Screenshots / gif / video?

Step left/right buttons are broken. I think the button should be at the top of the step and never move vertically.

I'll try putting it on top and see if it helps.

The Mask step shouldn't have the expand/contract arrow because it doesn't actually do anything. I think you should only have it for steps that have user controls (sliders, checkboxes, etc).

Something like

if (step.getOperation().getInputSockets().stream()
    .map(Socket::getView)
    .anyMatch(view -> !view.equals(View.NONE)) {
  // This step takes user input, add the collapse/expand arrow
}

Current coverage is 58.17% (diff: 98.30%)

Merging #639 into master will decrease coverage by 0.77%

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I'm pretty happy with this. Let me know if you think anything can be improved.

Sockets are not returned to their original locations right now: https://www.youtube.com/watch?v=3We9orzIyb0&feature=youtu.be

This might be beyond the bonds of this pr but an animation would be a cool thing to add to this.

I agree that it would be cool but it's probably better to just get this working and add the animation later in a different pull request.

See: http://stackoverflow.com/questions/13990664/how-to-make-a-vbox-with-animated-close-up

Should be able to call input.getRoot().setVisible(false) for each unconnected input, then collapse the pane containing the inputs

The animations are really nice! But I've found some problems with it