Integrate httpgd

[nx10]

Update: To check the PR, you need to have httpgd installed and set options(vsc.use_httpgd = TRUE) in your .Rprofile.

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What problem did you solve?
This PR contains a very basic integration of httpgd to display plots.
It is intended to be a WIP PR and a continuation of (#614).

I added the implementation of a httpgd server connection backend drafted by @ManuelHentschel and removed the plot styling to make it compatible with all httpgd versions (current CRAN and GitHub master).

@ManuelHentschel will now implement a custom plot viewer that integrates with and uses vscode controls.
The development is also discussed in nx10/httpgd#63.

(This Post will be updated with screenshots and setup instructions as the development continues. Currently these are identical to #614 with the exception that all httpgd versions can be used.)

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Edit: The viewer now uses the new api and includes some buttons in the titlebar to control it. In particular, it's possible to toggle between the original svg and the vscode-themed svg using the "Toggle Style" button.

[renkun-ken]

Another thing I notice is that when a number of plots are produced, and I click one thumbnail to navigate to different historic plots, then there's a significant delay to show the plot (nearly 1-2 seconds).

Have you changed the settings r.httpgd.timeouts.refreshTimeout and/or r.httpgd.timeouts.resizeTimeout at some point? These can be used to control how eagerly the viewer redraws the plots and might help here. If changing these to a different value (e.g. both 100) doesn't help, please post the code that produces the laggy plots.

Cannot reproduce the delay on macOS. It is probably caused by the plot is a quite comprehensive with too many elements.

[renkun-ken]

With the latest commit, the resizing seems a bit problematic that if you repeat running the same plot (e.g. plot(rnorm(100))), then the main plot area is getting smaller and smaller.

[ManuelHentschel]

With the latest commit, the resizing seems a bit problematic that if you repeat running the same plot (e.g. plot(rnorm(100))), then the main plot area is getting smaller and smaller.

Thanks for noting!

[renkun-ken]

LGTM. Thanks for the great work!

[renkun-ken]

@ManuelHentschel Would you like to update README.md (https://github.com/Ikuyadeu/vscode-R#available-functions-and-options) so that user knows about the vsc.use_httpgd option?

[ManuelHentschel]

Thanks for the thorough testing and constructive feedback @renkun-ken!

[nx10]

Great work @ManuelHentschel!

[psobolewskiPhD]

The new feature works really well!
Kudos to all involved!

I have a couple questions:

1. Is it possible to have the vscode theme just do color and not override my font choice (here Fira Sans).
2. Is it possible to show/hide the history/thumbnails?
3. the ... menu allows for export, but just svg. Is there a way to to have PNG like the original httpgd functionality?

[ManuelHentschel]

Thanks for the feedback!

A quick way to achieve 1. and 2. is to e.g. comment out the line https://github.com/Ikuyadeu/vscode-R/blob/master/html/httpgd/styleOverwrites.css#L9 and change https://github.com/Ikuyadeu/vscode-R/blob/master/html/httpgd/style.css#L53 to display: none;. You can try this out by opening the installation directory of the extension (F1 > Extensions: Open Extensions Folder) and modifying the .css files directly.

I'll also add proper commands/options for this.

Regarding 3., in nx10/httpgd#69 a modular renderering approach is being implemented that will allow exporting to a number of different formats. When this is merged in httpgd, we'll also add corresponding options in vscode-R.

[psobolewskiPhD]

Thank you for the clear instructions!
Two more questions:
I'm not in love with the white outline text vs. just white.

I thought I'd comment out the stroke and add fill: white; but that didn't work.
Is that an easy fix?
Edit: Adding !important worked! Much better!

Edit2: If white is too bright for folks, could use an off shade, but the outlining—to me—ruins the letter spacing and is not good.

And more importantly—to me anyways—I hate the boxes around the legend. How can I turn that off?!?

[psobolewskiPhD]

I played around a bit more and got—to my eye—very nice results:

Editted styleOverwrites.css as follows:

Edit:
Better yet, I got rid of the outlines around the points!

I know, I'm drunk on power, deleting things!
But here's the new styleOverwrites.css

[nx10]

The dynamic styling is basically just a proof of concept at this point. I plan on adding a second SVG renderer to httpgd that allows for mich easier styling at the expense of slightly increased file sizes (nx10/httpgd#65). This will be included in the next update with the modular rendering.

(It might take a couple weeks/months as I am currently busy writing my masters thesis.)

[psobolewskiPhD]

Honestly, it works great and—with the tweaks I just made—for me it looks great!
I really like the ability to easily flip plots from light vs dark mode for display purposes—saving the plots uses the normal (dark on white) colors, which is perfect.
Wonderful feature.
Kudos to you @nx10 and @ManuelHentschel plus everyone else involved in this extension.

[nx10]

Thanks! @ManuelHentschel did most of the work on the vscode-r integration and the theming is completely his idea.