$ show KDE/kmymoney
KMyMoney is a mature, open-source personal finance manager for the KDE desktop environment. It provides double-entry accounting with support for multiple accounts, currencies, investments, loans, budgets, and scheduled transactions. The application features a plugin architecture for import/export (QIF, CSV, OFX, GnuCash, iCalendar), online banking (AqBanking, OFX Direct Connect, Woob), and storage backends (XML, SQLite with encryption). The core domain model includes MyMoneyTransaction, MyMoneySplit, MyMoneyAccount, and related entities, all built on Qt's model/view framework. The codebase is large (over 3600 files) and has been under active development for over two decades, resulting in a rich feature set but also some legacy patterns and conditional compilation for Qt5/Qt6 compatibility. The architecture is a monolithic desktop application with a well-defined plugin system, extensive unit tests for core data objects, and a sophisticated reporting engine with pivot tables and charts.
The LLM identified 5 files worth highlighting for reuse:
Implements financial formulas (NPP, PV, PMT, FV, interest rate) used for loan calculations. The class is self-contained with no internal dependencies on KMyMoney domain objects, making it extractable for any financial application needing amortization or time-value-of-money calculations.
Provides an efficient date-keyed balance cache for accounts. Uses a sorted vector of (date, balance) pairs with binary search for fast lookups. The implementation is isolated and could be reused in any application needing historical balance queries with O(log n) performance.
A QSortFilterProxyModel subclass that supports configurable multi-column sorting with custom less-than logic for financial data (e.g., sorting by date, amount, payee). The pattern of delegating sort roles to a separate sort-order object is reusable for any table view needing flexible sorting.
Implements a visual validation feedback mechanism that frames input widgets with color-coded hints (green/red) based on validity state. The WidgetHintFrame and WidgetHintFrameCollection classes are decoupled from the application logic and can be extracted as a reusable Qt widget validation library.
A generic key-value container with XML serialization support, used to store arbitrary metadata on financial objects (e.g., loan parameters, online banking settings). The implementation is self-contained and could be reused in any project needing a typed key-value store with persistence.