feat: whiteboard, macos (#12780)

Signed-off-by: fufesou <linlong1266@gmail.com>

src/whiteboard/mod.rs

@@ -0,0 +1,35 @@
+use serde_derive::{Deserialize, Serialize};
+
+mod client;
+mod server;
+
+#[cfg(target_os = "windows")]
+mod windows;
+#[cfg(target_os = "macos")]
+mod macos;
+
+#[cfg(target_os = "windows")]
+use windows::create_event_loop;
+#[cfg(target_os = "macos")]
+use macos::create_event_loop;
+
+pub use client::*;
+pub use server::*;
+
+#[derive(Debug, Serialize, Deserialize, Clone)]
+#[serde(tag = "t", content = "c")]
+pub enum CustomEvent {
+    Cursor(Cursor),
+    Clear,
+    Exit,
+}
+
+#[derive(Debug, Serialize, Deserialize, Clone)]
+#[serde(tag = "t")]
+pub struct Cursor {
+    pub x: f32,
+    pub y: f32,
+    pub argb: u32,
+    pub btns: i32,
+    pub text: String,
+}