refactor: much better item UI handling

client/ui/hooks/use-inventory-slice.js

@@ -0,0 +1,22 @@
+// 3rd party.
+import * as I from 'immutable';
+import React, {useState} from 'react';
+// 1st party.
+import {useEvent} from './use-event';
+
+export function useInventorySlice(selfEntity, start, end) {
+  const [items, setItems] = useState(I.List());
+  useEvent(selfEntity, 'inventoryChanged', () => {
+    setItems(items.withMutations((items) => {
+      for (let i = start; i < end; ++i) {
+        const item = selfEntity.itemInSlot(i);
+        items.set(i, item ? item : undefined);
+      }
+    }));
+  });
+  const slice = [];
+  for (let i = start; i < end; ++i) {
+    slice.push(items.get(i));
+  }
+  return slice;
+}

client/ui/menu/hotbar.js

@@ -1,51 +1,32 @@
 // 3rd party.
 import classnames from 'classnames';
-import * as I from 'immutable';
-import React, {useEffect, useState} from 'react';
+import React from 'react';
 // 2nd party.
 import {compose} from '@avocado/core';
 import contempo from 'contempo';
 // 1st party.
-import {useEvent} from '../hooks/use-event';
 import {usePropertyChange} from '../hooks/use-property-change';
+import {useInventorySlice} from '../hooks/use-inventory-slice';
+
 import ItemSlot from './item-slot';
 
 const decorate = compose(
   contempo(require('./hotbar.raw.scss').default),
 );
 
-const HotbarComponent = ({app}) => {
-  const selfEntity = usePropertyChange(app, 'selfEntity');
-  const activeSlotIndex = usePropertyChange(selfEntity, 'activeSlotIndex');
-  const [items, setItems] = useState(I.List());
-  useEvent(selfEntity, 'inventoryChanged', () => {
-    setItems(items.withMutations((items) => {
-      for (let i = 0; i < 10; ++i) {
-        const item = selfEntity.itemInSlot(i);
-        if (!item) {
-          continue;
-        }
-        if (!items.has(i)) {
-          items.set(i, I.Map());
-        }
-        items.set(i, items.get(i).withMutations((listItem) => {
-          listItem.set('backgroundImage', item.imageForSlot());
-          listItem.set('qty', item.qty);
-        }));
-      }
-    }));
-  });
+const HotbarComponent = ({selfEntity}) => {
   const hotkeyForSlot = (index) => {
     return (index + 1) % 10;
   }
-  const slots = [];
-  for (let i = 0; i < 10; ++i) {
-    const slot = <ItemSlot
+  const activeSlotIndex = usePropertyChange(selfEntity, 'activeSlotIndex');
+  const itemSlice = useInventorySlice(selfEntity, 0, 10);
+  const itemSlots = itemSlice.map((item, i) => {
+    return <ItemSlot
+      key={i}
+      item={item}
       className={classnames(
         activeSlotIndex === i ? 'active' : '',
       )}
-      item={items.get(i)}
-      key={i}
       onClick={(event) => {
         if (selfEntity) {
           selfEntity.activeSlotIndex = i;
@@ -57,13 +38,12 @@ const HotbarComponent = ({app}) => {
     >
       <div className="hotbar-key">{hotkeyForSlot(i)}</div>
     </ItemSlot>;
-    slots.push(slot);
-  }
+  });
   return <div
     className="hotbar unselectable"
   >
     <div className="hotbar-inner">
-      {slots}
+      {itemSlots}
     </div>
   </div>;
 }

client/ui/menu/index.js

@@ -6,6 +6,7 @@ import {compose} from '@avocado/core';
 import contempo from 'contempo';
 // 1st party.
 import {useEvent} from '../hooks/use-event';
+import {usePropertyChange} from '../hooks/use-property-change';
 import QuickStatus from './quick-status';
 import Hotbar from './hotbar';
 import Inventory from './inventory';
@@ -17,6 +18,7 @@ const decorate = compose(
 
 const MenuComponent = ({app}) => {
   const [opened, setOpened] = useState(false);
+  const selfEntity = usePropertyChange(app, 'selfEntity');
   useEvent(app, 'isMenuOpenedChanged', (_, isOpened) => {
     setOpened(isOpened);
   });
@@ -25,10 +27,10 @@ const MenuComponent = ({app}) => {
       'menu-inner',
       opened ? 'open' : '',
     )}>
-      <Inventory app={app} />
+      <Inventory selfEntity={selfEntity} />
       <QuickStatus app={app} />
       <WorldTime worldTime={app.worldTime} />
-      <Hotbar app={app} />
+      <Hotbar selfEntity={selfEntity} />
     </div>
   </div>;
 }

client/ui/menu/inventory.js

@@ -1,24 +1,25 @@
 // 3rd party.
-import React, {useEffect, useState} from 'react';
+import React from 'react';
 // 2nd party.
 import {compose} from '@avocado/core';
 import contempo from 'contempo';
 // 1st party.
+import {useInventorySlice} from '../hooks/use-inventory-slice';
 import ItemSlot from './item-slot';
 
 const decorate = compose(
   contempo(require('./inventory.raw.scss').default),
 );
 
-const InventoryComponent = () => {
-  const bagSlots = [];
-  for (let i = 0; i < 40; ++i) {
-    bagSlots.push(<ItemSlot key={i} />);
-  }
-  const equipmentSlots = [];
-  for (let i = 0; i < 4; ++i) {
-    equipmentSlots.push(<ItemSlot key={i} />);
-  }
+const InventoryComponent = ({selfEntity}) => {
+  const bagSlice = useInventorySlice(selfEntity, 10, 50);
+  const bagSlots = bagSlice.map((item, i) => {
+    return <ItemSlot key={i} item={item} />;
+  });
+  const equipmentSlice = useInventorySlice(selfEntity, 50, 54);
+  const equipmentSlots = equipmentSlice.map((item, i) => {
+    return <ItemSlot key={i} item={item} />;
+  });
   return <div className="inventory unselectable">
     <div className="inventory-inner">
       <div className="bag">{bagSlots}</div>

client/ui/menu/item-slot.js

@@ -4,6 +4,8 @@ import React, {useEffect, useState} from 'react';
 // 2nd party.
 import {compose} from '@avocado/core';
 import contempo from 'contempo';
+// 1st party.
+import {useEvent} from '../hooks/use-event';
 
 const decorate = compose(
   contempo(require('./item-slot.raw.scss').default),
@@ -11,15 +13,15 @@ const decorate = compose(
 
 const ItemSlotComponent = (props) => {
   const {children, className, item, ...rest} = props;
+  const [qty, setQty] = useState(undefined);
+  useEvent(item, 'qtyChanged', (_, qty) => setQty(item.qty));
   let backgroundImageUri;
-  let qty;
   let qtyClass;
   if (item) {
-    const backgroundImage = item.get('backgroundImage');
+    const backgroundImage = item.imageForSlot();
     if (backgroundImage) {
       backgroundImageUri = backgroundImage.uri;
     }
-    qty = item.get('qty');
     if (qty > 9999) {
       qtyClass = 'e4';
     }