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Extends live source concept with emulated time algorithms


The goal of this MR is to expend live sources capabilities, with a new emulated time algorithm.

This changes allow being able to simulate real time for an algorithm (and therefore skip frames if necessary). An example for this algorithm could be: a LiveSource stream was recorded in a file, and I want to be able to replay it in the same condition / at the same speed.


  • Introduce a new class pqLiveSourceItem, which interacts with a live source proxy and has its own pqTimer. This design allows for the management of independent pqTimers for each LiveSource, enabling them to be refreshed at different intervals.
  • Add a LiveSource manager that can be accessed from pqPVApplicationCore. pqLiveSourceBehavior is now only used to enabled it.
  • Add a new vtkAlgorithm vtkEmulatedTimeAlgorithm, intended to be inherited by a temporal algorithm. This base class would be then used in the live source behavior to:
    • Get the time range of the reader with GetTimeRange
    • Update the current time with a modified GetNeedsUpdate that takes the shared "real" time. If the new time falls within the time range, the algorithm is updated accordingly.
  • Implement the concept of a shared "real" time in live sources. This time is synchronized among vtkEmulatedTimeAlgorithm (via LiveSource mecanism) and it skip any timesteps gaps if needed.
  • Update pqPauseLiveSourcePropertyWidget to only pause the current live source and add emulated time controls if the proxy is an emulated time algorithm (play/pause/reset). image

Issue related

Fixes #22229 (closed)

Edited by Timothée Couble

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