feat(menu): add Export as PNG using html2canvas

Author: Aditya Sarna

frontend/package.json

@@ -33,6 +33,8 @@
     "sass": "^1.50.0",
     "typescript": "^4.1.2",
     "web-vitals": "^1.0.1"
+    ,
+    "html2canvas": "^1.4.1"
   },
   "scripts": {
     "start": "PORT=4000 react-scripts start",
@@ -62,3 +64,4 @@
     "@types/lodash.clonedeep": "^4.5.9"
   }
 }
+

frontend/src/components/menu/index.tsx

@@ -1,5 +1,6 @@
 import { AppBar, Button, Toolbar, useTheme } from '@material-ui/core';
 import { ClickEvent, Menu, MenuItem, SubMenu } from '@szhsin/react-menu';
+import html2canvas from 'html2canvas';
 import React, { ChangeEvent } from 'react';
 import logo from '../../assets/images/logo.png';
 import { PROJECT_FILE_EXTENSION } from '../../core/constants';
@@ -196,6 +197,33 @@ function MenuBar(props: MenuBarProps) {
         }
     }
 
+    /**
+     * Export the current canvas as a PNG image.
+     * Captures the element with id 'canvas-container' using html2canvas and triggers a download.
+     */
+    const exportAsPNG = (_event: ClickEvent) => {
+        const container = document.getElementById('canvas-container');
+        if (!container) {
+            alert('Canvas area not found.');
+            return;
+        }
+        // Use promise chain so handler remains synchronous for the menu component
+        html2canvas(container as HTMLElement, { backgroundColor: null })
+            .then((canvas: HTMLCanvasElement) => {
+                const url = canvas.toDataURL('image/png');
+                const link = document.createElement('a');
+                link.href = url;
+                link.download = editor.getName() + '.png';
+                document.body.appendChild(link);
+                link.click();
+                document.body.removeChild(link);
+            })
+            .catch((err: any) => {
+                console.error('Error exporting canvas as PNG:', err);
+                alert('Could not export canvas as PNG. See console for details.');
+            });
+    }
+
     /**
      * Recursive helper function to generate menu options for the Blocks menu.
      * @param blocks Map containing Blocks menu structure
@@ -235,6 +263,7 @@ function MenuBar(props: MenuBarProps) {
                     <MenuItem onClick={saveBlock}>Save Block</MenuItem>
                     <MenuItem onClick={addAsBlock}>Add as block</MenuItem>
                     <MenuItem onClick={buildAndDownload}>Build and Download</MenuItem>
+                    <MenuItem onClick={exportAsPNG}>Export as PNG</MenuItem>
                 </Menu>
                 <Menu
                     menuButton={<Button className='menu-button'>Edit</Button>}