From d1271ddb4e115f481d1dda808f65cc4de42a07bb Mon Sep 17 00:00:00 2001
From: Tobias Ellinghaus <me@houz.org>
Date: Thu, 11 Dec 2014 00:04:18 +0100
Subject: [PATCH] Add a script that generates txt files for images

---
 official/generate_image_txt.lua | 101 ++++++++++++++++++++++++++++++++
 1 file changed, 101 insertions(+)
 create mode 100644 official/generate_image_txt.lua

diff --git a/official/generate_image_txt.lua b/official/generate_image_txt.lua
new file mode 100644
index 0000000..fce063c
--- /dev/null
+++ b/official/generate_image_txt.lua
@@ -0,0 +1,101 @@
+--[[
+    This file is part of darktable,
+    copyright (c) 2014 Tobias Ellinghaus
+
+    darktable 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.
+
+    darktable 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 darktable.  If not, see <http://www.gnu.org/licenses/>.
+]]
+
+-- TODO:
+--  * enable showing of the txt file (plugins/lighttable/draw_custom_metadata) if this script is enabled
+--  * make filenames with double quotes (") work
+
+dt = require "darktable"
+require "darktable.debug"
+
+-- version check to make sure that we have the new callback to register to
+local min_api_version = "2.1.0-dev"
+if dt.configuration.api_version_string < min_api_version then
+  dt.print_error("[generate_image_txt] lua api too old, at least "..min_api_version.." is required, but "..dt.configuration.api_version_string.." was found")
+  return
+end
+
+dt.preferences.register("generate_image_txt",
+                        "enabled",
+                        "bool",
+                        "create txt sidecars to display with images",
+                        "the txt files created get shown when the lighttable is zoomed in to one image. also enable the txt overlay setting in the gui tab",
+                        false)
+
+dt.preferences.register("generate_image_txt",
+                        "command",
+                        "string",
+                        "command to generate the txt sidecar",
+                        "the output of this command gets written to the txt file. use $(FILE_NAME) for the image file",
+                        "exiv2 $(FILE_NAME)")
+
+
+local check_command = function(command)
+  if not command:find("$(FILE_NAME)", 1, true) then
+    dt.print("the command for txt sidecars looks bad. better check the preferences")
+  end
+end
+
+
+local command_setting = dt.preferences.read("generate_image_txt", "command", "string")
+check_command(command_setting)
+
+dt.register_event("mouse-over-image-changed", function(event, img)
+    -- no need to waste processing time if the image has a txt file already
+    if not img or img.has_txt or not dt.preferences.read("generate_image_txt", "enabled", "bool") then
+      return
+    end
+
+    -- there should be at least one "$(FILE_NAME)" in the command. warn if not, but only once
+    local _command_setting = dt.preferences.read("generate_image_txt", "command", "string")
+    if not (command_setting == _command_setting) then
+      command_setting = _command_setting
+      check_command(command_setting)
+    end
+
+    -- set the flag to true first so that subsequent runs don't mess with the txt
+    img.has_txt = true
+
+    -- next: create the txt
+
+    local img_filename = img.path.."/"..img.filename
+    local txt_filename = img.path.."/"..img.filename:match("^[^.]*")..".txt"
+
+    -- better safe than sorry: check if the file maybe exists. this is for example true when shooting raw+jpg
+    local file = io.open(txt_filename, "r")
+    if file then
+      file.close()
+      return
+    end
+
+    -- we are confident now that it's safe to write the file
+
+    -- compose the command to run
+    local command = command_setting:gsub("%$%(FILE_NAME%)", '"'..img_filename..'"')..' > "'..txt_filename..'"'
+
+    -- finally, run it
+    -- I am using os.execute here since we are in our own thread anyway, and for some reason coroutine.yield doesn't work reliable for me
+    os.execute(command)
+--     coroutine.yield("RUN_COMMAND", command)
+--     coroutine.yield("RUN_COMMAND", "echo foo") -- only gets fired once
+  end
+)
+
+
+-- vim: shiftwidth=2 expandtab tabstop=2 cindent
+-- kate: tab-indents: off; indent-width 2; replace-tabs on; remove-trailing-space on;