1 files changed, 103 insertions, 0 deletions
diff --git a/plugins/markers.lua b/plugins/markers.lua
new file mode 100644
index 0000000..6e397d7
--- /dev/null
+++ b/plugins/markers.lua
@@ -0,0 +1,103 @@
+-- Markers plugin for lite text editor
+-- original implementation by Petri Häkkinen
+
+local core = require "core"
+local command = require "core.command"
+local keymap = require "core.keymap"
+local style = require "core.style"
+local DocView = require "core.docview"
+local Doc = require "core.doc"
+
+local cache = {}  -- this table contains subtables for each document, each subtable is a set of line numbers
+setmetatable(cache, {
+  __mode = "k",
+  __index = function(t, k)
+    t[k] = {}
+    return t[k]
+  end,
+})
+
+
+local function shift_lines(doc, at, diff)
+  if diff == 0 then return end
+  local t = {}
+  for line in pairs(cache[doc]) do
+    line = line >= at and line + diff or line
+    t[line] = true
+  end
+  cache[doc] = t
+end
+
+
+local raw_insert = Doc.raw_insert
+
+function Doc:raw_insert(line, col, text, ...)
+  raw_insert(self, line, col, text, ...)
+  local line_count = 0
+  for _ in text:gmatch("\n") do
+    line_count = line_count + 1
+  end
+  shift_lines(self, line, line_count)
+end
+
+
+local raw_remove = Doc.raw_remove
+
+function Doc:raw_remove(line1, col1, line2, col2, ...)
+  raw_remove(self, line1, col1, line2, col2, ...)
+  shift_lines(self, line2, line1 - line2)
+end
+
+
+local draw_line_gutter = DocView.draw_line_gutter
+
+function DocView:draw_line_gutter(idx, x, y)
+  if cache[self.doc] and cache[self.doc][idx] then
+    local h = self:get_line_height()
+    renderer.draw_rect(x, y, style.padding.x * 0.4, h, style.selection)
+  end
+  draw_line_gutter(self, idx, x, y)
+end
+
+
+command.add("core.docview", {
+  ["markers:toggle-marker"] = function()
+    local doc = core.active_view.doc
+    local line = doc:get_selection()
+    local markers = cache[doc]
+
+    if markers[line] then
+      markers[line] = nil
+    else
+      markers[line] = true
+    end
+  end,
+
+  ["markers:go-to-next-marker"] = function()
+    local doc = core.active_view.doc
+    local line = doc:get_selection()
+    local markers = cache[doc]
+
+    local first_marker = math.huge
+    local next_marker = math.huge
+    for l, _ in pairs(markers) do
+      if l > line and l < next_marker then
+        next_marker = l
+      end
+      first_marker = math.min(first_marker, l)
+    end
+    if next_marker == math.huge then
+      next_marker = first_marker
+    end
+    if next_marker ~= math.huge then
+      doc:set_selection(next_marker, 1)
+      core.active_view:scroll_to_line(next_marker, true)
+    end
+  end,
+})
+
+
+keymap.add {
+  ["ctrl+f2"] = "markers:toggle-marker",
+  ["f2"] = "markers:go-to-next-marker",
+}