-- TIME_STAMP   2016-01-25 22:32:53

ConvertTabHit = EventClass:new(Common)

local iTabsize = tonumber(props['tabsize'])
local tDiff = {}
for i = iTabsize, 1, -1 do table.insert(tDiff, i) end

function ConvertTabHit:OnKey(_keycode, _shift, _ctrl, _alt)
	if not (tonumber(props['convert.tabs.to.spaces']) == 1) and (_keycode ~= 8 or _keycode ~= 9) then return nil end
	if not _shift and not _ctrl and not _alt then
		local iPosCurrent = editor.CurrentPos
		local iCol = editor.Column[iPosCurrent]
		if _keycode == 8  then  -- Backspace
		    local iPosLeft = iPosCurrent - (iCol % iTabsize)
			if iPosLeft == iPosCurrent then iPosLeft = iPosCurrent - iTabsize end
			editor:SetSelection(iPosLeft, iPosCurrent)
			if editor:GetSelText():gsub('[%s%t]*', '') == '' then
				editor:BeginUndoAction()
				editor:ReplaceSel('')
				editor:EndUndoAction()
				return true
			end
			editor.CurrentPos = iPosCurrent
			return nil
		end
		if _keycode == 9  then  -- Tab
			editor:BeginUndoAction()
			editor:insert(iPosCurrent, (' '):rep(tDiff[(iCol % iTabsize)+1]))
			editor:LineEnd()
			editor:EndUndoAction()
			return true
		end
	end
end