Don't use saved editor dialog size in single-window-mode.

[rcorre]

Fixes #75084.

If single_window_mode is enabled, trying to place editor dialogs with a saved size
often looks wrong if the main editor window has been resized.
This can result in windows being partially (or mostly) off-screen,
or just off-centered.

[rcorre]

It might be nice to re-position the dialog if the parent window size changes, but I checked godot3 and it doesn't do that either, so at least that part isn't a regression.

[YuriSizov]

I don't think this improves the situation meaningfully. If a dialog has a big enough size by default, it will still slide off of the screen. I think we should address this properly, instead of restoring a behavior to be similar to 3.x.

Dialogs need to respect the size of their parent window when embedded, and treat it as their max size. This should likely be an option, not a default behavior, as the opposite may still be useful in games and apps made with Godot.

[rcorre]

Thanks for the feedback @YuriSizov. I agree this isn't ideal, but I'm not quite following you. Are you saying that if popup is called with bounds that do not fit within the parent, it should adjust the bounds so they do? That is, we'd either (A) clamp the offending bounds or (B) shift the bounds?

[YuriSizov]

I think you follow me quite well :) IMO we should try both. If the size is within the parent's size, just slide it over. If it's bigger, then resize it to fit.

But again, this should probably be a flag on the Window node, and not the default behavior. We need it for the editor, but it may still be desirable for other projects to spawn windows out of frame.

Or it can be a new method that takes a rect2 and fits it into the Window's area. So you can use this feature dynamically instead, whenever you need to.

[rcorre]

Aha, it looks like my issue was a dupe of #37792.
8be16e0 added the necessary setting, but it wasn't actually set on any of the editor dialogs.

[rcorre]

NVM. 8be16e0 was just about being able to drag windows outside the editor bounds. clamp_to_embedder only applies to drag events. Should clamp_to_embedder also work on popup and parent window resize events, or should that be a separate setting?

[YuriSizov]

I think it should apply here, yes. If you can't drag a window outside, then I think it's safe to assume you don't want to spawn it outside either.

[rcorre]

I updated it so windows that are clamped to their embedder are now automatically shifted/resized on popup, and when the parent is resized.

In the recording, there's a lag when I resize the parent. That only happens when I'm recording, so I'm guessing it's something weird with X11 and SSR? It seems reponsive when I'm not recording the screen.

ssr-2023-03-24_21.12.37.mp4

[YuriSizov]

This looks great to me! Will wait a bit for another review, but this should be good to merge.

[YuriSizov]

Thanks!