From a3a10ca6e4d1da630f4633b735d29fc8cd1df5e2 Mon Sep 17 00:00:00 2001
From: Nat Quayle Nelson <natquaylenelson@gmail.com>
Date: Sat, 14 Jun 2025 19:56:50 -0500
Subject: [PATCH] undo/redo for placing and pasting specials

---
 src/scenedit/scen.actions.cpp | 11 ++++++++++-
 src/scenedit/scen.keydlgs.cpp |  3 ++-
 src/scenedit/scen.undo.cpp    | 15 ++++++++-------
 src/scenedit/scen.undo.hpp    |  8 +++++---
 4 files changed, 25 insertions(+), 12 deletions(-)

diff --git a/src/scenedit/scen.actions.cpp b/src/scenedit/scen.actions.cpp
index 6767d1f6..28d91796 100644
--- a/src/scenedit/scen.actions.cpp
+++ b/src/scenedit/scen.actions.cpp
@@ -945,6 +945,8 @@ static bool handle_terrain_action(location the_point, bool ctrl_hit) {
 							if(specials[x].spec < 0) {
 								specials[x] = spot_hit;
 								specials[x].spec = spec->first;
+								undo_list.add(action_ptr(new aPlaceEraseSpecial("Paste Special Encounter", true, specials[x])));
+								update_edit_menu();
 								break;
 							}
 						}
@@ -1141,7 +1143,7 @@ static bool handle_terrain_action(location the_point, bool ctrl_hit) {
 								specials.pop_back();
 							} while(!specials.empty() && specials.back().spec < 0);
 						}
-						undo_action.reset(new aEraseSpecial(for_redo));
+						undo_action.reset(new aPlaceEraseSpecial("Erase Special", false, for_redo));
 						break;
 					}
 				overall_mode = MODE_DRAWING;
@@ -2774,6 +2776,7 @@ void place_edit_special(location loc) {
 	for(short i = 0; i < specials.size(); i++)
 		if(specials[i] == loc && specials[i].spec >= 0) {
 			edit_spec_enc(specials[i].spec, editing_town ? 2 : 1, nullptr);
+			// TODO add the edit specials actions
 			return;
 		}
 	// new special
@@ -2785,6 +2788,9 @@ void place_edit_special(location loc) {
 			if(edit_spec_enc(spec, editing_town ? 2: 1, nullptr)) {
 				specials[i] = loc;
 				specials[i].spec = spec;
+				undo_list.add(action_ptr(new aPlaceEraseSpecial("Place Special Encounter", true, specials[i])));
+				// TODO add the edit specials actions
+				update_edit_menu();
 			}
 			break;
 		}
@@ -2813,6 +2819,9 @@ void set_special(location spot_hit) {
 			if(spec >= 0) {
 				specials[x] = spot_hit;
 				specials[x].spec = spec;
+				undo_list.add(action_ptr(new aPlaceEraseSpecial("Place Special Encounter", true, specials[x])));
+				// TODO if create/edit was used, add those actions
+				update_edit_menu();
 			}
 			break;
 		}
diff --git a/src/scenedit/scen.keydlgs.cpp b/src/scenedit/scen.keydlgs.cpp
index 180ce150..79762f40 100644
--- a/src/scenedit/scen.keydlgs.cpp
+++ b/src/scenedit/scen.keydlgs.cpp
@@ -1380,6 +1380,7 @@ static bool edit_spec_enc_value(cDialog& me, std::string item_hit, node_stack_t&
 }
 
 // mode - 0 scen 1 - out 2 - town
+// TODO collect a list of undo actions that can be committed to undo_list by the calling code
 bool edit_spec_enc(short which_node,short mode,cDialog* parent) {
 	using namespace std::placeholders;
 	cSpecial the_node;
@@ -1653,7 +1654,7 @@ static bool edit_special_num_event_filter(cDialog& me, std::string item_hit, sho
 short edit_special_num(short mode,short what_start) {
 	using namespace std::placeholders;
 
-	size_t num_specs = 0;
+	short num_specs = 0;
 	switch(mode) {
 		case 0: num_specs = scenario.scen_specials.size(); break;
 		case 1: num_specs = current_terrain->specials.size(); break;
diff --git a/src/scenedit/scen.undo.cpp b/src/scenedit/scen.undo.cpp
index e42a1c73..87c9f07a 100644
--- a/src/scenedit/scen.undo.cpp
+++ b/src/scenedit/scen.undo.cpp
@@ -76,18 +76,19 @@ void cTerrainAction::redo() {
 
 // Undo/Redo implementations for actions:
 
-bool aEraseSpecial::undo_me() {
+bool aPlaceEraseSpecial::undo_me() {
+	cArea* cur_area = get_current_area();
+	auto& specials = cur_area->special_locs;
+	specials.erase(std::remove(specials.begin(), specials.end(), for_redo));
+	return true;
+}
+
+bool aPlaceEraseSpecial::redo_me() {
 	cArea* cur_area = get_current_area();
 	auto& specials = cur_area->special_locs;
 	specials.push_back(for_redo);
 	return true;
 }
-bool aEraseSpecial::redo_me() {
-	cArea* cur_area = get_current_area();
-	auto& specials = cur_area->special_locs;
-	specials.pop_back();
-	return true;
-}
 
 aCreateDeleteTown::aCreateDeleteTown(bool create, cTown* t)
 	: cAction(create ? "Create Town" : "Delete Last Town", !create)
diff --git a/src/scenedit/scen.undo.hpp b/src/scenedit/scen.undo.hpp
index 0e1c46af..10fe77dd 100644
--- a/src/scenedit/scen.undo.hpp
+++ b/src/scenedit/scen.undo.hpp
@@ -63,10 +63,12 @@ public:
 		old_property(old_property) {}
 };
 
-/// Action that erased a special encounter from a spot
-class aEraseSpecial : public cTerrainAction {
+/// Action that places or erases a special encounter from a spot
+class aPlaceEraseSpecial : public cTerrainAction {
 public:
-	aEraseSpecial(spec_loc_t special) : cTerrainAction("Erase Special Encounter", special), for_redo(special) {}
+	aPlaceEraseSpecial(std::string name, bool place, spec_loc_t special) :
+		cTerrainAction(name, special, !place),
+		for_redo(special) {}
 	bool undo_me() override;
 	bool redo_me() override;
 private: