feat: load blocks from previous session

also remove annoying unsaved changes popup

package.json

@@ -34,6 +34,7 @@
 		"embla-carousel-react": "^8.6.0",
 		"lucide-react": "^0.544.0",
 		"nbtify": "^2.2.0",
+		"pako": "^2.1.0",
 		"pixi.js": "^8.13.2",
 		"react": "^19.1.1",
 		"react-device-detect": "^2.2.3",
@@ -46,6 +47,7 @@
 		"@eslint/js": "^9.36.0",
 		"@tailwindcss/postcss": "^4.1.14",
 		"@types/node": "^24.6.1",
+		"@types/pako": "^2.0.4",
 		"@types/react": "^19.1.17",
 		"@types/react-dom": "^19.1.11",
 		"@vitejs/plugin-react": "^5.0.4",

pnpm-lock.yaml

@@ -80,6 +80,9 @@ importers:
       nbtify:
         specifier: ^2.2.0
         version: 2.2.0
+      pako:
+        specifier: ^2.1.0
+        version: 2.1.0
       pixi.js:
         specifier: ^8.13.2
         version: 8.13.2
@@ -111,6 +114,9 @@ importers:
       '@types/node':
         specifier: ^24.6.1
         version: 24.6.1
+      '@types/pako':
+        specifier: ^2.0.4
+        version: 2.0.4
       '@types/react':
         specifier: ^19.1.17
         version: 19.1.17
@@ -1270,6 +1276,9 @@ packages:
   '@types/node@24.6.1':
     resolution: {integrity: sha512-ljvjjs3DNXummeIaooB4cLBKg2U6SPI6Hjra/9rRIy7CpM0HpLtG9HptkMKAb4HYWy5S7HUvJEuWgr/y0U8SHw==}
 
+  '@types/pako@2.0.4':
+    resolution: {integrity: sha512-VWDCbrLeVXJM9fihYodcLiIv0ku+AlOa/TQ1SvYOaBuyrSKgEcro95LJyIsJ4vSo6BXIxOKxiJAat04CmST9Fw==}
+
   '@types/react-dom@19.1.11':
     resolution: {integrity: sha512-3BKc/yGdNTYQVVw4idqHtSOcFsgGuBbMveKCOgF8wQ5QtrYOc3jDIlzg3jef04zcXFIHLelyGlj0T+BJ8+KN+w==}
     peerDependencies:
@@ -2090,6 +2099,9 @@ packages:
     resolution: {integrity: sha512-LaNjtRWUBY++zB5nE/NwcaoMylSPk+S+ZHNB1TzdbMJMny6dynpAGt7X/tl/QYq3TIeE6nxHppbo2LGymrG5Pw==}
     engines: {node: '>=10'}
 
+  pako@2.1.0:
+    resolution: {integrity: sha512-w+eufiZ1WuJYgPXbV/PO3NCMEc3xqylkKHzp8bxp1uW4qaSNQUkwmLLEc3kKsfz8lpV1F8Ht3U1Cm+9Srog2ug==}
+
   parent-module@1.0.1:
     resolution: {integrity: sha512-GQ2EWRpQV8/o+Aw8YqtfZZPfNRWZYkbidE9k5rpl/hC3vtHHBfGm2Ifi6qWV+coDGkrUKZAxE3Lot5kcsRlh+g==}
     engines: {node: '>=6'}
@@ -3479,6 +3491,8 @@ snapshots:
     dependencies:
       undici-types: 7.13.0
 
+  '@types/pako@2.0.4': {}
+
   '@types/react-dom@19.1.11(@types/react@19.1.17)':
     dependencies:
       '@types/react': 19.1.17
@@ -4347,6 +4361,8 @@ snapshots:
     dependencies:
       p-limit: 3.1.0
 
+  pako@2.1.0: {}
+
   parent-module@1.0.1:
     dependencies:
       callsites: 3.1.0

src/components/canvas/Canvas.tsx

@@ -456,18 +456,6 @@ function Canvas() {
 		return () => resizeObserver.disconnect();
 	}, [loading, setStageSize]);
 
-	// Window events handler
-	useEffect(() => {
-		const onBeforeUnload = (e: BeforeUnloadEvent) => {
-			e.preventDefault();
-		};
-
-		window.addEventListener("beforeunload", onBeforeUnload);
-		return () => {
-			window.removeEventListener("beforeunload", onBeforeUnload);
-		};
-	}, [onKeyDown, onKeyUp]);
-
 	useGesture(
 		{
 			onPinch: ({ offset: [d] }) => {

src/components/sidebar/History.tsx

@@ -17,6 +17,7 @@ import {
 	SquareDashedIcon,
 	Trash2Icon,
 	WandIcon,
+	SaveIcon,
 } from "lucide-react";
 
 import { HistoryContext } from "@/context/History";
@@ -32,6 +33,7 @@ const iconMap = {
 	"Magic Wand": WandIcon,
 	"Move Selection": MoveIcon,
 	"New Canvas": PresentationIcon,
+	"Load Previous Session": SaveIcon,
 	"Open Image": ImageIcon,
 	"Open Schematic": FileIcon,
 	"Paint Bucket": PaintBucketIcon,

src/context/Canvas.tsx

@@ -1,4 +1,5 @@
 import React, { createContext, ReactNode, useCallback, useContext, useEffect, useMemo, useState } from "react";
+import pako from "pako";
 
 import { HistoryContext } from "./History";
 import welcomeBlocksData from "@/data/welcome.json";
@@ -89,14 +90,49 @@ export const CanvasProvider = ({ children }: Props) => {
 	}, [canvasSize, stageSize]);
 
 	useEffect(() => {
-		addHistory(
+		// Load blocks from previous session (if any)
-			"New Canvas",
+		const localStorageBlocks = localStorage.getItem("blocks");
-			() => setBlocks(welcomeBlocksData),
+		if (localStorageBlocks) {
-			() => setBlocks([])
+			try {
-		);
+				// Convert stored string (Base64) back to bytes
-		// eslint-disable-next-line react-hooks/exhaustive-deps
+				const compressedData = Uint8Array.from(atob(localStorageBlocks), (c) => c.charCodeAt(0));
+				const decompressed = pako.inflate(compressedData, { to: "string" });
+				const parsedBlocks = JSON.parse(decompressed);
+
+				setBlocks(parsedBlocks);
+				addHistory(
+					"Load Previous Session",
+					() => setBlocks(parsedBlocks),
+					() => setBlocks(welcomeBlocksData)
+				);
+			} catch (err) {
+				console.error("Failed to load blocks from localStorage:", err);
+				localStorage.removeItem("blocks");
+			}
+		} else {
+			// Add history entry for new canvas
+			addHistory(
+				"New Canvas",
+				() => setBlocks(welcomeBlocksData),
+				() => setBlocks([])
+			);
+		}
 	}, []);
 
+	// Set blocks to localStorage for session persistence
+	useEffect(() => {
+		// If blocks are the same as the starting welcome blocks, return
+		if (JSON.stringify(blocks) === JSON.stringify(welcomeBlocksData)) return;
+
+		const encoder = new TextEncoder();
+		const data = encoder.encode(JSON.stringify(blocks));
+		const compressed = pako.deflate(data);
+
+		// Store compressed data as Base64 string
+		const base64 = btoa(String.fromCharCode(...compressed));
+		localStorage.setItem("blocks", base64);
+	}, [blocks]);
+
 	return (
 		<CanvasContext.Provider
 			value={{