From 52acdb9036b463e528e2fb27cc44bc4507ecb141 Mon Sep 17 00:00:00 2001
From: Bill Ferguson <wpferguson@gmail.com>
Date: Sun, 9 Aug 2020 00:45:27 -0400
Subject: [PATCH] Added check to ensure we are in lighttable view prior to
 callling darktable.register_lib.  If darktable was invoked in single image
 (darkroom) mode, then an event handler is registered to detect the change
 from darkroom mode to lighttable mode so that we can then call
 darktable.register_lib.

---
 contrib/copy_attach_detach_tags.lua | 65 ++++++++++++++++++++---------
 1 file changed, 45 insertions(+), 20 deletions(-)

diff --git a/contrib/copy_attach_detach_tags.lua b/contrib/copy_attach_detach_tags.lua
index 2fb8330..9b43c47 100644
--- a/contrib/copy_attach_detach_tags.lua
+++ b/contrib/copy_attach_detach_tags.lua
@@ -51,6 +51,11 @@ local function _(msgid)
     return gettext.dgettext("copy_attach_detach_tags", msgid)
 end
 
+local cadt = {}
+cadt.module_installed = false
+cadt.event_registered = false
+cadt.widget_table = {}
+
 
 local image_tags = {}
 
@@ -156,6 +161,26 @@ local function replace_tags()
   dt.print(_('Tags replaced'))
 end
 
+local function install_module()
+  if not cadt.module_installed then
+    dt.register_lib("tagging_addon","Tagging addon",true,true,{
+        [dt.gui.views.lighttable] = {"DT_UI_CONTAINER_PANEL_RIGHT_CENTER",500}
+        },
+        dt.new_widget("box") {
+      --    orientation = "vertical",
+          reset_callback = function()
+                        taglist_label.label = ""
+                        image_tags = {}
+                        end,
+          table.unpack(cadt.widget_table),
+          },
+       nil,
+       nil
+      )
+    cadt.module_installed = true
+  end
+end
+
 -- create modul Tagging addons
 taglist_label.reset_callback = mcopy_tags
 
@@ -190,31 +215,31 @@ local box2 = dt.new_widget("box"){
 local sep = dt.new_widget("separator"){}
 
 -- pack elements into widget table for a nicer layout
-local widget_table = {}
 
-widget_table[1] = box1
-widget_table[#widget_table+1] = box2
+cadt.widget_table[1] = box1
+cadt.widget_table[#cadt.widget_table+1] = box2
 
-widget_table[#widget_table+1] = sep
-widget_table[#widget_table+1] = taglabel
-widget_table[#widget_table+1] = taglist_label
+cadt.widget_table[#cadt.widget_table+1] = sep
+cadt.widget_table[#cadt.widget_table+1] = taglabel
+cadt.widget_table[#cadt.widget_table+1] = taglist_label
 
 
 -- create modul
-dt.register_lib("tagging_addon","Tagging addon",true,true,{
-    [dt.gui.views.lighttable] = {"DT_UI_CONTAINER_PANEL_RIGHT_CENTER",500}
-    },
-    dt.new_widget("box") {
-  --    orientation = "vertical",
-      reset_callback = function()
-                    taglist_label.label = ""
-                    image_tags = {}
-                    end,
-      table.unpack(widget_table),
-      },
-   nil,
-   nil
-  )
+if dt.gui.current_view().name == "lighttable" then
+  install_module()
+else
+  if not cadt.event_registered then
+    dt.register_event(
+      "view-changed",
+      function(event, old_view, new_view)
+        if new_view.name == "lighttable" and old_view.name == "darkroom" then
+          install_module()
+         end
+      end
+    )
+    cadt.event_registered = true
+  end
+end
 
 
 -- shortcut for copy