Disk Usage Visualizer with Treemap and Sunburst Views

Disks fill up silently: a developer's machine accumulates Docker layers, node_modules folders, video renders and forgotten downloads until the operating system starts complaining. Built-in tools list folders by size in a flat table, which hides the structure — a 2 GB folder of videos looks identical to a 2 GB folder of source code. Area-based visualization solves this: a treemap makes each file and folder a rectangle sized by its bytes, so space hogs are visible at a glance, while a sunburst shows the same hierarchy radially. DiskLens implements both views in a single-file web app — a squarified treemap layout, a two-level sunburst chart, click-to-drill-down with breadcrumbs, live search filtering, hover tooltips and a per-folder analytics panel — demonstrating data-structure traversal, layout algorithms and canvas rendering in one build.

1. A realistic filesystem snapshot is embedded as a nested JSON tree of folders, files, sizes and categories.
2. A rollup pass computes each subtree's total size, file count and dominant category before rendering.
3. The squarified treemap algorithm partitions the current folder's children into area-proportional rectangles; the sunburst maps the same sizes to arc angles across two rings.
4. Canvas hit-testing drives hover tooltips (name, size, category) and click drill-down, which updates the breadcrumbs, the folder panel and the top-items list.
5. Typing in the search box filters the tree by name; matching items are re-rendered live in both views.
6. The selected-folder panel aggregates size, file count and the largest children for whatever level is open.

Tech stack:

• HTML5 canvas
• Vanilla JavaScript (ES6)
• Squarified treemap layout algorithm
• Canvas hit-testing for interaction
• JSON data model for the filesystem snapshot
• Single-file build, zero dependencies

• [Squarified treemap] The layout algorithm partitions each folder into area-proportional rectangles with good aspect ratios, rendered to canvas — the largest space hogs are unmissable.
• [Sunburst chart] The same hierarchy drawn as radial arcs across two rings, with canvas hit-testing so arcs can be hovered and clicked like the treemap.
• [Drill-down navigation] Click any rectangle or arc to descend into that folder; breadcrumbs track the path and one click returns to any level.
• [Live search filter] Type to filter the tree across files and folders; the views re-render instantly around the matching items.
• [Per-folder analytics panel] The selected folder shows its total size, file count, dominant category and a ranked list of its largest children.
• [Top-items list] A global ranked list of the largest files and folders in the current view, clickable to jump straight to them.
• [Category color coding] Items are colored by category — code, media, documents, system, archives, other — with a legend, so composition is readable at a glance.
• [Scan animation] An opening scan sequence with progress readout sets up the analytics-dashboard feel before the views render.

• Working DiskLens web app (single HTML file)
• Complete commented source code
• User guide: views, navigation, search, extending the snapshot data
• Project report PDF (visualization theory, algorithm design, implementation)
• PPT presentation for final review
• Viva Q&A preparation document (treemaps, sunbursts, layout algorithms, canvas rendering)