From 5f5ad426bf1acbbfa3b28a7717a9d2aa83a9d007 Mon Sep 17 00:00:00 2001
From: Bill Ferguson <wpferguson@gmail.com>
Date: Sun, 9 Aug 2020 01:01:33 -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/rename-tags.lua | 29 +++++++++++++++++++++++++++--
 1 file changed, 27 insertions(+), 2 deletions(-)

diff --git a/contrib/rename-tags.lua b/contrib/rename-tags.lua
index a0c70be..f385a7a 100644
--- a/contrib/rename-tags.lua
+++ b/contrib/rename-tags.lua
@@ -35,6 +35,10 @@ local debug = require "darktable.debug"
 -- check API version
 du.check_min_api_version("3.0.0", "rename-tags") 
 
+local rt = {}
+rt.module_installed = false
+rt.event_registered = false
+
 -- GUI entries
 local old_tag = darktable.new_widget("entry") { tooltip = "Enter old tag" }
 local new_tag = darktable.new_widget("entry") { tooltip = "Enter new tag" }
@@ -99,6 +103,13 @@ local function rename_tags()
   rename_reset()
 end
 
+local function install_module()
+  if not rt.module_installed then
+    darktable.register_lib ("rename_tags", "rename tag", true, true, {[darktable.gui.views.lighttable] = {"DT_UI_CONTAINER_PANEL_RIGHT_CENTER", 20},}, rt.rename_widget, nil, nil)
+    rt.module_installed = true
+  end
+end
+
 -- GUI
 local old_widget = darktable.new_widget ("box") {
     orientation = "horizontal",
@@ -112,7 +123,7 @@ local new_widget = darktable.new_widget ("box") {
     new_tag
 }
 
-local rename_widget = darktable.new_widget ("box") {
+rt.rename_widget = darktable.new_widget ("box") {
     orientation = "vertical",
     reset_callback = rename_reset,
     old_widget,
@@ -120,6 +131,20 @@ local rename_widget = darktable.new_widget ("box") {
     darktable.new_widget("button") { label = "Go", clicked_callback = rename_tags }
 }
 
+if darktable.gui.current_view().name == "lighttable" then
+  install_module()
+else
+  if not rt.event_registered then
+    darktable.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
+    )
+    rt.event_registered = true
+  end
+end
 
-darktable.register_lib ("rename_tags", "rename tag", true, true, {[darktable.gui.views.lighttable] = {"DT_UI_CONTAINER_PANEL_RIGHT_CENTER", 20},}, rename_widget, nil, nil)