dtlua/add_lens_info.lua

--[[

    add_lens_info.lua - add user specifed lens information to exif_lens field

    Copyright (C) 2025 Bill Ferguson <wpferguson@gmail.com>.

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 3 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
]]
--[[
    add_lens_info - add user specifed lens information to exif_lens field

    apply_lens_info takes user specified lens information strings and applies
    them to the image database entries in darktable.

    ADDITIONAL SOFTWARE NEEDED FOR THIS SCRIPT
    none

    USAGE
    * start script from script manager
    * add lens information string and save it
    * select lens information string in module
    * select image(s) to apply the lens information to
    * click apply lens information button, or use shortcut to apply the change

    BUGS, COMMENTS, SUGGESTIONS
    Bill Ferguson <wpferguson@gmail.com>

    CHANGES
]]

local dt = require "darktable"
local du = require "lib/dtutils"
-- local df = require "lib/dtutils.file"
-- local ds = require "lib/dtutils.string"
-- local dtsys = require "lib/dtutils.system"
local log = require "lib/dtutils.log"
-- local debug = require "darktable.debug"


-- - - - - - - - - - - - - - - - - - - - - - - - 
-- C O N S T A N T S
-- - - - - - - - - - - - - - - - - - - - - - - - 

local MODULE <const> = "add_lens_info"
local DEFAULT_LOG_LEVEL <const> = log.warn
local TMP_DIR <const> = dt.configuration.tmp_dir

-- path separator
local PS <const> = dt.configuration.running_os == "windows" and "\\" or "/"

-- command separator
local CS <const> = dt.configuration.running_os == "windows" and "&" or ";"

-- - - - - - - - - - - - - - - - - - - - - - - - 
-- A P I  C H E C K
-- - - - - - - - - - - - - - - - - - - - - - - - 

du.check_min_api_version("7.0.0", MODULE)   -- choose the minimum version that contains the features you need


-- - - - - - - - - - - - - - - - - - - - - - - - - -
-- I 1 8 N
-- - - - - - - - - - - - - - - - - - - - - - - - - -

local os_path_seperator = "/"
local scriptfile = debug.getinfo( 1, "S" )
local localedir = dt.configuration.config_dir..'/lua/locale/'
if scriptfile ~= nil and scriptfile.source ~= nil then
  local path = scriptfile.source:match( "[^@].*[/\\]" )
  localedir = path..os_path_seperator..'locale'
end
dt.print_log( "localedir: "..localedir )

local gettext = dt.gettext
gettext.bindtextdomain(MODULE, localedir)

local function _(msgid)
    return gettext.dgettext(MODULE, msgid)
end


-- - - - - - - - - - - - - - - - - - - - - - - - - -
-- S C R I P T  M A N A G E R  I N T E G R A T I O N
-- - - - - - - - - - - - - - - - - - - - - - - - - -

local script_data = {}

script_data.destroy = nil           -- function to destory the script
script_data.destroy_method = nil    -- set to hide for libs since we can't destroy them commpletely yet
script_data.restart = nil           -- how to restart the (lib) script after it's been hidden - i.e. make it visible again
script_data.show = nil              -- only required for libs since the destroy_method only hides them

script_data.metadata = {
  name = _("add lens info"),         -- visible name of script
  purpose = _("add user specifed lens information to exif_lens field"),   -- purpose of script
  author = "Bill Ferguson <wpferguson@gmail.com>",   -- your name and optionally e-mail address
  help = ""                   -- URL to help/documentation
}


-- - - - - - - - - - - - - - - - - - - - - - - - 
-- L O G  L E V E L
-- - - - - - - - - - - - - - - - - - - - - - - - 

log.log_level(DEFAULT_LOG_LEVEL)

-- - - - - - - - - - - - - - - - - - - - - - - - 
-- N A M E  S P A C E
-- - - - - - - - - - - - - - - - - - - - - - - - 

local add_lens_info = {}

-- - - - - - - - - - - - - - - - - - - - - - - - 
-- G L O B A L  V A R I A B L E S
-- - - - - - - - - - - - - - - - - - - - - - - - 

-- the lenses we know about
add_lens_info.lenses = {}

-- - - - - - - - - - - - - - - - - - - - - - - - 
-- P R E F E R E N C E S
-- - - - - - - - - - - - - - - - - - - - - - - - 

-- lens data is stored in a string in the darktablerc file

-- - - - - - - - - - - - - - - - - - - - - - - - 
-- A L I A S E S
-- - - - - - - - - - - - - - - - - - - - - - - - 

local namespace = add_lens_info
local ali = add_lens_info

-- - - - - - - - - - - - - - - - - - - - - - - - 
-- F U N C T I O N S
-- - - - - - - - - - - - - - - - - - - - - - - - 

local function read_lens_preferences()
  local lenses = dt.preferences.read(MODULE, "lenses", "string")
  if string.len(lenses) > 1 then
    if string.match(lenses, ".+$.+") then
      ali.lenses = du.split(lenses, '%$')
    else
      table.insert(ali.lenses, lenses)
    end
  end
end

local function save_lens_preferences()
  dt.preferences.write(MODULE, "lenses", "string", table.concat(ali.lenses, '$'))
end

local function set_buttons_sensitive()
  if #dt.gui.action_images > 0 then
    ali.apply_lens_selection.sensitive = true
    dt.gui.libs.image.set_sensitive(MODULE, true)
  else
    ali.apply_lens_selection.sensitive = false
    dt.gui.libs.image.set_sensitive(MODULE, false)
  end
end

local function apply_lens_name()
  local images = dt.gui.action_images

  dt.print_log("image count is " .. #images)

  for _, image in ipairs(images) do
    image.exif_lens = ali.lenses[ali.select_lens_name.selected]
  end
end

local function install_module()
  if not namespace.module_installed then
    dt.register_lib(
      MODULE,     -- Module name
      script_data.metadata.name,     -- Visible name
      true,                -- expandable
      false,               -- resetable
      {[dt.gui.views.lighttable] = {"DT_UI_CONTAINER_PANEL_RIGHT_CENTER", 400}},   -- containers
      namespace.main_widget,
      nil,-- view_enter
      nil -- view_leave
    )
    namespace.module_installed = true
  end
end

local function update_combobox_choices(combobox, choice_table, selected)
  local items = #combobox
  local choices = #choice_table
  for i, name in ipairs(choice_table) do 
    combobox[i] = name
  end
  if choices < items then
    for j = items, choices + 1, -1 do
      combobox[j] = nil
    end
  end
  combobox.value = selected
end

-- - - - - - - - - - - - - - - - - - - - - - - - 
-- U S E R  I N T E R F A C E
-- - - - - - - - - - - - - - - - - - - - - - - - 

ali.stack_selector = dt.new_widget("combobox"){
  tooltip = "choose to add a lens or select the lens name to be applied",
  selected = dt.preferences.read(MODULE, "selector", "integer") > 0 and dt.preferences.read(MODULE, "selector", "integer") or 1,
  _("add new lens name"),
  _("select lens name"),
  changed_callback = function(this)
    dt.preferences.write(MODULE, "selector", "integer", this.selected)
    if ali.module_installed then
      ali.stack.active = this.selected
    end
  end
}

ali.lens_name = dt.new_widget("entry"){
  placeholder = _("lens name/identification"),
  text = ""
}

ali.add_lens = dt.new_widget("button"){
  label = _("add new lens"),
  tooltip = _("add new lens string to choices"),
  clicked_callback = function(this)
    table.insert(ali.lenses, ali.lens_name.text)
    table.sort(ali.lenses)
    local new_lens_place
    for i, lens_name in ipairs(ali.lenses) do
      if ali.lens_name.text == lens_name then
        new_lens_place = i
        break
      end
    end
    update_combobox_choices(ali.select_lens_name, ali.lenses, new_lens_place)
    ali.lens_name.text = ""
    save_lens_preferences()
  end
}

ali.add_new_lens = dt.new_widget("box"){
  orientation = "vertical",
  dt.new_widget("label"){ label = _("add new lens") },
  ali.lens_name,
  ali.add_lens
}

ali.select_lens_name = dt.new_widget("combobox"){
  tooltip = _("select lens name to apply to images"),
}
read_lens_preferences()
if #ali.lenses > 0 then
  update_combobox_choices(ali.select_lens_name, ali.lenses, 1)
end

ali.apply_lens_selection = dt.new_widget("button"){
  label = _("apply lens name"),
  tooltip = _("apply lens name to selected images"),
  sensitive = false,
  clicked_callback = function(this)
    apply_lens_name()
  end
}

ali.select_lens = dt.new_widget("box"){
  orientation = "vertical",
  dt.new_widget("label"){ label = _("select lens name to apply") },
  ali.select_lens_name,
  ali.apply_lens_selection
}

ali.stack = dt.new_widget("stack"){
  ali.add_new_lens,
  ali.select_lens,
  active = 1
}

ali.stack_selector = dt.new_widget("combobox"){
  tooltip = "choose to add a lens or select the lens name to be applied",
  selected = dt.preferences.read(MODULE, "selector", "integer") > 0 and dt.preferences.read(MODULE, "selector", "integer") or 1,
  _("add new lens name"),
  _("select lens name"),
  changed_callback = function(this)
    dt.preferences.write(MODULE, "selector", "integer", this.selected)
    if ali.module_installed then
      ali.stack.active = this.selected
    else
      ali.stack.active = dt.preferences.read(MODULE, "selector", "integer")
    end
  end
}

ali.main_widget = dt.new_widget("box"){
  orientation = "vertical",
  ali.stack_selector,
  ali.stack
}

dt.gui.libs.image.register_action(MODULE, _("apply lens name"), apply_lens_name, _("apply lens name from apply lens info module to selected images"))
dt.gui.libs.image.set_sensitive(MODULE, false)
-- - - - - - - - - - - - - - - - - - - - - - - - 
-- M A I N  P R O G R A M
-- - - - - - - - - - - - - - - - - - - - - - - - 

read_lens_preferences()

if dt.gui.current_view().id == "lighttable" then
  install_module()
else
  if not namespace.event_registered then
    dt.register_event(MODULE, "view-changed",
      function(event, old_view, new_view)
        if new_view.name == "lighttable" and old_view.name == "darkroom" then
          install_module()
         end
      end
    )
    namespace.event_registered = true
  end
end

-- - - - - - - - - - - - - - - - - - - - - - - - 
-- D A R K T A B L E  I N T E G R A T I O N 
-- - - - - - - - - - - - - - - - - - - - - - - - 

local function destroy()
  dt.gui.libs[MODULE].visible = false

  if namespace.event_registered then
    dt.destroy_event(MODULE, "view-changed")
  end
  
  return
end

local function restart()
  dt.gui.libs[MODULE].visible = true

  return
end

script_data.destroy = destroy
script_data.restart = restart
script_data.destroy_method = "hide"
script_data.show = restart

-- - - - - - - - - - - - - - - - - - - - - - - - 
-- E V E N T S
-- - - - - - - - - - - - - - - - - - - - - - - - 

dt.register_event(MODULE, "shortcut",
  function(event, shortcut)
    apply_lens_name()
  end, _("apply lens name")
)

dt.register_event(MODULE, "selection-changed",
  function(event)
    set_buttons_sensitive()
  end
)

return script_data