fn set_fullscreen_inner()

in src/platform_impl/linux/x11/window.rs [586:705]

• 87 lines of code
• 5 McCabe index (conditional complexity)

    fn set_fullscreen_inner(&self, fullscreen: Option<Fullscreen>) -> Option<util::Flusher<'_>> {
        let mut shared_state_lock = self.shared_state.lock();

        match shared_state_lock.visibility {
            // Setting fullscreen on a window that is not visible will generate an error.
            Visibility::No | Visibility::YesWait => {
                shared_state_lock.desired_fullscreen = Some(fullscreen);
                return None;
            }
            Visibility::Yes => (),
        }

        let old_fullscreen = shared_state_lock.fullscreen.clone();
        if old_fullscreen == fullscreen {
            return None;
        }
        shared_state_lock.fullscreen = fullscreen.clone();

        match (&old_fullscreen, &fullscreen) {
            // Store the desktop video mode before entering exclusive
            // fullscreen, so we can restore it upon exit, as XRandR does not
            // provide a mechanism to set this per app-session or restore this
            // to the desktop video mode as macOS and Windows do
            (
                &None,
                &Some(Fullscreen::Exclusive(RootVideoMode {
                    video_mode: PlatformVideoMode::X(ref video_mode),
                })),
            )
            | (
                &Some(Fullscreen::Borderless(_)),
                &Some(Fullscreen::Exclusive(RootVideoMode {
                    video_mode: PlatformVideoMode::X(ref video_mode),
                })),
            ) => {
                let monitor = video_mode.monitor.as_ref().unwrap();
                shared_state_lock.desktop_video_mode =
                    Some((monitor.id, self.xconn.get_crtc_mode(monitor.id)));
            }
            // Restore desktop video mode upon exiting exclusive fullscreen
            (&Some(Fullscreen::Exclusive(_)), &None)
            | (&Some(Fullscreen::Exclusive(_)), &Some(Fullscreen::Borderless(_))) => {
                let (monitor_id, mode_id) = shared_state_lock.desktop_video_mode.take().unwrap();
                self.xconn
                    .set_crtc_config(monitor_id, mode_id)
                    .expect("failed to restore desktop video mode");
            }
            _ => (),
        }

        drop(shared_state_lock);

        match fullscreen {
            None => {
                let flusher = self.set_fullscreen_hint(false);
                let mut shared_state_lock = self.shared_state.lock();
                if let Some(position) = shared_state_lock.restore_position.take() {
                    drop(shared_state_lock);
                    self.set_position_inner(position.0, position.1).queue();
                }
                Some(flusher)
            }
            Some(fullscreen) => {
                let (video_mode, monitor) = match fullscreen {
                    Fullscreen::Exclusive(RootVideoMode {
                        video_mode: PlatformVideoMode::X(ref video_mode),
                    }) => (Some(video_mode), video_mode.monitor.clone().unwrap()),
                    Fullscreen::Borderless(Some(RootMonitorHandle {
                        inner: PlatformMonitorHandle::X(monitor),
                    })) => (None, monitor),
                    Fullscreen::Borderless(None) => (None, self.current_monitor()),
                    #[cfg(feature = "wayland")]
                    _ => unreachable!(),
                };

                // Don't set fullscreen on an invalid dummy monitor handle
                if monitor.is_dummy() {
                    return None;
                }

                if let Some(video_mode) = video_mode {
                    // FIXME: this is actually not correct if we're setting the
                    // video mode to a resolution higher than the current
                    // desktop resolution, because XRandR does not automatically
                    // reposition the monitors to the right and below this
                    // monitor.
                    //
                    // What ends up happening is we will get the fullscreen
                    // window showing up on those monitors as well, because
                    // their virtual position now overlaps with the monitor that
                    // we just made larger..
                    //
                    // It'd be quite a bit of work to handle this correctly (and
                    // nobody else seems to bother doing this correctly either),
                    // so we're just leaving this broken. Fixing this would
                    // involve storing all CRTCs upon entering fullscreen,
                    // restoring them upon exit, and after entering fullscreen,
                    // repositioning displays to the right and below this
                    // display. I think there would still be edge cases that are
                    // difficult or impossible to handle correctly, e.g. what if
                    // a new monitor was plugged in while in fullscreen?
                    //
                    // I think we might just want to disallow setting the video
                    // mode higher than the current desktop video mode (I'm sure
                    // this will make someone unhappy, but it's very unusual for
                    // games to want to do this anyway).
                    self.xconn
                        .set_crtc_config(monitor.id, video_mode.native_mode)
                        .expect("failed to set video mode");
                }

                let window_position = self.outer_position_physical();
                self.shared_state.lock().restore_position = Some(window_position);
                let monitor_origin: (i32, i32) = monitor.position().into();
                self.set_position_inner(monitor_origin.0, monitor_origin.1)
                    .queue();
                Some(self.set_fullscreen_hint(true))
            }
        }
    }