yayacal/CLAUDE.md

CLAUDE.md

This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.

Project Overview

YaYa is a calendar app built with Kotlin Multiplatform (KMP) + Compose Multiplatform, targeting Android and iOS. The shared UI is written entirely in Compose Multiplatform with Material 3.

Build Commands

# Build Android debug APK
./gradlew :androidApp:assembleDebug

# Run shared module tests
./gradlew :shared:testAndroidHostTest

# Run a single test class
./gradlew :shared:testAndroidHostTest --tests "plus.rua.project.ui.CalendarUtilsTest"

# Build iOS app — open iosApp/ in Xcode and run from there

Gradle configuration cache and build cache are enabled by default (gradle.properties).

Architecture

Two-module structure:

• :shared — all Compose UI, ViewModel, and business logic (KMP library)
• :androidApp — thin Android shell (MainActivity → App())

iOS entry point is MainViewController.kt in shared/src/iosMain/, consumed by the Xcode project in iosApp/.

Shared source sets:

• commonMain — all Compose UI and ViewModel code
• commonTest — shared tests (run via :shared:allTests or :shared:androidHostTest)
• androidMain — Android-specific platform impl + preview tooling
• iosMain — ComposeUIViewController factory

Calendar UI composition (all in plus.rua.project.ui):

CalendarMonthView          ← top-level screen (MonthHeader + WeekdayHeader + pager + BottomCard)
  ├── MonthHeader          ← year/month label + ISO week number
  ├── WeekdayHeader        ← fixed "一二三四五六日" row
  ├── CalendarPager        ← HorizontalPager with Int.MAX_VALUE pages (month view)
  │     └── CalendarMonthPage  ← 6×7 grid of DayCell with collapse animation
  │           └── DayCell      ← single day circle with selection/today states
  ├── WeekPager            ← HorizontalPager for single-week view (collapsed state)
  │     └── DayCell
  └── BottomCard           ← drag handle card, drives collapse/expand gestures

Collapse/expand animation: CalendarMonthView supports month↔week transition via CalendarViewModel.collapseProgress (0f=month, 1f=week). BottomCard captures vertical drag gestures and calls viewModel.onDrag()/onExpandDrag(). When progress crosses 50% on release, a spring animation snaps to the nearest state. CalendarMonthPage compresses non-selected weeks toward zero height during collapse. When fully collapsed, WeekPager replaces CalendarPager for efficient single-week paging.

Pager page mapping: Both CalendarPager and WeekPager use Int.MAX_VALUE pages centered at Int.MAX_VALUE / 2. Page-to-date conversion is arithmetic — no index-based list. CalendarPager maps pages to yearMonth; WeekPager maps pages to week-Monday dates. Both skip the initial snapshotFlow emission (.drop(1)) to preserve the "today" selection on first render.

CalendarViewModel holds selectedDate and isCollapsed state, computes month day grids (6×7=42 cells) and ISO week numbers. Week starts on Monday (ISO 8601).

Key Dependencies

• Kotlin 2.3.21, Compose Multiplatform 1.10.3, Material 3 1.10.0-alpha05
• kotlinx-datetime 0.8.0 for all date logic (no java.util.Calendar)
• AGP 9.2.1, compileSdk/targetSdk 36, minSdk 24
• JVM target: 17

Conventions

• Package: plus.rua.project (shared), plus.rua.project.ui (UI composables)
• Version catalog at gradle/libs.versions.toml — all dependency versions declared there
• @Suppress("DEPRECATION") used for monthNumber access on kotlinx.datetime.LocalDate — must include inline comment explaining reason
• UI text is in Chinese (weekday labels, month header format "2026年5月")
• Public @Composable functions require KDoc per COMMENTS.md
• Modifier parameter always last in composable signatures
• Callback parameters use on prefix (onDateClick, onMonthChanged)