1 files changed, 40 insertions, 0 deletions
diff --git a/indentguide.lua b/indentguide.lua
new file mode 100644
index 0000000..9d903b7
--- /dev/null
+++ b/indentguide.lua
@@ -0,0 +1,40 @@
+local style = require "core.style"
+local config = require "core.config"
+local DocView = require "core.docview"
+
+
+local function get_line_spaces(doc, idx, dir)
+  local text = doc.lines[idx]
+  if not text then
+    return 0
+  end
+  local s, e = text:find("^%s*")
+  if e == #text then
+    return get_line_spaces(doc, idx + dir, dir)
+  end
+  return e - s + 1
+end
+
+
+local function get_line_indent_guide_spaces(doc, idx)
+  if doc.lines[idx]:find("^%s*\n") then
+    return math.max(
+      get_line_spaces(doc, idx - 1, -1),
+      get_line_spaces(doc, idx + 1,  1))
+  end
+  return get_line_spaces(doc, idx)
+end
+
+
+local draw_line_text = DocView.draw_line_text
+
+function DocView:draw_line_text(idx, x, y)
+  local spaces = get_line_indent_guide_spaces(self.doc, idx)
+  local sw = self:get_font():get_width(" ")
+  local h = self:get_line_height()
+  for i = 0, spaces - 1, config.indent_size do
+    local color = style.guide or style.selection
+    renderer.draw_rect(x + sw * i, y, style.divider_size, h, color)
+  end
+  draw_line_text(self, idx, x, y)
+end