Projects:ARRA:SlicerEM:Developer:WorkflowManager

Summary

• EMSegmenter has a fairly complicated workflow
• Need a mechanism to validate user input and transition appropriately between steps of the workflow
• Should be dependent on Qt only (and not VTK)
• Current plan (subject to change) = use Qt's state machine implementation, with our own workflow manager on top

Previous workflow manager implementation in KWWidgets

• Please see the documentation here, as it is already well described

Uses:

• KWWidgets state machines - incorporates states (ex. user interaction within a workflow step, validation of the user input within a workflow step), transitions (between states), and inputs (pushed onto a queue to trigger transitions)
• KWWidgets wizard workflow - provides additional functionality to manage workflow using a state machine (ex. bundles pairs of user interaction and validation states into a workflow "step", handles a navigation stack of steps encountered along the way that triggers updates of widgets and/or dialogs)

Transition from KWWidgets state machines to Qt state machines

• Core functionality in KWWidgets state machines that would be replicated for a "straight-forward" conversion:
  • Representation of

Transition from KWWidgets workflow manager to a workflow manager using Qt's state machines

• Will likely need to reimplement the four KWWidget workflow manager classes:
  • vtkKWWizardStep: a wizard step
  • vtkKWWizardWorkflow : a wizard workflow
  • vtkKWWizardWidget : a wizard widget, embedding UI (buttons) and a wizard workflow engine
  • vtkKWWizardDialog : a wizard dialog, embedding a wizard widget in a toplevel/dialog window.

GUI implementation in Qt

• qStackedWidget and/or qTabWidget
• plus qDialog

Considerations to keep in mind

• Undo / redo and forward/back transitions
• Branching workflows / skipped states