# TaskbarCalculator

TaskbarCalculator is a C++/Win32 application for Windows 11 that sits in the notification
area (system tray) and shows an always-on-top calculator window driven by keyboard input.

The project started as a migration of a previous DeskBand (an in-process COM extension
hosted by the taskbar), which Windows 11 no longer loads for third-party shell extensions.
The current version is a standalone executable that adds a tray icon: left-click
shows/hides the window, right-click opens a menu with Show/Hide, Start at login, About, and
Exit. A global hotkey, **Win+Alt+C**, toggles the window from any application (if the
combination is already taken by another app it is silently ignored, and the tray click
still works).

**Supported platforms:** Windows 10 and later (start-at-login relies on the WinRT
`StartupTask` API, which requires Windows 10+).

## Code layout

- `App.cpp` — entry point (`wWinMain`), single-instance handling, tray icon, and hidden
  owner window.
- `CalculatorWindow.cpp/.h` — calculator window, keyboard input handling, number
  formatting based on regional settings, positioning and persistence.
- `Calculator.cpp/.h` — calculation engine, independent from the UI, based on a state
  machine (`init`, `first_oper`, `operation`, `second_oper`, `result`, `error`). Supports
  the four basic operations, square root, percentage, sign change, and reciprocal (1/x).
- `Settings.cpp/.h`, `StartupManager.cpp/.h`, `VisualStyle.cpp/.h`, `TrayIcon.cpp/.h`,
  `Utils.cpp/.h` — support modules (registry-based window position/visibility, start at
  login, classic/themed visuals, tray icon, misc utilities).

More detailed architecture and conventions are documented in `CLAUDE.md`.

## Build

Requires Visual Studio 2022 (v143 toolset), Windows SDK 10.0.26100.0, and the C++/WinRT
components for the start-at-login feature.

```
msbuild TaskbarCalculator.vcxproj /p:Configuration=Debug   /p:Platform=x64
msbuild TaskbarCalculator.vcxproj /p:Configuration=Release /p:Platform=x64
```

Build the `.vcxproj` directly, not the `.sln` (which references a setup project not
included in this repository). The executable is produced at
`x64\<Config>\TaskbarCalculator.exe`.

## Test

The calculation engine (`Calculator.cpp/.h`) is decoupled from the precompiled header and
is compiled and run separately with a small header-only harness:

```
tests\build-and-run.cmd
```

from an "x64 Native Tools Command Prompt".

## Packaging

Two distribution paths are supported:

- **Classic installer**: `Packaging\TaskbarCalculatorSetup.iss`, compiled with Inno Setup
  (`ISCC.exe`), or via the `Packaging\build-setup.cmd` script, which runs a Release x64
  build and compiles the installer in one step.
- **MSIX**: PowerShell scripts in `Packaging\` (`MakeAssets.ps1`, `MakeCert.ps1`,
  `BuildMsix.ps1`), kept for a possible future Microsoft Store submission.

In both cases, start-at-login uses the MSIX `StartupTask` API when the app is packaged,
falling back to the `HKCU\...\Run` registry value when installed via the classic path.

## License

Copyright (C) 2026 Marco Maroni

TaskbarCalculator is free software: you can redistribute it and/or modify it under the
terms of the **GNU General Public License version 3** as published by the Free Software
Foundation. See the [`LICENSE`](LICENSE) file for the full text.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
The GPLv3 is a strong copyleft license: any derivative work must also be released as open
source under a GPL-compatible license, and incorporating this program into proprietary
software is not permitted.