[CEF 2171][Mac] Weird project tree scrollbar behavior

[redmunds]

I noticed this running (Client) Smoke Tests Steps 11 & 12.

On Mac 10.8, the I open the brackets repo and expand the project tree so that scrolling is required to see entire tree.

Scrollbars do not show up when I mouseover the tree! They only show up when I mouseover the scrollbar itself (and only if I mouseover scrollbar thumb, not if I mouseover scrollbar where there is no thumb).

Scrollbars do not go away when I mouseover or give focus to editor. The only way i've found to make scrollbars go away is if I mouseover resizer between left sidebar and editor, and then only adjacent to thumb.

Note: I'm using an external mouse

[RaymondLim]

I can repro with external mouse in cef 2171 build, but not in release 1.0 that used an older cef.

[ingorichter]

I can easily repro this without a mouse on 10.9. :-(

[JeffryBooher]

This occurs for the Project Tree in 10.9 for me with an external mouse but not the working set view or the Editor. It is very intermittent for me in the Project Tree but when it does occur the "Selection Extender" doesn't scroll with the selected element in real time -- it's very slow which makes me think it's a Javascript VM throttling issue. Nothing in the JS Console

[RaymondLim]

If you click on a file in the working set and then making edit in the document, then you will see the vertical scroll bar shows up in the working set. For project tree, if you select one file in there, then you will see vertical scrollbar on scrolling, but disappears once you stop scrolling.

[redmunds]

I'm seeing the same problem in the Working Set.

[RaymondLim]

On 10.8 without mouse I'm now seeing two separate thumbs in the project tree on scroll. The normal one on top and a smaller one below the selected file. The smaller one is the one that I see when an external mouse is used.

[peterflynn]

@redmunds That's a really valuable observation -- the DOM in the working set is much simpler than the file tree, so it should be much easier to isolate & test out fixes there.

[RaymondLim]

@redmunds I can also reproduce it in @peterflynn's http://jsfiddle.net/668m2L7r/. Make sure you click on Run button again if you just plug in the external mouse. Otherwise, you will still see the scroll bar that shows up at the time the mouse was plugged in.

[pthiess]

Milestone: moving to 1.2 -- not enough time.

[prksingh]

A quick fix I could think of was to move the hover behaviour from scroll-bar to the container div. Essentially we can make the scrollbars always visible and set overflow to hidden for the project tree which changes to overflow: auto on hover. I have pushed these changes to branch prksingh/issue-10175.

A side effect of this is that if the brackets app is not active or without focus scroll will not work for project tree on hover (similar to windows default behavior). This could be a problem on multiple monitors

[nethip]

Seems like CEF2171 broke this and it is easy to repro this outside Brackets. Moving this to 1.3 as this still needs some thinking to solve the actual problem.

[prafulVaishnav]

Its an CEF issue. I have got temporary fix which we can integrate till we update CEF. PR : #10592

[prksingh]

Most common cases for this issue should be fixed with #10592 There is still a case where the issue can be reproduced but its a rare case. Reducing priority and moving out of release

[peterflynn]

@prksingh Just for posterity, what are the steps for the one remaining repro case?

[redmunds]

@peterflynn The other case is described in pull request.

[peterflynn]

Ah, got it. That seems minor enough.