Remember the upzoned buildings, and add a button to clear the choices. #431

abstutil/src/collections.rs

@@ -50,6 +50,10 @@ where
         self.map.get(&key).unwrap_or(&self.empty)
     }
 
+    pub fn set(&mut self, key: K, values: BTreeSet<V>) {
+        self.map.insert(key, values);
+    }
+
     pub fn len(&self) -> usize {
         self.map.len()
     }
@@ -62,6 +66,15 @@ where
         self.map
     }
 }
+impl<K, V> std::default::Default for MultiMap<K, V>
+where
+    K: Ord + PartialEq + Clone,
+    V: Ord + PartialEq + Clone,
+{
+    fn default() -> MultiMap<K, V> {
+        MultiMap::new()
+    }
+}
 
 #[derive(Clone)]
 pub struct Counter<T: Ord + PartialEq + Clone> {

map_gui/src/lib.rs

@@ -7,7 +7,7 @@ use abstutil::Timer;
 use geom::{Duration, Pt2D, Time};
 use map_model::{AreaID, BuildingID, BusStopID, IntersectionID, LaneID, Map, ParkingLotID, RoadID};
 use sim::{AgentID, CarID, PedestrianID, Sim};
-use widgetry::{Cached, EventCtx, GfxCtx, State};
+use widgetry::{EventCtx, GfxCtx, State};
 
 pub use self::simple_app::SimpleApp;
 use crate::render::DrawOptions;

santa/src/before_level.rs

@@ -1,4 +1,4 @@
-use std::collections::HashSet;
+use std::collections::{BTreeSet, HashSet};
 
 use rand::seq::SliceRandom;
 use rand::SeedableRng;
@@ -30,7 +30,7 @@ pub struct Picker {
     upzone_panel: Panel,
     level: Level,
     bldgs: Buildings,
-    current_picks: HashSet<BuildingID>,
+    current_picks: BTreeSet<BuildingID>,
     draw_start: Drawable,
 }
 
@@ -103,13 +103,20 @@ impl Picker {
                     .color(RewriteColor::ChangeAll(Color::RED))
                     .centered_on(start);
 
+                let current_picks = app
+                    .session
+                    .upzones_per_level
+                    .get(level.title.clone())
+                    .clone();
+                let upzone_panel = make_upzone_panel(ctx, app, current_picks.len());
+
                 Transition::Replace(Box::new(Picker {
                     vehicle_panel: make_vehicle_panel(ctx, app),
-                    upzone_panel: make_upzone_panel(ctx, app, 0),
+                    upzone_panel,
                     instructions_panel,
                     level,
                     bldgs,
-                    current_picks: HashSet::new(),
+                    current_picks,
                     draw_start: ctx.upload(draw_start),
                 }))
             }),
@@ -166,18 +173,27 @@ impl State<App> for Picker {
             Outcome::Clicked(x) => match x.as_ref() {
                 "Start game" => {
                     app.current_selection = None;
+                    app.session
+                        .upzones_per_level
+                        .set(self.level.title.clone(), self.current_picks.clone());
+                    app.session.save();
+
                     return Transition::Replace(Game::new(
                         ctx,
                         app,
                         self.level.clone(),
                         Vehicle::get(&app.session.current_vehicle),
-                        self.current_picks.clone(),
+                        self.current_picks.clone().into_iter().collect(),
                     ));
                 }
                 "Randomly choose upzones" => {
                     self.randomly_pick_upzones(app);
                     self.upzone_panel = make_upzone_panel(ctx, app, self.current_picks.len());
                 }
+                "Clear upzones" => {
+                    self.current_picks.clear();
+                    self.upzone_panel = make_upzone_panel(ctx, app, self.current_picks.len());
+                }
                 "help" => {
                     return explain_upzoning(ctx);
                 }
@@ -306,11 +322,19 @@ fn make_upzone_panel(ctx: &mut EventCtx, app: &App, num_picked: usize) -> Panel
             "Upzones chosen:".draw_text(ctx),
             make_bar(ctx, Color::PINK, num_picked, app.session.upzones_unlocked),
         ]),
-        if num_picked == app.session.upzones_unlocked {
-            Btn::text_fg("Randomly choose upzones").inactive(ctx)
-        } else {
-            Btn::text_fg("Randomly choose upzones").build_def(ctx, None)
-        },
+        Widget::row(vec![
+            if num_picked == app.session.upzones_unlocked {
+                Btn::text_fg("Randomly choose upzones").inactive(ctx)
+            } else {
+                Btn::text_fg("Randomly choose upzones").build_def(ctx, None)
+            },
+            if num_picked == 0 {
+                Btn::text_fg("Clear upzones").inactive(ctx)
+            } else {
+                Btn::text_fg("Clear upzones").build_def(ctx, None)
+            }
+            .align_right(),
+        ]),
         if num_picked == app.session.upzones_unlocked {
             Btn::text_bg2("Start game").build_def(ctx, Key::Enter)
         } else {

santa/src/session.rs

@@ -2,7 +2,8 @@ use std::collections::{BTreeSet, HashMap};
 
 use serde::{Deserialize, Serialize};
 
-use abstutil::Timer;
+use abstutil::{deserialize_multimap, serialize_multimap, MultiMap, Timer};
+use map_model::BuildingID;
 use widgetry::{Color, EventCtx};
 
 use crate::levels::Level;
@@ -23,6 +24,14 @@ pub struct Session {
     pub vehicles_unlocked: BTreeSet<String>,
     pub upzones_unlocked: usize,
     pub upzones_explained: bool,
+    // This was added after the main release, so keep old save files working by allowing it to be
+    // missing.
+    #[serde(
+        serialize_with = "serialize_multimap",
+        deserialize_with = "deserialize_multimap",
+        default
+    )]
+    pub upzones_per_level: MultiMap<String, BuildingID>,
 
     #[serde(skip_serializing, skip_deserializing)]
     pub music: Music,
@@ -84,6 +93,7 @@ impl Session {
             vehicles_unlocked: vec!["bike".to_string()].into_iter().collect(),
             upzones_unlocked: 0,
             upzones_explained: false,
+            upzones_per_level: MultiMap::new(),
 
             music: Music::empty(),
             play_music: true,