tts: add native tts plugin for Android (#1376)

apps/readest-app/src-tauri/plugins/tauri-plugin-native-tts/src/error.rs

@@ -0,0 +1,25 @@
+use serde::{ser::Serializer, Serialize};
+
+pub type Result<T> = std::result::Result<T, Error>;
+
+#[derive(Debug, thiserror::Error)]
+pub enum Error {
+    #[error("Unsupported platform for this plugin")]
+    UnsupportedPlatformError,
+    #[error("Native tts error: {0}")]
+    NativeTTSError(String),
+    #[error(transparent)]
+    Io(#[from] std::io::Error),
+    #[cfg(mobile)]
+    #[error(transparent)]
+    PluginInvoke(#[from] tauri::plugin::mobile::PluginInvokeError),
+}
+
+impl Serialize for Error {
+    fn serialize<S>(&self, serializer: S) -> std::result::Result<S::Ok, S::Error>
+    where
+        S: Serializer,
+    {
+        serializer.serialize_str(self.to_string().as_ref())
+    }
+}