From Static Timeline to Fully Interactive Scheduler: Drag & Drop in My React Native Library

Source: Dev.to

Why I Built It

If you’ve ever tried building a scheduling UI in React Native, you probably know how tricky it gets.
Challenges include:

• Precisely positioning events based on time
• Handling horizontal and vertical scrolling simultaneously
• Virtualizing large datasets for performance
• Synchronizing headers and content
• Supporting TV platforms and remote navigation
• Keeping performance smooth on tablets and lower‑end devices

There wasn’t a flexible, production‑ready solution that covered these needs, so I decided to build one.

Core Capabilities

• Render events across a horizontal time axis
• Group events by rows (resources, users, rooms, etc.)
• Scroll horizontally through time
• Scroll vertically across resources
• Handle large datasets efficiently
• Customize rendering and styling
• Automatically detect and stack overlapping events

The timeline works across iOS, Android, and TV platforms, and is built purely in React Native.

New Interactive Features

The library now supports full gesture‑based editing:

• Drag horizontally – change an event’s start/end time
• Drag vertically – move an event between rows
• Resize from the left edge – update the start time
• Resize from the right edge – update the end time

Resize handlers feel natural and responsive, even during fast interactions. All calculations happen in real time—no hacks, no WebViews.

Overlap Detection & Stacking

When events overlap in time, they are stacked vertically within the same row, similar to professional calendar systems. This provides:

• Clear visual hierarchy
• No hidden events
• Accurate collision handling
• Smooth recalculation while dragging or resizing

Technical Challenges Solved

• Simultaneous vertical + horizontal gestures
• Real‑time time recalculation during drag
• Snap‑to‑time logic
• Dynamic width adjustments while resizing
• Collision detection during movement
• Overlap stacking recalculation
• Preventing layout thrashing
• Maintaining high FPS during re‑renders
• Avoiding unnecessary computations

Performance was a top priority from day one.

Use Cases

The interactive scheduler is ready for serious scheduling scenarios:

• 📅 Booking systems
• 🏥 Medical scheduling
• 👥 Shift planning
• 📺 TV program guides (EPG)
• 🏢 Resource management tools
• 🛠 Production planning systems
• 🏫 Classroom or training schedules

It’s no longer just a timeline—it’s a fully interactive scheduler engine.

Current Status & Roadmap

The library is currently in beta. Ongoing improvements include:

• API ergonomics
• Performance optimizations
• Edge‑case handling
• Documentation enhancements
• TypeScript support
• Advanced stacking configuration options

Planned Enhancements

• More advanced collision rules
• Enhanced performance profiling tools
• Additional customization hooks

Building a robust scheduling timeline in React Native is much harder than it looks. Adding smooth drag‑and‑drop, resize handlers, and real‑time overlap stacking—while keeping performance high across devices—was a serious engineering challenge. The component now feels complete.

If you’re building anything time‑based in React Native, I’d love to hear your thoughts or feedback. The journey continues.