tauri_swift_runtime/
desktop.rs

1use serde::de::DeserializeOwned;
2use swift_rs::SRString;
3use tauri::{ipc::Channel, plugin::PluginApi, AppHandle, Manager, Runtime};
4
5use serde::Serialize;
6use serde_json::Value as JsonValue;
7
8use memoffset::offset_of;
9
10use std::{
11  collections::HashMap,
12  fmt,
13  sync::{mpsc::channel, Mutex, OnceLock},
14};
15
16use std::sync::atomic::{AtomicI32, Ordering};
17
18use std::sync::Arc;
19
20type PluginResponse = Result<serde_json::Value, serde_json::Value>;
21
22type PendingPluginCallHandler = Box<dyn FnOnce(PluginResponse) + Send + 'static>;
23
24static PENDING_PLUGIN_CALLS_ID: AtomicI32 = AtomicI32::new(0);
25static PENDING_PLUGIN_CALLS: OnceLock<Mutex<HashMap<i32, PendingPluginCallHandler>>> =
26  OnceLock::new();
27static CHANNELS: OnceLock<Mutex<HashMap<u32, Channel<serde_json::Value>>>> = OnceLock::new();
28
29/// Error response from the Kotlin and Swift backends.
30#[derive(Debug, thiserror::Error, Clone, serde::Deserialize)]
31pub struct ErrorResponse<T = ()> {
32  /// Error code.
33  pub code: Option<String>,
34  /// Error message.
35  pub message: Option<String>,
36  /// Optional error data.
37  #[serde(flatten)]
38  pub data: T,
39}
40
41impl<T> fmt::Display for ErrorResponse<T> {
42  fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
43    if let Some(code) = &self.code {
44      write!(f, "[{code}]")?;
45      if self.message.is_some() {
46        write!(f, " - ")?;
47      }
48    }
49    if let Some(message) = &self.message {
50      write!(f, "{message}")?;
51    }
52    Ok(())
53  }
54}
55
56/// Possible errors when invoking a plugin.
57#[derive(Debug, thiserror::Error)]
58pub enum PluginInvokeError {
59  /// Failed to reach platform webview handle.
60  #[error("the webview is unreachable")]
61  UnreachableWebview,
62  /// Error returned from direct mobile plugin invoke.
63  #[error(transparent)]
64  InvokeRejected(#[from] ErrorResponse),
65  /// Failed to deserialize response.
66  #[error("failed to deserialize response: {0}")]
67  CannotDeserializeResponse(serde_json::Error),
68  /// Failed to serialize request payload.
69  #[error("failed to serialize payload: {0}")]
70  CannotSerializePayload(serde_json::Error),
71}
72
73#[repr(C)]
74pub struct PluginApiRef<R: Runtime, C: DeserializeOwned> {
75  handle: AppHandle<R>,
76  name: &'static str,
77  raw_config: Arc<JsonValue>,
78  config: C,
79}
80
81#[repr(C)]
82pub struct PluginApiExt<R: Runtime, C: DeserializeOwned>(PluginApi<R, C>);
83
84impl<R: Runtime, C: DeserializeOwned> From<PluginApi<R, C>> for PluginApiExt<R, C> {
85    fn from(api: PluginApi<R, C>) -> Self {
86        PluginApiExt(api)
87    }
88}
89
90impl<R: Runtime, C: DeserializeOwned> PluginApiExt<R, C> {
91  /// Returns the app handle.
92  pub fn app(&self) -> &AppHandle<R> {
93    self.0.app()
94  }
95
96  /// Returns the plugin name.
97  pub fn name(&self) -> &str {    
98    let self_ptr = &self.0 as *const PluginApi<R, C> as *const u8;
99    let offset = offset_of!(PluginApiRef<R, C>, name);
100    
101    let name: &'static str = unsafe {
102        let field_ptr = self_ptr.add(offset) as *const &'static str;
103        *field_ptr
104    };
105    name
106  }
107
108  /// Returns the raw plugin configuration.
109  pub fn raw_config(&self) -> Arc<JsonValue> {
110    let self_ptr = self as *const PluginApiExt<R, C> as *const u8;
111    let offset = offset_of!(PluginApiRef<R, C>, raw_config);
112
113    let rc_ptr = unsafe { self_ptr.add(offset) as *const Arc<JsonValue> };
114    let rc_ref = unsafe { &*rc_ptr };
115    rc_ref.clone()
116  }
117}
118
119#[cfg(any(target_os = "macos", target_os = "ios"))]
120impl<R: Runtime, C: DeserializeOwned> PluginApiExt<R, C> {
121  /// Registers a Swift plugin.
122  pub fn register_swift_plugin(
123    &self,
124    init_fn: unsafe fn() -> *const std::ffi::c_void,
125  ) -> Result<PluginHandleExt<R>, PluginInvokeError> {
126    if let Some(webview) = self.app().webviews().values().next() {
127      let (tx, rx) = channel();
128      let name = self.name();
129      let config = self.raw_config().clone();
130      let name = name.to_string();
131      let config = serde_json::to_string(&config).unwrap();
132      webview
133        .with_webview(move |w| {
134          unsafe {
135            crate::macos::swift_register_plugin(
136              &SRString::from(name.as_str()),
137              init_fn(),
138              &serde_json::to_string(&config).unwrap().as_str().into(),
139              w.inner() as _,
140            )
141          };
142          tx.send(()).unwrap();
143        })
144        .map_err(|_| PluginInvokeError::UnreachableWebview)?;
145      rx.recv().unwrap();
146    } else {
147      unsafe {
148        crate::macos::swift_register_plugin(
149          &SRString::from(self.name()),
150          init_fn(),
151          &serde_json::to_string(&self.raw_config())
152            .unwrap()
153            .as_str()
154            .into(),
155          std::ptr::null(),
156        )
157      };
158    }
159
160    Ok(PluginHandleExt {
161      name: self.name().to_string(),
162      handle: self.app().clone(),
163    })
164  }
165}
166
167pub struct PluginHandleExt<R: Runtime> {
168  name: String,
169  handle: AppHandle<R>,
170}
171
172impl<R: Runtime> PluginHandleExt<R> {
173  /// Executes the given Swift command.
174  pub fn run_swift_plugin<T: DeserializeOwned>(
175    &self,
176    command: impl AsRef<str>,
177    payload: impl Serialize,
178  ) -> Result<T, PluginInvokeError> {
179    let (tx, rx) = channel();
180
181    run_command(
182      &self.name,
183      &self.handle,
184      command,
185      serde_json::to_value(payload).map_err(PluginInvokeError::CannotSerializePayload)?,
186      move |response| {
187        tx.send(response).unwrap();
188      },
189    )?;
190
191    let response = rx.recv().unwrap();
192    match response {
193      Ok(r) => serde_json::from_value(r).map_err(PluginInvokeError::CannotDeserializeResponse),
194      Err(r) => Err(
195        serde_json::from_value::<ErrorResponse>(r)
196          .map(Into::into)
197          .map_err(PluginInvokeError::CannotDeserializeResponse)?,
198      ),
199    }
200  }
201}
202
203pub(crate) fn run_command<R: Runtime, C: AsRef<str>, F: FnOnce(PluginResponse) + Send + 'static>(
204  name: &str,
205  _handle: &AppHandle<R>,
206  command: C,
207  payload: serde_json::Value,
208  handler: F,
209) -> Result<(), PluginInvokeError> {
210  use std::{
211    ffi::CStr,
212    os::raw::{c_char, c_int, c_ulonglong},
213  };
214
215  let id: i32 = PENDING_PLUGIN_CALLS_ID.fetch_add(1, Ordering::Relaxed);
216  PENDING_PLUGIN_CALLS
217    .get_or_init(Default::default)
218    .lock()
219    .unwrap()
220    .insert(id, Box::new(handler));
221
222  unsafe {
223    extern "C" fn plugin_command_response_handler(
224      id: c_int,
225      success: c_int,
226      payload: *const c_char,
227    ) {
228      let payload = unsafe {
229        assert!(!payload.is_null());
230        CStr::from_ptr(payload)
231      };
232
233      if let Some(handler) = PENDING_PLUGIN_CALLS
234        .get_or_init(Default::default)
235        .lock()
236        .unwrap()
237        .remove(&id)
238      {
239        let json = payload.to_str().unwrap();
240        match serde_json::from_str(json) {
241          Ok(payload) => {
242            handler(if success == 1 {
243              Ok(payload)
244            } else {
245              Err(payload)
246            });
247          }
248          Err(err) => {
249            handler(Err(format!("{err}, data: {json}").into()));
250          }
251        }
252      }
253    }
254
255    extern "C" fn send_channel_data_handler(id: c_ulonglong, payload: *const c_char) {
256      let payload = unsafe {
257        assert!(!payload.is_null());
258        CStr::from_ptr(payload)
259      };
260
261      if let Some(channel) = CHANNELS
262        .get_or_init(Default::default)
263        .lock()
264        .unwrap()
265        .get(&(id as u32))
266      {
267        let payload: serde_json::Value = serde_json::from_str(payload.to_str().unwrap()).unwrap();
268        let _ = channel.send(payload);
269      }
270    }
271
272    crate::macos::swift_run_plugin_command(
273      id,
274      &name.into(),
275      &command.as_ref().into(),
276      &serde_json::to_string(&payload).unwrap().as_str().into(),
277      crate::macos::PluginMessageCallback(plugin_command_response_handler),
278      crate::macos::ChannelSendDataCallback(send_channel_data_handler),
279    );
280  }
281
282  Ok(())
283}
tauri_swift_runtime/desktop.rs

tauri_swift_runtime/
desktop.rs
