[devtools.html] Range.getBoundingClientRect support

[jryans]

In meta-issue #8973 to get devtools.html loading, we noticed getBoundingClientRect is not supported yet.

CodeMirror (which we use as an editor throughout various parts of our tools) relies on this for various metrics and expects it to be available.

[Ms2ger]

getBoundingClientRect is defined on Element. Can you give some more context on how this breaks?

[jryans]

@bgrins, do you have more details about this? When running the latest servo-client branch, I did not see this error directly, but perhaps you have more local changes?

[bgrins]

I did have a workaround for #8981 locally but I've now pushed that in joewalker/devtools.html@b1cb205.

So if you pull the latest servo-client branch then do:

• ./mach run http://localhost:8081/client/framework/toolbox-wrapper.html
• Wait around for a couple of seconds
• I see this in the output: TypeError: range(...).getBoundingClientRect is not a function

[jdm]

This is Range.getBoundingClientRect, which isn't implemented yet:

// http://dev.w3.org/csswg/cssom-view/#extensions-to-the-range-interface
partial interface Range {
  // DOMRectList? getClientRects();
  // DOMRect getBoundingClientRect();
};

[jaysonsantos]

Hey @jdm I would like to try this one.

[jdm]

Please ask questions if anything's unclear. We can start with using the existing support for Element.getClientRects and Element.getBoundingClientRect and then extend it to support the special behaviour described for slices of text nodes.

[KiChjang]

Previous attempt in #10828.

[jryans]

@jdm can you assign this one to me? I'd like to give it a try.

[jdm]

It's already marked as assigned, and we can't set the assignee field to people who aren't part of the servo organization.

[jdm]

So yes, go ahead :)

[jryans]

In case anyone is wondering, I did make some progress toward an implementation here, but then I got stuck when I started writing tests and noticed that every engine seems to give different results for these APIs. I wasn't sure how to resolve that... If anyone has suggestions, maybe I can continue to push forward.

[paulrouget]

Isn't there some wpt test for getClientRects and getBoudingClientRect?

[jaysonsantos]

@jryans when I was trying to do it i created some sort of tests but every browser will return a different value which makes that a bit hard to do but here [1] is the closed pr.
[1] https://github.com/servo/servo/pull/10828/files

[Ms2ger]

Doesn't look like there's any tests for getBoundingClientRect on Range.

[jryans]

If someone wants to pick up where I left off with this, here's my branch:

https://github.com/jryans/servo/commits/range-client-rects