BUG: Scrollable onStart/onEnd/updateTarget not Overridable

Version: 0.17.3

Are you able to reproduce the bug from the demo?

• Yes
• No

What is the expected behavior?

Being able to override onStart, onEnd, and updateTarget in a component's model.default.scrollable, as detailed in the documentation.

Describe the bug detailed

I have created a component that extends ComponentImage. The content is not a static image but rendered as necessary, and when the destination size changes, it has to be rerendered.

According to the documentation, I should be able to define onEnd in model.default.scrollable to trigger the rerender from there after the resizing is done (I don't want to continually redraw while the user is still resizing).

What is the current behavior?

When I define any onEnd function, it overrides the onEnd defined in SelectComponent.js, which breaks the whole state machine there. For example, since toggleFramesEvents is no longer called, the whole iframe is wrapped in pointer-events: none and thus doesn't respond to any user interaction any more.

Describe the bug detailed

Since this is not a class I'm overriding, but just some inline functions that get overwritten, I can't call the parent function, since it doesn't exist any more within the scrollable. I also can't copy/paste the content of the parent function into mine, because it references local variables I don't have access to.

The same issue exists with all other functions that are defined in SelectComponent.js there, which are onStart, onMove, and updateTarget.