Add Android example.

Cargo.toml

@@ -41,4 +41,9 @@ wasm-bindgen = "0.2"
 web-sys = { version = "0.3", features = ["EventTarget", "SpeechSynthesis", "SpeechSynthesisErrorCode", "SpeechSynthesisErrorEvent", "SpeechSynthesisEvent", "SpeechSynthesisUtterance", "Window", ] }
 
 [target.'cfg(target_os="android")'.dependencies]
-jni = "0.18"
+jni = "0.18"
+ndk-glue = "0.2"
+
+[[example]]
+name = "hello_world_android"
+crate-type = ["cdylib"]

examples/hello_world_android.rs

@@ -0,0 +1,89 @@
+use std::io;
+
+#[cfg(target_os = "macos")]
+use cocoa_foundation::base::id;
+#[cfg(target_os = "macos")]
+use cocoa_foundation::foundation::NSRunLoop;
+#[cfg(target_os = "macos")]
+use objc::{msg_send, sel, sel_impl};
+
+use tts::*;
+
+// Use a separate function so the same examples run everywhere.
+fn run() -> Result<(), Error> {
+    env_logger::init();
+    let mut tts = TTS::default()?;
+    let Features {
+        utterance_callbacks,
+        ..
+    } = tts.supported_features();
+    if utterance_callbacks {
+        tts.on_utterance_begin(Some(Box::new(|utterance| {
+            println!("Started speaking {:?}", utterance)
+        })))?;
+        tts.on_utterance_end(Some(Box::new(|utterance| {
+            println!("Finished speaking {:?}", utterance)
+        })))?;
+        tts.on_utterance_stop(Some(Box::new(|utterance| {
+            println!("Stopped speaking {:?}", utterance)
+        })))?;
+    }
+    let Features { is_speaking, .. } = tts.supported_features();
+    if is_speaking {
+        println!("Are we speaking? {}", tts.is_speaking()?);
+    }
+    tts.speak("Hello, world.", false)?;
+    let Features { rate, .. } = tts.supported_features();
+    if rate {
+        let original_rate = tts.get_rate()?;
+        tts.speak(format!("Current rate: {}", original_rate), false)?;
+        tts.set_rate(tts.max_rate())?;
+        tts.speak("This is very fast.", false)?;
+        tts.set_rate(tts.min_rate())?;
+        tts.speak("This is very slow.", false)?;
+        tts.set_rate(tts.normal_rate())?;
+        tts.speak("This is the normal rate.", false)?;
+        tts.set_rate(original_rate)?;
+    }
+    let Features { pitch, .. } = tts.supported_features();
+    if pitch {
+        let original_pitch = tts.get_pitch()?;
+        tts.set_pitch(tts.max_pitch())?;
+        tts.speak("This is high-pitch.", false)?;
+        tts.set_pitch(tts.min_pitch())?;
+        tts.speak("This is low pitch.", false)?;
+        tts.set_pitch(tts.normal_pitch())?;
+        tts.speak("This is normal pitch.", false)?;
+        tts.set_pitch(original_pitch)?;
+    }
+    let Features { volume, .. } = tts.supported_features();
+    if volume {
+        let original_volume = tts.get_volume()?;
+        tts.set_volume(tts.max_volume())?;
+        tts.speak("This is loud!", false)?;
+        tts.set_volume(tts.min_volume())?;
+        tts.speak("This is quiet.", false)?;
+        tts.set_volume(tts.normal_volume())?;
+        tts.speak("This is normal volume.", false)?;
+        tts.set_volume(original_volume)?;
+    }
+    tts.speak("Goodbye.", false)?;
+    let mut _input = String::new();
+    // The below is only needed to make the example run on MacOS because there is no NSRunLoop in this context.
+    // It shouldn't be needed in an app or game that almost certainly has one already.
+    #[cfg(target_os = "macos")]
+    {
+        let run_loop: id = unsafe { NSRunLoop::currentRunLoop() };
+        unsafe {
+            let _: () = msg_send![run_loop, run];
+        }
+    }
+    io::stdin().read_line(&mut _input)?;
+    Ok(())
+}
+
+#[cfg(target_os = "android")]
+#[cfg_attr(target_os = "android", ndk_glue::main(backtrace = "on"))]
+fn main() {
+    run().expect("Failed to run");
+}