Hmm, this seems quite obscure and is fairly easily achievable with the objc module, e.g.

const objc = require('objc')
const nativeWindowHandle = mainWindow.getNativeWindowHandle().readPointer()
const nsview = objc.wrap(nativeWindowHandle)
nsview.window().invalidateShadow()

I'm not necessarily against adding this API but I'd like to understand a bit more about whether we can avoid adding it!

@codebytere can you rebase this? that should get rid of the linux failure

@jkleinsc done!

Let's investigate whether there's a way we can automatically behave correctly instead of requiring the user to give this signal.

I haven't been able to find a way that this could be automatically triggered, so API LGTM.

I haven't been able to find a way that this could be automatically triggered, so API LGTM.

@nornagon why can't we call this internally whenever users are expected to call it? I'm not sure I fully understand when / how frequently users are expected to call this though, could you please explain that?

I haven't been able to find a way that this could be automatically triggered, so API LGTM.

@nornagon why can't we call this internally whenever users are expected to call it? I'm not sure I fully understand when / how frequently users are expected to call this though, could you please explain that?

Users should call this method when the outline of their window has changed. The vast majority of apps never need to call it.

Users should call this method when the outline of their window has changed. The vast majority of apps never need to call it.

@nornagon then we should be able to run an event handler when the outline of the window changes only for transparent windows that just calls this function. That way, we can abstract away this functionality from our users.

Users should call this method when the outline of their window has changed. The vast majority of apps never need to call it.

@nornagon then we should be able to run an event handler when the outline of the window changes only for transparent windows that just calls this function. That way, we can abstract away this functionality from our users.

Yep! The only catch is, there's no such event, as far as I can tell. Chromium doesn't tell us when the outline of the window changes.

Users should call this method when the outline of their window has changed. The vast majority of apps never need to call it.

@nornagon then we should be able to run an event handler when the outline of the window changes only for transparent windows that just calls this function. That way, we can abstract away this functionality from our users.

Yep! The only catch is, there's no such event, as far as I can tell. Chromium doesn't tell us when the outline of the window changes.

@nornagon ah, but then how are users going to figure out when this API should be called if we can't expose a listener for the outline changing event?

Any progress?

@RaisinTen you've misunderstood when the function needs to be called; it's not just when the window is moved or resized, but whenever the outline of the window changes. in this example, that happens whenever the number is updated, or when the window scrolls.

I think this is reasonable to land; we've looked for a different way to do it and haven't found one. It makes sense to allow apps to invalidate their window shadows when they know the window shape has changed.

Release Notes Persisted

Exposed window.invalidateShadow() to clear residual visual artifacts on macOS.

I have automatically backported this PR to "23-x-y", please check out #36533

Can this be merged into 20.xy and 21.xy ?

@codebytere Can this be merged into 20.xy and 21.xy ?

@codebytere @RaisinTen Electron 23 no longer supports Windows 7, can this PR be merged into 22.x.y? I want to try this API :)