feat: highlight improvemnets

doc/fugitive-ts.nvim.txt

@@ -56,7 +56,7 @@ CONFIGURATION                                               *fugitive-ts-config*
                              Example: >lua
                                  disabled_languages = { 'markdown', 'text' }
 <
-        {debounce_ms}        (integer, default: 50)
+        {debounce_ms}        (integer, default: 0)
                              Debounce delay in milliseconds for re-highlighting
                              after buffer changes. Lower values feel snappier
                              but use more CPU.
@@ -66,9 +66,11 @@ CONFIGURATION                                               *fugitive-ts-config*
                              this many lines. Prevents lag on massive diffs.
 
         {hide_prefix}        (boolean, default: true)
-                             Hide diff prefixes (`+`/`-`/` `) using conceal.
-                             Makes code appear flush left without the leading
-                             diff character. Sets `conceallevel=1` on attach.
+                             Hide diff prefixes (`+`/`-`/` `) using virtual
+                             text overlay. Makes code appear without the
+                             leading diff character. When `highlights.background`
+                             is also enabled, the overlay inherits the line's
+                             background color.
 
         {highlights}         (table, default: see below)
                              Controls which highlight features are enabled.

lua/fugitive-ts/highlight.lua

@@ -141,11 +141,14 @@ function M.highlight_hunk(bufnr, ns, hunk, opts)
     local is_diff_line = prefix == '+' or prefix == '-'
     local line_hl = is_diff_line and (prefix == '+' and 'FugitiveTsAdd' or 'FugitiveTsDelete')
       or nil
+    local number_hl = is_diff_line and (prefix == '+' and 'FugitiveTsAddNr' or 'FugitiveTsDeleteNr')
+      or nil
 
     if opts.hide_prefix then
+      local virt_hl = (opts.highlights.background and line_hl) or nil
       pcall(vim.api.nvim_buf_set_extmark, bufnr, ns, buf_line, 0, {
-        end_col = 1,
-        conceal = '',
+        virt_text = { { ' ', virt_hl } },
+        virt_text_pos = 'overlay',
       })
     end
 
@@ -155,7 +158,7 @@ function M.highlight_hunk(bufnr, ns, hunk, opts)
         priority = 198,
       }
       if opts.highlights.gutter then
-        extmark_opts.number_hl_group = line_hl
+        extmark_opts.number_hl_group = number_hl
       end
       pcall(vim.api.nvim_buf_set_extmark, bufnr, ns, buf_line, 0, extmark_opts)
     end

lua/fugitive-ts/init.lua

@@ -25,15 +25,45 @@ local parser = require('fugitive-ts.parser')
 
 local ns = vim.api.nvim_create_namespace('fugitive_ts')
 
+---@param hex integer
+---@param bg_hex integer
+---@param alpha number
+---@return integer
+local function blend_color(hex, bg_hex, alpha)
+  local r = bit.band(bit.rshift(hex, 16), 0xFF)
+  local g = bit.band(bit.rshift(hex, 8), 0xFF)
+  local b = bit.band(hex, 0xFF)
+
+  local bg_r = bit.band(bit.rshift(bg_hex, 16), 0xFF)
+  local bg_g = bit.band(bit.rshift(bg_hex, 8), 0xFF)
+  local bg_b = bit.band(bg_hex, 0xFF)
+
+  local blend_r = math.floor(r * alpha + bg_r * (1 - alpha))
+  local blend_g = math.floor(g * alpha + bg_g * (1 - alpha))
+  local blend_b = math.floor(b * alpha + bg_b * (1 - alpha))
+
+  return bit.bor(bit.lshift(blend_r, 16), bit.lshift(blend_g, 8), blend_b)
+end
+
+---@param name string
+---@return vim.api.keyset.hl_info
+local function resolve_hl(name)
+  local hl = vim.api.nvim_get_hl(0, { name = name })
+  while hl.link do
+    hl = vim.api.nvim_get_hl(0, { name = hl.link })
+  end
+  return hl
+end
+
 ---@type fugitive-ts.Config
 local default_config = {
   enabled = true,
   debug = false,
   languages = {},
   disabled_languages = {},
-  debounce_ms = 50,
+  debounce_ms = 0,
   max_lines_per_hunk = 500,
-  hide_prefix = true,
+  hide_prefix = false,
   highlights = {
     treesitter = true,
     background = true,
@@ -122,10 +152,6 @@ function M.attach(bufnr)
 
   dbg('attaching to buffer %d', bufnr)
 
-  if config.hide_prefix then
-    vim.api.nvim_set_option_value('conceallevel', 1, { win = 0 })
-  end
-
   local debounced = create_debounced_highlight(bufnr)
 
   highlight_buffer(bufnr)
@@ -185,10 +211,25 @@ function M.setup(opts)
   parser.set_debug(config.debug)
   highlight.set_debug(config.debug)
 
+  local normal = vim.api.nvim_get_hl(0, { name = 'Normal' })
   local diff_add = vim.api.nvim_get_hl(0, { name = 'DiffAdd' })
   local diff_delete = vim.api.nvim_get_hl(0, { name = 'DiffDelete' })
-  vim.api.nvim_set_hl(0, 'FugitiveTsAdd', { bg = diff_add.bg })
-  vim.api.nvim_set_hl(0, 'FugitiveTsDelete', { bg = diff_delete.bg })
+  local diff_added = resolve_hl('diffAdded')
+  local diff_removed = resolve_hl('diffRemoved')
+
+  local bg = normal.bg or 0x1e1e2e
+  local add_bg = diff_add.bg or 0x2e4a3a
+  local del_bg = diff_delete.bg or 0x4a2e3a
+  local add_fg = diff_added.fg or diff_add.fg or 0x80c080
+  local del_fg = diff_removed.fg or diff_delete.fg or 0xc08080
+
+  local blended_add = blend_color(add_bg, bg, 0.4)
+  local blended_del = blend_color(del_bg, bg, 0.4)
+
+  vim.api.nvim_set_hl(0, 'FugitiveTsAdd', { bg = blended_add })
+  vim.api.nvim_set_hl(0, 'FugitiveTsDelete', { bg = blended_del })
+  vim.api.nvim_set_hl(0, 'FugitiveTsAddNr', { fg = add_fg, bg = blended_add })
+  vim.api.nvim_set_hl(0, 'FugitiveTsDeleteNr', { fg = del_fg, bg = blended_del })
 end
 
 return M

spec/highlight_spec.lua

@@ -241,7 +241,7 @@ describe('highlight', function()
       delete_buffer(bufnr)
     end)
 
-    it('applies conceal extmarks when hide_prefix enabled', function()
+    it('applies overlay extmarks when hide_prefix enabled', function()
       local bufnr = create_buffer({
         '@@ -1,1 +1,2 @@',
         ' local x = 1',
@@ -258,17 +258,17 @@ describe('highlight', function()
       highlight.highlight_hunk(bufnr, ns, hunk, default_opts({ hide_prefix = true }))
 
       local extmarks = get_extmarks(bufnr)
-      local conceal_count = 0
+      local overlay_count = 0
       for _, mark in ipairs(extmarks) do
-        if mark[4] and mark[4].conceal == '' then
-          conceal_count = conceal_count + 1
+        if mark[4] and mark[4].virt_text_pos == 'overlay' then
+          overlay_count = overlay_count + 1
         end
       end
-      assert.are.equal(2, conceal_count)
+      assert.are.equal(2, overlay_count)
       delete_buffer(bufnr)
     end)
 
-    it('does not apply conceal extmarks when hide_prefix disabled', function()
+    it('does not apply overlay extmarks when hide_prefix disabled', function()
       local bufnr = create_buffer({
         '@@ -1,1 +1,2 @@',
         ' local x = 1',
@@ -285,13 +285,13 @@ describe('highlight', function()
       highlight.highlight_hunk(bufnr, ns, hunk, default_opts({ hide_prefix = false }))
 
       local extmarks = get_extmarks(bufnr)
-      local conceal_count = 0
+      local overlay_count = 0
       for _, mark in ipairs(extmarks) do
-        if mark[4] and mark[4].conceal == '' then
-          conceal_count = conceal_count + 1
+        if mark[4] and mark[4].virt_text_pos == 'overlay' then
+          overlay_count = overlay_count + 1
         end
       end
-      assert.are.equal(0, conceal_count)
+      assert.are.equal(0, overlay_count)
       delete_buffer(bufnr)
     end)