Initial Commit

src/main.rs

@@ -0,0 +1,253 @@
+use std::{fs::File, io::Write, os::unix::prelude::AsRawFd};
+
+use wayland_client::{
+    protocol::{
+        wl_buffer, wl_compositor, wl_keyboard, wl_pointer, wl_registry, wl_seat, wl_shm,
+        wl_shm_pool, wl_surface,
+    },
+    Connection, Dispatch, Proxy, QueueHandle,
+};
+
+use wayland_protocols_wlr::layer_shell::v1::client::{
+    zwlr_layer_shell_v1::{self, Layer},
+    zwlr_layer_surface_v1::{self, Anchor},
+};
+
+use wayland_protocols::xdg::shell::client::xdg_wm_base;
+
+struct State {
+    running: bool,
+
+    cursor_size: u32,
+
+    compositor: Option<wl_compositor::WlCompositor>,
+    base_surface: Option<wl_surface::WlSurface>,
+    layer_shell: Option<zwlr_layer_shell_v1::ZwlrLayerShellV1>,
+    layer_surface: Option<zwlr_layer_surface_v1::ZwlrLayerSurfaceV1>,
+    buffer: Option<wl_buffer::WlBuffer>,
+    wm_base: Option<xdg_wm_base::XdgWmBase>,
+    pointer: Option<wl_pointer::WlPointer>,
+}
+
+fn main() {
+    let conn = Connection::connect_to_env().unwrap();
+
+    let mut event_queue = conn.new_event_queue();
+    let qhandle = event_queue.handle();
+
+    let display = conn.display();
+    display.get_registry(&qhandle, ());
+
+    let mut state = State {
+        running: true,
+        cursor_size: 10,
+        compositor: None,
+        base_surface: None,
+        layer_shell: None,
+        layer_surface: None,
+        buffer: None,
+        wm_base: None,
+        pointer: None,
+    };
+
+    event_queue.blocking_dispatch(&mut state).unwrap();
+
+    if state.layer_shell.is_some() && state.wm_base.is_some() {
+        state.init_layer_surface(&qhandle);
+    }
+
+    while state.running {
+        event_queue.blocking_dispatch(&mut state).unwrap();
+    }
+}
+
+impl Dispatch<wl_registry::WlRegistry, ()> for State {
+    fn event(
+        state: &mut Self,
+        registry: &wl_registry::WlRegistry,
+        event: wl_registry::Event,
+        _: &(),
+        _: &Connection,
+        qh: &QueueHandle<Self>,
+    ) {
+        eprintln!("WlRegistry event {event:#?}");
+        if let wl_registry::Event::Global {
+            name,
+            interface,
+            version,
+        } = event
+        {
+            if interface == zwlr_layer_shell_v1::ZwlrLayerShellV1::interface().name {
+                let wl_layer = registry.bind::<zwlr_layer_shell_v1::ZwlrLayerShellV1, _, _>(
+                    name,
+                    version,
+                    qh,
+                    (),
+                );
+                state.layer_shell = Some(wl_layer);
+            } else if interface == wl_compositor::WlCompositor::interface().name {
+                let compositor =
+                    registry.bind::<wl_compositor::WlCompositor, _, _>(name, version, qh, ());
+                let surface = compositor.create_surface(qh, ());
+                state.base_surface = Some(surface);
+                state.compositor = Some(compositor);
+            } else if interface == wl_shm::WlShm::interface().name {
+                let shm = registry.bind::<wl_shm::WlShm, _, _>(name, version, qh, ());
+
+                let (init_w, init_h) = (state.cursor_size, state.cursor_size);
+
+                let mut file = tempfile::tempfile().unwrap();
+                draw(&mut file, (init_w, init_h));
+                let pool = shm.create_pool(file.as_raw_fd(), (init_w * init_h * 4) as i32, qh, ());
+                let buffer = pool.create_buffer(
+                    0,
+                    init_w as i32,
+                    init_h as i32,
+                    (init_w * 4) as i32,
+                    wl_shm::Format::Argb8888,
+                    qh,
+                    (),
+                );
+                state.buffer = Some(buffer);
+            } else if interface == wl_seat::WlSeat::interface().name {
+                let seat = registry.bind::<wl_seat::WlSeat, _, _>(name, version, qh, ());
+                state.pointer = Some(seat.get_pointer(qh, ()));
+            } else if interface == xdg_wm_base::XdgWmBase::interface().name {
+                let wm_base = registry.bind::<xdg_wm_base::XdgWmBase, _, _>(name, 1, qh, ());
+                state.wm_base = Some(wm_base);
+            }
+        }
+    }
+}
+
+impl Dispatch<wl_pointer::WlPointer, ()> for State {
+    fn event(
+        state: &mut Self,
+        _: &wl_pointer::WlPointer,
+        event: wl_pointer::Event,
+        _: &(),
+        _: &Connection,
+        qh: &QueueHandle<Self>,
+    ) {
+        eprintln!("WlPointer event {event:#?}");
+        match event {
+            wl_pointer::Event::Enter { .. } => {
+                if let Some(surface) = &state.base_surface {
+                    surface.destroy();
+                }
+                state.base_surface = None;
+            }
+            wl_pointer::Event::Leave { .. } => {
+                let surface = state.compositor.as_ref().unwrap().create_surface(qh, ());
+                state.base_surface = Some(surface);
+
+                state.init_layer_surface(qh);
+            }
+            _ => {}
+        }
+    }
+}
+
+fn draw(tmp: &mut File, (buf_x, buf_y): (u32, u32)) {
+    let mut buf = std::io::BufWriter::new(tmp);
+    for y in 0..buf_y {
+        for x in 0..buf_x {
+            let ix = x as i32;
+            let iy = y as i32;
+
+            let dist = if x <= (buf_x / 2) {
+                ix + iy - (buf_y as i32)
+            } else {
+                iy - ix
+            };
+
+            let a: u32 = match dist.abs() {
+                0 => 0xFF,
+                1 => 0x88,
+                _ => 0x00,
+            };
+
+            let c: u32 = match dist.abs() {
+                0 => 0xFF,
+                1 => 0x88,
+                _ => 0x00,
+            };
+
+            let color = (a << 24) + (c << 16) + (c << 8) + c;
+            buf.write_all(&color.to_ne_bytes()).unwrap();
+        }
+    }
+    buf.flush().unwrap();
+}
+
+impl State {
+    fn init_layer_surface(&mut self, qh: &QueueHandle<State>) {
+        let layer = self.layer_shell.as_ref().unwrap().get_layer_surface(
+            self.base_surface.as_ref().unwrap(),
+            None,
+            Layer::Overlay,
+            "crosshair".to_string(),
+            qh,
+            (),
+        );
+        // Center the window
+        layer.set_anchor(Anchor::Top | Anchor::Right | Anchor::Bottom | Anchor::Left);
+        layer.set_keyboard_interactivity(zwlr_layer_surface_v1::KeyboardInteractivity::None);
+        layer.set_size(self.cursor_size, self.cursor_size);
+        // A negative value means we will be centered on the screen
+        // independently of any other xdg_layer_shell
+        layer.set_exclusive_zone(-1);
+        self.base_surface.as_ref().unwrap().commit();
+
+        self.layer_surface = Some(layer);
+    }
+}
+
+impl Dispatch<zwlr_layer_surface_v1::ZwlrLayerSurfaceV1, ()> for State {
+    fn event(
+        state: &mut Self,
+        surface: &zwlr_layer_surface_v1::ZwlrLayerSurfaceV1,
+        event: <zwlr_layer_surface_v1::ZwlrLayerSurfaceV1 as Proxy>::Event,
+        _data: &(),
+        _conn: &Connection,
+        _qhandle: &QueueHandle<Self>,
+    ) {
+        eprintln!("ZwlrLayerSurfaceV1 event {event:#?}");
+        if let zwlr_layer_surface_v1::Event::Configure { serial, .. } = event {
+            surface.ack_configure(serial);
+            if let (Some(surface), Some(buffer)) = (&state.base_surface, &state.buffer) {
+                surface.attach(Some(buffer), 0, 0);
+                surface.commit();
+            }
+        }
+    }
+}
+
+// ignored
+
+macro_rules! impl_dispatch_log {
+    ($DispatchStruct: path) => {
+        impl Dispatch<$DispatchStruct, ()> for State {
+            fn event(
+                _: &mut Self,
+                _: &$DispatchStruct,
+                event: <$DispatchStruct as Proxy>::Event,
+                _: &(),
+                _: &Connection,
+                _: &QueueHandle<Self>,
+            ) {
+                eprintln!("{} event {:#?}", stringify!($DispatchStruct), event);
+            }
+        }
+    };
+}
+
+impl_dispatch_log!(wl_buffer::WlBuffer);
+impl_dispatch_log!(wl_compositor::WlCompositor);
+impl_dispatch_log!(wl_keyboard::WlKeyboard);
+impl_dispatch_log!(wl_seat::WlSeat);
+impl_dispatch_log!(wl_shm_pool::WlShmPool);
+impl_dispatch_log!(wl_shm::WlShm);
+impl_dispatch_log!(wl_surface::WlSurface);
+impl_dispatch_log!(xdg_wm_base::XdgWmBase);
+impl_dispatch_log!(zwlr_layer_shell_v1::ZwlrLayerShellV1);