macos: enable running lan-mouse on macos (#42)

* macos: initial support

- adapted conditional compilation
- moved lan-mouse socket to ~/Library/Caches/lan-mouse-socket.sock instead of XDG_RUNTIME_DIR
- support for mouse input emulation
TODO: Keycode translation, input capture

src/backend/consumer.rs

@@ -1,14 +1,17 @@
 #[cfg(windows)]
 pub mod windows;
 
-#[cfg(all(unix, feature = "x11"))]
+#[cfg(all(unix, feature = "x11", not(target_os = "macos")))]
 pub mod x11;
 
-#[cfg(all(unix, feature = "wayland"))]
+#[cfg(all(unix, feature = "wayland", not(target_os = "macos")))]
 pub mod wlroots;
 
-#[cfg(all(unix, feature = "xdg_desktop_portal"))]
+#[cfg(all(unix, feature = "xdg_desktop_portal", not(target_os = "macos")))]
 pub mod xdg_desktop_portal;
 
-#[cfg(all(unix, feature = "libei"))]
+#[cfg(all(unix, feature = "libei", not(target_os = "macos")))]
 pub mod libei;
+
+#[cfg(target_os = "macos")]
+pub mod macos;

src/backend/consumer/macos.rs

@@ -0,0 +1,221 @@
+use crate::client::{ClientEvent, ClientHandle};
+use crate::consumer::EventConsumer;
+use crate::event::{Event, KeyboardEvent, PointerEvent};
+use anyhow::{anyhow, Result};
+use async_trait::async_trait;
+use core_graphics::display::CGPoint;
+use core_graphics::event::{
+    CGEvent, CGEventTapLocation, CGEventType, CGMouseButton, ScrollEventUnit,
+};
+use core_graphics::event_source::{CGEventSource, CGEventSourceStateID};
+use std::ops::{Index, IndexMut};
+
+pub struct MacOSConsumer {
+    pub event_source: CGEventSource,
+    button_state: ButtonState,
+}
+
+struct ButtonState {
+    left: bool,
+    right: bool,
+    center: bool,
+}
+
+impl Index<CGMouseButton> for ButtonState {
+    type Output = bool;
+
+    fn index(&self, index: CGMouseButton) -> &Self::Output {
+        match index {
+            CGMouseButton::Left => &self.left,
+            CGMouseButton::Right => &self.right,
+            CGMouseButton::Center => &self.center,
+        }
+    }
+}
+
+impl IndexMut<CGMouseButton> for ButtonState {
+    fn index_mut(&mut self, index: CGMouseButton) -> &mut Self::Output {
+        match index {
+            CGMouseButton::Left => &mut self.left,
+            CGMouseButton::Right => &mut self.right,
+            CGMouseButton::Center => &mut self.center,
+        }
+    }
+}
+
+unsafe impl Send for MacOSConsumer {}
+
+impl MacOSConsumer {
+    pub fn new() -> Result<Self> {
+        let event_source = match CGEventSource::new(CGEventSourceStateID::CombinedSessionState) {
+            Ok(e) => e,
+            Err(_) => return Err(anyhow!("event source creation failed!")),
+        };
+        let button_state = ButtonState {
+            left: false,
+            right: false,
+            center: false,
+        };
+        Ok(Self {
+            event_source,
+            button_state,
+        })
+    }
+
+    fn get_mouse_location(&self) -> Option<CGPoint> {
+        let event: CGEvent = CGEvent::new(self.event_source.clone()).ok()?;
+        Some(event.location())
+    }
+}
+
+#[async_trait]
+impl EventConsumer for MacOSConsumer {
+    async fn consume(&mut self, event: Event, _client_handle: ClientHandle) {
+        match event {
+            Event::Pointer(pointer_event) => match pointer_event {
+                PointerEvent::Motion {
+                    time: _,
+                    relative_x,
+                    relative_y,
+                } => {
+                    let mut mouse_location = match self.get_mouse_location() {
+                        Some(l) => l,
+                        None => {
+                            log::warn!("could not get mouse location!");
+                            return;
+                        }
+                    };
+                    mouse_location.x += relative_x;
+                    mouse_location.y += relative_y;
+
+                    let mut event_type = CGEventType::MouseMoved;
+                    if self.button_state.left {
+                        event_type = CGEventType::LeftMouseDragged
+                    } else if self.button_state.right {
+                        event_type = CGEventType::RightMouseDragged
+                    } else if self.button_state.center {
+                        event_type = CGEventType::OtherMouseDragged
+                    };
+                    let event = match CGEvent::new_mouse_event(
+                        self.event_source.clone(),
+                        event_type,
+                        mouse_location,
+                        CGMouseButton::Left,
+                    ) {
+                        Ok(e) => e,
+                        Err(_) => {
+                            log::warn!("mouse event creation failed!");
+                            return;
+                        }
+                    };
+                    event.post(CGEventTapLocation::HID);
+                }
+                PointerEvent::Button {
+                    time: _,
+                    button,
+                    state,
+                } => {
+                    let (event_type, mouse_button) = match (button, state) {
+                        (b, 1) if b == crate::event::BTN_LEFT => {
+                            (CGEventType::LeftMouseDown, CGMouseButton::Left)
+                        }
+                        (b, 0) if b == crate::event::BTN_LEFT => {
+                            (CGEventType::LeftMouseUp, CGMouseButton::Left)
+                        }
+                        (b, 1) if b == crate::event::BTN_RIGHT => {
+                            (CGEventType::RightMouseDown, CGMouseButton::Right)
+                        }
+                        (b, 0) if b == crate::event::BTN_RIGHT => {
+                            (CGEventType::RightMouseUp, CGMouseButton::Right)
+                        }
+                        (b, 1) if b == crate::event::BTN_MIDDLE => {
+                            (CGEventType::OtherMouseDown, CGMouseButton::Center)
+                        }
+                        (b, 0) if b == crate::event::BTN_MIDDLE => {
+                            (CGEventType::OtherMouseUp, CGMouseButton::Center)
+                        }
+                        _ => {
+                            log::warn!("invalid button event: {button},{state}");
+                            return;
+                        }
+                    };
+                    // store button state
+                    self.button_state[mouse_button] = if state == 1 { true } else { false };
+
+                    let location = self.get_mouse_location().unwrap();
+                    let event = match CGEvent::new_mouse_event(
+                        self.event_source.clone(),
+                        event_type,
+                        location,
+                        mouse_button,
+                    ) {
+                        Ok(e) => e,
+                        Err(()) => {
+                            log::warn!("mouse event creation failed!");
+                            return;
+                        }
+                    };
+                    event.post(CGEventTapLocation::HID);
+                }
+                PointerEvent::Axis {
+                    time: _,
+                    axis,
+                    value,
+                } => {
+                    let value = value as i32 / 10; // FIXME: high precision scroll events
+                    let (count, wheel1, wheel2, wheel3) = match axis {
+                        0 => (1, value, 0, 0), // 0 = vertical => 1 scroll wheel device (y axis)
+                        1 => (2, 0, value, 0), // 1 = horizontal => 2 scroll wheel devices (y, x) -> (0, x)
+                        _ => {
+                            log::warn!("invalid scroll event: {axis}, {value}");
+                            return;
+                        }
+                    };
+                    let event = match CGEvent::new_scroll_event(
+                        self.event_source.clone(),
+                        ScrollEventUnit::LINE,
+                        count,
+                        wheel1,
+                        wheel2,
+                        wheel3,
+                    ) {
+                        Ok(e) => e,
+                        Err(()) => {
+                            log::warn!("scroll event creation failed!");
+                            return;
+                        }
+                    };
+                    event.post(CGEventTapLocation::HID);
+                }
+                PointerEvent::Frame { .. } => {}
+            },
+            Event::Keyboard(keyboard_event) => match keyboard_event {
+                KeyboardEvent::Key { .. } => {
+                    /*
+                    let code = CGKeyCode::from_le(key as u16);
+                    let event = match CGEvent::new_keyboard_event(
+                        self.event_source.clone(),
+                        code,
+                        match state { 1 => true, _ => false }
+                    ) {
+                        Ok(e) => e,
+                        Err(_) => {
+                            log::warn!("unable to create key event");
+                            return
+                        }
+                    };
+                    event.post(CGEventTapLocation::HID);
+                    */
+                }
+                KeyboardEvent::Modifiers { .. } => {}
+            },
+            Event::Release() => {}
+            Event::Ping() => {}
+            Event::Pong() => {}
+        }
+    }
+
+    async fn notify(&mut self, _client_event: ClientEvent) {}
+
+    async fn destroy(&mut self) {}
+}

src/backend/producer.rs

@@ -1,8 +1,10 @@
-#[cfg(all(unix, feature = "libei"))]
+#[cfg(all(unix, feature = "libei", not(target_os = "macos")))]
 pub mod libei;
-#[cfg(all(unix, feature = "wayland"))]
+#[cfg(target_os = "macos")]
+pub mod macos;
+#[cfg(all(unix, feature = "wayland", not(target_os = "macos")))]
 pub mod wayland;
 #[cfg(windows)]
 pub mod windows;
-#[cfg(all(unix, feature = "x11"))]
+#[cfg(all(unix, feature = "x11", not(target_os = "macos")))]
 pub mod x11;

src/backend/producer/macos.rs

@@ -0,0 +1,28 @@
+use crate::client::{ClientEvent, ClientHandle};
+use crate::event::Event;
+use crate::producer::EventProducer;
+use futures_core::Stream;
+use std::task::{Context, Poll};
+use std::{io, pin::Pin};
+
+pub struct MacOSProducer;
+
+impl MacOSProducer {
+    pub fn new() -> Self {
+        Self {}
+    }
+}
+
+impl Stream for MacOSProducer {
+    type Item = io::Result<(ClientHandle, Event)>;
+
+    fn poll_next(self: Pin<&mut Self>, _cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
+        Poll::Pending
+    }
+}
+
+impl EventProducer for MacOSProducer {
+    fn notify(&mut self, _event: ClientEvent) {}
+
+    fn release(&mut self) {}
+}

src/consumer.rs

@@ -1,7 +1,7 @@
 use async_trait::async_trait;
 use std::future;
 
-#[cfg(unix)]
+#[cfg(all(unix, not(target_os = "macos")))]
 use std::env;
 
 use crate::{
@@ -11,7 +11,7 @@ use crate::{
 };
 use anyhow::Result;
 
-#[cfg(unix)]
+#[cfg(all(unix, not(target_os = "macos")))]
 #[derive(Debug)]
 enum Backend {
     Wlroots,
@@ -37,7 +37,10 @@ pub async fn create() -> Result<Box<dyn EventConsumer>> {
     #[cfg(windows)]
     return Ok(Box::new(consumer::windows::WindowsConsumer::new()));
 
-    #[cfg(unix)]
+    #[cfg(target_os = "macos")]
+    return Ok(Box::new(consumer::macos::MacOSConsumer::new()?));
+
+    #[cfg(all(unix, not(target_os = "macos")))]
     let backend = match env::var("XDG_SESSION_TYPE") {
         Ok(session_type) => match session_type.as_str() {
             "x11" => {
@@ -87,7 +90,7 @@ pub async fn create() -> Result<Box<dyn EventConsumer>> {
         }
     };
 
-    #[cfg(unix)]
+    #[cfg(all(unix, not(target_os = "macos")))]
     match backend {
         Backend::Libei => {
             #[cfg(not(feature = "libei"))]

src/event.rs

@@ -3,6 +3,11 @@ use std::{
     fmt::{self, Display},
 };
 
+// FIXME
+pub(crate) const BTN_LEFT: u32 = 0x110;
+pub(crate) const BTN_RIGHT: u32 = 0x111;
+pub(crate) const BTN_MIDDLE: u32 = 0x112;
+
 #[derive(Debug, Clone, Copy)]
 pub enum PointerEvent {
     Motion {

src/frontend.rs

@@ -126,7 +126,7 @@ pub struct FrontendListener {
 }
 
 impl FrontendListener {
-    #[cfg(unix)]
+    #[cfg(all(unix, not(target_os = "macos")))]
     pub fn socket_path() -> Result<PathBuf> {
         let xdg_runtime_dir = match env::var("XDG_RUNTIME_DIR") {
             Ok(d) => d,
@@ -136,6 +136,20 @@ impl FrontendListener {
         Ok(xdg_runtime_dir.join("lan-mouse-socket.sock"))
     }
 
+    #[cfg(all(unix, target_os = "macos"))]
+    pub fn socket_path() -> Result<PathBuf> {
+        let home = match env::var("HOME") {
+            Ok(d) => d,
+            Err(e) => return Err(anyhow!("could not find HOME: {e}")),
+        };
+        let home = Path::new(home.as_str());
+        let path = home
+            .join("Library")
+            .join("Caches")
+            .join("lan-mouse-socket.sock");
+        Ok(path)
+    }
+
     pub async fn new() -> Option<Result<Self>> {
         #[cfg(unix)]
         let (socket_path, listener) = {

src/producer.rs

@@ -9,10 +9,10 @@ use crate::{
     event::Event,
 };
 
-#[cfg(unix)]
+#[cfg(all(unix, not(target_os = "macos")))]
 use std::env;
 
-#[cfg(unix)]
+#[cfg(all(unix, not(target_os = "macos")))]
 enum Backend {
     LayerShell,
     Libei,
@@ -20,10 +20,13 @@ enum Backend {
 }
 
 pub async fn create() -> Result<Box<dyn EventProducer>> {
+    #[cfg(target_os = "macos")]
+    return Ok(Box::new(producer::macos::MacOSProducer::new()));
+
     #[cfg(windows)]
     return Ok(Box::new(producer::windows::WindowsProducer::new()));
 
-    #[cfg(unix)]
+    #[cfg(all(unix, not(target_os = "macos")))]
     let backend = match env::var("XDG_SESSION_TYPE") {
         Ok(session_type) => match session_type.as_str() {
             "x11" => {
@@ -56,7 +59,7 @@ pub async fn create() -> Result<Box<dyn EventProducer>> {
         }
     };
 
-    #[cfg(unix)]
+    #[cfg(all(unix, not(target_os = "macos")))]
     match backend {
         Backend::X11 => {
             #[cfg(not(feature = "x11"))]