Add an History Panel

[PierreRaybaut]

Here is what an History Panel could looks like:

2024-07-22.13-46-56.mp4

Main features of the History Panel:

• Record all actions from signal/image creation to processing actions
• Ability to replay a single action or a sequence of actions
• Restore the selection state (optionally) before replaying the action
• Save/load history actions to/from the workspace HDF5 file

[PierreRaybaut]

Issue: Development Ideas for the History Panel

Branch: feature/history-panel

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Summary of Original Ideas (for posterity)

1. Action Tracking

   • Each action is represented as a line, allowing replaying the workflow from the start.
   • Actions are objects containing:
     • A description (displayed in the UI).
     • Method identifier (class name, method name) and associated arguments:
       • Dataset-type parameters.
       • Signal/image arguments replaced with local identifiers (e.g., s003).
     • An attribute with the DataLab workspace state:
       • Determines if the action can be executed.
       • Validates the number of signals/images and data array dimensions.
     • Serialization/deserialization methods for the action object.
     • A method to execute the action.

2. History Panel Management

   • Contains multiple lists of actions:
     • A new list is created each time the workspace is cleared.
     • Each list may have a default title based on the timestamp.
   • Handles backward compatibility:
     • Verifies action references upon initialization.
     • Removes incompatible actions, optionally warning the user.
     • Future support for backward compatibility by updating method/class names.

3. Widget Capabilities

   • Visualize the action tree: branches correspond to action lists.
   • Remove action lists or specific actions.
   • Display workspace state for each action:
     • Left: table of signals with data sizes.
     • Right: table of images with dimensions.
   • Highlight executable actions (with icons).
   • Execute actions or sequences from a compatible workspace state:
     • Replay actions with stored parameters or user-modified ones.
     • Support interactive execution (dialogs open with saved parameters).
     • Enable non-interactive execution (reuse parameters without dialogs).

4. Advanced Features

   • Button to generate macros from all or part of the history.

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Suggested Priority

• Critical:

  • Implement action serialization/deserialization and execution.
  • Add workspace state validation for actions.

• Medium:

  • Backward compatibility handling.
  • Widget enhancements for visualization and usability.

• Optional:

  • Non-interactive execution.
  • Macro generation.

[dappham-CODRA]

Implementation – Notable Deviations from Initial Scope
The following elements were added or improved beyond the originally specified requirements:

• Session navigation enhancements
  Introduction of navigation arrows between histoical items to improve usability when browsing history.

• Operational macro export
  Macro generation is not only available but fully functional and integrated with the dedicated macro tab.

• Improved action chaining logic (image/signal panel)
  -> Robust handling of action removal by automatically reconnecting adjacent steps in the chain.
  -> Specific handling of 2→1 transformations, where the first input is retained as the source.

• Consistency improvements
  Better synchronization between action descriptions, metadata, and parameters.

• Replay/edit mode correction
  Parameter dialogs are now strictly view-only during replay, fixing inconsistent edit/view behavior.

• Propagation fixes
  Correct update of all subsequent steps when an action is modified.

• Enhanced history persistence
  History saving now includes all required elements to ensure full operability when reloaded.

Pending work / technical debt

• Unit tests still need to be fully implemented and stabilized.
• An architectural refactoring is required, as the current implementation has grown too large and would benefit from better modularization and separation of concerns.

[dappham-CODRA]

Update architecture is done in this commit 3a55ab0 (2026-06-04).

• clean unit tests.
• auto record at launching

Added the ability to create a new session.
Added the ability to fully duplicate a session to facilitate comparison when modifying settings.
Improved session saving (panel history + session elements)

Improvement to do in the future:

• Icons more relevant
• Performance optimization

[dappham-CODRA]

Each of the above changes was made in response to an underlying issue (particularly in the case of the mode edit with the replay feature and the recalculation of the processing chain and its export).

A change was made to the replay in edit mode to display only the parameters.
You must edit the parameters directly within the processing panel (under signal/image view) or by deleting an element.

Note1: That some elements do not have processing; a more comprehensive redesign may be necessary to be edited - any regression.

Note2: Incorporating changes into the workflow might be useful (as a step), but this would require significant work on the history panel, which would then become a workflow panel.