curtains 0.9.0

Wrap a scrollable with scrim Curtains while not at the start or end, alluding to unrevealed content.

📜 Curtains

Wrap a scrollable with scrim 📜 Curtains while not at the start or end, alluding to unrevealed content.

 

📖 Reference

• Advanced usage with 📜 Curtains.fancy & 📜 Curtains.regal
• [Elevation]'s two static methods for passing elevation through [kElevationToShadow]
  • Elevation.asBoxShadows(double elevation)
  • Elevation.asBoxDecoration(double elevation)
• [Curtains.NILL] for const BoxDecoration()
• [_SensitivityList], a List extension for verifying a [Curtains.sensitivity]

🧫 Examples

See demonstrations of the 📜 Curtains package for Flutter:

• 📜 Curtains Demo source: /example/lib/main.dart
• 📜 Curtains Demo APK

Simple 📜 Curtains

Widget build(BuildContext context) {
  return Curtains(
    child: ListView(
      children: List.generate(
        25,
        (i) => ListTile(title: Text('ListTile #${i+1}')),
      ),
    ),
    // Consider [Material.elevation], but see [Elevation]; defaults `9.0`.
    elevation: 24,
  );
}

It's that easy!

Fancy 📜 Curtains

Curtains.fancy(
  /// 🕴 Default constructor 📜 [Curtains] employs `Elevation.asBoxDecoration` to
  /// render its decorations; but feel free to use these static methods, too.
  startCurtain: Elevation.asBoxDecoration(12.0), // 🕴
  endCurtain: BoxDecoration(boxShadow: Elevation.asBoxShadows(12.0)), // 🕴
  child: ListView(
    children: List.generate(
      25,
      (i) => ListTile(title: Text('ListTile #${i+1}')),
    ),
  ),
);

It's similarly easy!

Regal 📜 Curtains

This instance of regal 📜 Curtains has custom, animated BoxDecorations as well as sensitivity at the start and end.

Curtains.regal(
  // If wrapping a horizontal scrollable, initialize here, too.
  scrollDirection: Axis.horizontal, // ↔
  startCurtain: buildCurtain(),
  endCurtain: buildCurtain(isStart: false),
  // Provide `spread` to [Curtains] for decoration support beyond [BoxShadow]s.
  // (Gives "girth" to individual [_Curtain] containers; otherwise `0`.)
  spread: 50.0,
  // ⚖ `start` appears once scrolled `350` px beyond start
  // ⚖ `end` appears once scrolled `175` px beyond end
  sensitivity: const [350.0, 175.0],
  // Regal 📜 Curtains are animated.
  duration: const Duration(milliseconds: 600),
  curve: Curves.fastOutSlowIn,
  child: ListView(
    scrollDirection: Axis.horizontal, // ↔
    itemExtent: 100.0,
    children: List.generate(
      25,
      (i) => ListTile(title: Text('ListTile #${i+1}')),
    ),
  ),
);

BoxDecoration buildCurtain({bool isStart = true}) => BoxDecoration(
  gradient: LinearGradient(
    colors: [Colors.green[400]!, Colors.green[400]!.withOpacity(0)],
    begin: (isStart) ? Alignment.centerLeft : Alignment.centerRight,
    end: (isStart) ? Alignment.centerRight : Alignment.centerLeft,
  ),
  boxShadow: const [
    BoxShadow(color: Color(0x22FF0000), spreadRadius: 0.0, blurRadius: 5.0),
    BoxShadow(color: Color(0x66FF0000), spreadRadius: 10.0, blurRadius: 30.0),
    BoxShadow(color: Color(0x22FF0000), spreadRadius: 60.0, blurRadius: 150.0),
  ],
);

But look here, and we can get pretty complex and creative.

🐞 Bugs

One known bug:

• Even with Curtains.spread set non-negligibly, BoxDecoration.backgroundBlendMode does not work correctly.