A small desktop application scaffold using Python and PySide6 (the official Qt bindings). Its interface is maintained in Qt Designer and it includes a main window, menu bar, blank central workspace, common keyboard shortcuts, and persisted window geometry. The application forces Qt's light Fusion palette, so it remains light even when the operating-system theme is dark.

Run it

Python 3.10 or newer is required. From this directory:

python -m venv .venv

Activate the environment:

Windows PowerShell: .venv\Scripts\Activate.ps1
Windows Command Prompt: .venv\Scripts\activate.bat
Linux/macOS: source .venv/bin/activate

Then install and launch:

python -m pip install --upgrade pip
python -m pip install -e ".[dev]"
python -m bedit

After installation, the bedit command also launches the application.

Project layout

.
├── pyproject.toml          dependencies, package metadata, and `bedit` command
├── README.md
├── ui/main_window.ui       editable Qt Designer source
└── src/bedit
    ├── __main__.py         supports `python -m bedit`
    ├── app.py              starts Qt and applies the forced light palette
    ├── main_window.py      behavior and signal connections
    └── ui_main_window.py   generated from the Designer file; do not hand-edit

Designing the UI further

The project now uses Qt Designer. It is included with PySide6 on most installations. Open the existing form with:

pyside6-designer ui/main_window.ui

In Designer, use the Widget Box to add controls, the Object Inspector to select them, and the Property Editor to name and configure them. Always put widgets in a layout (horizontal, vertical, grid, or form) so the window resizes correctly.

Save the form, close the running application if necessary, then regenerate its Python wrapper:

pyside6-uic ui/main_window.ui -o src/bedit/ui_main_window.py

Do not hand-edit the generated Python file; change the .ui file and regenerate it. Add behavior and signal connections in main_window.py. Widget names from Designer are available there through self.ui, such as self.ui.editor.

In VS Code, the same commands are available through Terminal → Run Task:

Qt: Open Main Window in Designer opens the form for visual editing.
Qt: Build Designer Files compiles resources and then regenerates the UI wrapper. It is the default build task, available with Ctrl+Shift+B.
The separate resource and UI compilation tasks remain available when only one generated file needs rebuilding.

A sensible next design pass

Sketch the main tasks and screens before choosing widgets.
Turn each major area into its own widget class in src/bedit/widgets/.
Use a QStackedWidget for page-like navigation, or QDockWidget for movable tool panels in an editor-style application.
Use reusable QAction objects for menu commands and any future toolbars.
Keep file/data operations outside widget classes as the application grows.
Add icons through a Qt resource file (.qrc) so packaging is reliable.
Test on Windows regularly; fonts, scaling, and native dialogs vary by platform.

Optional tools

You do not need another GUI framework. Useful additions are:

Qt Designer for drag-and-drop form layout.
Ruff for formatting/linting (ruff check .).
pytest-qt later for GUI interaction tests.
PyInstaller or Nuitka later to produce a Windows .exe.

The light colors are defined in apply_light_theme() in src/bedit/app.py. Adjust that palette if you want different light colors. Avoid a large stylesheet unless the application needs highly customized controls; palettes preserve more of Qt's standard behavior.