Add client side decorations to toplevels

These simple decorations will be rendered only when the host compositor doesn't
support server side decorations and the X11 window does not render its own
decorations.

Closes #31

src/server/tests.rs

@@ -8,7 +8,7 @@ use std::io::Write;
 use std::os::fd::{AsRawFd, BorrowedFd};
 use std::os::unix::net::UnixStream;
 use std::sync::{Arc, Mutex};
-use testwl::SendDataForMimeFn;
+use testwl::{SendDataForMimeFn, SurfaceRole};
 use wayland_client::{
     backend::{protocol::Message, Backend, ObjectData, ObjectId, WaylandError},
     protocol::{
@@ -27,6 +27,7 @@ use wayland_client::{
     },
     Connection, Proxy, WEnum,
 };
+use wayland_protocols::xdg::decoration::zv1::server::zxdg_toplevel_decoration_v1;
 use wayland_protocols::{
     wp::{
         linux_dmabuf::zv1::client::zwp_linux_dmabuf_v1::ZwpLinuxDmabufV1,
@@ -2600,6 +2601,83 @@ fn scaled_pointer_lock_position_hint() {
     );
 }
 
+#[test]
+fn client_side_decorations() {
+    let (mut f, compositor) = TestFixture::new_with_compositor();
+    let window = unsafe { Window::new(1) };
+    let (_, id) = f.create_toplevel(&compositor, window);
+    f.testwl
+        .force_decoration_mode(id, zxdg_toplevel_decoration_v1::Mode::ClientSide);
+    f.run();
+
+    let subsurface_id = f.testwl.last_created_surface_id().unwrap();
+    assert_ne!(subsurface_id, id);
+    let data = f.testwl.get_surface_data(subsurface_id).unwrap();
+    let Some(SurfaceRole::Subsurface(subsurface)) = &data.role else {
+        panic!("surface was not a subsurface: {:?}", data.role);
+    };
+
+    assert_eq!(subsurface.position, testwl::Vec2 { x: 0, y: -25 });
+    assert_eq!(subsurface.parent, id);
+    let subsurface = subsurface.subsurface.clone();
+
+    f.testwl
+        .force_decoration_mode(id, zxdg_toplevel_decoration_v1::Mode::ServerSide);
+    f.run();
+
+    assert!(f.testwl.get_surface_data(subsurface_id).is_none());
+    assert!(!subsurface.is_alive());
+}
+
+#[test]
+fn client_side_decorations_no_global() {
+    let mut f = TestFixture::new_pre_connect(|testwl| {
+        testwl.disable_decorations_global();
+    });
+    let compositor = f.compositor();
+    let window = unsafe { Window::new(1) };
+    let (buffer, surface) = compositor.create_surface();
+
+    let data = WindowData {
+        mapped: true,
+        dims: WindowDims {
+            x: 0,
+            y: 0,
+            width: 50,
+            height: 50,
+        },
+        fullscreen: false,
+    };
+
+    f.new_window(window, false, data);
+    f.map_window(&compositor, window, &surface.obj, &buffer);
+    f.run();
+
+    let surfaces = f.testwl.created_surfaces();
+    assert_eq!(surfaces.len(), 2);
+    let mut toplevel = None;
+    let mut subsurface_parent = None;
+    for id in surfaces {
+        let data = f.testwl.get_surface_data(*id).unwrap();
+        match data
+            .role
+            .as_ref()
+            .expect("A surface was created without a role")
+        {
+            SurfaceRole::Toplevel(_) => {
+                toplevel = Some(*id);
+            }
+            SurfaceRole::Subsurface(sub) => {
+                assert_eq!(sub.position, testwl::Vec2 { x: 0, y: -25 });
+                subsurface_parent = Some(sub.parent);
+            }
+            other => panic!("got surface with unexpected role: {other:?}"),
+        }
+    }
+
+    assert_eq!(toplevel.unwrap(), subsurface_parent.unwrap());
+}
+
 /// See Pointer::handle_event for an explanation.
 #[test]
 fn popup_pointer_motion_workaround() {}