Add a document outline widget for R Markdown documents

[kevinushey]

Not ready for merge but basic functionality is there (so we can start discussing styling + other behaviours + UI we might like)

Some of the nice features so far:

• Click to navigate to chunk
• Chunks that are currently visible get a different UI treatment

TODO

• Include a tab bar above the outline widget
• Consider sub-items for chunks (e.g. functions)
• Use appropriate icon for tree entries [decided to use no icon]
• Add an icon to show / hide the outline for the document widget
• Optimize scope tree updates (don't re-generate the scope tree on every render)
• Option to allow outline to track editor position (e.g. as the user scrolls)
• Other styling
• Add markdown headers to scope tree
• Handle sub-headers in Markdown
• Latch the outline icon
• Use vertical bar instead of background color for active chunk
• Inherit colors from current editor theme
• UI / document preference for the outline widget size

[znmeb]

Nice! I could really use something like this - I'm trying to write a book and a good outliner like LyX has is pretty much mandatory.

[jjallaire]

Fantastic! I'll send Paul on email on Monday morning to start tweaking out
the UI.

On Fri, May 29, 2015 at 6:09 PM, M. Edward (Ed) Borasky <
notifications@github.com> wrote:

Nice! I could really use something like this - I'm trying to write a book
and a good outliner like LyX has is pretty much mandatory.

—
Reply to this email directly or view it on GitHub
#436 (comment).

[kevinushey]

Great! FWIW here's what things look like right now:

We should make it clear that we would like to support a generic tree-based view as well (ie not just top-level chunks in the display)

[znmeb]

Will it have the usual outliner UI? Indent, outdent, drag nodes, cut, paste, etc.?

[jjallaire]

We won't do that now (it will just be an outline view) but we'll definitely
consider adding more interactivity after we get the initial version out.

On Sun, May 31, 2015 at 1:23 AM, M. Edward (Ed) Borasky <
notifications@github.com> wrote:

Will it have the usual outliner UI? Indent, outdent, drag nodes, cut,
paste, etc.?

—
Reply to this email directly or view it on GitHub
#436 (comment).

[kevinushey]

Okay, the widget is getting pretty close (coordinating hide + show events unfortunately requires a surprising amount of plumbing -- I'm not sure if there's a better way to handle this or not):

Once I'm sure that the chevron behaves well when showing + hiding the outline I think we should be close to merge.

[kevinushey]

@jjallaire, I think this should be good to go (at least for the dailies). There's likely other refinements / changes we'll want to make but I think it's good enough that we can expose people running the dailies now. (It would also be good to get more feedback from e.g. @hadley)

[jjallaire]

We're not quite ready for merge (see the shared document for various bugs I found and some small appearance tweaks).

[rmflight]

Will y'all comment what daily build this gets incorporated into? Really looking forward to seeing this in action.

[kevinushey]

Thanks @jjallaire -- I'll start tracking these down and ping you once I've fixed them.

@rmflight, we'll comment after this gets merged + what daily build it appears in.

[kevinushey]

Okay @jjallaire, I think this should be go -- I resolved the bug(s) you reported earlier (basically due to Qt WebKit not implementing startsWith on the String prototype) and tweaked the display.

Here's what it looks like now:

Can you give it another quick spin and merge if you think all looks well?

[jjallaire]

@rmflight The latest daily build (v0.99.585) has the outline view (note there is no windows version yet, the build failed for some reason). http://www.rstudio.org/download/daily/desktop/