Add `align_carets` (#89)

2 files changed, 81 insertions, 0 deletions

diff --git a/README.md b/README.md
index 1dbd246..c38e812 100644
--- a/README.md
+++ b/README.md
@@ -26,6 +26,7 @@ to something other than a raw file it should be marked with an asterisk.*
 
 | Plugin                                                                                                         | Description                                                                                                                                                                                                                                                                                     |
 | -------------------------------------------------------------------------------------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
+| [`align_carets`](plugins/align_carets.lua?raw=1)                                                               | Align multiple carets and selections *([clip](https://user-images.githubusercontent.com/2798487/165631951-532f8d24-d596-4dd0-9d21-ff53c71ed32f.mp4))*                                                                                                                                           |
 | [`autoinsert`](plugins/autoinsert.lua?raw=1)                                                                   | Automatically inserts closing brackets and quotes. Also allows selected text to be wrapped with brackets or quotes.                                                                                                                                                                             |
 | [`autosave`](plugins/autosave.lua?raw=1)                                                                       | Automatically saves files when they are changed                                                                                                                                                                                                                                                 |
 | [`autosaveonfocuslost`](plugins/autosaveonfocuslost.lua?raw=1)                                                 | Automatically saves files that were changed when the main window loses focus by switching to another application                                                                                                                                                                                |
diff --git a/plugins/align_carets.lua b/plugins/align_carets.lua
new file mode 100644
index 0000000..95d64d5
--- /dev/null
+++ b/plugins/align_carets.lua
@@ -0,0 +1,80 @@
+-- mod-version:2 -- lite-xl 2.0
+local core = require "core"
+local command = require "core.command"
+local DocView = require "core.docview"
+
+
+local function check_doc()
+  local av = core.active_view
+  return av:is(DocView) and #av.doc.selections > 4
+end
+
+
+-- returns:
+-- * if the doc has selections
+-- * if the selections span multiple lines
+local function doc_get_selection_status(doc)
+  local selections = false
+  for _,line1,col1,line2,col2 in doc:get_selections() do
+    if line1 ~= line2 then
+      return true, true
+    end
+    if col1 ~= col2 then
+      selections = true
+    end
+  end
+  return selections, false
+end
+
+
+local function has_selections()
+  if not check_doc() then return false end
+  local selections, has_multilines = doc_get_selection_status(core.active_view.doc)
+  -- we want this to be true if there are only single lines selections
+  return selections and not has_multilines
+end
+
+
+local function has_no_selections()
+  if not check_doc() then return false end
+  return not doc_get_selection_status(core.active_view.doc)
+end
+
+
+local function align(right)
+  local doc = core.active_view.doc
+  local max_col = 0
+  local done = { }
+
+  -- get alignment column
+  for _,line1,col1,_,col2 in doc:get_selections(true) do
+    -- only use the first caret in a line
+    if not done[line1] then
+      done[line1] = true
+      max_col = math.max(max_col, right and col2 or col1)
+    end
+  end
+
+  done = { }
+  for idx,line1,col1,line2,col2 in doc:get_selections(true) do
+  -- only align the first caret in a line
+    if not done[line1] then
+      done[line1] = true
+      local diff = max_col - (right and col2 or col1)
+      if diff > 0 then
+        doc:insert(line1, col1, string.rep(" ", diff))
+      end
+      doc:set_selections(idx, line1, col1 + diff, line2, col2 + diff, right)
+    end
+  end
+end
+
+
+command.add(has_no_selections, {
+  ["doc:align-carets"] = align,
+})
+
+command.add(has_selections, {
+  ["doc:left-align-selections"] = align,
+  ["doc:right-align-selections"] = function() align(true) end,
+})