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The Graphical Interface

The GUI is built with PyQt6 (through qtpy for cross-toolkit compatibility) and reuses PyMeasure's managed-window machinery. It lives in laser_setup/display/. There are three windows and a handful of reusable widgets, all driven by CONFIG.Qt.

Entry point: display_window()

display/app.py:display_window(procedure=None) is the single GUI entry point. It:

  • creates the QApplication singleton,
  • shows the splash screen,
  • applies the configured style, palette (dark mode) and font from CONFIG.Qt.GUI,
  • installs a global ShortcutFilter for keyboard shortcuts, and
  • opens either the MainWindow (no procedure) or an ExperimentWindow (a procedure class/instance).
Shortcut Action
Ctrl+W Close the current window
Ctrl++ / Ctrl+- Zoom in / out
F11 Toggle maximize

Main Window

display/windows/main_window.py is the hub. Its menu bar is generated entirely from configuration:

Menu Built from Opens
Procedures CONFIG.procedures._types an ExperimentWindow (Ctrl+1, Ctrl+2 …)
Sequences CONFIG.sequences._types a SequenceWindow (Ctrl+Shift+1 …)
Scripts CONFIG.scripts runs a function (Alt+1 …)
View — database browser, camera, terminal, logs
Config — edit / import / export configuration
Help CONFIG.instruments per-instrument docstrings

It also shows the project README in the central panel and a status bar with a red Reload button (Ctrl+R) that becomes active when configuration changes. A background Worker thread polls a status message periodically.

Why a Reload button?

CONFIG is read once at startup. Editing config (in a file or via the Config editor) requires a reload to rebuild it, which restarts the window.

Experiment Window

display/windows/experiment_window.py subclasses PyMeasure's ManagedWindowBase and runs one procedure with live visualization.

On construction it validates that the procedure has at least two DATA_COLUMNS (the first two become the default x/y axes) and builds:

  • a Plot widget (x vs y, with axis selectors),
  • a Dock of stacked plots (Qt.ExperimentWindow.dock_plot_number),
  • a Log widget capturing the run's log records,
  • a Text/Info widget rendering Qt.ExperimentWindow.info_file (Markdown).

When you press Queue:

  1. a Results object is created with a unique filename (see Data & Output Files),
  2. the procedure's patch_parameters() hook runs,
  3. PyMeasure's manager runs startup() → execute() → shutdown() in a background thread, streaming emit('results', …) to the plots and emit('progress', …) to the progress bar.

Procedures derived from BaseProcedure also get a Shutdown button that calls instruments.shutdown_all() for a safe power-down.

Dark-mode plots

In dark mode the plot backgrounds are set to black explicitly, because pyqtgraph defaults to a white canvas (which would hide light-colored curves).

Sequence Window

display/windows/sequence_window.py runs a chain of procedures. It reads a Sequence class (.procedures, .common_procedure, .inputs_ignored) and builds:

  • a common-parameter panel (inputs shared by all steps), and
  • a column per step with its unique inputs, a color-coded status icon, and two timers (time-in-step + and cumulative =).

Queue runs each step in order using a blocking event loop (the window stays responsive to abort but processes steps sequentially). On failure it shows an abort dialog with a countdown (Qt.SequenceWindow.abort_timeout). Instruments are shut down after the final step. See Sequences.

Widgets

display/widgets/ provides the reusable pieces:

Widget Role
InputsWidget Parameter input form (wraps PyMeasure's, accepts a class or instance).
LogWidget / LogsWidget Live, colorized log capture.
TextWidget Read-only Markdown/text viewer (the Info tab, README).
SQLiteWidget Browse the parameters database in a sortable table.
ConfigWidget Edit CONFIG as a parameter tree and save back to YAML.
CameraWidget Live camera feed (OpenCV) — e.g. to watch the sample/laser spot.

Threading model

  • PyMeasure's manager runs each procedure in its own background thread, so the GUI stays responsive during a measurement.
  • The Worker helper (display/Qt.py) runs short background tasks (camera scanning, status polling) on a QThread and signals completion.
  • The SequenceWindow intentionally drives steps from a blocking event loop so it can monitor them one at a time.

Configuration cheat-sheet

All window behavior is under CONFIG.Qt:

Qt:
  GUI: {style, dark_mode, font, font_size, splash_image}
  MainWindow: {title, readme_file, size, widget_size, icon}
  ExperimentWindow: {title, inputs_in_scrollarea, dock_plot_number, info_file, icon}
  SequenceWindow: {abort_timeout}

See the Configuration reference for defaults.