Correctly clean up callback references based on whether `Arc` remains cloned on drop.

This commit is contained in:
Nolan Darilek 2022-03-10 11:12:46 -06:00
parent 5944794980
commit 888e6a3dfa
2 changed files with 94 additions and 3 deletions

89
examples/clone_drop.rs Normal file
View File

@ -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::*;
fn main() -> Result<(), Error> {
env_logger::init();
let tts = Tts::default()?;
let mut tts_clone = tts.clone();
drop(tts);
if Tts::screen_reader_available() {
println!("A screen reader is available on this platform.");
} else {
println!("No screen reader is available on this platform.");
}
let Features {
utterance_callbacks,
..
} = tts_clone.supported_features();
if utterance_callbacks {
tts_clone.on_utterance_begin(Some(Box::new(|utterance| {
println!("Started speaking {:?}", utterance)
})))?;
tts_clone.on_utterance_end(Some(Box::new(|utterance| {
println!("Finished speaking {:?}", utterance)
})))?;
tts_clone.on_utterance_stop(Some(Box::new(|utterance| {
println!("Stopped speaking {:?}", utterance)
})))?;
}
let Features { is_speaking, .. } = tts_clone.supported_features();
if is_speaking {
println!("Are we speaking? {}", tts_clone.is_speaking()?);
}
tts_clone.speak("Hello, world.", false)?;
let Features { rate, .. } = tts_clone.supported_features();
if rate {
let original_rate = tts_clone.get_rate()?;
tts_clone.speak(format!("Current rate: {}", original_rate), false)?;
tts_clone.set_rate(tts_clone.max_rate())?;
tts_clone.speak("This is very fast.", false)?;
tts_clone.set_rate(tts_clone.min_rate())?;
tts_clone.speak("This is very slow.", false)?;
tts_clone.set_rate(tts_clone.normal_rate())?;
tts_clone.speak("This is the normal rate.", false)?;
tts_clone.set_rate(original_rate)?;
}
let Features { pitch, .. } = tts_clone.supported_features();
if pitch {
let original_pitch = tts_clone.get_pitch()?;
tts_clone.set_pitch(tts_clone.max_pitch())?;
tts_clone.speak("This is high-pitch.", false)?;
tts_clone.set_pitch(tts_clone.min_pitch())?;
tts_clone.speak("This is low pitch.", false)?;
tts_clone.set_pitch(tts_clone.normal_pitch())?;
tts_clone.speak("This is normal pitch.", false)?;
tts_clone.set_pitch(original_pitch)?;
}
let Features { volume, .. } = tts_clone.supported_features();
if volume {
let original_volume = tts_clone.get_volume()?;
tts_clone.set_volume(tts_clone.max_volume())?;
tts_clone.speak("This is loud!", false)?;
tts_clone.set_volume(tts_clone.min_volume())?;
tts_clone.speak("This is quiet.", false)?;
tts_clone.set_volume(tts_clone.normal_volume())?;
tts_clone.speak("This is normal volume.", false)?;
tts_clone.set_volume(original_volume)?;
}
tts_clone.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(())
}

View File

@ -656,9 +656,11 @@ impl Tts {
impl Drop for Tts {
fn drop(&mut self) {
if let Some(id) = self.0.read().unwrap().id() {
let mut callbacks = CALLBACKS.lock().unwrap();
callbacks.remove(&id);
if Arc::strong_count(&self.0) <= 1 {
if let Some(id) = self.0.read().unwrap().id() {
let mut callbacks = CALLBACKS.lock().unwrap();
callbacks.remove(&id);
}
}
}
}