feat: Add POS UI optimization module for low-RAM devices, implementing incremental loading and safely removing event listeners.

.gitignore

@@ -0,0 +1,6 @@
+*.pyc
+*~
+__pycache__/
+.DS_Store
+.vscode/
+.idea/

README.md

@@ -0,0 +1,27 @@
+# POS UI Optimization
+
+This Odoo 19 module optimizes the Point of Sale (POS) user interface for low-RAM devices (e.g., Android tablets with 2GB RAM).
+
+## Features
+
+- **Product List Incremental Loading**: Renders products in batches of 40 as you scroll, significantly reducing memory usage in categories with many products.
+- **Order Cart Incremental Loading**: Efficiently handles large orders by rendering order lines incrementally as you scroll through the cart.
+- **Improved Responsiveness**: Keeps the browser DOM light and prevents "white blank" screens caused by memory exhaustion.
+- **Legacy Browser Support**: Designed without modern ES2020 JavaScript syntax (like optional chaining `?.`) to ensure compatibility with older Android browser engines found on specific legacy POS hardware.
+
+## Installation
+
+1. Place the `pos_ui_optimization` folder in your Odoo custom addons directory.
+2. Restart your Odoo server.
+3. In Odoo, activate **Developer Mode**.
+4. Go to **Apps** -> **Update Apps List**.
+5. Search for `POS UI Optimization`.
+6. Click **Install**.
+
+## Technical Details
+
+This module uses Odoo's JavaScript patching mechanism (`patch` from `@web/core/utils/patch`) to extend the core POS components:
+- `ProductScreen`: Adds `displayedProductsCount` state via `owl`'s `useEffect` and an overridden `onScroll` hook to the product container.
+- `OrderDisplay`: Adds `displayedCount` state and a scroll listener to the combo sorted order lines container.
+
+No core Odoo files are modified.

static/src/app/components/order_display/order_display_patch.js

@@ -35,7 +35,10 @@ patch(OrderDisplay.prototype, {
         });
 
         onWillUnmount(() => {
-            this.scrollableRef.el?.removeEventListener("scroll", this.onScroll);
+            const el = this.scrollableRef.el;
+            if (el) {
+                el.removeEventListener("scroll", this.onScroll);
+            }
         });
     },