This patch introduces a new protocol proxy, which multiplxes Wayland
clients into a single connection, allowing us to redirect calls (e.g.
create toplevel -> create subsurface). Mixed with some state tracking
and emulation, we can embed a full-featured client into the editor.
Previously, on Linux and BSD, inhibiting the screensaver was handled
using the org.freedesktop.ScreenSaver D-Bus API. Unfortunately, this API
is not available in a Flatpak sandbox. (This is because there is a
desire to tie inhibit sessions to a specific app and visible window; but
the org.freedesktop.ScreenSaver API does not support this.)
As a result, when using the Flatpak build of the Godot Editor (or a
Flatpak-ed build of a game) and using a controller to play a game, the
session will become idle after a few minutes.
The XDG desktop portal -- which is already used for color-picking, file
choosing, and querying the system theme -- has an Inhibit interface that
provides a superset of the functionality of the
org.freedesktop.ScreenSaver API, and is available to any sandboxed app.
Refactor code for making XDG portal requests that was previously
duplicated for the FileChooser and ColorPicker portal code. Check the
portal version to determine whether these portals can be used:
- FileChooser portal version 3 is required due to the use of the
"directory" parameter.
- On the Settings portal, the only addition in version 2 is the
ReadOne() method which is not used here, so version 1 suffices.
- On the Screenshot portal, the only addition in version 2 is the
"interactive" parameter to the Screenshot() method; this code only
uses the PickColor() method, so version 1 suffices.
Then, add support for the Inhibit portal. Use it if available and if
running in a sandbox. Prefer to use org.freedesktop.ScreenSaver if not
running in a sandbox, even if the portal is available, because (at least
in the GNOME 43 implementation of the portal) it does not work correctly
if the portal cannot map the request to a running app. This adds a small
amount of complexity to the implementation, but supporting both APIs is
necessary anyway (there are many systems in the wild that support
org.freedesktop.ScreenSaver but not the desktop portal).
Fixes https://github.com/godotengine/godot/issues/108634
On OS with Chinese locale, you might receive the following message
when running an editor using the `--verbose` option:
```
ERROR: Error on D-Bus communication: æªæ ¾å°è¯·æ±ç
设置
at: read_setting (platform/linuxbsd/freedesktop_portal_desktop.cpp:144)
```
