Creating player with isPlaying=true doesn't work

[cornerstonejs]

Creating player with isPlaying=true doesn't work

[dannyrb]

@dbousamra are you comfortable authoring a pull request to fix this issue?

[dbousamra]

Sure. Just wanted to check this was an actual issue and not something I was misunderstanding. What is the actual fix though? That conditional check: const shouldStart = isPlaying !== prevIsPlaying && isPlaying; is there for a reason, but I don't fully understand it. Presumably there as an optimisation to prevent calling playClip more than it needs to. However, not checking against prevIsPlaying seems to work fine, and I can't see anything immediately broken. Perhaps the call is idempotent and isn't an issue to spam call.

[dannyrb]

I think you've correctly identified the intent and the issue at hand. We default to false when we use this component in OHIF. After that, we make changes by toggling isPlaying or the frameRate; which is why we haven't observed this issue.

This is the logic for playClip: src/stackTools/playClip.js

Starts playing a clip or adjusts the frame rate of an already playing clip. framesPerSecond is optional and defaults to 30 if not specified. A negative framesPerSecond will play the clip in reverse. The element must be a stack of images

I think there's two ways we could fix this:

In componentDidMount, if isPlaying is true, we could call playClip. This takes care of setting the initial state based on props.

OR

In componentDidUpdate we remove the prevIsPlaying checks.

I think I prefer the first approach. It looks like if we call playClip for other prop updates, it would stop, update the settings, start. I'm unsure of how this would impact the behavior.

[dbousamra]

Thanks, this was a great summary. I've attached a PR that should fix things.

[ohif-bot]

🎉 This issue has been resolved in version 2.2.2 🎉

The release is available on:

• npm package (@latest dist-tag)
• GitHub release

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