Print time taken and request attention when lightmaps are done baking

Since lightmap baking can take a very long time, printing the time
spent can be useful for users tweaking the lightmap settings
to optimize bake times.

Completing lightmap baking will also request attention, which is
useful if you're doing something else while waiting for lightmaps
to bake.

editor/plugins/lightmap_gi_editor_plugin.cpp

@@ -33,13 +33,14 @@
 void LightmapGIEditorPlugin::_bake_select_file(const String &p_file) {
 	if (lightmap) {
 		LightmapGI::BakeError err;
+		const uint64_t time_started = OS::get_singleton()->get_ticks_msec();
 		if (get_tree()->get_edited_scene_root() && get_tree()->get_edited_scene_root() == lightmap) {
 			err = lightmap->bake(lightmap, p_file, bake_func_step);
 		} else {
 			err = lightmap->bake(lightmap->get_parent(), p_file, bake_func_step);
 		}
 
-		bake_func_end();
+		bake_func_end(time_started);
 
 		switch (err) {
 			case LightmapGI::BAKE_ERROR_NO_SAVE_PATH: {
@@ -104,11 +105,18 @@ bool LightmapGIEditorPlugin::bake_func_step(float p_progress, const String &p_de
 	return tmp_progress->step(p_description, p_progress * 1000, p_refresh);
 }
 
-void LightmapGIEditorPlugin::bake_func_end() {
+void LightmapGIEditorPlugin::bake_func_end(uint64_t p_time_started) {
 	if (tmp_progress != nullptr) {
 		memdelete(tmp_progress);
 		tmp_progress = nullptr;
 	}
+
+	const int time_taken = (OS::get_singleton()->get_ticks_msec() - p_time_started) * 0.001;
+	print_line(vformat("Done baking lightmaps in %02d:%02d:%02d.", time_taken / 3600, (time_taken % 3600) / 60, time_taken % 60));
+	// Request attention in case the user was doing something else.
+	// Baking lightmaps is likely the editor task that can take the most time,
+	// so only request the attention for baking lightmaps.
+	DisplayServer::get_singleton()->window_request_attention();
 }
 
 void LightmapGIEditorPlugin::_bind_methods() {

editor/plugins/lightmap_gi_editor_plugin.h

@@ -47,7 +47,7 @@ class LightmapGIEditorPlugin : public EditorPlugin {
 	EditorFileDialog *file_dialog;
 	static EditorProgress *tmp_progress;
 	static bool bake_func_step(float p_progress, const String &p_description, void *, bool p_refresh);
-	static void bake_func_end();
+	static void bake_func_end(uint64_t p_time_started);
 
 	void _bake_select_file(const String &p_file);
 	void _bake();