Setting play to true in NGL trajectory viewer by default

[Taylor-96]

Hello,

I was wondering if it is possible to have the animation of a trajectory shown in an NGL viewer set to play by default rather than requiring the user to press play first? On a similar note, would it also be possible to have looping set to true by default at initialization of the viewer? Cheers!

[hainm]

hi @Taylor-96

Please adapt below code. It should reply to two of your questions:

import nglview as nv
from nglview import SimpletrajTrajectory

traj = SimpletrajTrajectory(nv.datafiles.XTC, nv.datafiles.PDB)
view = nv.show_simpletraj(traj)

stop = False
def loop(view):
    import time
    def do():
        while True and not stop:
            if view.frame == view.max_frame:
                view.frame = 0
            view.frame = view.frame + 1
            time.sleep(0.2)
    view._run_on_another_thread(do)
        
view.on_displayed(loop)
view

To stop, just stop = True in another notebook cell.

Cheers

[Taylor-96]

Hi, thanks a lot - that works great. I was just wondering if there is a way to access the values/status of the play button and loop button so that it is possible for the user to stop the animation by pressing the play button rather than manually putting stop=True in another cell?

Thanks again!

[hainm]

Hi, thanks a lot - that works great. I was just wondering if there is a way to access the values/status of the play button and loop button so that it is possible for the user to stop the animation by pressing the play button rather than manually putting stop=True in another cell?

Thanks again!

I don't know a solution on top of my head. You can access to the player via view._iplayer.children[0]. It's ipywidgets' Play https://ipywidgets.readthedocs.io/en/stable/examples/Widget%20List.html#Play-(Animation)-widget

https://github.com/nglviewer/nglview/blob/master/nglview/widget.py#L300-L303

[Taylor-96]

Hi, thanks a lot for the suggestion and for the help with this problem. I'll look into using this to update the status of the player then.

Best wishes,

Taylor