Saturday, January 31, 2026

Reverse-Engineered IDE-Grade Drag & Drop: Built a Framework-Agnostic Layout Engine

Profile Pic of Akash AmanAkash Aman

Updated: January 2026

Table of Contents

๐Ÿš€ The Case Study ๐Ÿš€

  • I come from a non-CSE background ๐ŸŽ“, but Iโ€™ve always been deeply drawn to problem-solving ๐Ÿงฉ. Early on, I spent a lot of time solving LeetCode problems, and thatโ€™s where I first encountered sophisticated drag-and-drop tab implementations in the LeetCode site. Watching complex UIs behave so smoothly inside the browser genuinely fascinated meโ€”and I became a huge fan of this interaction pattern. โœจ

  • Curious to understand how it worked, I started reverse-engineering the behavior and researching existing solutions. To my surprise, I couldnโ€™t find any npm package that offered this level of functionality. It became clear that this system had been built entirely in-house. That realization sparked an idea: Why not build this myself and open-source it? ๐Ÿ’ก



The Investigation: Reverse Engineering the "Magic" ๐Ÿ”

The challenge was that I didnโ€™t fully understand how everything worked under the hood. So I dug deeperโ€”inspecting compiled JavaScript, monitoring the Network tab, and analyzing Local Storage ๐Ÿ› ๏ธ. Thatโ€™s when I noticed something interesting: the layout persisted across page refreshes. The state had to be stored somewhere, and sure enough, it was being saved in Local Storage as a serialized JSON structure ๐Ÿ“‹.

Once I examined this JSON, I realized it was the key to the entire solution. The data represented a complex tree structure that powered all the drag-and-drop and tab-switching behavior ๐ŸŒณ. I carefully analyzed this structure and began implementing my own tree-based algorithm to support every possible tab interaction.

Along the way, I ran into numerous challenges: ๐Ÿง—

  • Calculating dynamic widths correctly ๐Ÿ“.
  • Eliminating unnecessary computations โšก.
  • Fixing performance bottlenecks to maintain smooth 60-FPS interactions ๐ŸŽ๏ธ.
  • Handling edge cases and avoiding tight coupling to reduce refactoring costs ๐Ÿ”—.
  • Keeping time complexity under control โณ.

Decoding the Solution: Logic Over Framework ๐Ÿ› ๏ธ

I decided to stop fighting the frameworks and start fresh. I built a framework-agnostic "brain" ๐Ÿง  in pure, zero-dependency TypeScript. This core handles the recursive tree logic, while the React and SolidJS wrappers act as thin, performant "bodies." ๐Ÿค–

The result? A library where you can go from npm install to a fully functional, resizable IDE layout in under five minutes. โฑ๏ธ

ts
import { DynamixLayout } from '@dynamix-layout/react' import '@dynamix-layout/react/style.css' function App() { const tabList = [ ['editor', <div style={{ background: '#c0ca33', height: '100%' }}>Editor (Green)</div>], ['preview', <div style={{ background: '#66bb6a', height: '100%' }}>Preview (Sky/Light Green)</div>], ['terminal', <div style={{ background: '#ffc400', height: '100%' }}>Terminal (Orange)</div>], ] return ( <DynamixLayout tabs={tabList} style={{ height: '100vh', width: '100vw' }} /> ) } export default App

The Long Game: The "Part-Time" Marathon ๐Ÿƒ

Building Dynamix Layout wasn't an overnight success. Because I was working full-time as a Senior Software Engineer, this became my "night and weekend" obsession ๐ŸŒ™.

The project spanned several months because the logic was dense. I spent my late nights solving "mini-algorithms" within the engine: ๐Ÿ•ต๏ธโ€โ™‚๏ธ

  • The Math of Resizing: Calculating relative widths across nested containers without cumulative rounding errors ๐Ÿงฎ.
  • The 60fps Rule: Optimizing the core so that dragging a panel didn't trigger a "re-render apocalypse" in React ๐Ÿ”ฅ.
  • Edge Case Hunting: Managing state when a panel is minimized or handling the removal of the last tab in a split ๐Ÿ”.

Key Features: Engineering a Better Developer Experience ๐ŸŒŸ

To make this vision a reality, I focused on six pillars that transform a simple layout into a professional-grade interface:

  • ๐Ÿงฉ Draggable Tabs with Contextual Intelligence: Moving tabs shouldn't just feel like moving items in a list. You can drag and drop tabs to rearrange them within a group or move them across different panels entirely with intuitive visual feedback ๐Ÿ–ฑ๏ธ.
  • ๐Ÿ“ High-Performance Resizable Panels: Smooth interactions are non-negotiable. Users can click and drag the "gutters" between panels to resize them dynamically at a consistent 60fps ๐Ÿ’จ.
  • โœ‚๏ธ Intuitive Dynamic Splits: The hallmark of a great IDE. By dropping a tab onto the edges of an existing panel, the engine automatically calculates the new tree node and creates a horizontal or vertical split with a real-time preview ๐Ÿ—๏ธ.
  • ๐Ÿ’พ Robust Save & Restore (Serialization): I built serialization directly into the core. You can save the entire complex layout state into a clean JSON object, making it trivial to restore user workspaces from a database โ˜๏ธ.
  • ๐Ÿง  Framework-Agnostic "Brain": The heavy lifting is handled by a core logic engine written in pure, zero-dependency TypeScript. This keeps the engine lightweight, fast, and maintainable โš›๏ธ.
  • โš›๏ธ Seamless React & Solid Integration: While the "brain" is agnostic, Iโ€™ve built official wrappers for React and SolidJS that provide feature-rich components like <DynamixLayout /> and intuitive hooks like useLayout ๐Ÿ› ๏ธ.

Why I Made it Open Source ๐Ÿค

I built this because I remember the frustration of finding "proprietary walls" when I just wanted to build something cool. Dynamix Layout is my way of giving that power back to the community ๐ŸŒ.

Whether you are building a dashboard, a data tool, or the next great web IDE, you now have access to a high-performance engine that handles the math so you can focus on the features. The project is a testament to the idea that coming from a "non-traditional" background isn't a barrierโ€”itโ€™s a superpower ๐Ÿ’ช that lets you see the algorithms behind the pixels. ๐ŸŽจ

Ready to Build? ๐Ÿ› ๏ธ