gipson-dev/labelprinterapp

1. Overall shape: This is a single-process Windows desktop application built with C++/CMake + Qt 6. There is no server or cloud boundary; the app’s main responsibility is to turn label definitions and CSV data into raw ZPL and send that ZPL directly to a Zebra printer.

2. Core domain model: The core/ folder holds the app’s central data model. LabelTemplate, LabelElement, and PrinterSettings represent the editable label design and printer configuration. These are the objects that move through the rest of the system.

3. Template persistence boundary: TemplateStorage is the persistence layer for label templates. Templates are stored as JSON files under templates/, which makes them both user-loadable in the UI and easy to version/control as assets.

4. CSV ingestion boundary: CsvImporter reads external CSV files into row data for batch printing. The README indicates support for Quantity/Qty columns, selected rows, and full-file printing, so CSV data is not just imported but also drives print multiplicity.

5. Variable resolution layer: VariableResolver sits between data input and rendering. It resolves placeholders like {ItemNumber}, {Lot}, {Date}, {Time}, {Serial}, and {RecordIndex} against the current record or print context, so the same template can be reused across single labels, serial ranges, and CSV batches.

6. ZPL generation pipeline: ZplGenerator converts the template model into Zebra Programming Language. This is the key transformation step in the architecture: structured label elements and resolved variables become printer-ready command text. The repo includes docs/example_generated.zpl and label.zpl as concrete output/reference artifacts.

7. Printer output boundary: ZebraPrinter is the hardware-facing adapter. It sends the generated raw ZPL to a Windows printer configured for Zebra/ZPL output. The app’s printing model is therefore “generate ZPL locally, send it directly to the driver/printer,” not rasterize or spool through a separate print service.

8. Qt UI composition: The ui/ folder contains the interactive front end. MainWindow is the shell that exposes the app’s major modes/tabs: Design, Elements, Data, Print, Templates, and Settings. ElementEditorWidget edits the properties of the selected label element, and PreviewWidget is the visual label canvas.

9. Editing and preview flow: User interaction starts in the UI, updates the template model, and immediately feeds preview/rendering and later print generation. Dragging in the preview changes element placement; property edits change typography, barcode/QR options, rotation, alignment, wrapping, margins, and other label settings.

10. Batch-print flow: For CSV-driven printing, the flow is: import CSV → optionally map columns to template placeholders → select rows or choose all → resolve variables per row → generate ZPL per label → send to printer. This is the main data path for operational use.

11. Template library and examples: The templates/ folder contains ready-made label definitions such as inventory, shelf/bin, price, serial number, asset QR, and mini shipping labels. examples/sample_items.csv provides a sample batch input file. These assets define the “starter content” boundary of the app.

12. Validation and regression coverage: tests/model_zpl_tests.cpp suggests automated coverage around the model-to-ZPL transformation, which is the most critical non-UI logic in the system. That implies the core rendering/output behavior is intended to be stable independent of the UI.

13. Build and release tooling: The repository is packaged as a CMake project with Windows-focused scripts in scripts/, plus GitHub Actions workflows for build and release. windeployqt support in packaging indicates a Qt desktop distribution that bundles runtime dependencies into dist/LabelPrinterApp.

14. Architecture in one sentence: The app is a Qt desktop editor + batch-print tool where the UI edits a JSON-backed label model, CSV data fills template variables, core services generate ZPL, and a printer adapter streams that ZPL to a Zebra printer.