Using items

src/main.rs

@@ -47,6 +47,7 @@ const MSG_X: i32 = BAR_WIDTH + 2;
 const MSG_WIDTH: i32 = SCREEN_WIDTH - BAR_WIDTH - 2;
 const MSG_HEIGHT: usize = PANEL_HEIGHT as usize - 1;
 const MAX_ROOM_ITEMS: i32 = 2;
+const INVENTORY_WIDTH: i32 = 50;
 
 struct Tcod {
   root: Root,
@@ -68,6 +69,7 @@ struct Object {
   alive: bool,
   fighter: Option<Fighter>,
   ai: Option<Ai>,
+  item: Option<Item>,
 }
 
 impl Object {
@@ -82,6 +84,7 @@ impl Object {
       alive: false,
       fighter: None,
       ai: None,
+      item: None,
     }
   }
 
@@ -316,6 +319,27 @@ fn handle_keys(tcod: &mut Tcod, game: &mut Game, objects: &mut Vec<Object>) -> P
       TookTurn
     }
 
+    (Key { code: Text, .. }, "g", true) => {
+      // Pick up an item
+      let item_id = objects
+        .iter()
+        .position(|object| object.pos() == objects[PLAYER].pos() && object.item.is_some());
+      if let Some(item_id) = item_id {
+        pick_item_up(item_id, game, objects);
+      }
+      DidntTakeTurn
+    }
+
+    (Key { code: Text, .. }, "i", true) => {
+      // Show the inventory
+      inventory_menu(
+        &game.inventory,
+        "Press the key next to an item to use it, or any other to cancel.\n",
+        &mut tcod.root,
+      );
+      TookTurn
+    }
+
     _ => DidntTakeTurn,
   }
 }
@@ -438,6 +462,7 @@ fn place_objects(room: Rect, map: &Map, objects: &mut Vec<Object>) {
     if !is_blocked(x, y, map, objects) {
       // Create a healing potion
       let mut object = Object::new(x, y, '!', "healing potion", VIOLET, false);
+      object.item = Some(Item::Heal);
       objects.push(object);
     }
   }
@@ -546,6 +571,85 @@ fn monster_death(monster: &mut Object, game: &mut Game) {
   monster.name = format!("remains of {}", monster.name);
 }
 
+fn menu<T: AsRef<str>>(header: &str, options: &[T], width: i32, root: &mut Root) -> Option<usize> {
+  // Limit the amount of menu options
+  assert!(
+    options.len() <= 26,
+    "Cannot have a menu with more than 26 options."
+  );
+
+  // Calculate total height for the header (after auto-wrap) and one line per option
+  let header_height = root.get_height_rect(0, 0, width, SCREEN_HEIGHT, header);
+  let height = options.len() as i32 + header_height;
+
+  // Create an off-screen console that represents the menu's window
+  let mut window = Offscreen::new(width, height);
+
+  // Print the header, with auto-wrap
+  window.set_default_foreground(WHITE);
+  window.print_rect_ex(
+    0,
+    0,
+    width,
+    height,
+    BackgroundFlag::None,
+    TextAlignment::Left,
+    header,
+  );
+
+  // Print all the options
+  for (index, option_text) in options.iter().enumerate() {
+    let menu_letter = (b'a' + index as u8) as char;
+    let text = format!("({}) {}", menu_letter, option_text.as_ref());
+    window.print_ex(
+      0,
+      header_height + index as i32,
+      BackgroundFlag::None,
+      TextAlignment::Left,
+      text,
+    );
+  }
+
+  // Blit the contents of the menu window to the root console
+  let x = SCREEN_WIDTH / 2 - width / 2;
+  let y = SCREEN_HEIGHT / 2 - height / 2;
+  blit(&window, (0, 0), (width, height), root, (x, y), 1.0, 0.7);
+
+  // Present the root console to the player and wait for a key-press
+  root.flush();
+  let key = root.wait_for_keypress(true);
+
+  // Convert the ASCII code to an index; if it corresponds to an option, return it
+  if key.printable.is_alphabetic() {
+    let index = key.printable.to_ascii_lowercase() as usize - 'a' as usize;
+    if index < options.len() {
+      Some(index)
+    } else {
+      None
+    }
+  } else {
+    None
+  }
+}
+
+fn inventory_menu(inventory: &[Object], header: &str, root: &mut Root) -> Option<usize> {
+  // Show a menu with each inventory item as an option
+  let options = if inventory.len() == 0 {
+    vec!["Inventory is empty.".into()]
+  } else {
+    inventory.iter().map(|item| item.name.clone()).collect()
+  };
+
+  let inventory_index = menu(header, &options, INVENTORY_WIDTH, root);
+
+  // If an item was chosen, return it
+  if inventory.len() > 0 {
+    inventory_index
+  } else {
+    None
+  }
+}
+
 fn render_bar(
   panel: &mut Offscreen,
   x: i32,