MechCalc

MechCalc 是一款面向 Android 的本地优先计算工具箱。它使用 Flutter 构建界面与交互，将科学计算器、工程计算工具、函数图形、数据拟合、笔记和计算历史整合在一个轻量应用中。

项目目标是提供一个可以长期维护的移动端计算工作台：功能足够实用，数据默认留在本机，代码结构清晰，发布流程可复现。

Overview

MechCalc 适合日常计算、学习推导、工程估算、数据检查和移动端快速记录。应用不依赖云服务，计算历史、工具结果、笔记、收藏、最近使用工具和设置均存储在本机 SQLite 中。

当前 1.2 beta 预览版重点关注四件事：

• 清晰的计算体验：基础运算、科学函数、角度/弧度、记忆寄存器、光标编辑和数学符号显示。
• 实用的工具体系：覆盖数学、工程、电路、财务、物理、单位换算、编程、文本和数据处理。
• 可靠的数据管理：SQLite 持久化、笔记描述检索、历史去重、备份导出与导入前校验。
• 可维护的工程结构：Feature-first + Clean Architecture 简化分层，避免 UI、业务逻辑和数据访问混在一起。

Features

• Scientific calculator with basic arithmetic, common functions, less-used functions, constants, memory keys, haptic feedback, and responsive input.
• Function graphing with pan/zoom, multiple functions, zeros, intersections, local extrema, highlighted points, and selectable point details.
• Data Fit Chart tool for Excel-like list data, including multi-series input, axes, grid, fitted curves, residuals, R², and RMSE.
• Engineering and utility tools for math, electronics, mechanics, finance, physics, unit conversion, programming data, and text workflows.
• Notes and history backed by SQLite, with searchable title, description, body, calculation history, and tool history.
• JSON backup and restore with schema validation before database import.
• Light/dark theme support, stable release icons, optional haptics, and local state restoration.

Architecture

The project uses a simplified Feature-first + Clean Architecture layout. The intent is practical separation: UI handles interaction, application controllers coordinate state, domain code owns calculation rules, data code owns persistence, and core code contains shared math and formatting utilities.

lib/
├── main.dart                        # Flutter entry point
├── app.dart                         # App root, theme, settings, and shell wiring
├── application/                     # Controllers, application state, settings orchestration
├── core/                            # Math parser, formatting, platform helpers, shared utilities
├── data/                            # SQLite database, repositories, backup persistence
├── domain/                          # Entities, tool catalog, use cases, calculation logic
├── features/                        # Feature-first screens, widgets, animations, interactions
└── shared/                          # App chrome, theme, reusable presentation components

More details:

• Architecture
• File Structure
• Release Checklist

Requirements

• Flutter 3.x
• Android SDK
• Android Studio or a working command-line Android toolchain

Install dependencies:

flutter pub get

Run static checks and tests:

flutter analyze
flutter test

Run on a connected Android device:

flutter run

Build

Build a universal release APK:

flutter build apk --release

Build split APKs by ABI:

flutter build apk --release --split-per-abi

Release outputs:

build/app/outputs/flutter-apk/app-release.apk
build/app/outputs/flutter-apk/app-arm64-v8a-release.apk
build/app/outputs/flutter-apk/app-armeabi-v7a-release.apk
build/app/outputs/flutter-apk/app-x86_64-release.apk

Release Signing

Local debug builds can run without a release keystore. Public release builds should use android/key.properties, based on the template in android/key.properties.example.

The real keystore and android/key.properties must stay outside git. They are ignored by .gitignore.

storeFile=/absolute/path/to/mechcalc-release.jks
storePassword=change-me
keyAlias=mechcalc
keyPassword=change-me

Before publishing, run:

scripts/release_android.sh

The release script runs format checks, static analysis, tests, split APK builds, the universal APK build, artifact copying, and SHA-256 generation.

Data And Privacy

MechCalc is local-first. It stores app data in SQLite on the device and does not upload user data to a server.

Stored data includes:

• Calculator history
• Tool result history
• Notes with title, description, and body
• Favorite tools and recent tools
• Settings
• User-created backup files

Full privacy details are available in PRIVACY.md.

Android Studio

Open the repository root, the directory containing pubspec.yaml. The Android host project lives in android/.

If a local Flutter installation is missing packages/flutter_tools/gradle, the project can use the local .flutter/flutter_tools_gradle compatibility layer. That directory is machine-specific cache and is ignored by git.

Release

Current prerelease version: v1.2.0-beta.1

GitHub releases include split APKs for common Android ABIs and an optional universal APK:

• arm64-v8a for most modern Android phones
• armeabi-v7a for older 32-bit Android devices
• x86_64 for emulator and x86 Android environments
• universal when one APK must cover all supported ABIs

See CHANGELOG.md for release history.

Documentation

• Architecture
• File Structure
• Release Checklist
• Privacy Policy
• Changelog

License

See LICENSE.