feat: Add basic support for foreign top level management.

- Allow users to minimize other applications by sending a
`ForeignToplevelEvent`.

src/foreign_toplevel_manager.rs

@@ -0,0 +1,96 @@
+use bevy::prelude::*;
+use smithay_client_toolkit::{
+    reexports::client::{event_created_child, Dispatch, QueueHandle},
+    registry::RegistryState,
+};
+use wayland_protocols_wlr::foreign_toplevel::v1::client::{
+    zwlr_foreign_toplevel_handle_v1::{self, ZwlrForeignToplevelHandleV1},
+    zwlr_foreign_toplevel_manager_v1::{self, ZwlrForeignToplevelManagerV1},
+};
+
+use crate::WaylandState;
+#[derive(Debug, Copy, Clone, Event)]
+pub enum ForeignToplevelEvent {
+    MinimizeOthers,
+}
+
+#[derive(Default, Deref, DerefMut)]
+struct ForeignToplevels(Vec<ZwlrForeignToplevelHandleV1>);
+
+pub struct ForeignToplevelManagerPlugin;
+impl Plugin for ForeignToplevelManagerPlugin {
+    fn build(&self, app: &mut App) {
+        let registry_state = app.world().non_send_resource::<RegistryState>();
+        let queue_handle = app.world().non_send_resource::<QueueHandle<WaylandState>>();
+        let foreign_top_level_manager =
+            registry_state.bind_one::<ZwlrForeignToplevelManagerV1, _, _>(queue_handle, 2..=3, ());
+        if let Ok(foreign_top_level_manager) = foreign_top_level_manager {
+            info!("Foreign toplevel manager was bound!");
+            app.insert_non_send_resource(foreign_top_level_manager);
+            app.insert_non_send_resource(ForeignToplevels::default());
+            app.add_event::<ForeignToplevelEvent>();
+            app.add_systems(Update, foreign_top_level_event_handler);
+        } else {
+            let bind_error = foreign_top_level_manager.err().unwrap();
+            error!("Couldn't bind foreign toplevel manager! {:?}", bind_error);
+        }
+    }
+}
+
+fn foreign_top_level_event_handler(
+    foreign_top_levels: NonSendMut<ForeignToplevels>,
+    mut events: EventReader<ForeignToplevelEvent>,
+) {
+    for event in events.read() {
+        match event {
+            ForeignToplevelEvent::MinimizeOthers => {
+                info!("Minimizing other windows");
+                for toplevel in foreign_top_levels.iter() {
+                    toplevel.set_minimized();
+                }
+            }
+        }
+    }
+}
+
+impl Dispatch<ZwlrForeignToplevelManagerV1, ()> for WaylandState {
+    fn event(
+        state: &mut Self,
+        _proxy: &ZwlrForeignToplevelManagerV1,
+        event: <ZwlrForeignToplevelManagerV1 as smithay_client_toolkit::reexports::client::Proxy>::Event,
+        _data: &(),
+        _conn: &smithay_client_toolkit::reexports::client::Connection,
+        _qhandle: &QueueHandle<Self>,
+    ) {
+        let mut foreign_toplevels = state
+            .world_mut()
+            .non_send_resource_mut::<ForeignToplevels>();
+        match event {
+            wayland_protocols_wlr::foreign_toplevel::v1::client::zwlr_foreign_toplevel_manager_v1::Event::Toplevel { toplevel } => {
+                foreign_toplevels.push(toplevel);
+            },
+            wayland_protocols_wlr::foreign_toplevel::v1::client::zwlr_foreign_toplevel_manager_v1::Event::Finished => {},
+            _ => {},
+        }
+    }
+
+    event_created_child!(WaylandState, ZwlrForeignToplevelManagerV1, [
+        // Opcode 0 is the `toplevel` event. It creates a new `zwlr_foreign_toplevel_handle_v1`.
+        zwlr_foreign_toplevel_manager_v1::EVT_TOPLEVEL_OPCODE => (
+            zwlr_foreign_toplevel_handle_v1::ZwlrForeignToplevelHandleV1,
+            ()
+        )
+    ]);
+}
+
+impl Dispatch<ZwlrForeignToplevelHandleV1, ()> for WaylandState {
+    fn event(
+        _state: &mut Self,
+        _proxy: &ZwlrForeignToplevelHandleV1,
+        _event: <ZwlrForeignToplevelHandleV1 as smithay_client_toolkit::reexports::client::Proxy>::Event,
+        _data: &(),
+        _conn: &smithay_client_toolkit::reexports::client::Connection,
+        _qhandle: &QueueHandle<Self>,
+    ) {
+    }
+}

src/lib.rs

@@ -1,5 +1,4 @@
 use std::{
-    num::NonZero,
     sync::mpsc::SendError,
     time::{Duration, Instant},
 };
@@ -18,6 +17,7 @@ use smithay_client_toolkit::{
     seat::SeatState,
 };
 
+pub mod foreign_toplevel_manager;
 mod input_handler;
 pub mod input_region;
 pub mod layer_shell;
@@ -85,6 +85,7 @@ impl Plugin for WaylandPlugin {
             layer_shell::LayerShellPlugin,
             session_lock::SessionLockPlugin,
             input_region::InputRegionPlugin,
+            foreign_toplevel_manager::ForeignToplevelManagerPlugin,
         ));
         app.set_runner(|app| runner(app, event_loop));
     }