[macOS, Windows] Add support for excluding windows from a screenshot.

[bruvzg]

Adds flag to exclude window for screenshots taken by DisplayServer, allowing it to stay on to of the screen part that is captured.

Intended for better color picker and similar overlays (e.g., magnifier, color blindness simulator tool).

TODO:

• Use it for the Godot color picking controls.
• Check if it's possible to implement on X11 and Wayland as well.

Screen.Recording.2024-02-28.at.12.14.34.mov

[Riteo]

and Wayland as well.

There are only two (actively supported) ways of capturing the screen AFAIK: the wlroots protocol and the desktop portal.

The wlroots protocol (wlr-screencopy-unstable-v1¹) allows only grabbing the whole output or parts of it and it is supported, as the name implies, only on wlroots compositors (and mir apparently, whatever it is under the hood).

The portal instead depends on D-Bus (which we support :D ), XDG portals (which we support :DD ) and PipeWire (which we don't support yet :( ). It apparently supports multiple "sources"² but I'm not entirely sure how it's supposed to exclude things or if they work "dynamically"... Heh, we'll see.

I suppose we'll eventually have to implement both methods in general for screencasting (fallbacks and whatnot) but this specific window excluding logic could maybe be implemented only in the portal backend.

Footnotes

1. https://wayland.app/protocols/wlr-screencopy-unstable-v1 ↩

2. https://flatpak.github.io/xdg-desktop-portal/docs/doc-org.freedesktop.portal.ScreenCast.html ↩

[fire]

I am not familiar with the technical details, but from a usability point of view this is great.

[bruvzg]

Updated to incorporate #98411 changes (for both native and legacy picker):

Screen.Recording.2024-12-06.at.20.43.52.mov

Tested on both macOS and Windows (on Windows, exclude window for screenshots is global, and therefore it won't show on screen recording).

[Repiteo]

Thanks!

[WhalesState]

This Makes the picking unusable on Linux, not working at all, I have tried to fix it, but I couldn't exclude the picking popup from screen capture, the only way is to offset the picker window to the left or right based on mouse screen position or to hide the picking popup.

Screencast.from.01-08-2025.05.25.25.AM.webm

Should i open a new bug for this ?

Screencast.from.01-08-2025.03.04.55.AM.webm

[fire]

Please open a new bug.