	minimal = { type = "boolean" },
 	disable_default_keymaps = { type = "boolean" },
 	debounce_ms = { type = "number", min = 100, max = 5000 },
+	ui = {
+		type = "table",
+		fields = {
+			position = {
+				type = "string",
+				allowed = { "center", "top_center", "bottom_center" },
+			},
+		},
+	},
 }
 
 local config = {}

lua/marksman/ui.lua

@@ -624,8 +624,43 @@ function M.show_marks_window(marks, project_name, search_query)
 		pcall(vim.api.nvim_buf_add_highlight, buf, -1, hl.hl_group, hl.line, hl.col, hl.end_col)
 	end
 
-	-- Calculate window position (centered)
-	local row = math.floor((vim.o.lines - WINDOW_HEIGHT) / 2)
+	-- Calculate window position based on user configuration.  By default the
+	-- marks window is centered in the editor, but users can override
+	-- this by specifying ui.position in their plugin configuration.  A
+	-- value of "top_center" positions the window near the top of the
+	-- screen, while "bottom_center" aligns it near the bottom.  Any
+	-- unrecognised value falls back to the centered position.  We also
+	-- clamp the row so the window never renders outside the visible
+	-- editor lines.  Note: vim.o.lines returns the total number of
+	-- lines in the UI (not just the buffer), so subtracting the window
+	-- height ensures the window is fully on screen.
+	local pos = nil
+	if config and type(config.ui) == "table" then
+		pos = config.ui.position
+	end
+	local row
+	if pos == "top_center" then
+		-- Place the window a couple of lines down to avoid
+		-- overlapping the very top of the UI.  A value of 1 gives
+		-- a small margin but still keeps the window anchored near
+		-- the top.
+		row = 1
+	elseif pos == "bottom_center" then
+		-- Place the window a couple of lines above the bottom to
+		-- leave room for command line and status line.  We subtract
+		-- 2 to account for the border and padding.
+		row = vim.o.lines - WINDOW_HEIGHT - 2
+	else
+		-- Default to center positioning
+		row = math.floor((vim.o.lines - WINDOW_HEIGHT) / 2)
+	end
+	-- Ensure row stays within valid bounds
+	if row < 0 then
+		row = 0
+	elseif row > vim.o.lines - WINDOW_HEIGHT then
+		row = math.max(vim.o.lines - WINDOW_HEIGHT, 0)
+	end
+	-- Always center horizontally
 	local col = math.floor((vim.o.columns - WINDOW_WIDTH) / 2)
 
 	-- Window title
@@ -701,3 +736,4 @@ function M.cleanup()
 end
 
 return M
+