Swiftui Liquid Glass

# Liquid Glass API Reference for SwiftUI

## Contents

- [Overview](#overview)
- [glassEffect(_:in:)](#glasseffect_in)
- [Glass](#glass)
- [GlassEffectContainer](#glasseffectcontainer)
- [glassEffectID(_:in:)](#glasseffectid_in)
- [glassEffectUnion(id:namespace:)](#glasseffectunionidnamespace)
- [glassEffectTransition(_:)](#glasseffecttransition_)
- [GlassEffectTransition](#glasseffecttransition)
- [Button Styles](#button-styles)
- [DefaultGlassEffectShape](#defaultglasseffectshape)
- [Scroll Edge Effect](#scroll-edge-effect)
- [Background Extension (Split Views)](#background-extension-split-views)
- [Availability Gating](#availability-gating)
- [Performance Guidelines](#performance-guidelines)
- [Accessibility Considerations](#accessibility-considerations)
- [Best Practices Summary](#best-practices-summary)
- [Apple Documentation Links](#apple-documentation-links)

## Overview

Liquid Glass is a dynamic translucent material available on iOS 26.0+, iPadOS 26.0+,
macOS 26.0+, Mac Catalyst 26.0+, tvOS 26.0+, and watchOS 26.0+. It blurs content
behind it, reflects color and light from surrounding content, and reacts to touch and
pointer interactions in real time. Standard SwiftUI components (tab bars, toolbars,
navigation bars, sheets, popovers) adopt Liquid Glass automatically when built with
the latest SDK.

This reference covers the complete API surface for applying Liquid Glass to custom views.

## glassEffect(_:in:)

Applies the Liquid Glass effect behind a view.

```swift
nonisolated func glassEffect(
    _ glass: Glass = .regular,
    in shape: some Shape = DefaultGlassEffectShape()
) -> some View
```

The system renders a shape anchored behind the view with the Liquid Glass material and
applies foreground effects over the view content. The default shape is `Capsule`.

Apply this modifier **after** other modifiers that affect the view's appearance (padding,
frame, font, foregroundStyle).

### Basic usage

```swift
Text("Hello, World!")
    .font(.title)
    .padding()
    .glassEffect()
```

### Custom shape

```swift
Text("Hello, World!")
    .font(.title)
    .padding()
    .glassEffect(in: .rect(cornerRadius: 16.0))
```

Common shapes: `.capsule` (default), `.rect(cornerRadius:)`, `.circle`.

### Tinted and interactive

```swift
Text("Hello, World!")
    .font(.title)
    .padding()
    .glassEffect(.regular.tint(.orange).interactive())
```

## Glass

A structure that defines the configuration of the Liquid Glass material. Conforms to
`Equatable`, `Sendable`, and `SendableMetatype`.

### Type Properties

| Property | Description |
|---|---|
| `.regular` | Standard Liquid Glass material |
| `.clear` | Clear variant with minimal visual weight |
| `.identity` | No-op; content appears as if no glass effect was applied |

### Instance Methods

| Method | Description |
|---|---|
| `.tint(_ color: Color)` | Returns a copy with a color tint to suggest prominence |
| `.interactive(_ isInteractive: Bool = true)` | Returns a copy that reacts to touch and pointer interactions |

Methods are chainable:

```swift
.glassEffect(.regular.tint(.blue).interactive())
```

## GlassEffectContainer

A view that combines multiple Liquid Glass shapes into a single rendering pass. Enables
blending and morphing between individual shapes.

```swift
@MainActor @preconcurrency
struct GlassEffectContainer<Content> where Content : View
```

Conforms to `View`, `Sendable`, `SendableMetatype`.

### Initializer

```swift
init(spacing: CGFloat, @ViewBuilder content: () -> Content)
```

The `spacing` parameter controls how glass shapes interact:

- **Larger spacing**: Shapes begin blending at greater distances; morphing starts sooner.
- **Smaller spacing**: Shapes must be closer before blending occurs.

Match the container spacing to the interior layout spacing so shapes remain separate at
rest but merge during animated transitions.

### Example

```swift
GlassEffectContainer(spacing: 40.0) {
    HStack(spacing: 40.0) {
        Image(systemName: "scribble.