Huawei Mate XTs Triple-Fold Development: Layout Adaptation & Free Multi-Window Features

On September 4, Huawei launched the Mate XTs, a triple-fold smartphone that extends the foldable form factor into three distinct usage states. To help developers deliver high-quality experiences on this device, Huawei published the Triple-Fold Application Development Best Practices guide, covering layout adaptation, window management, and new interaction capabilities.

1. Triple-Fold Layout Adaptation

HarmonyOS's "develop once, deploy across multiple endpoints" responsive layout capability lets apps efficiently adapt to the Mate XTs' different display requirements.

1.1 Usage Form Factors

The triple-fold offers three form factors, each with unique strengths:

Single-screen state: Classic slab design, one-handed operation.

Dual-screen state: Split-screen collaboration for parallel multitasking.

Triple-screen state: 10.2-inch expanded canvas for shopping, office work, and entertainment.

Developers should consult the best-practices guide to choose the most suitable layout for each form factor, maximizing product advantages while ensuring a consistent, complete experience.

1.2 Window Modes

The device supports three window modes:

Full-screen: Immersive, focused presentation for video, reading, and creation.

Split-screen: Two tasks side-by-side without interference.

Floating window: Flexible, draggable small window for simultaneous information management, video watching, and messaging.

1.3 Screen Orientation

Landscape/portrait rotation adaptation is straightforward. By calling the window module APIs, apps automatically adjust layout based on screen orientation.

2. Mate XTs New Capabilities

2.1 Free Multi-Window — PC-Like Fluidity

The Mate XTs introduces a free multi-window mode that breaks traditional mobile window constraints. In the triple-screen state, apps can float, drag, resize, and layer just like on a desktop. By adapting to HarmonyOS's horizontal breakpoint layout mechanism and configuring free multi-window mode, an app detects the free-window width and automatically switches to the optimal UI layout, enabling smooth multi-app parallelism.

2.2 Large-Screen Experience Enhanced by Stylus

The Mate XTs ships with a stylus that works out of the box. System-level features include global annotation, voice-synced annotation, quick note-taking, and button remote control — all "ready to use" without extra adaptation.

For deeper integration, Huawei opens the Pen Kit handwriting suite, providing:

Rich materials: 7 brush effects and 100+ color choices.

Stroke prediction: Pre-renders predicted points based on writing trajectory.

One-stroke shape: Automatically converts a single stroke into a regular geometric shape.

Full-screen color picker: Samples color from any screen region.

Stylus interaction: Supports double-tap and pinch gestures on the stylus.

3. Get Started Now

The Mate XTs creates new space for innovative app experiences. The simultaneously released Triple-Fold Application Development Best Practices provides end-to-end guidance — from layout adaptation and window management to interaction optimization — helping developers quickly master core adaptation points. For full details, visit the Huawei Developer website and read the Triple-Fold Application Development best practices.