static keys - items in inventory will save their assigned key

precursor to cleaning up/modularising inventory display, instead of needing to iterate through every item held to find unique copies, we can just check if the button pressed corresponds to any entity's Key {} index

src/invkeys.rs

@@ -0,0 +1,55 @@
+use std::sync::Mutex;
+use std::collections::{ HashMap };
+use specs::prelude::*;
+use crate::gui::UniqueInventoryItem;
+
+lazy_static! {
+    pub static ref INVKEYS: Mutex<HashMap<UniqueInventoryItem, usize>> = Mutex::new(HashMap::new());
+    pub static ref ASSIGNEDKEYS: Mutex<Vec<bool>> = Mutex::new(vec![false; 52]);
+}
+
+/// For (de)serialization.
+pub fn clone_invkeys() -> HashMap<UniqueInventoryItem, usize> {
+    let invkeys = INVKEYS.lock().unwrap();
+    invkeys.clone()
+}
+pub fn restore_invkeys(invkeys: HashMap<UniqueInventoryItem, usize>) {
+    INVKEYS.lock().unwrap().clear();
+    INVKEYS.lock().unwrap().extend(invkeys);
+}
+
+pub fn item_exists(item: &UniqueInventoryItem) -> Option<usize> {
+    let invkeys = INVKEYS.lock().unwrap();
+    use bracket_lib::prelude::*;
+    console::log(&format!("{:?}", item));
+    if invkeys.contains_key(item) {
+        Some(*invkeys.get(item).unwrap())
+    } else {
+        None
+    }
+}
+
+pub fn assign_next_available() -> Option<usize> {
+    let mut lock = ASSIGNEDKEYS.lock().unwrap();
+    for (i, key) in lock.iter_mut().enumerate() {
+        if !*key {
+            *key = true;
+            return Some(i);
+        }
+    }
+    None
+}
+
+pub fn register_stackable(stacks: bool, item: UniqueInventoryItem, idx: usize) {
+    if stacks {
+        let mut invkeys = INVKEYS.lock().unwrap();
+        invkeys.insert(item, idx);
+    }
+}
+
+pub fn clear_idx(idx: usize) {
+    let mut lock = ASSIGNEDKEYS.lock().unwrap();
+    lock[idx] = false;
+    let mut invkeys = INVKEYS.lock().unwrap();
+    invkeys.retain(|_k, v| *v != idx);
+}