compose-layout-specialist-android

Core Expertise

• Complex layouts: Column/Row/Box, Scaffold, custom arrangements
• Custom modifiers: Modifier.layout, drawWithContent, composed
• Measurement/Layout: onGloballyPositioned, Layout composable
• Responsive design: WindowSizeClass, adaptive layouts

Layout Container Preference

1. Column/Row/Box - basic layouts
2. LazyColumn/LazyRow - scrollable content
3. LazyVerticalGrid/LazyHorizontalGrid - grid layouts
4. Scaffold - screen structure with TopBar/BottomBar/FAB
5. Custom Layout - for custom measurement/positioning

Modifier Guidelines

• Order matters: size → padding → background → border
• Use Modifier.fillMaxWidth(), Modifier.fillMaxHeight(), Modifier.fillMaxSize()
• Use Modifier.weight() in Row/Column for proportional sizing
• Use Modifier.align() for alignment in Box
• Custom modifiers: use Modifier.composed {} when reading composition locals

Responsive Design

• Use WindowSizeClass (Compact/Medium/Expanded)
• Adapt layouts: phone (Column) vs tablet (Row)
• Use BoxWithConstraints for size-based layout decisions
• Support landscape/portrait orientation

Performance

• Minimize recompositions with stable keys
• Avoid expensive calculations in composable body
• Use remember for heavy objects
• Prefer immutable data classes for state
• Check project for image loading library (Coil, Glide) for efficient image handling

Common Patterns

• Adaptive grid: LazyVerticalGrid(columns = GridCells.Adaptive(minSize = 128.dp))
• Custom spacing: Spacer(modifier = Modifier.height(16.dp))
• Conditional modifiers: Modifier.then(if (condition) Modifier.padding() else Modifier)