refactor(dap): simplify hover tree rendering architecture

- Add row/column tracking to Content for multi-line highlight support
- Switch from Node:format() returning Content to Node:format_into(content)
- Remove complex highlight offset calculations and manual text merging
- Use content:current_line() instead of tracking line_number in nodes
- Fix pointer child formatting to use item.name directly
- Clean up unused imports and simplify render_node method

lua/ow/dap/hover.lua

@@ -38,11 +38,9 @@ function Window.compute_width(lines)
 end
 
 ---Create and display hover window with tree content
----@param session dap.Session
----@param item ow.dap.Item
 ---@param lines string[]
 ---@param content ow.dap.hover.Content
-function Window.show(session, item, lines, content)
+function Window.show(lines, content)
     -- Create buffer
     local orig_buf = vim.api.nvim_get_current_buf()
     local buf = vim.api.nvim_create_buf(false, true)
@@ -108,7 +106,7 @@ function Window.expand_at_cursor(buf)
         local ok, err = xpcall(function()
             -- Toggle expansion
             local cursor = vim.api.nvim_win_get_cursor(Window.current_win)
-            local success = Window.tree:toggle_at_line(cursor[1] - 1)
+            local success = Window.tree:toggle_at_line(cursor[1])
             if not success then
                 return
             end
@@ -205,7 +203,7 @@ local function hover_eval(
     Window.tree = tree
 
     -- Show hover window
-    Window.show(session, item, lines, content)
+    Window.show(lines, content)
 end
 
 ---Public hover function

lua/ow/dap/hover/content.lua

@@ -1,5 +1,4 @@
 -- Highlighted text content builder for DAP tree display
-local log = require("ow.log")
 ---@class ow.dap.hover.content.Capture
 ---@field start_col integer
 ---@field end_col integer
@@ -9,12 +8,15 @@ local log = require("ow.log")
 
 ---@class ow.dap.hover.Highlight
 ---@field group string Highlight group name
+---@field start_row integer Start line (0-indexed)
 ---@field start_col integer Start column (0-indexed)
+---@field end_row integer End line (0-indexed)
 ---@field end_col integer End column (0-indexed)
 
 ---@class ow.dap.hover.Content
 ---@field text string The complete text content
 ---@field highlights ow.dap.hover.Highlight[] List of highlights to apply
+---@field _current_row integer Current line position (for building)
 ---@field _current_col integer Current column position (for building)
 local Content = {}
 Content.__index = Content
@@ -25,15 +27,23 @@ function Content.new()
     return setmetatable({
         text = "",
         highlights = {},
+        _current_row = 0,
         _current_col = 0,
     }, Content)
 end
 
+---@return integer
+function Content:current_line()
+    return self._current_row + 1
+end
+
 ---Add text with optional highlighting
----@param text string Text to add
+---@param text string Text to add. May not contain line breaks.
 ---@param highlight_group? string Optional highlight group
 function Content:add(text, highlight_group)
+    local start_row = self._current_row
     local start_col = self._current_col
+    local end_row = self._current_row
     local end_col = start_col + #text
 
     self.text = self.text .. text
@@ -42,16 +52,19 @@ function Content:add(text, highlight_group)
     if highlight_group then
         table.insert(self.highlights, {
             group = highlight_group,
+            start_row = start_row,
             start_col = start_col,
+            end_row = end_row,
             end_col = end_col,
         })
     end
 end
 
 ---Add text with tree-sitter syntax highlighting
----@param text string The text to highlight
+---@param text string Text to add. May not contain line breaks.
----@param lang string Language for tree-sitter
+---@param lang string Language for tree-sitter highlighting
 function Content:add_with_treesitter(text, lang)
+    local start_row = self._current_row
     local start_col = self._current_col
 
     -- First, just add the text normally
@@ -76,22 +89,23 @@ function Content:add_with_treesitter(text, lang)
     -- Add highlights for all captures (overlapping is fine)
     for id, node in query:iter_captures(tree:root(), text, 0, -1) do
         local capture_name = query.captures[id]
-        local start_row, start_col_rel, end_row, end_col_rel = node:range()
+        local start_row_rel, start_col_rel, end_row_rel, end_col_rel =
+            node:range()
 
-        -- TODO: keep track of text as lines instead, so we can handle multiline
+        -- Convert to absolute positions
-        --       highlights
+        local abs_start_row = start_row + start_row_rel
-        if start_row == end_row then -- Single line only
+        local abs_end_row = start_row + end_row_rel
-            -- Convert to absolute column positions
+        local abs_start_col = start_col + start_col_rel
-            local abs_start_col = start_col + start_col_rel
+        local abs_end_col = start_col + end_col_rel
-            local abs_end_col = start_col + end_col_rel
 
-            -- Add the highlight
+        -- Add the highlight
-            table.insert(self.highlights, {
+        table.insert(self.highlights, {
-                group = "@" .. capture_name,
+            group = "@" .. capture_name,
-                start_col = abs_start_col,
+            start_row = abs_start_row,
-                end_col = abs_end_col,
+            start_col = abs_start_col,
-            })
+            end_row = abs_end_row,
-        end
+            end_col = abs_end_col,
+        })
     end
 end
 
@@ -99,6 +113,7 @@ end
 function Content:newline()
     self:add("\n")
     self._current_col = 0
+    self._current_row = self._current_row + 1
 end
 
 ---Get the lines as a table
@@ -110,35 +125,14 @@ end
 ---Apply highlights to a buffer
 ---@param ns_id integer
 ---@param buf integer Buffer handle
----@param line_offset? integer Line offset to apply highlights at (default 0)
+function Content:apply_highlights(ns_id, buf)
-function Content:apply_highlights(ns_id, buf, line_offset)
-    line_offset = line_offset or 0
-    local lines = self:get_lines()
-    local current_line = 0
-    local line_start_col = 0
-
     for _, highlight in ipairs(self.highlights) do
-        -- Find which line this highlight belongs to
-        while
-            current_line < #lines - 1
-            and highlight.start_col
-                >= line_start_col + #lines[current_line + 1] + 1
-        do
-            line_start_col = line_start_col + #lines[current_line + 1] + 1 -- +1 for newline
-            current_line = current_line + 1
-        end
-
-        -- Calculate column positions relative to line start
-        local start_col = highlight.start_col - line_start_col
-        local end_col = highlight.end_col - line_start_col
-
-        -- Apply highlight
         vim.hl.range(
             buf,
             ns_id,
             highlight.group,
-            { line_offset + current_line, start_col },
+            { highlight.start_row, highlight.start_col },
-            { line_offset + current_line, end_col }
+            { highlight.end_row, highlight.end_col }
         )
     end
 end

lua/ow/dap/hover/node.lua

@@ -1,13 +1,10 @@
 -- Tree node representation for DAP variables
-local Content = require("ow.dap.hover.content")
-local log = require("ow.log")
 
 ---@class ow.dap.hover.Node
 ---@field item ow.dap.Item The DAP item this node represents
 ---@field parent ow.dap.hover.Node? Parent node
 ---@field children ow.dap.hover.Node[] Child nodes
 ---@field is_expanded boolean Whether this node is expanded
----@field line_number integer Buffer line number where this node is displayed
 ---@field is_last_child boolean Whether this is the last child of its parent
 local Node = {}
 Node.__index = Node
@@ -17,14 +14,15 @@ Node.__index = Node
 ---@param parent ow.dap.hover.Node?
 ---@return ow.dap.hover.Node
 function Node.new(item, parent)
-    return setmetatable({
+    local node = setmetatable({
         item = item,
         parent = parent,
         children = {},
         is_expanded = false,
-        line_number = -1,
         is_last_child = false,
     }, Node)
+
+    return node
 end
 
 ---Check if this node represents a container (struct/array)
@@ -79,7 +77,7 @@ function Node:is_c_pointer_child()
 end
 
 ---@return string
-function Node:format_c_expression()
+function Node:format_c()
     if self:is_c_array_element() then
         return string.format(
             "%s = (%s) %s",
@@ -90,7 +88,7 @@ function Node:format_c_expression()
     end
 
     if self:is_c_pointer_child() then
-        return string.format("*%s = %s", self.parent.item.name, self.item.value)
+        return string.format("%s = %s", self.item.name, self.item.value)
     end
 
     return string.format(
@@ -101,13 +99,10 @@ function Node:format_c_expression()
     )
 end
 
----Format this node as highlighted content
+---Format this node into the provided content
 ---@param session dap.Session DAP session for making requests
----@return ow.dap.hover.Content
+---@param content ow.dap.hover.Content
-function Node:format(session)
+function Node:format_into(session, content)
-    local content = Content.new()
-
-    -- Add expansion marker for containers
     if self:is_container() then
         local marker = self.is_expanded and "-" or "+"
         content:add(marker .. " ", "@comment")
@@ -115,27 +110,25 @@ function Node:format(session)
         content:add("  ")
     end
 
-    -- Add tree prefix
     local tree_prefix = self:get_tree_prefix()
     if tree_prefix ~= "" then
         content:add(tree_prefix, "@comment")
     end
 
-    local stmt
+    local text
     if session.filetype == "c" or session.filetype == "cpp" then
-        stmt = self:format_c_expression()
+        text = self:format_c()
     else
         error(
             string.format("Formatting for %s not implemented", session.filetype)
         )
     end
-    content:add_with_treesitter(stmt, session.filetype)
+
+    content:add_with_treesitter(text, session.filetype)
 
     if self.item.value == "" then
         content:add("...", "@comment")
     end
-
-    return content
 end
 
 return Node

lua/ow/dap/hover/tree.lua

@@ -1,7 +1,6 @@
 -- Tree-based DAP variable formatter with expand/collapse support
 local Content = require("ow.dap.hover.content")
 local Node = require("ow.dap.hover.node")
-local log = require("ow.log")
 
 ---@class ow.dap.hover.Tree
 ---@field session dap.Session
@@ -88,7 +87,7 @@ function Tree:render()
     local content = Content.new()
     self.line_to_node = {}
 
-    self:render_node(self.root_node, content, 0)
+    self:render_subtree(self.root_node, content)
     return content
 end
 
@@ -96,38 +95,20 @@ end
 ---@async
 ---@param node ow.dap.hover.Node
 ---@param content ow.dap.hover.Content
----@param line_number integer Current line number
+function Tree:render_subtree(node, content)
----@return integer new_line_number Updated line number after rendering
-function Tree:render_node(node, content, line_number)
     -- Store line mapping
-    node.line_number = line_number
+    self.line_to_node[content:current_line()] = node
-    self.line_to_node[line_number] = node
 
     -- Format this node
-    local node_content = node:format(self.session)
+    node:format_into(self.session, content)
-    content.text = content.text .. node_content.text
-
-    -- Copy highlights, adjusting for current position
-    local text_offset = #content.text - #node_content.text
-    for _, highlight in ipairs(node_content.highlights) do
-        table.insert(content.highlights, {
-            group = highlight.group,
-            start_col = highlight.start_col + text_offset,
-            end_col = highlight.end_col + text_offset,
-        })
-    end
-
-    content:newline()
-    line_number = line_number + 1
 
     -- Render expanded children
     if node.is_expanded then
         for _, child in ipairs(node.children) do
-            line_number = self:render_node(child, content, line_number)
+            content:newline()
+            self:render_subtree(child, content)
         end
     end
-
-    return line_number
 end
 
 ---Toggle expansion state of node at given line