OpenSpace/scripts/drag_drop_handler.lua

-- This script gets two parameters in its global scope:
-- filename:   The full path for the file that was dropped on the application.
--             Example:  C:/OpenSpace/openspace.cfg
-- basename:   Only the name of the actual file with extension, but without the full rest
--             of the path.
--             Example:  openspace.cfg
-- extension:  The extention of the file
--             Example: .cfg
--
-- From this script, we need to return the script that we want to be executed in response
-- to the drag event.  If we don't want anything to happen, don't return anything or
-- return an empty string

if filename == nil or filename == "" or
   basename == nil or basename == "" or
   extension == nil or extension == "" then
  do return "" end
end

-- Lua doesn't enjoy \ that are used by Windows extensively. So we convert all \ into /
filename = filename:gsub("\\", "/")
basename = basename:gsub("\\", "/")
basename_without_extension = basename:sub(0, #basename - extension:len())

is_image_file = function(extension)
  return extension == ".png" or extension == ".jpg" or extension == ".jpeg" or
         extension == ".tif" or extension == ".tga" or extension == ".bmp" or
         extension == ".psd" or extension == ".gif" or extension == ".hdr" or
         extension == ".pic" or extension == ".pnm"
end

local ReloadUIScript = [[ if openspace.hasProperty('Modules.CefWebGui.Reload') then openspace.setPropertyValue('Modules.CefWebGui.Reload', nil) end ]]

if is_image_file(extension) then
  return [[
  openspace.addScreenSpaceRenderable({
    Identifier = openspace.makeIdentifier("]] .. basename_without_extension .. [["),
    Type = "ScreenSpaceImageLocal",
    TexturePath = "]] .. filename .. [["
  });]] .. ReloadUIScript
elseif extension == ".asset" then
  return [[
    if openspace.asset.isLoaded("]] .. filename .. [[") ~= true then
      openspace.printInfo("Adding asset: ']] .. filename .. [[' (drag-and-drop)");
    end
    openspace.asset.add("]] .. filename .. '");' .. ReloadUIScript
elseif extension == ".osrec" or extension == ".osrectxt" then
  return 'openspace.sessionRecording.startPlayback("' .. filename .. '")'
end