clickOnTrack should jump in chunks of just under the height of the viewport

[vitch]

This seems to be how native scrollbars behave. So you can easily click once on the track and it will jump down a page and you can carry on reading from where you had got up to.

[aivopaas]

This is fixed in my pull request.

[vitch]

Pulled in aivopaas's changes... However, I'm still not sure that the behaviour is the same as with a native scrollbar. It currently scrolls a percentage of the height of the viewport when you click on the track. You can set scrollPagePercent to set this percentage. However, the native implementation seems to scroll "100% minus one line height" regardless of the height of the viewport... I'll look into implementing this alternative behaviour as soon as I have a chance...

[aivopaas]

It depends on the browser. On Chrome, it actually does scroll about 80% of the container's height. So, when you have 5 lines visible, it sure does scroll 1 line less than viewport, but having tested with higher containers, it leaves more lines of old content visible.
Firefox seems to be on the "one old line" side. So there are at least 2 different native implementations. I like when there's a little more than a single line lef so you don't have to read exactly to the bottom.
And of course, I have nothing against making it configureable.