Editor screen: Advanced scroll features about ghost

[matthojo]

Depending when you want it done, you can assign this to me.
I'll be pretty busy till the 22nd, but after that it is full steam ahead.

[JohnONolan]

Currently, scrolling the edit panel causes the preview panel to scroll at the same speed. However scrolling the preview panel does not scroll the edit panel.

Intentional!

A simple(ish) fix for this problem would be to scroll the two panels by the same percentage, rather than by the same distance. This should keep them more in sync, and at the very least they would both reach the end together.

That is exactly (to the letter) what is currently implemented.

A more complex fix would be to try to keep headings and other blocks aligned. Without investigating further the APIs provided by CodeMirror and showdown I'm not sure if or how this would be possible.

Agreed that would be better - also agreed that CodeMirror is not going to make this easy.

[ErisDS]

Currently, scrolling the edit panel causes the preview panel to scroll at the same speed. However scrolling the preview panel does not scroll the edit panel.

Intentional!

Ok, I raised this here because I've been using Ghost a lot (every wiki page and readme on GitHub was authored in Ghost) and I have found this to be a problem.

A simple(ish) fix for this problem would be to scroll the two panels by the same percentage, rather than by the same distance. This should keep them more in sync, and at the very least they would both reach the end together.

That is exactly (to the letter) what is currently implemented.

Odd.. it didn't seem to be happening for me. I need to review this and double check. However, if it is the case it's obviously not a great stop gap as it doesn't appear to work.

A more complex fix would be to try to keep headings and other blocks aligned. Without investigating further the APIs provided by CodeMirror and showdown I'm not sure if or how this would be possible.

Agreed that would be better - also agreed that CodeMirror is not going to make this easy.

Perhaps we should create an investigation task for this?

[JohnONolan]

This has become massively laggy/horrible for me - I think due to #297? Why are we doing that?

(I've bumped this up to the 0.3 Milestone just to make sure we get it at least working in a basic way)

[matthojo]

The debounce stops the 'advanced scrolling' from happening on every scroll event fired. This is probably the reason why it feels laggy. It should improve performance, so it is a case of finding the right amount of timing between each update so it stays visually smooth.

[ErisDS]

We might want to switch to throttle rather than debounce, have raised it as a bug as this issue is more to do with intelligent scrolling between the two panes.

[SoftwareDreamer]

It seems there were big improvements in codemirror4 in regarding to scrolling and layout perf, you might want to check it out:
https://groups.google.com/d/msg/codemirror/zQC6VQJuv20/IZXGi_Llv58J

[JohnONolan]

@ErisDS This issue becomes irrelevant with planned new editor features. Suggest close

[ErisDS]

Closing as wontfix against #1294

[fallerOfFalls]

@ErisDS:

Also, the preview panel scrolls the same amount, or to the same position as the edit panel. This appears to work well at first, but the content in the preview panel takes up different amounts of space, and in longer posts with lots of titles and code blocks the two panels quickly become out of sync visually.

Has this part of the issue been addressed?

[ErisDS]

@harpereaves no this was closed as a wontfix pending a different approach entirely

[fallerOfFalls]

ah ok, thanks!