web_sys: missing set_transform with matrix function

[stephanemagnenat]

Motivation

The function setTransform on Canvas 2D can accept a matrix on modern browsers. This is currently not exposed in web_sys. However, the sister function getTransform is exposed.

Proposed Solution

Expose a set_transform_with_matrix function, to match the get_transform ones.

[daxpedda]

Isn't it this one: https://docs.rs/web-sys/0.3.64/web_sys/struct.CanvasRenderingContext2d.html#method.set_transform?

[stephanemagnenat]

No, if you look at the documentation page, there is a second version that takes a single DomMatrix parameter, and that was introduced at the same time getTransform was.

So I find it illogical that web_sys provides get_transform but not that second version of set_transform.

[daxpedda]

Thanks!
Made a fix here: #3580.

[stephanemagnenat]

Thank you for the very fast answer!

A small question, get_transform returns a DomMatrix while the new set_transform takes a DomMatrix2dInit, are these compatible? A typical use as described here is to combined these two functions to save and restore the canvas transformation matrix.

[daxpedda]

It should work, because DOMMatrixInit inherits DOMMatrix2DInit, unfortunately our WebIDL generator doesn't support inheritance on dictionaries. I think you can just use unchecked_into().

Btw, if you want to create a PR implementing this conversion I'm happy to review it.