ux

A Flutter toolkit for building fluid, native-feeling UIs.

UxKeyboard

Frame-accurate keyboard height tracking for iOS and Android, with interactive dismiss.

Flutter's built-in MediaQuery.viewInsets.bottom lags behind the actual keyboard position and doesn't support interactive dismiss. UxKeyboard reads the keyboard height directly from the native layer via FFI — zero channel latency, every frame.

Features

• Real-time height — reads the keyboard's actual position each frame via FFI (iOS) / JNI (Android)
• Native animation curves — sampled from CADisplayLink (iOS) and WindowInsetsAnimation (Android), with adaptive learning that refines the curve from observations
• Interactive dismiss — swipe the keyboard down like iMessage/Telegram, with snap-back or dismiss
• Scroll freeze — isTracking flag lets you freeze scrolling during interactive dismiss

Quick start

final keyboard = UxKeyboard.instance;

// Enable swipe-to-dismiss. trackingInset is the height of your input bar.
keyboard.enableInteractiveDismiss(trackingInset: 56);

Use ListenableBuilder to rebuild when the keyboard height changes:

Scaffold(
  resizeToAvoidBottomInset: false, // we handle it ourselves
  body: ListenableBuilder(
    listenable: keyboard,
    builder: (context, _) {
      final keyboardHeight = keyboard.height;
      final safeBottom = MediaQuery.viewPaddingOf(context).bottom;
      final bottom = max(keyboardHeight, safeBottom);

      return Column(
        children: [
          Expanded(
            child: ListView.builder(
              reverse: true,
              // Freeze scrolling during interactive dismiss
              physics: keyboard.isTracking
                  ? NeverScrollableScrollPhysics()
                  : null,
              // ...
            ),
          ),
          Container(
            padding: EdgeInsets.only(bottom: 8 + bottom),
            // your input bar
          ),
        ],
      );
    },
  ),
);

API

Member	Description
UxKeyboard.instance	Singleton instance
.height	Current keyboard height in logical pixels
.systemHeight	Last system-reported keyboard height
.isOpen	Whether the keyboard is visible
.isTracking	Whether a dismiss pan gesture is active
.enableInteractiveDismiss({trackingInset})	Enable swipe-to-dismiss
.disableInteractiveDismiss()	Disable swipe-to-dismiss
addListener / removeListener	Standard ChangeNotifier API

Key points

• Set resizeToAvoidBottomInset: false on your Scaffold — otherwise Flutter's built-in resize fights with UxKeyboard
• Use MediaQuery.viewPaddingOf(context).bottom for the safe area (not paddingOf, which is consumed by Scaffold)
• Use max(keyboardHeight, safeBottom) for bottom padding — the keyboard height includes the safe area when open, and safeBottom covers the home indicator when closed

Other utilities

• BendBox — a flexible layout widget
• Bezier — bezier curve utilities