Feature request: Let me opt out of web_sys preventDefaults on a per-event basis

[mcclure]

Description

I have a web app: https://data.runhello.com/j/wgpu/special/winit-swallow/
That URL is https://github.com/mcclure/webgpu-tutorial-rs/ commit a8fa378.
It is built with Rust + Trunk + winit + webgpu (so it will only work on Chrome or possibly Firefox Nightly).

It has a problem, which is that it swallows right clicks. So if I or a user want to look at the Chrome Inspector, they can't just right click the way they're used to.
I find the documentation explains that winit by default calls preventDefault() on every event; and if I add window.set_prevent_default(false); to line 979, right after initializing the window, then as documented winit will not do this, pass on the events, and right click works.

But, I do not want all events preventDefaulted! For example I don't want the scrollwheel to trigger, and I plan to add special behaviors for click-and-drag. There doesn't currently seem to be a way to request preventDefault for some events but not all.

So, here is my feature request: add to either Event<T> or ActiveEventLoop a function named like prevent_default_current(p: bool) which, if calls, overrides the set_prevent_default for the current event. That way I could default to preventing default, but prevent_default_current(false) on right-clicks specifically, and that way get the behavior I want in all cases with little hassle.

Relevant platforms

Web

[daxpedda]

This is a duplicate of #2831.
While we concluded there that it might not be needed to do fine-grained filtering because the only relevant use case is the clipboard, allowing the developer console specifically is a use case that might change this outlook.

Note that you can use WindowAttributes::with_prevent_default() to do this before creating the window.