1 files changed, 62 insertions, 0 deletions
diff --git a/plugins/spellcheck.lua b/plugins/spellcheck.lua
new file mode 100644
index 0000000..bb6f835
--- /dev/null
+++ b/plugins/spellcheck.lua
@@ -0,0 +1,62 @@
+local core = require "core"
+local style = require "core.style"
+local config = require "core.config"
+local command = require "core.command"
+local DocView = require "core.docview"
+
+config.spellcheck_files = { "%.txt$", "%.md$", "%.markdown$" }
+config.dictionary_file = "/usr/share/dict/words"
+
+local words
+
+core.add_thread(function()
+  local t = {}
+  local i = 0
+  for line in io.lines(config.dictionary_file) do
+    for word in line:gmatch("%a+") do
+      t[word:lower()] = true
+    end
+    i = i + 1
+    if i % 1000 == 0 then coroutine.yield() end
+  end
+  words = t
+  core.redraw = true
+  core.log_quiet("Finished loading dictionary file: \"%s\"", config.dictionary_file)
+end)
+
+
+local function matches_any(filename, ptns)
+  for _, ptn in ipairs(ptns) do
+    if filename:find(ptn) then return true end
+  end
+end
+
+
+local draw_line_text = DocView.draw_line_text
+
+function DocView:draw_line_text(idx, x, y)
+  draw_line_text(self, idx, x, y)
+
+  if not words
+  or not matches_any(self.doc.filename or "", config.spellcheck_files) then
+    return
+  end
+
+  local s, e = 0, 0
+  local text = self.doc.lines[idx]
+  local l, c = self.doc:get_selection()
+
+  while true do
+    s, e = text:find("%a+", e + 1)
+    if not s then break end
+    local word = text:sub(s, e):lower()
+    if not words[word] and not (l == idx and c == e + 1) then
+      local color = style.spellcheck_error or style.syntax.keyword2
+      local x1 = x + self:get_col_x_offset(idx, s)
+      local x2 = x + self:get_col_x_offset(idx, e + 1)
+      local h = style.divider_size
+      renderer.draw_rect(x1, y + self:get_line_height() - h, x2 - x1, h, color)
+    end
+  end
+end
+