Toggle signals on click

tests/test_game.py

@@ -846,7 +846,7 @@ def test_creating_signal_creates_two_signal_blocks(self, game: Game):
             .-.h.-.
             """,
         )
-        game.grid.create_signals_at_click_position(60, 15)
+        game.grid.toggle_signals_at_click_position(60, 15)
         # Sort the blocks so that the test becomes predictable
         blocks = sorted(
             game.signal_controller._signal_blocks, key=lambda b: sorted(b.positions)[0]
@@ -870,6 +870,22 @@ def test_clicking_grid_in_signal_mode_creates_signal(self, game: Game):
         game.on_left_click(61, 1)
         assert len(game.grid.signals) == 2
 
+    def test_clicking_signal_in_signal_mode_removes_signal(self, game: Game):
+        create_objects(
+            game.grid,
+            """
+        .h.
+        """,
+        )
+        game.gui.disable()
+        game.gui.mode = Mode.SIGNAL
+
+        assert len(game.grid.signals) == 2
+
+        game.on_left_click(45, 15)
+
+        assert len(game.grid.signals) == 0
+
     def test_clicking_grid_in_signal_mode_when_no_rail_does_nothing(self, game: Game):
         """For code coverage."""
         game.gui.disable()

tests/util.py

@@ -47,7 +47,7 @@ def _create_rails(grid: Grid, lines: list[str]):
             if character in "-h|v/\\":
                 grid.create_rail({Rail(x1, y1, x2, y2)})
             if character in "hv":
-                grid.create_signals_at_grid_position(abs(x1 + x2) / 2, abs(y1 + y2) / 2)
+                grid.toggle_signals_at_grid_position(abs(x1 + x2) / 2, abs(y1 + y2) / 2)
 
 
 def _remove_offset(lines: Iterable[str]):

trainfinity2/game.py

@@ -209,7 +209,7 @@ def on_left_click(self, x, y):
                 x, y
             )
             self.drawer.handle_events(
-                self.grid.create_signals_at_click_position(world_x_float, world_y_float)
+                self.grid.toggle_signals_at_click_position(world_x_float, world_y_float)
             )
         elif self.gui.mode == Mode.DESTROY:
             self.grid.remove_rail(Vec2(world_x, world_y))

trainfinity2/grid.py

@@ -392,22 +392,27 @@ def distance_to_rail(rail: Rail, x: float, y: float):
         closest_rail, distance = sorted(rails_and_distances, key=lambda x: x[1])[0]
         return closest_rail if distance < 1 else None
 
-    def create_signals_at_click_position(
+    def toggle_signals_at_click_position(
         self, world_x: float, world_y: float
     ) -> Sequence[Event]:
         # Transpose half a box since rail coordinates are in the bottom left
         # of each grid cell while they are visible in the middle
         x = world_x - 0.5
         y = world_y - 0.5
-        return self.create_signals_at_grid_position(x, y)
+        return self.toggle_signals_at_grid_position(x, y)
 
-    def create_signals_at_grid_position(self, x: float, y: float) -> Sequence[Event]:
+    def toggle_signals_at_grid_position(self, x: float, y: float) -> Sequence[Event]:
         events = []
         if rail := self._closest_rail(x, y):
             for position in rail.positions:
-                signal = Signal(position, rail)
-                self.signals[(position, rail)] = signal
-                events.append(CreateEvent(signal))
+                signal = self.signals.get((position, rail))
+                if signal:
+                    del self.signals[(position, rail)]
+                    events.append(DestroyEvent(signal))
+                else:
+                    signal = Signal(position, rail)
+                    self.signals[(position, rail)] = signal
+                    events.append(CreateEvent(signal))
         self._signal_controller.create_signal_blocks(self, list(self.signals.values()))
         return events