Main View Model

Relevant source files

The following files were used as context for generating this wiki page:

• src/presentation/MainViewModel.cpp
• src/presentation/MainViewModel.h
• src/domain/SsaTypes.h
• src/presentation/FilterPanelViewModel.h
• src/presentation/SsaTableModel.h
• src/presentation/ColumnSettingsModel.h
• src/query/SsaQueryService.h

The MainViewModel serves as the central orchestrator for the SSA Consulta Rapida presentation layer. It coordinates various specialized sub-viewmodels, manages the application state (such as pagination, sorting, and UI preferences), and interfaces with the domain query services to fetch and display SSA (Solicitação de Serviço de Apoio) records.

As a QObject based class, it exposes properties and slots to the QML-based user interface, enabling a reactive data flow between the C++ backend and the visual components. It is responsible for handling high-level user actions like searching, navigating pages, and applying column configurations.

Sources: src/presentation/MainViewModel.h:23-25, src/presentation/MainViewModel.cpp:18-30

Architecture and Composition

The MainViewModel follows a compositional architecture, aggregating several specialized view models that handle specific UI concerns. This separation of concerns ensures that the main controller remains manageable while delegating specific logic to dedicated components.

Core Components

Component	Class	Responsibility
Search	SearchViewModel	Handles the global search text and trigger logic.
Filters	FilterPanelViewModel	Manages complex column-based filters and quick sector selections.
Table Data	SsaTableModel	A QAbstractTableModel implementation for displaying paged results.
Details	DetailsViewModel	Manages the display of the currently selected record's detailed fields.
Settings	ColumnSettingsModel	Handles visibility and width for data columns.
Status	StatusViewModel	Provides loading states, error messages, and result summaries.

Sources: src/presentation/MainViewModel.h:27-33, src/presentation/MainViewModel.cpp:33-59

Relationship Diagram

The following diagram illustrates how the MainViewModel aggregates its children and interacts with the domain service layer.

Data Query Flow

Data retrieval is handled asynchronously to keep the UI responsive. When a query is triggered (via apply(), load(), or pagination), the MainViewModel constructs an SsaPageRequest object and executes it using QtConcurrent.

Query Execution Sequence

This diagram shows the lifecycle of a data request from the UI trigger to the table update.

Request Parameters

The SsaPageRequest structure encapsulates all necessary data for the domain layer to perform the search:

• Pagination: pageIndex and pageSize (clamped between 10 and 500).
• Criteria: searchText, columnFilters (map), and quickSector.
• Sorting: SortSpec containing columnKey and ascending flag.
• View: visibleColumns list to optimize database selection.

Sources: src/domain/SsaTypes.h:15-17, src/domain/SsaTypes.h:105-114

State Management and Preferences

The MainViewModel manages persistent user settings through an IUserPreferencesStore. Changes to the UI state are often debounced and saved automatically.

UI Configuration Properties

Property	Type	Description
theme	QString	Current UI theme (e.g., "system", "dark").
density	QString	UI spacing density ("compact", "normal", "comfortable").
detailsVisible	bool	Toggle for the side details panel visibility.
detailsPanelWidth	int	Width of the details panel, clamped between 280 and 680.
pageSize	int	Number of records per page.

Sources: src/presentation/MainViewModel.h:34-42, src/domain/SsaTypes.h:18-20, src/presentation/MainViewModel.cpp:73-108

Persistence Logic

The view model uses a QTimer (preferencesSaveTimer_) set to 250ms to debounce save operations. When a preference-related property is changed, scheduleSavePreferences() is called, which starts the timer. On timeout, savePreferences() is executed asynchronously.

Navigation and Selection

The model provides standard paged navigation and record selection logic.

• Pagination: nextPage() and previousPage() increment or decrement the pageIndex_ before calling load(). Boundary checks are performed against pageCount().
• Sorting: sortByColumn(int column) retrieves the column key from the table model. If the same column is clicked twice, it toggles the sort order; otherwise, it defaults to ascending.
• Selection: selectRow(int row) updates the DetailsViewModel with the record at the specified index from the SsaTableModel.

Sources: src/presentation/MainViewModel.cpp:153-182

Summary

The MainViewModel acts as the engine of the presentation layer, bridging the gap between the stateless domain/query logic and the stateful user interface. It manages a complex lifecycle of asynchronous data fetching, preference persistence, and component coordination, ensuring that the UI remains consistent with the underlying data and user configurations.

Sources: src/presentation/MainViewModel.cpp:18-59, src/presentation/MainViewModel.h:23-50