Cancel Auto-complete If Single Item Matches Text

[eric-hemasystems]

I have my auto-complete set to automatically show up after every character insert. I find this helps me use the auto-complete a lot more than if I had to hit a key combo to activate it. I'm doing this with:

buffer.auto_c_choose_single = false
events.connect(events.CHAR_ADDED, function()
  textadept.editing.autocomplete('word')
end)

Overall this is working fairly well. One thing that would make it nicer is if there is a single item in the auto-complete list and it entirely matches what has already been typed it would be nice if it could auto-cancel.

For example if I type end and end is the only possible auto-complete for that buffer then the auto-complete popup doesn't really help me as I have entirely typed the only option. It would be better if it could just go away vs me having to hit enter (to accept what I have already completely typed) or esc (to manually cancel the auto complete list).

I attempted to look for some way to do that. My pseudo code might be something like:

events.connect(events.AUTO_C_OPTIONS, function()
  local single_item = buffer.auto_c_items_count == 1
  local typed_text = buffer:text_range(buffer:auto_c_pos_start(), buffer.current_pos)
  local typed_completely = buffer.auto_c_current_text == typed_text
  if single_item and typed_completely then
    buffer:auto_c_cancel()
  end
end)

What I'm missing in the above is:

• A way to know how many items are in the auto-complete list (i.e. my auto_c_items_count).
• An event to know when auto-complete has offered new options (i.e. my AUTO_C_OPTIONS event).
• auto_c_pos_start isn't really doing what I want here. Instead of returning the start of when I first started auto-completing it is returning the position the auto-complete was last activated on (the most recent character).

Are there some aspects to the API that I could use to implement something like this?

[snoopy]

I use a similar setup and this seems to work for me:

events.connect(events.CHAR_ADDED, function(code)
  if code >= 48 and code <= 57 or code >= 65 and code <= 90 or code >= 97 and code <= 122 or code == 95 then
    textadept.editing.autocomplete('word')
    if buffer:auto_c_active() then
      return
    end
    textadept.editing.autocomplete(buffer:get_lexer(true))
  end
end)

events.connect(events.KEYPRESS, function(code)
  if buffer:auto_c_active() and code ~= 65505 then
    buffer:auto_c_cancel()
  end
end)

Additionally I also cancel on some other keys:

keys['\n'] = function()
  if buffer:auto_c_active() then
    buffer:auto_c_complete()
    return true
  end
  return false
end

keys.up = function()
  if buffer:auto_c_active() then
    buffer:auto_c_cancel()
    return false
  end
  return false
end

keys.down = function()
  if buffer:auto_c_active() then
    buffer:auto_c_cancel()
    return false
  end
  return false
end

keys['home'] = function()
  if buffer:auto_c_active() then
    buffer:auto_c_cancel()
    return false
  end
  return false
end

keys['end'] = function()
  if buffer:auto_c_active() then
    buffer:auto_c_cancel()
    return false
  end
  return false
end

[eric-hemasystems]

Just to follow up on this. I think I may have a way to auto-cancel the auto-complete if there is only a single suggested item and that item has been fully typed out. The following is my entire auto-complete customization code:

-- Since we auto-activate auto complete we don't want to auto-choose on single
-- in case they are typing an entirely new term.
buffer.auto_c_choose_single = false

-- It is typical for one buffer to make use of structures in another buffer
-- so scan all open buffers for auto-complete.
textadept.editing.autocomplete_all_words = true

-- Monkey-patch buffer.auto_c_show to record the most recently displayed list
buffer.autocomplete_items = ''
events.connect(events.INITIALIZED, function()
  if not buffer.old_auto_c_show then
    buffer.old_auto_c_show = buffer.auto_c_show

    buffer.auto_c_show = function (buffer, len_entered, items)
      buffer.autocomplete_items = items
      return buffer:old_auto_c_show(len_entered, items)
    end
  end
end)

local function cancel()
  if buffer:auto_c_active() then
    buffer:auto_c_cancel()
  end
end

-- Each time a character is added activate auto-complete. If there is only a
-- single item and it has already been fully typed out then auto-close the list
events.connect(events.CHAR_ADDED, function()
  -- Clear list from last activiation
  buffer.autocomplete_items = ''

  textadept.editing.autocomplete('word')

  -- No matches were made so cancel and return early
  if( buffer.autocomplete_items == '' ) then return cancel() end

  local _, sep_count = buffer.autocomplete_items:gsub(string.char(buffer.auto_c_separator), "")
  local single_item = sep_count == 0

  if not single_item then return end

  local recent_chars = buffer:text_range(buffer.current_pos - buffer.autocomplete_items:len(), buffer.current_pos)
  local fully_typed = recent_chars == buffer.autocomplete_items

  if not fully_typed then return end
  cancel()
end)

The trick here is that I am monkey-patching buffer.auto_c_show so that the most recent auto-complete list is captured. Then after activating the auto-complete if I see it meets my criteria (that list just has one item and that item exactly matches the preceding characters) then it will auto-close that auto-complete list.

[eric-hemasystems]

I thought this was working but now it doesn't seem to be so back to more debugging....

[eric-hemasystems]

Updated with a bit better version. I was getting an issue after calling reset() so moved the captured list into a variable off of buffer so the monkey-patch is still writing to a location the post-reset module can see.

There is still some funkyness because of this early return in Textadept so will have to revisit later.

[eric-hemasystems]

I think I made this whole thing way too hard. I think it should just be:

buffer.auto_c_choose_single = false
events.connect(events.CHAR_ADDED, function()
  if buffer:auto_c_active() then
    buffer:auto_c_cancel()
  end

  textadept.editing.autocomplete('word')
end)

This isn't much more complicated than what I had originally. The only change is that I close the auto complete if it is already open. This works because Textadept is only looking for matching terms that are larger than what I already typed.

The reason this doesn't work without closing first is because if you exactly match the only item in your list then that means it doesn't find any terms it returns early never displaying the auto-complete. But if the auto-complete list was already displayed from the previous character (when the item was bigger than the typed term) you still had the old list displayed.

By closing the list before attempting to display again it clears out that old list.