Refactor potion, and its associated components to be more generic

src/components.rs

@@ -72,7 +72,7 @@ impl SufferDamage {
 pub struct Item {}
 
 #[derive(Component, Debug)]
-pub struct Potion {
+pub struct ProvidesHealing {
     pub heal_amount: i32,
 }
 
@@ -88,11 +88,14 @@ pub struct WantsToPickupItem {
 }
 
 #[derive(Component, Debug)]
-pub struct WantsToDrinkPotion {
+pub struct WantsToUseItem {
-    pub potion: Entity,
+    pub item: Entity,
 }
 
 #[derive(Component, Debug, Clone)]
 pub struct WantsToDropItem {
     pub item: Entity,
 }
+
+#[derive(Component, Debug)]
+pub struct Consumable {}

src/inventory_system.rs

@@ -1,6 +1,6 @@
 use crate::{
-    game_log::GameLog, CombatStats, InBackpack, Name, Position, Potion, WantsToDrinkPotion,
+    game_log::GameLog, CombatStats, Consumable, InBackpack, Map, Name, Position, ProvidesHealing,
-    WantsToDropItem, WantsToPickupItem,
+    WantsToDropItem, WantsToPickupItem, WantsToUseItem,
 };
 use specs::prelude::*;
 
@@ -44,17 +44,19 @@ impl<'a> System<'a> for ItemCollectionSystem {
     }
 }
 
-pub struct PotionUseSystem {}
+pub struct ItemUseSystem {}
 
-impl<'a> System<'a> for PotionUseSystem {
+impl<'a> System<'a> for ItemUseSystem {
     #[allow(clippy::type_complexity)]
     type SystemData = (
         ReadExpect<'a, Entity>,
         WriteExpect<'a, GameLog>,
+        ReadExpect<'a, Map>,
         Entities<'a>,
-        WriteStorage<'a, WantsToDrinkPotion>,
+        WriteStorage<'a, WantsToUseItem>,
         ReadStorage<'a, Name>,
-        ReadStorage<'a, Potion>,
+        ReadStorage<'a, Consumable>,
+        ReadStorage<'a, ProvidesHealing>,
         WriteStorage<'a, CombatStats>,
     );
 
@@ -62,33 +64,42 @@ impl<'a> System<'a> for PotionUseSystem {
         let (
             player_entity,
             mut gamelog,
+            map,
             entities,
-            mut wants_drink,
+            mut wants_use,
             names,
-            potions,
+            consumables,
+            healing,
             mut combat_stats,
         ) = data;
 
-        for (entity, drink, stats) in (&entities, &wants_drink, &mut combat_stats).join() {
+        for (entity, useitem, stats) in (&entities, &wants_use, &mut combat_stats).join() {
-            match potions.get(drink.potion) {
+            match healing.get(useitem.item) {
                 None => {}
-                Some(potion) => {
+                Some(healer) => {
-                    stats.hp = i32::min(stats.max_hp, stats.hp + potion.heal_amount);
+                    stats.hp = i32::min(stats.max_hp, stats.hp + healer.heal_amount);
                     if entity == *player_entity {
                         gamelog.entries.push(format!(
                             "You drink the {}, healing {} hp.",
-                            names.get(drink.potion).unwrap().name,
+                            names.get(useitem.item).unwrap().name,
-                            potion.heal_amount
+                            healer.heal_amount
                         ));
                     }
-                    entities
-                        .delete(drink.potion)
-                        .expect("Failed to delete potion");
-                }
                 }
             }
 
-        wants_drink.clear();
+            let consumable = consumables.get(useitem.item);
+            match consumable {
+                None => {}
+                Some(_) => {
+                    entities
+                        .delete(useitem.item)
+                        .expect("Failed to consume item");
+                }
+            }
+        }
+
+        wants_use.clear();
     }
 }
 

src/main.rs

@@ -18,7 +18,7 @@ mod visibility_system;
 pub use components::*;
 use damage_system::DamageSystem;
 pub use game_log::GameLog;
-use inventory_system::{ItemCollectionSystem, ItemDropSystem, PotionUseSystem};
+use inventory_system::{ItemCollectionSystem, ItemDropSystem, ItemUseSystem};
 pub use map::*;
 use map_indexing_system::MapIndexingSystem;
 use melee_combat_system::MeleeCombatSystem;
@@ -55,6 +55,10 @@ pub struct State {
 }
 
 impl State {
+    fn new() -> Self {
+        State { ecs: World::new() }
+    }
+
     fn run_systems(&mut self) {
         let mut vis = VisibilitySystem {};
         vis.run_now(&self.ecs);
@@ -74,8 +78,8 @@ impl State {
         let mut pickup = ItemCollectionSystem {};
         pickup.run_now(&self.ecs);
 
-        let mut potions = PotionUseSystem {};
+        let mut items = ItemUseSystem {};
-        potions.run_now(&self.ecs);
+        items.run_now(&self.ecs);
 
         let mut drop_items = ItemDropSystem {};
         drop_items.run_now(&self.ecs);
@@ -140,15 +144,15 @@ impl GameState for State {
                     gui::ItemMenuResult::NoResponse => {}
                     gui::ItemMenuResult::Selected => {
                         let item_entity = result.1.unwrap();
-                        let mut intent = self.ecs.write_storage::<WantsToDrinkPotion>();
+                        let mut intent = self.ecs.write_storage::<WantsToUseItem>();
                         intent
                             .insert(
                                 *self.ecs.fetch::<Entity>(),
-                                WantsToDrinkPotion {
+                                WantsToUseItem {
-                                    potion: item_entity,
+                                    item: item_entity,
                                 },
                             )
-                            .expect("failed to add intent to drink potion");
+                            .expect("failed to add intent to use item");
 
                         newrunstate = RunState::PlayerTurn;
                     }
@@ -192,7 +196,7 @@ fn main() -> rltk::BError {
         .with_title("Roguelike Tutorial")
         .build()?;
 
-    let mut gs = State { ecs: World::new() };
+    let mut gs = State::new();
 
     register!(
         gs <-
@@ -207,14 +211,15 @@ fn main() -> rltk::BError {
         WantsToMelee,
         SufferDamage,
         Item,
-        Potion,
+        ProvidesHealing,
         InBackpack,
         WantsToPickupItem,
-        WantsToDrinkPotion,
+        WantsToUseItem,
         WantsToDropItem,
+        Consumable,
     );
 
-    let map: Map = Map::new_map_rooms_and_corridors();
+    let map = Map::new_map_rooms_and_corridors();
     let (player_x, player_y) = map.rooms[0].center();
 
     let player_entity = spawner::player(&mut gs.ecs, player_x, player_y);

src/spawner.rs

@@ -1,6 +1,6 @@
 use crate::{
-    BlocksTile, CombatStats, Item, Monster, Name, Player, Position, Potion, Rect, Renderable,
+    BlocksTile, CombatStats, Consumable, Item, Monster, Name, Player, Position, ProvidesHealing,
-    Viewshed, MAP_WIDTH,
+    Rect, Renderable, Viewshed, MAP_WIDTH,
 };
 use rltk::{RandomNumberGenerator, RGB};
 use specs::prelude::*;
@@ -160,6 +160,7 @@ fn health_potion(ecs: &mut World, x: i32, y: i32) {
             name: "Health Potion".to_string(),
         })
         .with(Item {})
-        .with(Potion { heal_amount: 8 })
+        .with(Consumable {})
+        .with(ProvidesHealing { heal_amount: 8 })
         .build();
 }