From bd57075d53fcce210a6411ebb8d4d0b0e937a56c Mon Sep 17 00:00:00 2001
From: Nolan Darilek <nolan@thewordnerd.info>
Date: Wed, 23 Sep 2020 11:28:56 -0500
Subject: [PATCH] Implement unused framework for AVFoundation callbacks.

---
 src/backends/appkit.rs        | 10 +++++++---
 src/backends/av_foundation.rs | 27 ++++++++++++++++++++++-----
 src/backends/mod.rs           |  4 ++--
 src/lib.rs                    |  4 +++-
 4 files changed, 34 insertions(+), 11 deletions(-)

diff --git a/src/backends/appkit.rs b/src/backends/appkit.rs
index 4b9a089..647cc3f 100644
--- a/src/backends/appkit.rs
+++ b/src/backends/appkit.rs
@@ -7,12 +7,12 @@ use objc::declare::ClassDecl;
 use objc::runtime::*;
 use objc::*;
 
-use crate::{Backend, Error, Features, UtteranceId};
+use crate::{Backend, BackendId, Error, Features, UtteranceId};
 
-pub struct AppKit(*mut Object, *mut Object);
+pub(crate) struct AppKit(*mut Object, *mut Object);
 
 impl AppKit {
-    pub fn new() -> Self {
+    pub(crate) fn new() -> Self {
         info!("Initializing AppKit backend");
         unsafe {
             let obj: *mut Object = msg_send![class!(NSSpeechSynthesizer), new];
@@ -91,6 +91,10 @@ impl AppKit {
 }
 
 impl Backend for AppKit {
+    fn id(&self) -> Option<BackendId> {
+        None
+    }
+
     fn supported_features(&self) -> Features {
         Features {
             stop: true,
diff --git a/src/backends/av_foundation.rs b/src/backends/av_foundation.rs
index be1eb6d..bdd5620 100644
--- a/src/backends/av_foundation.rs
+++ b/src/backends/av_foundation.rs
@@ -1,36 +1,52 @@
 #[cfg(any(target_os = "macos", target_os = "ios"))]
 #[link(name = "AVFoundation", kind = "framework")]
+use std::sync::Mutex;
+
 use cocoa_foundation::base::{id, nil};
 use cocoa_foundation::foundation::NSString;
+use lazy_static::lazy_static;
 use log::{info, trace};
 use objc::runtime::*;
 use objc::*;
 
-use crate::{Backend, Error, Features, UtteranceId};
+use crate::{Backend, BackendId, Error, Features, UtteranceId};
 
-pub struct AvFoundation {
+pub(crate) struct AvFoundation {
+    id: BackendId,
     synth: *mut Object,
     rate: f32,
     volume: f32,
     pitch: f32,
 }
 
+lazy_static! {
+    static ref NEXT_BACKEND_ID: Mutex<u64> = Mutex::new(0);
+}
+
 impl AvFoundation {
-    pub fn new() -> Self {
+    pub(crate) fn new() -> Self {
         info!("Initializing AVFoundation backend");
-        unsafe {
+        let mut backend_id = NEXT_BACKEND_ID.lock().unwrap();
+        let rv = unsafe {
             let synth: *mut Object = msg_send![class!(AVSpeechSynthesizer), new];
             AvFoundation {
+                id: BackendId::AvFoundation(*backend_id),
                 synth: synth,
                 rate: 0.5,
                 volume: 1.,
                 pitch: 1.,
             }
-        }
+        };
+        *backend_id += 1;
+        rv
     }
 }
 
 impl Backend for AvFoundation {
+    fn id(&self) -> Option<BackendId> {
+        Some(self.id)
+    }
+
     fn supported_features(&self) -> Features {
         Features {
             stop: true,
@@ -38,6 +54,7 @@ impl Backend for AvFoundation {
             pitch: true,
             volume: true,
             is_speaking: true,
+            utterance_callbacks: true,
         }
     }
 
diff --git a/src/backends/mod.rs b/src/backends/mod.rs
index a9f094f..3e7106b 100644
--- a/src/backends/mod.rs
+++ b/src/backends/mod.rs
@@ -26,7 +26,7 @@ pub use self::tolk::*;
 pub use self::web::*;
 
 #[cfg(target_os = "macos")]
-pub use self::appkit::*;
+pub(crate) use self::appkit::*;
 
 #[cfg(any(target_os = "macos", target_os = "ios"))]
-pub use self::av_foundation::*;
+pub(crate) use self::av_foundation::*;
diff --git a/src/lib.rs b/src/lib.rs
index b9d4aba..ced1f17 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -55,7 +55,7 @@ pub enum BackendId {
     #[cfg(windows)]
     WinRT(u64),
     #[cfg(any(target_os = "macos", target_os = "ios"))]
-    AvFoundation(id),
+    AvFoundation(u64),
 }
 
 #[derive(Clone, Debug, PartialEq)]
@@ -66,6 +66,8 @@ pub enum UtteranceId {
     Web(u64),
     #[cfg(windows)]
     WinRT(MediaPlaybackItem),
+    #[cfg(any(target_os = "macos", target_os = "ios"))]
+    AvFoundation(id),
 }
 
 pub struct Features {