2024-11-13 06:29:36 +00:00
53 changed files with 423 additions and 2891 deletions
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@ -1,21 +1,69 @@
-name: Release
-
-on:
-  push:
-    tags:
-      - "v*"
-
-jobs:
-  publish:
-    name: Publish
-    runs-on: ubuntu-22.04
-    env:
-      CARGO_TOKEN: ${{ secrets.CARGO_TOKEN }}
-    steps:
-      - uses: actions/checkout@v4
-      - run: |
-          sudo apt-get update
-          sudo apt-get install -y libspeechd-dev
-          cargo login $CARGO_TOKEN
-          rustup toolchain install stable
-          cargo publish
+name: Release
+
+on:
+  push:
+    tags:
+      - "v*"
+
+jobs:
+
+  build_linux:
+    name: Build Linux
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - run: |
+          sudo apt-get update
+          sudo apt-get install -y libspeechd-dev
+          cargo build --release
+          rustup target add wasm32-unknown-unknown
+          cargo build --release --target wasm32-unknown-unknown
+
+  build_windows:
+    name: Build Windows
+    runs-on: windows-latest
+    steps:
+      - uses: actions/checkout@v2
+      - run: |
+          choco install -y llvm
+          cargo build --release
+
+  build_macos:
+    name: Build MacOS
+    runs-on: macos-latest
+    steps:
+      - uses: actions/checkout@v2
+      - run: |
+          cargo build --release
+          rustup target add aarch64-apple-ios x86_64-apple-ios
+          cargo install cargo-lipo
+          cargo lipo --release
+
+  publish_winrt_bindings:
+    name: Publish winrt_bindings
+    runs-on: windows-latest
+    needs: [build_windows]
+    env:
+      CARGO_TOKEN: ${{ secrets.CARGO_TOKEN }}
+    steps:
+      - uses: actions/checkout@v2
+      - run: |
+          choco install -y llvm
+          cargo login $CARGO_TOKEN
+          cd winrt_bindings
+          cargo package
+          cargo publish || true
+
+  publish:
+    name: Publish
+    runs-on: ubuntu-latest
+    needs: [build_linux, build_windows, build_macos]
+    env:
+      CARGO_TOKEN: ${{ secrets.CARGO_TOKEN }}
+    steps:
+      - uses: actions/checkout@v2
+      - run: |
+          sudo apt-get update
+          sudo apt-get install -y libspeechd-dev
+          cargo login $CARGO_TOKEN
+          cargo publish
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@ -1,62 +1,39 @@
-name: Test
-
-on:
-  push:
-  pull_request:
-
-jobs:
-  check_formatting:
-    name: Check Formatting
-    runs-on: ubuntu-22.04
-    steps:
-      - uses: actions/checkout@v4
-      - run: |
-          rustup toolchain install stable
-          cargo fmt --all --check
-          cd examples/web
-          cargo fmt --all --check
-
-  check:
-    name: Check
-    strategy:
-      matrix:
-        os: [windows-latest, ubuntu-22.04, macos-latest]
-    runs-on: ${{ matrix.os }}
-    steps:
-      - uses: actions/checkout@v4
-      - run: sudo apt-get update; sudo apt-get install -y libspeechd-dev
-        if: ${{ runner.os == 'Linux' }}
-      - run: |
-          rustup toolchain install stable
-          cargo clippy --all-targets
-
-  check_web:
-    name: Check Web
-    runs-on: ubuntu-22.04
-    steps:
-      - uses: actions/checkout@v4
-      - run: |
-          rustup target add wasm32-unknown-unknown
-          rustup toolchain install stable
-          cargo clippy --all-targets --target wasm32-unknown-unknown
-
-  check_android:
-    name: Check Android
-    runs-on: ubuntu-22.04
-    steps:
-      - uses: actions/checkout@v4
-      - run: |
-          rustup target add aarch64-linux-android
-          rustup toolchain install stable
-          cargo clippy --all-targets --target aarch64-linux-android
-
-  check_web_example:
-    name: Check Web Example
-    runs-on: ubuntu-22.04
-    steps:
-      - uses: actions/checkout@v4
-      - run: |
-          rustup target add wasm32-unknown-unknown
-          rustup toolchain install stable
-          cd examples/web
-          cargo build --target wasm32-unknown-unknown
+name: Test
+
+on:
+  push:
+  pull_request:
+
+jobs:
+
+  build_linux:
+    name: Build Linux
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - run: |
+          sudo apt-get update
+          sudo apt-get install -y libspeechd-dev
+          cargo build --release
+          rustup target add wasm32-unknown-unknown
+          cargo build --release --target wasm32-unknown-unknown
+
+  build_windows:
+    name: Build Windows
+    runs-on: windows-latest
+    steps:
+      - uses: actions/checkout@v2
+      - run: |
+          choco install -y llvm
+          cargo build --release
+
+  build_macos:
+    name: Build MacOS
+    runs-on: macos-latest
+    steps:
+      - uses: actions/checkout@v2
+      - run: |
+          cargo build --release
+          rustup target add aarch64-apple-ios x86_64-apple-ios
+          cargo install cargo-lipo
+          cargo lipo --release
--- a/.gitignore
+++ b/.gitignore
@ -1,3 +1,2 @@
 Cargo.lock
 target
-*.dll
--- a/Cargo.toml
+++ b/Cargo.toml
@ -1,71 +1,36 @@
 [package]
 name = "tts"
-version = "0.26.3"
+version = "0.6.0"
 authors = ["Nolan Darilek <nolan@thewordnerd.info>"]
 repository = "https://github.com/ndarilek/tts-rs"
 description = "High-level Text-To-Speech (TTS) interface"
-documentation = "https://docs.rs/tts"
 license = "MIT"
 exclude = ["*.cfg", "*.yml"]
-edition = "2021"
+edition = "2018"

 [lib]
-crate-type = ["lib", "cdylib", "staticlib"]
-
-[features]
-speech_dispatcher_0_9 = ["speech-dispatcher/0_9"]
-speech_dispatcher_0_10 = ["speech-dispatcher/0_10"]
-speech_dispatcher_0_11 = ["speech-dispatcher/0_11"]
-default = ["speech_dispatcher_0_11"]
+crate-type = ["lib", "staticlib"]

 [dependencies]
-dyn-clonable = "0.9"
-oxilangtag = "0.1"
-lazy_static = "1"
 log = "0.4"
-serde = { version = "1", optional = true, features = ["derive"] }
 thiserror = "1"

 [dev-dependencies]
-env_logger = "0.11"
+env_logger = "0.7"

 [target.'cfg(windows)'.dependencies]
-tolk = { version = "0.5", optional = true }
-windows = { version = "0.58", features = [
-    "Foundation",
-    "Foundation_Collections",
-    "Media_Core",
-    "Media_Playback",
-    "Media_SpeechSynthesis",
-    "Storage_Streams",
-] }
+tolk = "0.2"
+winrt = "0.7"
+tts_winrt_bindings = { version = "0.1", path="winrt_bindings" }

 [target.'cfg(target_os = "linux")'.dependencies]
-speech-dispatcher = { version = "0.16", default-features = false }
+speech-dispatcher = "0.4"

 [target.'cfg(any(target_os = "macos", target_os = "ios"))'.dependencies]
 cocoa-foundation = "0.1"
-core-foundation = "0.9"
 libc = "0.2"
-objc = { version = "0.2", features = ["exception"] }
+objc = "0.2"

 [target.wasm32-unknown-unknown.dependencies]
 wasm-bindgen = "0.2"
-web-sys = { version = "0.3", features = [
-    "EventTarget",
-    "SpeechSynthesis",
-    "SpeechSynthesisErrorCode",
-    "SpeechSynthesisErrorEvent",
-    "SpeechSynthesisEvent",
-    "SpeechSynthesisUtterance",
-    "SpeechSynthesisVoice",
-    "Window",
-] }
-
-[target.'cfg(target_os="android")'.dependencies]
-jni = "0.21"
-ndk-context = "0.1"
-
-[package.metadata.docs.rs]
-no-default-features = true
-features = ["speech_dispatcher_0_11"]
+web-sys = { version = "0.3", features = ["SpeechSynthesis", "SpeechSynthesisUtterance", "Window", ] }
--- a/Makefile.toml
+++ b/Makefile.toml
@ -1,33 +0,0 @@
-[tasks.build-android-example]
-script = [
-    "cd examples/android",
-    "./gradlew assembleDebug",
-]
-
-[tasks.run-android-example]
-script = [
-    "cd examples/android",
-    "./gradlew runDebug",
-]
-
-[tasks.log-android]
-command = "adb"
-args = ["logcat", "RustStdoutStderr:D", "*:S"]
-
-[tasks.install-trunk]
-install_crate = { crate_name = "trunk", binary = "trunk", test_arg = "--help" }
-
-[tasks.install-wasm-bindgen-cli]
-install_crate = { crate_name = "wasm-bindgen-cli", binary = "wasm-bindgen", test_arg = "--help" }
-
-[tasks.build-web-example]
-dependencies = ["install-trunk", "install-wasm-bindgen-cli"]
-cwd = "examples/web"
-command = "trunk"
-args = ["build"]
-
-[tasks.run-web-example]
-dependencies = ["install-trunk", "install-wasm-bindgen-cli"]
-cwd = "examples/web"
-command = "trunk"
-args = ["serve"]
--- a/README.md
+++ b/README.md
@ -3,23 +3,10 @@
 This library provides a high-level Text-To-Speech (TTS) interface supporting various backends. Currently supported backends are:

 * Windows
-  * Screen readers/SAPI via Tolk (requires `tolk` Cargo feature)
+  * Screen readers/SAPI via Tolk
  * WinRT
 * Linux via [Speech Dispatcher](https://freebsoft.org/speechd)
-* MacOS/iOS
+* MacOS
  * AppKit on MacOS 10.13 and below
  * AVFoundation on MacOS 10.14 and above, and iOS
-* Android
 * WebAssembly
-
-## Android Setup
-
-On most platforms, this library is plug-and-play. Because of JNI's complexity, Android setup is a bit more involved. In general, look to the Android example for guidance. Here are some rough steps to get going:
-
-* Set up _Cargo.toml_ as the example does. Be sure to depend on `ndk-glue`.
-* Place _Bridge.java_ appropriately in your app. This is needed to support various Android TTS callbacks.
-* Create a main activity similar to _MainActivity.kt_. In particular, you need to derive `android.app.NativeActivity`, and you need a `System.loadLibrary(...)` call appropriate for your app. `System.loadLibrary(...)` is needed to trigger `JNI_OnLoad`.
-* * Even though you've loaded the library in your main activity, add a metadata tag to your activity in _AndroidManifest.xml_ referencing it. Yes, this is redundant but necessary.
-* Set if your various build.gradle scripts to reference the plugins, dependencies, etc. from the example. In particular, you'll want to set up [cargo-ndk-android-gradle](https://github.com/willir/cargo-ndk-android-gradle/) and either [depend on androidx.annotation](https://developer.android.com/reference/androidx/annotation/package-summary) or otherwise configure your app to keep the class _rs.tts.Bridge_.
-
-And I think that should about do it. Good luck!
--- a/build.rs
+++ b/build.rs
@ -1,11 +1,15 @@
+// Copyright 2013-2015 The Servo Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
 fn main() {
    if std::env::var("TARGET").unwrap().contains("-apple") {
+        println!("cargo:rustc-link-lib=framework=AppKit");
        println!("cargo:rustc-link-lib=framework=AVFoundation");
-        if !std::env::var("CARGO_CFG_TARGET_OS")
-            .unwrap()
-            .contains("ios")
-        {
-            println!("cargo:rustc-link-lib=framework=AppKit");
-        }
    }
 }
--- a/examples/99bottles.rs
+++ b/examples/99bottles.rs
@ -1,39 +0,0 @@
-use std::io;
-use std::{thread, time};
-
-#[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 mut tts = Tts::default()?;
-    let mut bottles = 99;
-    while bottles > 0 {
-        tts.speak(format!("{} bottles of beer on the wall,", bottles), false)?;
-        tts.speak(format!("{} bottles of beer,", bottles), false)?;
-        tts.speak("Take one down, pass it around", false)?;
-        tts.speak("Give us a bit to drink this...", false)?;
-        let time = time::Duration::from_secs(15);
-        thread::sleep(time);
-        bottles -= 1;
-        tts.speak(format!("{} bottles of beer on the wall,", bottles), 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(())
-}
--- a/examples/android/.gitignore
+++ b/examples/android/.gitignore
@ -1,16 +0,0 @@
-*.iml
-.gradle
-/local.properties
-/.idea/caches
-/.idea/libraries
-/.idea/modules.xml
-/.idea/workspace.xml
-/.idea/navEditor.xml
-/.idea/assetWizardSettings.xml
-.DS_Store
-/build
-/captures
-.externalNativeBuild
-.cxx
-local.properties
-Cargo.lock
--- a/examples/android/.idea/.gitignore
+++ b/examples/android/.idea/.gitignore
@ -1,3 +0,0 @@
-# Default ignored files
-/shelf/
-/workspace.xml
--- a/examples/android/.idea/compiler.xml
+++ b/examples/android/.idea/compiler.xml
@ -1,6 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<project version="4">
-  <component name="CompilerConfiguration">
-    <bytecodeTargetLevel target="1.6" />
-  </component>
-</project>
--- a/examples/android/.idea/gradle.xml
+++ b/examples/android/.idea/gradle.xml
@ -1,21 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<project version="4">
-  <component name="GradleMigrationSettings" migrationVersion="1" />
-  <component name="GradleSettings">
-    <option name="linkedExternalProjectsSettings">
-      <GradleProjectSettings>
-        <option name="testRunner" value="PLATFORM" />
-        <option name="distributionType" value="DEFAULT_WRAPPED" />
-        <option name="externalProjectPath" value="$PROJECT_DIR$" />
-        <option name="gradleJvm" value="11" />
-        <option name="modules">
-          <set>
-            <option value="$PROJECT_DIR$" />
-          </set>
-        </option>
-        <option name="resolveModulePerSourceSet" value="false" />
-        <option name="useQualifiedModuleNames" value="true" />
-      </GradleProjectSettings>
-    </option>
-  </component>
-</project>
--- a/examples/android/.idea/jarRepositories.xml
+++ b/examples/android/.idea/jarRepositories.xml
@ -1,25 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<project version="4">
-  <component name="RemoteRepositoriesConfiguration">
-    <remote-repository>
-      <option name="id" value="central" />
-      <option name="name" value="Maven Central repository" />
-      <option name="url" value="https://repo1.maven.org/maven2" />
-    </remote-repository>
-    <remote-repository>
-      <option name="id" value="jboss.community" />
-      <option name="name" value="JBoss Community repository" />
-      <option name="url" value="https://repository.jboss.org/nexus/content/repositories/public/" />
-    </remote-repository>
-    <remote-repository>
-      <option name="id" value="BintrayJCenter" />
-      <option name="name" value="BintrayJCenter" />
-      <option name="url" value="https://jcenter.bintray.com/" />
-    </remote-repository>
-    <remote-repository>
-      <option name="id" value="Google" />
-      <option name="name" value="Google" />
-      <option name="url" value="https://dl.google.com/dl/android/maven2/" />
-    </remote-repository>
-  </component>
-</project>
--- a/examples/android/.idea/misc.xml
+++ b/examples/android/.idea/misc.xml
@ -1,9 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<project version="4">
-  <component name="ProjectRootManager" version="2" languageLevel="JDK_1_6" default="false" project-jdk-name="1.8" project-jdk-type="JavaSDK">
-    <output url="file://$PROJECT_DIR$/build/classes" />
-  </component>
-  <component name="ProjectType">
-    <option name="id" value="Android" />
-  </component>
-</project>
--- a/examples/android/.idea/vcs.xml
+++ b/examples/android/.idea/vcs.xml
@ -1,6 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<project version="4">
-  <component name="VcsDirectoryMappings">
-    <mapping directory="$PROJECT_DIR$/../.." vcs="Git" />
-  </component>
-</project>
--- a/examples/android/app/.gitignore
+++ b/examples/android/app/.gitignore
@ -1 +0,0 @@
-/build
--- a/examples/android/app/build.gradle
+++ b/examples/android/app/build.gradle
@ -1,56 +0,0 @@
-plugins {
-    id "com.android.application"
-    id "org.mozilla.rust-android-gradle.rust-android"
-}
-
-android {
-    namespace "rs.tts"
-    compileSdkVersion 33
-    ndkVersion "25.1.8937393"
-    defaultConfig {
-        applicationId "rs.tts"
-        minSdkVersion 21
-        targetSdkVersion 33
-        versionCode 1
-        versionName "1.0"
-    }
-
-    buildTypes {
-        release {
-            minifyEnabled false
-            proguardFiles getDefaultProguardFile("proguard-android-optimize.txt"), "proguard-rules.pro"
-        }
-    }
-}
-
-dependencies {
-    implementation "androidx.core:core-ktx:1.2.0"
-    implementation "androidx.annotation:annotation:1.1.0"
-    implementation "com.google.android.material:material:1.1.0"
-    implementation "androidx.constraintlayout:constraintlayout:1.1.3"
-}
-
-apply plugin: "org.mozilla.rust-android-gradle.rust-android"
-
-cargo {
-    module  = "."
-    libname = "tts"
-    targets = ["arm", "x86"]
-}
-
-tasks.whenTaskAdded { task ->
-    if ((task.name == 'javaPreCompileDebug' || task.name == 'javaPreCompileRelease')) {
-        task.dependsOn "cargoBuild"
-    }
-}
-
-project.afterEvaluate {
-    android.applicationVariants.all { variant ->
-        task "run${variant.name.capitalize()}"(type: Exec, dependsOn: "install${variant.name.capitalize()}", group: "run") {
-            commandLine = ["adb", "shell", "monkey", "-p", variant.applicationId + " 1"]
-            doLast {
-                println "Launching ${variant.applicationId}"
-            }
-        }
-    }
-}
--- a/examples/android/app/proguard-rules.pro
+++ b/examples/android/app/proguard-rules.pro
@ -1,21 +0,0 @@
-# Add project specific ProGuard rules here.
-# You can control the set of applied configuration files using the
-# proguardFiles setting in build.gradle.
-#
-# For more details, see
-#   http://developer.android.com/guide/developing/tools/proguard.html
-
-# If your project uses WebView with JS, uncomment the following
-# and specify the fully qualified class name to the JavaScript interface
-# class:
-#-keepclassmembers class fqcn.of.javascript.interface.for.webview {
-#   public *;
-#}
-
-# Uncomment this to preserve the line number information for
-# debugging stack traces.
-#-keepattributes SourceFile,LineNumberTable
-
-# If you keep the line number information, uncomment this to
-# hide the original source file name.
-#-renamesourcefileattribute SourceFile
--- a/examples/android/app/src/main/.gitignore
+++ b/examples/android/app/src/main/.gitignore
@ -1 +0,0 @@
-jniLibs
--- a/examples/android/app/src/main/AndroidManifest.xml
+++ b/examples/android/app/src/main/AndroidManifest.xml
@ -1,13 +0,0 @@
-<?xml version="1.0" encoding="utf-8"?>
-<manifest xmlns:android="http://schemas.android.com/apk/res/android">
-
-    <application android:allowBackup="true" android:label="@string/app_name">
-        <activity android:name=".MainActivity" android:exported="true">
-            <meta-data android:name="android.app.lib_name" android:value="hello_world" />
-            <intent-filter>
-                <action android:name="android.intent.action.MAIN" />
-                <category android:name="android.intent.category.LAUNCHER" />
-            </intent-filter>
-        </activity>
-    </application>
-</manifest>
--- a/examples/android/app/src/main/java/rs/tts/Bridge.java
+++ b/examples/android/app/src/main/java/rs/tts/Bridge.java
@ -1,24 +0,0 @@
-package rs.tts;
-
-import android.speech.tts.TextToSpeech;
-import android.speech.tts.UtteranceProgressListener;
-
-@androidx.annotation.Keep
-public class Bridge extends UtteranceProgressListener implements TextToSpeech.OnInitListener {
-    public int backendId;
-
-    public Bridge(int backendId) {
-        this.backendId = backendId;
-    }
-
-    public native void onInit(int status);
-
-    public native void onStart(String utteranceId);
-
-    public native void onStop(String utteranceId, Boolean interrupted);
-
-    public native void onDone(String utteranceId);
-
-    public native void onError(String utteranceId) ;
-
-}
--- a/examples/android/app/src/main/java/rs/tts/MainActivity.kt
+++ b/examples/android/app/src/main/java/rs/tts/MainActivity.kt
@ -1,11 +0,0 @@
-package rs.tts
-
-import android.app.NativeActivity
-
-class MainActivity : NativeActivity() {
-    companion object {
-        init {
-            System.loadLibrary("hello_world")
-        }
-    }
-}
--- a/examples/android/app/src/main/res/values/strings.xml
+++ b/examples/android/app/src/main/res/values/strings.xml
@ -1,3 +0,0 @@
-<resources>
-    <string name="app_name">TTS-RS</string>
-</resources>
--- a/examples/android/build.gradle
+++ b/examples/android/build.gradle
@ -1,29 +0,0 @@
-// Top-level build file where you can add configuration options common to all sub-projects/modules.
-
-buildscript {                                                                                                                                                                 
-    repositories {                                                                                                                                                            
-        google()                                                                                                                                                              
-        mavenCentral()                                                                                                                                                        
-        maven {
-            url "https://plugins.gradle.org/m2/"
-        }
-    }                                                                                                                                                                         
-}                                                                                                                                                                             
-
-plugins {
-    id "com.android.application" version "7.3.0" apply false
-    id "com.android.library" version "7.3.0" apply false
-    id "org.jetbrains.kotlin.android" version "1.7.21" apply false
-    id "org.mozilla.rust-android-gradle.rust-android" version "0.9.3" apply false
-}
-
-allprojects {
-    repositories {
-        google()
-        mavenCentral()
-    }                                                                                                                                                                         
-}                                                                                                                                                                             
-
-task clean(type: Delete) {
-    delete rootProject.buildDir
-}
--- a/examples/android/cargo.toml
+++ b/examples/android/cargo.toml
@ -1,14 +0,0 @@
-[package]
-name = "hello_world"
-version = "0.1.0"
-authors = ["Nolan Darilek <nolan@thewordnerd.info>"]
-edition = "2021"
-
-# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
-
-[lib]
-crate-type = ["dylib"]
-
-[dependencies]
-ndk-glue = "0.7"
-tts = { path = "../.." }
--- a/examples/android/gradle.properties
+++ b/examples/android/gradle.properties
@ -1,21 +0,0 @@
-# Project-wide Gradle settings.
-# IDE (e.g. Android Studio) users:
-# Gradle settings configured through the IDE *will override*
-# any settings specified in this file.
-# For more details on how to configure your build environment visit
-# http://www.gradle.org/docs/current/userguide/build_environment.html
-# Specifies the JVM arguments used for the daemon process.
-# The setting is particularly useful for tweaking memory settings.
-org.gradle.jvmargs=-Xmx2048m -Dfile.encoding=UTF-8
-# When configured, Gradle will run in incubating parallel mode.
-# This option should only be used with decoupled projects. More details, visit
-# http://www.gradle.org/docs/current/userguide/multi_project_builds.html#sec:decoupled_projects
-# org.gradle.parallel=true
-# AndroidX package structure to make it clearer which packages are bundled with the
-# Android operating system, and which are packaged with your app"s APK
-# https://developer.android.com/topic/libraries/support-library/androidx-rn
-android.useAndroidX=true
-# Automatically convert third-party libraries to use AndroidX
-android.enableJetifier=true
-# Kotlin code style for this project: "official" or "obsolete":
-kotlin.code.style=official
--- a/examples/android/gradle/wrapper/gradle-wrapper.jar
+++ b/examples/android/gradle/wrapper/gradle-wrapper.jar
--- a/examples/android/gradle/wrapper/gradle-wrapper.properties
+++ b/examples/android/gradle/wrapper/gradle-wrapper.properties
@ -1,6 +0,0 @@
-#Mon Dec 28 17:32:22 CST 2020
-distributionBase=GRADLE_USER_HOME
-distributionPath=wrapper/dists
-zipStoreBase=GRADLE_USER_HOME
-zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-7.5.1-bin.zip
--- a/examples/android/gradlew
+++ b/examples/android/gradlew
@ -1,172 +0,0 @@
-#!/usr/bin/env sh
-
-##############################################################################
-##
-##  Gradle start up script for UN*X
-##
-##############################################################################
-
-# Attempt to set APP_HOME
-# Resolve links: $0 may be a link
-PRG="$0"
-# Need this for relative symlinks.
-while [ -h "$PRG" ] ; do
-    ls=`ls -ld "$PRG"`
-    link=`expr "$ls" : '.*-> \(.*\)$'`
-    if expr "$link" : '/.*' > /dev/null; then
-        PRG="$link"
-    else
-        PRG=`dirname "$PRG"`"/$link"
-    fi
-done
-SAVED="`pwd`"
-cd "`dirname \"$PRG\"`/" >/dev/null
-APP_HOME="`pwd -P`"
-cd "$SAVED" >/dev/null
-
-APP_NAME="Gradle"
-APP_BASE_NAME=`basename "$0"`
-
-# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
-DEFAULT_JVM_OPTS=""
-
-# Use the maximum available, or set MAX_FD != -1 to use that value.
-MAX_FD="maximum"
-
-warn () {
-    echo "$*"
-}
-
-die () {
-    echo
-    echo "$*"
-    echo
-    exit 1
-}
-
-# OS specific support (must be 'true' or 'false').
-cygwin=false
-msys=false
-darwin=false
-nonstop=false
-case "`uname`" in
-  CYGWIN* )
-    cygwin=true
-    ;;
-  Darwin* )
-    darwin=true
-    ;;
-  MINGW* )
-    msys=true
-    ;;
-  NONSTOP* )
-    nonstop=true
-    ;;
-esac
-
-CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar
-
-# Determine the Java command to use to start the JVM.
-if [ -n "$JAVA_HOME" ] ; then
-    if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
-        # IBM's JDK on AIX uses strange locations for the executables
-        JAVACMD="$JAVA_HOME/jre/sh/java"
-    else
-        JAVACMD="$JAVA_HOME/bin/java"
-    fi
-    if [ ! -x "$JAVACMD" ] ; then
-        die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME
-
-Please set the JAVA_HOME variable in your environment to match the
-location of your Java installation."
-    fi
-else
-    JAVACMD="java"
-    which java >/dev/null 2>&1 || die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
-
-Please set the JAVA_HOME variable in your environment to match the
-location of your Java installation."
-fi
-
-# Increase the maximum file descriptors if we can.
-if [ "$cygwin" = "false" -a "$darwin" = "false" -a "$nonstop" = "false" ] ; then
-    MAX_FD_LIMIT=`ulimit -H -n`
-    if [ $? -eq 0 ] ; then
-        if [ "$MAX_FD" = "maximum" -o "$MAX_FD" = "max" ] ; then
-            MAX_FD="$MAX_FD_LIMIT"
-        fi
-        ulimit -n $MAX_FD
-        if [ $? -ne 0 ] ; then
-            warn "Could not set maximum file descriptor limit: $MAX_FD"
-        fi
-    else
-        warn "Could not query maximum file descriptor limit: $MAX_FD_LIMIT"
-    fi
-fi
-
-# For Darwin, add options to specify how the application appears in the dock
-if $darwin; then
-    GRADLE_OPTS="$GRADLE_OPTS \"-Xdock:name=$APP_NAME\" \"-Xdock:icon=$APP_HOME/media/gradle.icns\""
-fi
-
-# For Cygwin, switch paths to Windows format before running java
-if $cygwin ; then
-    APP_HOME=`cygpath --path --mixed "$APP_HOME"`
-    CLASSPATH=`cygpath --path --mixed "$CLASSPATH"`
-    JAVACMD=`cygpath --unix "$JAVACMD"`
-
-    # We build the pattern for arguments to be converted via cygpath
-    ROOTDIRSRAW=`find -L / -maxdepth 1 -mindepth 1 -type d 2>/dev/null`
-    SEP=""
-    for dir in $ROOTDIRSRAW ; do
-        ROOTDIRS="$ROOTDIRS$SEP$dir"
-        SEP="|"
-    done
-    OURCYGPATTERN="(^($ROOTDIRS))"
-    # Add a user-defined pattern to the cygpath arguments
-    if [ "$GRADLE_CYGPATTERN" != "" ] ; then
-        OURCYGPATTERN="$OURCYGPATTERN|($GRADLE_CYGPATTERN)"
-    fi
-    # Now convert the arguments - kludge to limit ourselves to /bin/sh
-    i=0
-    for arg in "$@" ; do
-        CHECK=`echo "$arg"|egrep -c "$OURCYGPATTERN" -`
-        CHECK2=`echo "$arg"|egrep -c "^-"`                                 ### Determine if an option
-
-        if [ $CHECK -ne 0 ] && [ $CHECK2 -eq 0 ] ; then                    ### Added a condition
-            eval `echo args$i`=`cygpath --path --ignore --mixed "$arg"`
-        else
-            eval `echo args$i`="\"$arg\""
-        fi
-        i=$((i+1))
-    done
-    case $i in
-        (0) set -- ;;
-        (1) set -- "$args0" ;;
-        (2) set -- "$args0" "$args1" ;;
-        (3) set -- "$args0" "$args1" "$args2" ;;
-        (4) set -- "$args0" "$args1" "$args2" "$args3" ;;
-        (5) set -- "$args0" "$args1" "$args2" "$args3" "$args4" ;;
-        (6) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" ;;
-        (7) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" ;;
-        (8) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" ;;
-        (9) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" "$args8" ;;
-    esac
-fi
-
-# Escape application args
-save () {
-    for i do printf %s\\n "$i" | sed "s/'/'\\\\''/g;1s/^/'/;\$s/\$/' \\\\/" ; done
-    echo " "
-}
-APP_ARGS=$(save "$@")
-
-# Collect all arguments for the java command, following the shell quoting and substitution rules
-eval set -- $DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS "\"-Dorg.gradle.appname=$APP_BASE_NAME\"" -classpath "\"$CLASSPATH\"" org.gradle.wrapper.GradleWrapperMain "$APP_ARGS"
-
-# by default we should be in the correct project dir, but when run from Finder on Mac, the cwd is wrong
-if [ "$(uname)" = "Darwin" ] && [ "$HOME" = "$PWD" ]; then
-  cd "$(dirname "$0")"
-fi
-
-exec "$JAVACMD" "$@"
--- a/examples/android/gradlew.bat
+++ b/examples/android/gradlew.bat
@ -1,84 +0,0 @@
-@if "%DEBUG%" == "" @echo off
-@rem ##########################################################################
-@rem
-@rem  Gradle startup script for Windows
-@rem
-@rem ##########################################################################
-
-@rem Set local scope for the variables with windows NT shell
-if "%OS%"=="Windows_NT" setlocal
-
-set DIRNAME=%~dp0
-if "%DIRNAME%" == "" set DIRNAME=.
-set APP_BASE_NAME=%~n0
-set APP_HOME=%DIRNAME%
-
-@rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
-set DEFAULT_JVM_OPTS=
-
-@rem Find java.exe
-if defined JAVA_HOME goto findJavaFromJavaHome
-
-set JAVA_EXE=java.exe
-%JAVA_EXE% -version >NUL 2>&1
-if "%ERRORLEVEL%" == "0" goto init
-
-echo.
-echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
-echo.
-echo Please set the JAVA_HOME variable in your environment to match the
-echo location of your Java installation.
-
-goto fail
-
-:findJavaFromJavaHome
-set JAVA_HOME=%JAVA_HOME:"=%
-set JAVA_EXE=%JAVA_HOME%/bin/java.exe
-
-if exist "%JAVA_EXE%" goto init
-
-echo.
-echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME%
-echo.
-echo Please set the JAVA_HOME variable in your environment to match the
-echo location of your Java installation.
-
-goto fail
-
-:init
-@rem Get command-line arguments, handling Windows variants
-
-if not "%OS%" == "Windows_NT" goto win9xME_args
-
-:win9xME_args
-@rem Slurp the command line arguments.
-set CMD_LINE_ARGS=
-set _SKIP=2
-
-:win9xME_args_slurp
-if "x%~1" == "x" goto execute
-
-set CMD_LINE_ARGS=%*
-
-:execute
-@rem Setup the command line
-
-set CLASSPATH=%APP_HOME%\gradle\wrapper\gradle-wrapper.jar
-
-@rem Execute Gradle
-"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -classpath "%CLASSPATH%" org.gradle.wrapper.GradleWrapperMain %CMD_LINE_ARGS%
-
-:end
-@rem End local scope for the variables with windows NT shell
-if "%ERRORLEVEL%"=="0" goto mainEnd
-
-:fail
-rem Set variable GRADLE_EXIT_CONSOLE if you need the _script_ return code instead of
-rem the _cmd.exe /c_ return code!
-if  not "" == "%GRADLE_EXIT_CONSOLE%" exit 1
-exit /b 1
-
-:mainEnd
-if "%OS%"=="Windows_NT" endlocal
-
-:omega
--- a/examples/android/settings.gradle
+++ b/examples/android/settings.gradle
@ -1,8 +0,0 @@
-pluginManagement {
-    repositories {
-        gradlePluginPortal()
-        google()
-        mavenCentral()
-    }
-}
-include ":app"
--- a/examples/android/src/lib.rs
+++ b/examples/android/src/lib.rs
@ -1,70 +0,0 @@
-use tts::*;
-
-// The `loop {}` below only simulates an app loop.
-// Without it, the `TTS` instance gets dropped before callbacks can run.
-#[allow(unreachable_code)]
-fn run() -> Result<(), Error> {
-    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)?;
-    loop {}
-    Ok(())
-}
-
-#[cfg_attr(target_os = "android", ndk_glue::main(backtrace = "on"))]
-pub fn main() {
-    run().expect("Failed to run");
-}
--- a/examples/clone_drop.rs
+++ b/examples/clone_drop.rs
@ -1,89 +0,0 @@
-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()?;
-    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.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 mut tts_clone = tts.clone();
-    drop(tts);
-    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(())
-}
--- a/examples/hello_world.rs
+++ b/examples/hello_world.rs
@ -11,31 +11,7 @@ use tts::*;

 fn main() -> Result<(), Error> {
    env_logger::init();
-    let mut tts = Tts::default()?;
-    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.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()?);
-    }
+    let mut tts = TTS::default()?;
    tts.speak("Hello, world.", false)?;
    let Features { rate, .. } = tts.supported_features();
    if rate {
@ -71,27 +47,8 @@ fn main() -> Result<(), Error> {
        tts.speak("This is normal volume.", false)?;
        tts.set_volume(original_volume)?;
    }
-    let Features { voice, .. } = tts.supported_features();
-    if voice {
-        let voices = tts.voices()?;
-        println!("Available voices:\n===");
-        for v in &voices {
-            println!("{:?}", v);
-        }
-        let Features { get_voice, .. } = tts.supported_features();
-        let original_voice = if get_voice { tts.voice()? } else { None };
-        for v in &voices {
-            tts.set_voice(v)?;
-            tts.speak(format!("This is {}.", v.name()), false)?;
-        }
-        if let Some(original_voice) = original_voice {
-            tts.set_voice(&original_voice)?;
-        }
-    }
    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() };
--- a/examples/latency.rs
+++ b/examples/latency.rs
@ -1,14 +0,0 @@
-use std::io;
-
-use tts::*;
-
-fn main() -> Result<(), Error> {
-    env_logger::init();
-    let mut tts = Tts::default()?;
-    println!("Press Enter and wait for speech.");
-    loop {
-        let mut _input = String::new();
-        io::stdin().read_line(&mut _input)?;
-        tts.speak("Hello, world.", true)?;
-    }
-}
--- a/examples/ramble.rs
+++ b/examples/ramble.rs
@ -1,32 +0,0 @@
-#[cfg(target_os = "macos")]
-use cocoa_foundation::base::id;
-#[cfg(target_os = "macos")]
-use cocoa_foundation::foundation::NSDefaultRunLoopMode;
-#[cfg(target_os = "macos")]
-use cocoa_foundation::foundation::NSRunLoop;
-#[cfg(target_os = "macos")]
-use objc::class;
-#[cfg(target_os = "macos")]
-use objc::{msg_send, sel, sel_impl};
-use std::{thread, time};
-use tts::*;
-
-fn main() -> Result<(), Error> {
-    env_logger::init();
-    let mut tts = Tts::default()?;
-    let mut phrase = 1;
-    loop {
-        tts.speak(format!("Phrase {}", phrase), false)?;
-        #[cfg(target_os = "macos")]
-        {
-            let run_loop: id = unsafe { NSRunLoop::currentRunLoop() };
-            unsafe {
-                let date: id = msg_send![class!(NSDate), distantFuture];
-                let _: () = msg_send![run_loop, runMode:NSDefaultRunLoopMode beforeDate:date];
-            }
-        }
-        let time = time::Duration::from_secs(5);
-        thread::sleep(time);
-        phrase += 1;
-    }
-}
--- a/examples/web/.cargo/config
+++ b/examples/web/.cargo/config
@ -1,2 +0,0 @@
-[build]
-target = "wasm32-unknown-unknown"
--- a/examples/web/.gitignore
+++ b/examples/web/.gitignore
@ -1 +0,0 @@
-dist
--- a/examples/web/Cargo.toml
+++ b/examples/web/Cargo.toml
@ -1,13 +0,0 @@
-[package]
-name = "web"
-version = "0.1.0"
-authors = ["Nolan Darilek <nolan@thewordnerd.info>"]
-edition = "2021"
-
-# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
-
-[dependencies]
-console_log = "0.2"
-log = "0.4"
-seed = "0.9"
-tts = { path = "../.." }
--- a/examples/web/index.html
+++ b/examples/web/index.html
@ -1,12 +0,0 @@
-<!DOCTYPE html>
-<html lang="en">
-
-<head>
-    <title>Example</title>
-</head>
-
-<body>
-    <div id="app"></div>
-</body>
-
-</html>
--- a/examples/web/src/main.rs
+++ b/examples/web/src/main.rs
@ -1,157 +0,0 @@
-#![allow(clippy::wildcard_imports)]
-use seed::{prelude::*, *};
-
-use tts::Tts;
-
-#[derive(Clone)]
-struct Model {
-    text: String,
-    tts: Tts,
-}
-
-#[derive(Clone)]
-enum Msg {
-    TextChanged(String),
-    RateChanged(String),
-    PitchChanged(String),
-    VolumeChanged(String),
-    VoiceChanged(String),
-    Speak,
-}
-
-fn init(_: Url, _: &mut impl Orders<Msg>) -> Model {
-    let mut tts = Tts::default().unwrap();
-    if tts.voices().unwrap().iter().len() > 0 {
-        if tts.voice().unwrap().is_none() {
-            tts.set_voice(tts.voices().unwrap().first().unwrap())
-                .expect("Failed to set voice");
-        }
-    }
-    Model {
-        text: "Hello, world. This is a test of the current text-to-speech values.".into(),
-        tts,
-    }
-}
-
-fn update(msg: Msg, model: &mut Model, _: &mut impl Orders<Msg>) {
-    use Msg::*;
-    match msg {
-        TextChanged(text) => model.text = text,
-        RateChanged(rate) => {
-            let rate = rate.parse::<f32>().unwrap();
-            model.tts.set_rate(rate).unwrap();
-        }
-        PitchChanged(pitch) => {
-            let pitch = pitch.parse::<f32>().unwrap();
-            model.tts.set_pitch(pitch).unwrap();
-        }
-        VolumeChanged(volume) => {
-            let volume = volume.parse::<f32>().unwrap();
-            model.tts.set_volume(volume).unwrap();
-        }
-        VoiceChanged(voice) => {
-            for v in model.tts.voices().unwrap() {
-                if v.id() == voice {
-                    model.tts.set_voice(&v).unwrap();
-                }
-            }
-        }
-        Speak => {
-            model.tts.speak(&model.text, false).unwrap();
-        }
-    }
-}
-
-fn view(model: &Model) -> Node<Msg> {
-    let should_show_voices = model.tts.voices().unwrap().iter().len() > 0;
-    form![
-        div![label![
-            "Text to speak",
-            input![
-                attrs! {
-                    At::Value => model.text,
-                    At::AutoFocus => AtValue::None,
-                },
-                input_ev(Ev::Input, Msg::TextChanged)
-            ],
-        ],],
-        div![label![
-            "Rate",
-            input![
-                attrs! {
-                    At::Type => "number",
-                    At::Value => model.tts.get_rate().unwrap(),
-                    At::Min => model.tts.min_rate(),
-                    At::Max => model.tts.max_rate()
-                },
-                input_ev(Ev::Input, Msg::RateChanged)
-            ],
-        ],],
-        div![label![
-            "Pitch",
-            input![
-                attrs! {
-                    At::Type => "number",
-                    At::Value => model.tts.get_pitch().unwrap(),
-                    At::Min => model.tts.min_pitch(),
-                    At::Max => model.tts.max_pitch()
-                },
-                input_ev(Ev::Input, Msg::PitchChanged)
-            ],
-        ],],
-        div![label![
-            "Volume",
-            input![
-                attrs! {
-                    At::Type => "number",
-                    At::Value => model.tts.get_volume().unwrap(),
-                    At::Min => model.tts.min_volume(),
-                    At::Max => model.tts.max_volume()
-                },
-                input_ev(Ev::Input, Msg::VolumeChanged)
-            ],
-        ],],
-        if should_show_voices {
-            div![
-                label!["Voice"],
-                select![
-                    model.tts.voices().unwrap().iter().map(|v| {
-                        let selected = if let Some(voice) = model.tts.voice().unwrap() {
-                            voice.id() == v.id()
-                        } else {
-                            false
-                        };
-                        option![
-                            attrs! {
-                                At::Value => v.id()
-                            },
-                            if selected {
-                                attrs! {
-                                    At::Selected => selected
-                                }
-                            } else {
-                                attrs! {}
-                            },
-                            v.name()
-                        ]
-                    }),
-                    input_ev(Ev::Change, Msg::VoiceChanged)
-                ]
-            ]
-        } else {
-            div!["Your browser does not seem to support selecting voices."]
-        },
-        button![
-            "Speak",
-            ev(Ev::Click, |e| {
-                e.prevent_default();
-                Msg::Speak
-            }),
-        ],
-    ]
-}
-
-fn main() {
-    console_log::init().expect("Error initializing logger");
-    App::start("app", init, update, view);
-}
--- a/src/backends/android.rs
+++ b/src/backends/android.rs
@ -1,402 +0,0 @@
-#[cfg(target_os = "android")]
-use std::{
-    collections::HashSet,
-    ffi::{CStr, CString},
-    os::raw::c_void,
-    sync::{Mutex, RwLock},
-    thread,
-    time::{Duration, Instant},
-};
-
-use jni::{
-    objects::{GlobalRef, JObject, JString},
-    sys::{jfloat, jint, JNI_VERSION_1_6},
-    JNIEnv, JavaVM,
-};
-use lazy_static::lazy_static;
-use log::{error, info};
-
-use crate::{Backend, BackendId, Error, Features, UtteranceId, Voice, CALLBACKS};
-
-lazy_static! {
-    static ref BRIDGE: Mutex<Option<GlobalRef>> = Mutex::new(None);
-    static ref NEXT_BACKEND_ID: Mutex<u64> = Mutex::new(0);
-    static ref PENDING_INITIALIZATIONS: RwLock<HashSet<u64>> = RwLock::new(HashSet::new());
-    static ref NEXT_UTTERANCE_ID: Mutex<u64> = Mutex::new(0);
-}
-
-#[allow(non_snake_case)]
-#[no_mangle]
-pub extern "system" fn JNI_OnLoad(vm: JavaVM, _: *mut c_void) -> jint {
-    let mut env = vm.get_env().expect("Cannot get reference to the JNIEnv");
-    let b = env
-        .find_class("rs/tts/Bridge")
-        .expect("Failed to find `Bridge`");
-    let b = env
-        .new_global_ref(b)
-        .expect("Failed to create `Bridge` `GlobalRef`");
-    let mut bridge = BRIDGE.lock().unwrap();
-    *bridge = Some(b);
-    JNI_VERSION_1_6
-}
-
-#[no_mangle]
-#[allow(non_snake_case)]
-pub unsafe extern "C" fn Java_rs_tts_Bridge_onInit(mut env: JNIEnv, obj: JObject, status: jint) {
-    let id = env
-        .get_field(obj, "backendId", "I")
-        .expect("Failed to get backend ID")
-        .i()
-        .expect("Failed to cast to int") as u64;
-    let mut pending = PENDING_INITIALIZATIONS.write().unwrap();
-    (*pending).remove(&id);
-    if status != 0 {
-        error!("Failed to initialize TTS engine");
-    }
-}
-
-#[no_mangle]
-#[allow(non_snake_case)]
-pub unsafe extern "C" fn Java_rs_tts_Bridge_onStart(
-    mut env: JNIEnv,
-    obj: JObject,
-    utterance_id: JString,
-) {
-    let backend_id = env
-        .get_field(obj, "backendId", "I")
-        .expect("Failed to get backend ID")
-        .i()
-        .expect("Failed to cast to int") as u64;
-    let backend_id = BackendId::Android(backend_id);
-    let utterance_id = CString::from(CStr::from_ptr(
-        env.get_string(&utterance_id).unwrap().as_ptr(),
-    ))
-    .into_string()
-    .unwrap();
-    let utterance_id = utterance_id.parse::<u64>().unwrap();
-    let utterance_id = UtteranceId::Android(utterance_id);
-    let mut callbacks = CALLBACKS.lock().unwrap();
-    let cb = callbacks.get_mut(&backend_id).unwrap();
-    if let Some(f) = cb.utterance_begin.as_mut() {
-        f(utterance_id);
-    }
-}
-
-#[no_mangle]
-#[allow(non_snake_case)]
-pub unsafe extern "C" fn Java_rs_tts_Bridge_onStop(
-    mut env: JNIEnv,
-    obj: JObject,
-    utterance_id: JString,
-) {
-    let backend_id = env
-        .get_field(obj, "backendId", "I")
-        .expect("Failed to get backend ID")
-        .i()
-        .expect("Failed to cast to int") as u64;
-    let backend_id = BackendId::Android(backend_id);
-    let utterance_id = CString::from(CStr::from_ptr(
-        env.get_string(&utterance_id).unwrap().as_ptr(),
-    ))
-    .into_string()
-    .unwrap();
-    let utterance_id = utterance_id.parse::<u64>().unwrap();
-    let utterance_id = UtteranceId::Android(utterance_id);
-    let mut callbacks = CALLBACKS.lock().unwrap();
-    let cb = callbacks.get_mut(&backend_id).unwrap();
-    if let Some(f) = cb.utterance_end.as_mut() {
-        f(utterance_id);
-    }
-}
-
-#[no_mangle]
-#[allow(non_snake_case)]
-pub unsafe extern "C" fn Java_rs_tts_Bridge_onDone(
-    mut env: JNIEnv,
-    obj: JObject,
-    utterance_id: JString,
-) {
-    let backend_id = env
-        .get_field(obj, "backendId", "I")
-        .expect("Failed to get backend ID")
-        .i()
-        .expect("Failed to cast to int") as u64;
-    let backend_id = BackendId::Android(backend_id);
-    let utterance_id = CString::from(CStr::from_ptr(
-        env.get_string(&utterance_id).unwrap().as_ptr(),
-    ))
-    .into_string()
-    .unwrap();
-    let utterance_id = utterance_id.parse::<u64>().unwrap();
-    let utterance_id = UtteranceId::Android(utterance_id);
-    let mut callbacks = CALLBACKS.lock().unwrap();
-    let cb = callbacks.get_mut(&backend_id).unwrap();
-    if let Some(f) = cb.utterance_stop.as_mut() {
-        f(utterance_id);
-    }
-}
-
-#[no_mangle]
-#[allow(non_snake_case)]
-pub unsafe extern "C" fn Java_rs_tts_Bridge_onError(
-    mut env: JNIEnv,
-    obj: JObject,
-    utterance_id: JString,
-) {
-    let backend_id = env
-        .get_field(obj, "backendId", "I")
-        .expect("Failed to get backend ID")
-        .i()
-        .expect("Failed to cast to int") as u64;
-    let backend_id = BackendId::Android(backend_id);
-    let utterance_id = CString::from(CStr::from_ptr(
-        env.get_string(&utterance_id).unwrap().as_ptr(),
-    ))
-    .into_string()
-    .unwrap();
-    let utterance_id = utterance_id.parse::<u64>().unwrap();
-    let utterance_id = UtteranceId::Android(utterance_id);
-    let mut callbacks = CALLBACKS.lock().unwrap();
-    let cb = callbacks.get_mut(&backend_id).unwrap();
-    if let Some(f) = cb.utterance_end.as_mut() {
-        f(utterance_id);
-    }
-}
-
-#[derive(Clone)]
-pub(crate) struct Android {
-    id: BackendId,
-    tts: GlobalRef,
-    rate: f32,
-    pitch: f32,
-}
-
-impl Android {
-    pub(crate) fn new() -> Result<Self, Error> {
-        info!("Initializing Android backend");
-        let mut backend_id = NEXT_BACKEND_ID.lock().unwrap();
-        let bid = *backend_id;
-        let id = BackendId::Android(bid);
-        *backend_id += 1;
-        drop(backend_id);
-        let ctx = ndk_context::android_context();
-        let vm = unsafe { jni::JavaVM::from_raw(ctx.vm().cast()) }?;
-        let context = unsafe { JObject::from_raw(ctx.context().cast()) };
-        let mut env = vm.attach_current_thread_permanently()?;
-        let bridge = BRIDGE.lock().unwrap();
-        if let Some(bridge) = &*bridge {
-            let bridge = env.new_object(bridge, "(I)V", &[(bid as jint).into()])?;
-            let tts = env.new_object(
-                "android/speech/tts/TextToSpeech",
-                "(Landroid/content/Context;Landroid/speech/tts/TextToSpeech$OnInitListener;)V",
-                &[(&context).into(), (&bridge).into()],
-            )?;
-            env.call_method(
-                &tts,
-                "setOnUtteranceProgressListener",
-                "(Landroid/speech/tts/UtteranceProgressListener;)I",
-                &[(&bridge).into()],
-            )?;
-            {
-                let mut pending = PENDING_INITIALIZATIONS.write().unwrap();
-                (*pending).insert(bid);
-            }
-            let tts = env.new_global_ref(tts)?;
-            // This hack makes my brain bleed.
-            const MAX_WAIT_TIME: Duration = Duration::from_millis(500);
-            let start = Instant::now();
-            // Wait a max of 500ms for initialization, then return an error to avoid hanging.
-            loop {
-                {
-                    let pending = PENDING_INITIALIZATIONS.read().unwrap();
-                    if !(*pending).contains(&bid) {
-                        break;
-                    }
-                    if start.elapsed() > MAX_WAIT_TIME {
-                        return Err(Error::OperationFailed);
-                    }
-                }
-                thread::sleep(Duration::from_millis(5));
-            }
-            Ok(Self {
-                id,
-                tts,
-                rate: 1.,
-                pitch: 1.,
-            })
-        } else {
-            Err(Error::NoneError)
-        }
-    }
-
-    fn vm() -> Result<JavaVM, jni::errors::Error> {
-        let ctx = ndk_context::android_context();
-        unsafe { jni::JavaVM::from_raw(ctx.vm().cast()) }
-    }
-}
-
-impl Backend for Android {
-    fn id(&self) -> Option<BackendId> {
-        Some(self.id)
-    }
-
-    fn supported_features(&self) -> Features {
-        Features {
-            stop: true,
-            rate: true,
-            pitch: true,
-            volume: false,
-            is_speaking: true,
-            utterance_callbacks: true,
-            voice: false,
-            get_voice: false,
-        }
-    }
-
-    fn speak(&mut self, text: &str, interrupt: bool) -> Result<Option<UtteranceId>, Error> {
-        let vm = Self::vm()?;
-        let mut env = vm.get_env()?;
-        let tts = self.tts.as_obj();
-        let text = env.new_string(text)?;
-        let queue_mode = if interrupt { 0 } else { 1 };
-        let mut utterance_id = NEXT_UTTERANCE_ID.lock().unwrap();
-        let uid = *utterance_id;
-        *utterance_id += 1;
-        drop(utterance_id);
-        let id = UtteranceId::Android(uid);
-        let uid = env.new_string(uid.to_string())?;
-        let rv = env.call_method(
-            tts,
-            "speak",
-            "(Ljava/lang/CharSequence;ILandroid/os/Bundle;Ljava/lang/String;)I",
-            &[
-                (&text).into(),
-                queue_mode.into(),
-                (&JObject::null()).into(),
-                (&uid).into(),
-            ],
-        )?;
-        let rv = rv.i()?;
-        if rv == 0 {
-            Ok(Some(id))
-        } else {
-            Err(Error::OperationFailed)
-        }
-    }
-
-    fn stop(&mut self) -> Result<(), Error> {
-        let vm = Self::vm()?;
-        let mut env = vm.get_env()?;
-        let tts = self.tts.as_obj();
-        let rv = env.call_method(tts, "stop", "()I", &[])?;
-        let rv = rv.i()?;
-        if rv == 0 {
-            Ok(())
-        } else {
-            Err(Error::OperationFailed)
-        }
-    }
-
-    fn min_rate(&self) -> f32 {
-        0.1
-    }
-
-    fn max_rate(&self) -> f32 {
-        10.
-    }
-
-    fn normal_rate(&self) -> f32 {
-        1.
-    }
-
-    fn get_rate(&self) -> Result<f32, Error> {
-        Ok(self.rate)
-    }
-
-    fn set_rate(&mut self, rate: f32) -> Result<(), Error> {
-        let vm = Self::vm()?;
-        let mut env = vm.get_env()?;
-        let tts = self.tts.as_obj();
-        let rate = rate as jfloat;
-        let rv = env.call_method(tts, "setSpeechRate", "(F)I", &[rate.into()])?;
-        let rv = rv.i()?;
-        if rv == 0 {
-            self.rate = rate;
-            Ok(())
-        } else {
-            Err(Error::OperationFailed)
-        }
-    }
-
-    fn min_pitch(&self) -> f32 {
-        0.1
-    }
-
-    fn max_pitch(&self) -> f32 {
-        2.
-    }
-
-    fn normal_pitch(&self) -> f32 {
-        1.
-    }
-
-    fn get_pitch(&self) -> Result<f32, Error> {
-        Ok(self.pitch)
-    }
-
-    fn set_pitch(&mut self, pitch: f32) -> Result<(), Error> {
-        let vm = Self::vm()?;
-        let mut env = vm.get_env()?;
-        let tts = self.tts.as_obj();
-        let pitch = pitch as jfloat;
-        let rv = env.call_method(tts, "setPitch", "(F)I", &[pitch.into()])?;
-        let rv = rv.i()?;
-        if rv == 0 {
-            self.pitch = pitch;
-            Ok(())
-        } else {
-            Err(Error::OperationFailed)
-        }
-    }
-
-    fn min_volume(&self) -> f32 {
-        todo!()
-    }
-
-    fn max_volume(&self) -> f32 {
-        todo!()
-    }
-
-    fn normal_volume(&self) -> f32 {
-        todo!()
-    }
-
-    fn get_volume(&self) -> Result<f32, Error> {
-        todo!()
-    }
-
-    fn set_volume(&mut self, _volume: f32) -> Result<(), Error> {
-        todo!()
-    }
-
-    fn is_speaking(&self) -> Result<bool, Error> {
-        let vm = Self::vm()?;
-        let mut env = vm.get_env()?;
-        let tts = self.tts.as_obj();
-        let rv = env.call_method(tts, "isSpeaking", "()Z", &[])?;
-        let rv = rv.z()?;
-        Ok(rv)
-    }
-
-    fn voice(&self) -> Result<Option<Voice>, Error> {
-        unimplemented!()
-    }
-
-    fn voices(&self) -> Result<Vec<Voice>, Error> {
-        unimplemented!()
-    }
-
-    fn set_voice(&mut self, _voice: &Voice) -> Result<(), Error> {
-        unimplemented!()
-    }
-}
--- a/src/backends/appkit.rs
+++ b/src/backends/appkit.rs
@ -1,4 +1,5 @@
 #[cfg(target_os = "macos")]
+#[link(name = "AppKit", kind = "framework")]
 use cocoa_foundation::base::{id, nil};
 use cocoa_foundation::foundation::NSString;
 use log::{info, trace};
@ -6,18 +7,17 @@ use objc::declare::ClassDecl;
 use objc::runtime::*;
 use objc::*;

-use crate::{Backend, BackendId, Error, Features, UtteranceId, Voice};
+use crate::{Backend, Error, Features};

-#[derive(Clone, Debug)]
-pub(crate) struct AppKit(*mut Object, *mut Object);
+pub struct AppKit(*mut Object, *mut Object);

 impl AppKit {
-    pub(crate) fn new() -> Result<Self, Error> {
+    pub fn new() -> Self {
        info!("Initializing AppKit backend");
        unsafe {
            let obj: *mut Object = msg_send![class!(NSSpeechSynthesizer), new];
-            let mut decl = ClassDecl::new("MyNSSpeechSynthesizerDelegate", class!(NSObject))
-                .ok_or(Error::OperationFailed)?;
+            let mut decl =
+                ClassDecl::new("MyNSSpeechSynthesizerDelegate", class!(NSObject)).unwrap();
            decl.add_ivar::<id>("synth");
            decl.add_ivar::<id>("strings");

@ -46,15 +46,13 @@ impl AppKit {
            ) {
                unsafe {
                    let strings: id = *this.get_ivar("strings");
+                    let str: id = msg_send!(strings, firstObject);
+                    let _: () = msg_send![str, release];
+                    let _: () = msg_send!(strings, removeObjectAtIndex:0);
                    let count: u32 = msg_send![strings, count];
                    if count > 0 {
                        let str: id = msg_send!(strings, firstObject);
-                        let _: () = msg_send![str, release];
-                        let _: () = msg_send!(strings, removeObjectAtIndex:0);
-                        if count > 1 {
-                            let str: id = msg_send!(strings, firstObject);
-                            let _: BOOL = msg_send![synth, startSpeakingString: str];
-                        }
+                        let _: BOOL = msg_send![synth, startSpeakingString: str];
                    }
                }
            }
@ -83,37 +81,27 @@ impl AppKit {

            let delegate_class = decl.register();
            let delegate_obj: *mut Object = msg_send![delegate_class, new];
-            delegate_obj
-                .as_mut()
-                .ok_or(Error::OperationFailed)?
-                .set_ivar("synth", obj);
+            delegate_obj.as_mut().unwrap().set_ivar("synth", obj);
            let strings: id = msg_send![class!(NSMutableArray), new];
-            delegate_obj
-                .as_mut()
-                .ok_or(Error::OperationFailed)?
-                .set_ivar("strings", strings);
+            delegate_obj.as_mut().unwrap().set_ivar("strings", strings);
            let _: Object = msg_send![obj, setDelegate: delegate_obj];
-            Ok(AppKit(obj, delegate_obj))
+            AppKit(obj, delegate_obj)
        }
    }
 }

 impl Backend for AppKit {
-    fn id(&self) -> Option<BackendId> {
-        None
-    }
-
    fn supported_features(&self) -> Features {
        Features {
            stop: true,
            rate: true,
+            pitch: false,
            volume: true,
            is_speaking: true,
-            ..Default::default()
        }
    }

-    fn speak(&mut self, text: &str, interrupt: bool) -> Result<Option<UtteranceId>, Error> {
+    fn speak(&mut self, text: &str, interrupt: bool) -> Result<(), Error> {
        trace!("speak({}, {})", text, interrupt);
        if interrupt {
            self.stop()?;
@ -122,7 +110,7 @@ impl Backend for AppKit {
            let str = NSString::alloc(nil).init_str(text);
            let _: () = msg_send![self.1, enqueueAndSpeak: str];
        }
-        Ok(None)
+        Ok(())
    }

    fn stop(&mut self) -> Result<(), Error> {
@ -205,19 +193,7 @@ impl Backend for AppKit {

    fn is_speaking(&self) -> Result<bool, Error> {
        let is_speaking: i8 = unsafe { msg_send![self.0, isSpeaking] };
-        Ok(is_speaking != NO as i8)
-    }
-
-    fn voice(&self) -> Result<Option<Voice>, Error> {
-        unimplemented!()
-    }
-
-    fn voices(&self) -> Result<Vec<Voice>, Error> {
-        unimplemented!()
-    }
-
-    fn set_voice(&mut self, _voice: &Voice) -> Result<(), Error> {
-        unimplemented!()
+        Ok(is_speaking == YES)
    }
 }

--- a/src/backends/av_foundation.rs
+++ b/src/backends/av_foundation.rs
@ -1,165 +1,36 @@
 #[cfg(any(target_os = "macos", target_os = "ios"))]
-use std::sync::Mutex;
-
-use cocoa_foundation::base::{id, nil, NO};
+#[link(name = "AVFoundation", kind = "framework")]
+use cocoa_foundation::base::{id, nil};
 use cocoa_foundation::foundation::NSString;
-use core_foundation::array::CFArray;
-use core_foundation::base::TCFType;
-use core_foundation::string::CFString;
-use lazy_static::lazy_static;
 use log::{info, trace};
-use objc::runtime::{Object, Sel};
-use objc::{class, declare::ClassDecl, msg_send, sel, sel_impl};
-use oxilangtag::LanguageTag;
+use objc::runtime::*;
+use objc::*;

-use crate::{Backend, BackendId, Error, Features, Gender, UtteranceId, Voice, CALLBACKS};
+use crate::{Backend, Error, Features};

-#[derive(Clone, Debug)]
-pub(crate) struct AvFoundation {
-    id: BackendId,
-    delegate: *mut Object,
+pub struct AvFoundation {
    synth: *mut Object,
    rate: f32,
    volume: f32,
    pitch: f32,
-    voice: Option<Voice>,
-}
-
-lazy_static! {
-    static ref NEXT_BACKEND_ID: Mutex<u64> = Mutex::new(0);
 }

 impl AvFoundation {
-    pub(crate) fn new() -> Result<Self, Error> {
+    pub fn new() -> Self {
        info!("Initializing AVFoundation backend");
-        let mut decl = ClassDecl::new("MyNSSpeechSynthesizerDelegate", class!(NSObject))
-            .ok_or(Error::OperationFailed)?;
-        decl.add_ivar::<u64>("backend_id");
-
-        extern "C" fn speech_synthesizer_did_start_speech_utterance(
-            this: &Object,
-            _: Sel,
-            _synth: *const Object,
-            utterance: id,
-        ) {
-            trace!("speech_synthesizer_did_start_speech_utterance");
-            unsafe {
-                let backend_id: u64 = *this.get_ivar("backend_id");
-                let backend_id = BackendId::AvFoundation(backend_id);
-                trace!("Locking callbacks");
-                let mut callbacks = CALLBACKS.lock().unwrap();
-                trace!("Locked");
-                let callbacks = callbacks.get_mut(&backend_id).unwrap();
-                if let Some(callback) = callbacks.utterance_begin.as_mut() {
-                    trace!("Calling utterance_begin");
-                    let utterance_id = UtteranceId::AvFoundation(utterance);
-                    callback(utterance_id);
-                    trace!("Called");
-                }
-            }
-            trace!("Done speech_synthesizer_did_start_speech_utterance");
-        }
-
-        extern "C" fn speech_synthesizer_did_finish_speech_utterance(
-            this: &Object,
-            _: Sel,
-            _synth: *const Object,
-            utterance: id,
-        ) {
-            trace!("speech_synthesizer_did_finish_speech_utterance");
-            unsafe {
-                let backend_id: u64 = *this.get_ivar("backend_id");
-                let backend_id = BackendId::AvFoundation(backend_id);
-                trace!("Locking callbacks");
-                let mut callbacks = CALLBACKS.lock().unwrap();
-                trace!("Locked");
-                let callbacks = callbacks.get_mut(&backend_id).unwrap();
-                if let Some(callback) = callbacks.utterance_end.as_mut() {
-                    trace!("Calling utterance_end");
-                    let utterance_id = UtteranceId::AvFoundation(utterance);
-                    callback(utterance_id);
-                    trace!("Called");
-                }
-            }
-            trace!("Done speech_synthesizer_did_finish_speech_utterance");
-        }
-
-        extern "C" fn speech_synthesizer_did_cancel_speech_utterance(
-            this: &Object,
-            _: Sel,
-            _synth: *const Object,
-            utterance: id,
-        ) {
-            trace!("speech_synthesizer_did_cancel_speech_utterance");
-            unsafe {
-                let backend_id: u64 = *this.get_ivar("backend_id");
-                let backend_id = BackendId::AvFoundation(backend_id);
-                trace!("Locking callbacks");
-                let mut callbacks = CALLBACKS.lock().unwrap();
-                trace!("Locked");
-                let callbacks = callbacks.get_mut(&backend_id).unwrap();
-                if let Some(callback) = callbacks.utterance_stop.as_mut() {
-                    trace!("Calling utterance_stop");
-                    let utterance_id = UtteranceId::AvFoundation(utterance);
-                    callback(utterance_id);
-                    trace!("Called");
-                }
-            }
-            trace!("Done speech_synthesizer_did_cancel_speech_utterance");
-        }
-
        unsafe {
-            decl.add_method(
-                sel!(speechSynthesizer:didStartSpeechUtterance:),
-                speech_synthesizer_did_start_speech_utterance
-                    as extern "C" fn(&Object, Sel, *const Object, id) -> (),
-            );
-            decl.add_method(
-                sel!(speechSynthesizer:didFinishSpeechUtterance:),
-                speech_synthesizer_did_finish_speech_utterance
-                    as extern "C" fn(&Object, Sel, *const Object, id) -> (),
-            );
-            decl.add_method(
-                sel!(speechSynthesizer:didCancelSpeechUtterance:),
-                speech_synthesizer_did_cancel_speech_utterance
-                    as extern "C" fn(&Object, Sel, *const Object, id) -> (),
-            );
-        }
-
-        let delegate_class = decl.register();
-        let delegate_obj: *mut Object = unsafe { msg_send![delegate_class, new] };
-        let mut backend_id = NEXT_BACKEND_ID.lock().unwrap();
-        let rv = unsafe {
-            trace!("Creating synth");
            let synth: *mut Object = msg_send![class!(AVSpeechSynthesizer), new];
-            trace!("Allocated {:?}", synth);
-            delegate_obj
-                .as_mut()
-                .unwrap()
-                .set_ivar("backend_id", *backend_id);
-            trace!("Set backend ID in delegate");
-            let _: () = msg_send![synth, setDelegate: delegate_obj];
-            trace!("Assigned delegate: {:?}", delegate_obj);
            AvFoundation {
-                id: BackendId::AvFoundation(*backend_id),
-                delegate: delegate_obj,
-                synth,
+                synth: synth,
                rate: 0.5,
                volume: 1.,
                pitch: 1.,
-                voice: None,
            }
-        };
-        *backend_id += 1;
-        Ok(rv)
+        }
    }
 }

 impl Backend for AvFoundation {
-    fn id(&self) -> Option<BackendId> {
-        Some(self.id)
-    }
-
    fn supported_features(&self) -> Features {
        Features {
            stop: true,
@ -167,43 +38,24 @@ impl Backend for AvFoundation {
            pitch: true,
            volume: true,
            is_speaking: true,
-            voice: true,
-            get_voice: false,
-            utterance_callbacks: true,
        }
    }

-    fn speak(&mut self, text: &str, interrupt: bool) -> Result<Option<UtteranceId>, Error> {
+    fn speak(&mut self, text: &str, interrupt: bool) -> Result<(), Error> {
        trace!("speak({}, {})", text, interrupt);
-        if interrupt && self.is_speaking()? {
+        if interrupt {
            self.stop()?;
        }
-        let mut utterance: id;
        unsafe {
-            trace!("Allocating utterance string");
-            let mut str = NSString::alloc(nil);
-            str = str.init_str(text);
-            trace!("Allocating utterance");
-            utterance = msg_send![class!(AVSpeechUtterance), alloc];
-            trace!("Initializing utterance");
-            utterance = msg_send![utterance, initWithString: str];
-            trace!("Setting rate to {}", self.rate);
+            let str = NSString::alloc(nil).init_str(text);
+            let utterance: id = msg_send![class!(AVSpeechUtterance), alloc];
+            let _: () = msg_send![utterance, initWithString: str];
            let _: () = msg_send![utterance, setRate: self.rate];
-            trace!("Setting volume to {}", self.volume);
            let _: () = msg_send![utterance, setVolume: self.volume];
-            trace!("Setting pitch to {}", self.pitch);
            let _: () = msg_send![utterance, setPitchMultiplier: self.pitch];
-            if let Some(voice) = &self.voice {
-                let mut vid = NSString::alloc(nil);
-                vid = vid.init_str(&voice.id());
-                let v: id = msg_send![class!(AVSpeechSynthesisVoice), voiceWithIdentifier: vid];
-                let _: () = msg_send![utterance, setVoice: v];
-            }
-            trace!("Enqueuing");
            let _: () = msg_send![self.synth, speakUtterance: utterance];
-            trace!("Done queuing");
        }
-        Ok(Some(UtteranceId::AvFoundation(utterance)))
+        Ok(())
    }

    fn stop(&mut self) -> Result<(), Error> {
@ -253,7 +105,6 @@ impl Backend for AvFoundation {
    }

    fn set_pitch(&mut self, pitch: f32) -> Result<(), Error> {
-        trace!("set_pitch({})", pitch);
        self.pitch = pitch;
        Ok(())
    }
@ -275,65 +126,19 @@ impl Backend for AvFoundation {
    }

    fn set_volume(&mut self, volume: f32) -> Result<(), Error> {
-        trace!("set_volume({})", volume);
        self.volume = volume;
        Ok(())
    }

    fn is_speaking(&self) -> Result<bool, Error> {
-        trace!("is_speaking()");
        let is_speaking: i8 = unsafe { msg_send![self.synth, isSpeaking] };
-        Ok(is_speaking != NO as i8)
-    }
-
-    fn voice(&self) -> Result<Option<Voice>, Error> {
-        unimplemented!()
-    }
-
-    fn voices(&self) -> Result<Vec<Voice>, Error> {
-        let voices: CFArray = unsafe {
-            CFArray::wrap_under_get_rule(msg_send![class!(AVSpeechSynthesisVoice), speechVoices])
-        };
-        let rv = voices
-            .iter()
-            .map(|v| {
-                let id: CFString = unsafe {
-                    CFString::wrap_under_get_rule(msg_send![*v as *const Object, identifier])
-                };
-                let name: CFString =
-                    unsafe { CFString::wrap_under_get_rule(msg_send![*v as *const Object, name]) };
-                let gender: i64 = unsafe { msg_send![*v as *const Object, gender] };
-                let gender = match gender {
-                    1 => Some(Gender::Male),
-                    2 => Some(Gender::Female),
-                    _ => None,
-                };
-                let language: CFString = unsafe {
-                    CFString::wrap_under_get_rule(msg_send![*v as *const Object, language])
-                };
-                let language = language.to_string();
-                let language = LanguageTag::parse(language).unwrap();
-                Voice {
-                    id: id.to_string(),
-                    name: name.to_string(),
-                    gender,
-                    language,
-                }
-            })
-            .collect();
-        Ok(rv)
-    }
-
-    fn set_voice(&mut self, voice: &Voice) -> Result<(), Error> {
-        self.voice = Some(voice.clone());
-        Ok(())
+        Ok(is_speaking == 1)
    }
 }

 impl Drop for AvFoundation {
    fn drop(&mut self) {
        unsafe {
-            let _: Object = msg_send![self.delegate, release];
            let _: Object = msg_send![self.synth, release];
        }
    }
--- a/src/backends/mod.rs
+++ b/src/backends/mod.rs
@ -1,11 +1,11 @@
 #[cfg(target_os = "linux")]
 mod speech_dispatcher;

-#[cfg(all(windows, feature = "tolk"))]
+#[cfg(windows)]
 mod tolk;

 #[cfg(windows)]
-mod winrt;
+pub(crate) mod winrt;

 #[cfg(target_arch = "wasm32")]
 mod web;
@ -16,26 +16,17 @@ mod appkit;
 #[cfg(any(target_os = "macos", target_os = "ios"))]
 mod av_foundation;

-#[cfg(target_os = "android")]
-mod android;
-
 #[cfg(target_os = "linux")]
-pub(crate) use self::speech_dispatcher::*;
-
-#[cfg(all(windows, feature = "tolk"))]
-pub(crate) use self::tolk::*;
+pub use self::speech_dispatcher::*;

 #[cfg(windows)]
-pub(crate) use self::winrt::*;
+pub use self::tolk::*;

 #[cfg(target_arch = "wasm32")]
-pub(crate) use self::web::*;
+pub use self::web::*;

 #[cfg(target_os = "macos")]
-pub(crate) use self::appkit::*;
+pub use self::appkit::*;

 #[cfg(any(target_os = "macos", target_os = "ios"))]
-pub(crate) use self::av_foundation::*;
-
-#[cfg(target_os = "android")]
-pub(crate) use self::android::*;
+pub use self::av_foundation::*;
--- a/src/backends/speech_dispatcher.rs
+++ b/src/backends/speech_dispatcher.rs
@ -1,116 +1,49 @@
 #[cfg(target_os = "linux")]
-use std::{collections::HashMap, sync::Mutex};
-
-use lazy_static::*;
 use log::{info, trace};
-use oxilangtag::LanguageTag;
 use speech_dispatcher::*;

-use crate::{Backend, BackendId, Error, Features, UtteranceId, Voice, CALLBACKS};
+use crate::{Backend, Error, Features};

-#[derive(Clone, Debug)]
-pub(crate) struct SpeechDispatcher(Connection);
-
-lazy_static! {
-    static ref SPEAKING: Mutex<HashMap<usize, bool>> = {
-        let m: HashMap<usize, bool> = HashMap::new();
-        Mutex::new(m)
-    };
-}
+pub struct SpeechDispatcher(Connection);

 impl SpeechDispatcher {
-    pub(crate) fn new() -> std::result::Result<Self, Error> {
+    pub fn new() -> Self {
        info!("Initializing SpeechDispatcher backend");
-        let connection = speech_dispatcher::Connection::open("tts", "tts", "tts", Mode::Threaded)?;
-        let sd = SpeechDispatcher(connection);
-        let mut speaking = SPEAKING.lock().unwrap();
-        speaking.insert(sd.0.client_id(), false);
-        sd.0.on_begin(Some(Box::new(|msg_id, client_id| {
-            let mut speaking = SPEAKING.lock().unwrap();
-            speaking.insert(client_id, true);
-            let mut callbacks = CALLBACKS.lock().unwrap();
-            let backend_id = BackendId::SpeechDispatcher(client_id);
-            let cb = callbacks.get_mut(&backend_id).unwrap();
-            let utterance_id = UtteranceId::SpeechDispatcher(msg_id as u64);
-            if let Some(f) = cb.utterance_begin.as_mut() {
-                f(utterance_id);
-            }
-        })));
-        sd.0.on_end(Some(Box::new(|msg_id, client_id| {
-            let mut speaking = SPEAKING.lock().unwrap();
-            speaking.insert(client_id, false);
-            let mut callbacks = CALLBACKS.lock().unwrap();
-            let backend_id = BackendId::SpeechDispatcher(client_id);
-            let cb = callbacks.get_mut(&backend_id).unwrap();
-            let utterance_id = UtteranceId::SpeechDispatcher(msg_id as u64);
-            if let Some(f) = cb.utterance_end.as_mut() {
-                f(utterance_id);
-            }
-        })));
-        sd.0.on_cancel(Some(Box::new(|msg_id, client_id| {
-            let mut speaking = SPEAKING.lock().unwrap();
-            speaking.insert(client_id, false);
-            let mut callbacks = CALLBACKS.lock().unwrap();
-            let backend_id = BackendId::SpeechDispatcher(client_id);
-            let cb = callbacks.get_mut(&backend_id).unwrap();
-            let utterance_id = UtteranceId::SpeechDispatcher(msg_id as u64);
-            if let Some(f) = cb.utterance_stop.as_mut() {
-                f(utterance_id);
-            }
-        })));
-        sd.0.on_pause(Some(Box::new(|_msg_id, client_id| {
-            let mut speaking = SPEAKING.lock().unwrap();
-            speaking.insert(client_id, false);
-        })));
-        sd.0.on_resume(Some(Box::new(|_msg_id, client_id| {
-            let mut speaking = SPEAKING.lock().unwrap();
-            speaking.insert(client_id, true);
-        })));
-        Ok(sd)
+        let connection = speech_dispatcher::Connection::open("tts", "tts", "tts", Mode::Single);
+        SpeechDispatcher(connection)
    }
 }

 impl Backend for SpeechDispatcher {
-    fn id(&self) -> Option<BackendId> {
-        Some(BackendId::SpeechDispatcher(self.0.client_id()))
-    }
-
    fn supported_features(&self) -> Features {
        Features {
            stop: true,
            rate: true,
            pitch: true,
            volume: true,
-            is_speaking: true,
-            voice: true,
-            get_voice: false,
-            utterance_callbacks: true,
+            is_speaking: false,
        }
    }

-    fn speak(&mut self, text: &str, interrupt: bool) -> Result<Option<UtteranceId>, Error> {
+    fn speak(&mut self, text: &str, interrupt: bool) -> Result<(), Error> {
        trace!("speak({}, {})", text, interrupt);
        if interrupt {
            self.stop()?;
        }
        let single_char = text.to_string().capacity() == 1;
        if single_char {
-            self.0.set_punctuation(Punctuation::All)?;
+            self.0.set_punctuation(Punctuation::All);
        }
-        let id = self.0.say(Priority::Important, text);
+        self.0.say(Priority::Important, text);
        if single_char {
-            self.0.set_punctuation(Punctuation::None)?;
-        }
-        if let Some(id) = id {
-            Ok(Some(UtteranceId::SpeechDispatcher(id)))
-        } else {
-            Err(Error::NoneError)
+            self.0.set_punctuation(Punctuation::None);
        }
+        Ok(())
    }

    fn stop(&mut self) -> Result<(), Error> {
        trace!("stop()");
-        self.0.cancel()?;
+        self.0.cancel();
        Ok(())
    }

@ -131,7 +64,7 @@ impl Backend for SpeechDispatcher {
    }

    fn set_rate(&mut self, rate: f32) -> Result<(), Error> {
-        self.0.set_voice_rate(rate as i32)?;
+        self.0.set_voice_rate(rate as i32);
        Ok(())
    }

@ -152,7 +85,7 @@ impl Backend for SpeechDispatcher {
    }

    fn set_pitch(&mut self, pitch: f32) -> Result<(), Error> {
-        self.0.set_voice_pitch(pitch as i32)?;
+        self.0.set_voice_pitch(pitch as i32);
        Ok(())
    }

@ -173,50 +106,11 @@ impl Backend for SpeechDispatcher {
    }

    fn set_volume(&mut self, volume: f32) -> Result<(), Error> {
-        self.0.set_volume(volume as i32)?;
+        self.0.set_volume(volume as i32);
        Ok(())
    }

    fn is_speaking(&self) -> Result<bool, Error> {
-        let speaking = SPEAKING.lock().unwrap();
-        let is_speaking = speaking.get(&self.0.client_id()).unwrap();
-        Ok(*is_speaking)
-    }
-
-    fn voices(&self) -> Result<Vec<Voice>, Error> {
-        let rv = self
-            .0
-            .list_synthesis_voices()?
-            .iter()
-            .filter(|v| LanguageTag::parse(v.language.clone()).is_ok())
-            .map(|v| Voice {
-                id: v.name.clone(),
-                name: v.name.clone(),
-                gender: None,
-                language: LanguageTag::parse(v.language.clone()).unwrap(),
-            })
-            .collect::<Vec<Voice>>();
-        Ok(rv)
-    }
-
-    fn voice(&self) -> Result<Option<Voice>, Error> {
        unimplemented!()
    }
-
-    fn set_voice(&mut self, voice: &Voice) -> Result<(), Error> {
-        for v in self.0.list_synthesis_voices()? {
-            if v.name == voice.name {
-                self.0.set_synthesis_voice(&v)?;
-                return Ok(());
-            }
-        }
-        Err(Error::OperationFailed)
-    }
-}
-
-impl Drop for SpeechDispatcher {
-    fn drop(&mut self) {
-        let mut speaking = SPEAKING.lock().unwrap();
-        speaking.remove(&self.0.client_id());
-    }
 }
--- a/src/backends/tolk.rs
+++ b/src/backends/tolk.rs
@ -1,16 +1,13 @@
-#[cfg(all(windows, feature = "tolk"))]
-use std::sync::Arc;
-
+#[cfg(windows)]
 use log::{info, trace};
 use tolk::Tolk as TolkPtr;

-use crate::{Backend, BackendId, Error, Features, UtteranceId, Voice};
+use crate::{Backend, Error, Features};

-#[derive(Clone, Debug)]
-pub(crate) struct Tolk(Arc<TolkPtr>);
+pub struct Tolk(TolkPtr);

 impl Tolk {
-    pub(crate) fn new() -> Option<Self> {
+    pub fn new() -> Option<Self> {
        info!("Initializing Tolk backend");
        let tolk = TolkPtr::new();
        if tolk.detect_screen_reader().is_some() {
@ -22,21 +19,20 @@ impl Tolk {
 }

 impl Backend for Tolk {
-    fn id(&self) -> Option<BackendId> {
-        None
-    }
-
    fn supported_features(&self) -> Features {
        Features {
            stop: true,
-            ..Default::default()
+            rate: false,
+            pitch: false,
+            volume: false,
+            is_speaking: false,
        }
    }

-    fn speak(&mut self, text: &str, interrupt: bool) -> Result<Option<UtteranceId>, Error> {
+    fn speak(&mut self, text: &str, interrupt: bool) -> Result<(), Error> {
        trace!("speak({}, {})", text, interrupt);
        self.0.speak(text, interrupt);
-        Ok(None)
+        Ok(())
    }

    fn stop(&mut self) -> Result<(), Error> {
@ -108,16 +104,4 @@ impl Backend for Tolk {
    fn is_speaking(&self) -> Result<bool, Error> {
        unimplemented!()
    }
-
-    fn voice(&self) -> Result<Option<Voice>, Error> {
-        unimplemented!()
-    }
-
-    fn voices(&self) -> Result<Vec<Voice>, Error> {
-        unimplemented!()
-    }
-
-    fn set_voice(&mut self, _voice: &Voice) -> Result<(), Error> {
-        unimplemented!()
-    }
 }
--- a/src/backends/web.rs
+++ b/src/backends/web.rs
@ -1,54 +1,27 @@
 #[cfg(target_arch = "wasm32")]
-use std::sync::Mutex;
-
-use lazy_static::lazy_static;
 use log::{info, trace};
-use oxilangtag::LanguageTag;
-use wasm_bindgen::prelude::*;
-use wasm_bindgen::JsCast;
-use web_sys::{
-    SpeechSynthesisErrorCode, SpeechSynthesisErrorEvent, SpeechSynthesisEvent,
-    SpeechSynthesisUtterance, SpeechSynthesisVoice,
-};
+use web_sys::SpeechSynthesisUtterance;

-use crate::{Backend, BackendId, Error, Features, UtteranceId, Voice, CALLBACKS};
+use crate::{Backend, Error, Features};

-#[derive(Clone, Debug)]
 pub struct Web {
-    id: BackendId,
    rate: f32,
    pitch: f32,
    volume: f32,
-    voice: Option<SpeechSynthesisVoice>,
-}
-
-lazy_static! {
-    static ref NEXT_BACKEND_ID: Mutex<u64> = Mutex::new(0);
-    static ref UTTERANCE_MAPPINGS: Mutex<Vec<(BackendId, UtteranceId)>> = Mutex::new(Vec::new());
-    static ref NEXT_UTTERANCE_ID: Mutex<u64> = Mutex::new(0);
 }

 impl Web {
    pub fn new() -> Result<Self, Error> {
        info!("Initializing Web backend");
-        let mut backend_id = NEXT_BACKEND_ID.lock().unwrap();
-        let rv = Web {
-            id: BackendId::Web(*backend_id),
+        Ok(Web {
            rate: 1.,
            pitch: 1.,
            volume: 1.,
-            voice: None,
-        };
-        *backend_id += 1;
-        Ok(rv)
+        })
    }
 }

 impl Backend for Web {
-    fn id(&self) -> Option<BackendId> {
-        Some(self.id)
-    }
-
    fn supported_features(&self) -> Features {
        Features {
            stop: true,
@ -56,69 +29,23 @@ impl Backend for Web {
            pitch: true,
            volume: true,
            is_speaking: true,
-            voice: true,
-            get_voice: true,
-            utterance_callbacks: true,
        }
    }

-    fn speak(&mut self, text: &str, interrupt: bool) -> Result<Option<UtteranceId>, Error> {
+    fn speak(&mut self, text: &str, interrupt: bool) -> Result<(), Error> {
        trace!("speak({}, {})", text, interrupt);
        let utterance = SpeechSynthesisUtterance::new_with_text(text).unwrap();
        utterance.set_rate(self.rate);
        utterance.set_pitch(self.pitch);
        utterance.set_volume(self.volume);
-        if self.voice.is_some() {
-            utterance.set_voice(self.voice.as_ref());
-        }
-        let id = self.id().unwrap();
-        let mut uid = NEXT_UTTERANCE_ID.lock().unwrap();
-        let utterance_id = UtteranceId::Web(*uid);
-        *uid += 1;
-        drop(uid);
-        let mut mappings = UTTERANCE_MAPPINGS.lock().unwrap();
-        mappings.push((self.id, utterance_id));
-        drop(mappings);
-        let callback = Closure::wrap(Box::new(move |_evt: SpeechSynthesisEvent| {
-            let mut callbacks = CALLBACKS.lock().unwrap();
-            let callback = callbacks.get_mut(&id).unwrap();
-            if let Some(f) = callback.utterance_begin.as_mut() {
-                f(utterance_id);
-            }
-        }) as Box<dyn Fn(_)>);
-        utterance.set_onstart(Some(callback.as_ref().unchecked_ref()));
-        let callback = Closure::wrap(Box::new(move |_evt: SpeechSynthesisEvent| {
-            let mut callbacks = CALLBACKS.lock().unwrap();
-            let callback = callbacks.get_mut(&id).unwrap();
-            if let Some(f) = callback.utterance_end.as_mut() {
-                f(utterance_id);
-            }
-            let mut mappings = UTTERANCE_MAPPINGS.lock().unwrap();
-            mappings.retain(|v| v.1 != utterance_id);
-        }) as Box<dyn Fn(_)>);
-        utterance.set_onend(Some(callback.as_ref().unchecked_ref()));
-        let callback = Closure::wrap(Box::new(move |evt: SpeechSynthesisErrorEvent| {
-            if evt.error() == SpeechSynthesisErrorCode::Canceled {
-                let mut callbacks = CALLBACKS.lock().unwrap();
-                let callback = callbacks.get_mut(&id).unwrap();
-                if let Some(f) = callback.utterance_stop.as_mut() {
-                    f(utterance_id);
-                }
-            }
-            let mut mappings = UTTERANCE_MAPPINGS.lock().unwrap();
-            mappings.retain(|v| v.1 != utterance_id);
-        }) as Box<dyn Fn(_)>);
-        utterance.set_onerror(Some(callback.as_ref().unchecked_ref()));
        if interrupt {
            self.stop()?;
        }
        if let Some(window) = web_sys::window() {
            let speech_synthesis = window.speech_synthesis().unwrap();
            speech_synthesis.speak(&utterance);
-            Ok(Some(utterance_id))
-        } else {
-            Err(Error::NoneError)
        }
+        Ok(())
    }

    fn stop(&mut self) -> Result<(), Error> {
@ -204,72 +131,4 @@ impl Backend for Web {
            Err(Error::NoneError)
        }
    }
-
-    fn voice(&self) -> Result<Option<Voice>, Error> {
-        if let Some(voice) = &self.voice {
-            Ok(Some(voice.clone().into()))
-        } else {
-            if let Some(window) = web_sys::window() {
-                let speech_synthesis = window.speech_synthesis().unwrap();
-                for voice in speech_synthesis.get_voices().iter() {
-                    let voice: SpeechSynthesisVoice = voice.into();
-                    if voice.default() {
-                        return Ok(Some(voice.into()));
-                    }
-                }
-            } else {
-                return Err(Error::NoneError);
-            }
-            Ok(None)
-        }
-    }
-
-    fn voices(&self) -> Result<Vec<Voice>, Error> {
-        if let Some(window) = web_sys::window() {
-            let speech_synthesis = window.speech_synthesis().unwrap();
-            let mut rv: Vec<Voice> = vec![];
-            for v in speech_synthesis.get_voices().iter() {
-                let v: SpeechSynthesisVoice = v.into();
-                rv.push(v.into());
-            }
-            Ok(rv)
-        } else {
-            Err(Error::NoneError)
-        }
-    }
-
-    fn set_voice(&mut self, voice: &Voice) -> Result<(), Error> {
-        if let Some(window) = web_sys::window() {
-            let speech_synthesis = window.speech_synthesis().unwrap();
-            for v in speech_synthesis.get_voices().iter() {
-                let v: SpeechSynthesisVoice = v.into();
-                if v.voice_uri() == voice.id {
-                    self.voice = Some(v);
-                    return Ok(());
-                }
-            }
-            Err(Error::OperationFailed)
-        } else {
-            Err(Error::NoneError)
-        }
-    }
-}
-
-impl Drop for Web {
-    fn drop(&mut self) {
-        let mut mappings = UTTERANCE_MAPPINGS.lock().unwrap();
-        mappings.retain(|v| v.0 != self.id);
-    }
-}
-
-impl From<SpeechSynthesisVoice> for Voice {
-    fn from(other: SpeechSynthesisVoice) -> Self {
-        let language = LanguageTag::parse(other.lang()).unwrap();
-        Voice {
-            id: other.voice_uri(),
-            name: other.name(),
-            gender: None,
-            language,
-        }
-    }
 }
--- a/src/backends/winrt.rs
+++ b/src/backends/winrt.rs
@ -1,150 +1,50 @@
 #[cfg(windows)]
-use std::{
-    collections::{HashMap, VecDeque},
-    sync::Mutex,
-};
-
-use lazy_static::lazy_static;
 use log::{info, trace};
-use oxilangtag::LanguageTag;
-use windows::{
-    Foundation::TypedEventHandler,
-    Media::{
-        Core::MediaSource,
-        Playback::{MediaPlayer, MediaPlayerAudioCategory},
-        SpeechSynthesis::{SpeechSynthesizer, VoiceGender, VoiceInformation},
-    },
+
+use tts_winrt_bindings::windows::media::core::MediaSource;
+use tts_winrt_bindings::windows::media::playback::{
+    MediaPlaybackItem, MediaPlaybackList, MediaPlaybackState, MediaPlayer,
 };
+use tts_winrt_bindings::windows::media::speech_synthesis::SpeechSynthesizer;

-use crate::{Backend, BackendId, Error, Features, Gender, UtteranceId, Voice, CALLBACKS};
+use crate::{Backend, Error, Features};

-impl From<windows::core::Error> for Error {
-    fn from(e: windows::core::Error) -> Self {
-        Error::WinRt(e)
+impl From<winrt::Error> for Error {
+    fn from(e: winrt::Error) -> Self {
+        Error::WinRT(e)
    }
 }

-#[derive(Clone)]
-pub struct WinRt {
-    id: BackendId,
+pub struct WinRT {
    synth: SpeechSynthesizer,
    player: MediaPlayer,
-    rate: f32,
-    pitch: f32,
-    volume: f32,
-    voice: VoiceInformation,
+    playback_list: MediaPlaybackList,
 }

-struct Utterance {
-    id: UtteranceId,
-    text: String,
-    rate: f32,
-    pitch: f32,
-    volume: f32,
-    voice: VoiceInformation,
-}
-
-lazy_static! {
-    static ref NEXT_BACKEND_ID: Mutex<u64> = Mutex::new(0);
-    static ref NEXT_UTTERANCE_ID: Mutex<u64> = Mutex::new(0);
-    static ref BACKEND_TO_SPEECH_SYNTHESIZER: Mutex<HashMap<BackendId, SpeechSynthesizer>> = {
-        let v: HashMap<BackendId, SpeechSynthesizer> = HashMap::new();
-        Mutex::new(v)
-    };
-    static ref BACKEND_TO_MEDIA_PLAYER: Mutex<HashMap<BackendId, MediaPlayer>> = {
-        let v: HashMap<BackendId, MediaPlayer> = HashMap::new();
-        Mutex::new(v)
-    };
-    static ref UTTERANCES: Mutex<HashMap<BackendId, VecDeque<Utterance>>> = {
-        let utterances: HashMap<BackendId, VecDeque<Utterance>> = HashMap::new();
-        Mutex::new(utterances)
-    };
-}
-
-impl WinRt {
+impl WinRT {
    pub fn new() -> std::result::Result<Self, Error> {
        info!("Initializing WinRT backend");
-        let synth = SpeechSynthesizer::new()?;
+        let playback_list = MediaPlaybackList::new()?;
        let player = MediaPlayer::new()?;
-        player.SetRealTimePlayback(true)?;
-        player.SetAudioCategory(MediaPlayerAudioCategory::Speech)?;
-        let mut backend_id = NEXT_BACKEND_ID.lock().unwrap();
-        let bid = BackendId::WinRt(*backend_id);
-        *backend_id += 1;
-        drop(backend_id);
-        {
-            let mut utterances = UTTERANCES.lock().unwrap();
-            utterances.insert(bid, VecDeque::new());
-        }
-        let mut backend_to_media_player = BACKEND_TO_MEDIA_PLAYER.lock().unwrap();
-        backend_to_media_player.insert(bid, player.clone());
-        drop(backend_to_media_player);
-        let mut backend_to_speech_synthesizer = BACKEND_TO_SPEECH_SYNTHESIZER.lock().unwrap();
-        backend_to_speech_synthesizer.insert(bid, synth.clone());
-        drop(backend_to_speech_synthesizer);
-        let bid_clone = bid;
-        player.MediaEnded(&TypedEventHandler::new(
-            move |sender: &Option<MediaPlayer>, _args| {
-                if let Some(sender) = sender {
-                    let backend_to_media_player = BACKEND_TO_MEDIA_PLAYER.lock().unwrap();
-                    let id = backend_to_media_player.iter().find(|v| v.1 == sender);
-                    if let Some((id, _)) = id {
-                        let mut utterances = UTTERANCES.lock().unwrap();
-                        if let Some(utterances) = utterances.get_mut(id) {
-                            if let Some(utterance) = utterances.pop_front() {
-                                let mut callbacks = CALLBACKS.lock().unwrap();
-                                let callbacks = callbacks.get_mut(id).unwrap();
-                                if let Some(callback) = callbacks.utterance_end.as_mut() {
-                                    callback(utterance.id);
-                                }
-                                if let Some(utterance) = utterances.front() {
-                                    let backend_to_speech_synthesizer =
-                                        BACKEND_TO_SPEECH_SYNTHESIZER.lock().unwrap();
-                                    let id = backend_to_speech_synthesizer
-                                        .iter()
-                                        .find(|v| *v.0 == bid_clone);
-                                    if let Some((_, tts)) = id {
-                                        tts.Options()?.SetSpeakingRate(utterance.rate.into())?;
-                                        tts.Options()?.SetAudioPitch(utterance.pitch.into())?;
-                                        tts.Options()?.SetAudioVolume(utterance.volume.into())?;
-                                        tts.SetVoice(&utterance.voice)?;
-                                        let text = &utterance.text;
-                                        let stream =
-                                            tts.SynthesizeTextToStreamAsync(&text.into())?.get()?;
-                                        let content_type = stream.ContentType()?;
-                                        let source =
-                                            MediaSource::CreateFromStream(&stream, &content_type)?;
-                                        sender.SetSource(&source)?;
-                                        sender.Play()?;
-                                        if let Some(callback) = callbacks.utterance_begin.as_mut() {
-                                            callback(utterance.id);
-                                        }
-                                    }
-                                }
-                            }
-                        }
-                    }
-                }
-                Ok(())
-            },
-        ))?;
+        player.set_auto_play(true)?;
+        player.set_source(&playback_list)?;
        Ok(Self {
-            id: bid,
-            synth,
-            player,
-            rate: 1.,
-            pitch: 1.,
-            volume: 1.,
-            voice: SpeechSynthesizer::DefaultVoice()?,
+            synth: SpeechSynthesizer::new()?,
+            player: player,
+            playback_list: playback_list,
        })
    }
+
+    fn reinit_player(&mut self) -> std::result::Result<(), Error> {
+        self.playback_list = MediaPlaybackList::new()?;
+        self.player = MediaPlayer::new()?;
+        self.player.set_auto_play(true)?;
+        self.player.set_source(&self.playback_list)?;
+        Ok(())
+    }
 }

-impl Backend for WinRt {
-    fn id(&self) -> Option<BackendId> {
-        Some(self.id)
-    }
-
+impl Backend for WinRT {
    fn supported_features(&self) -> Features {
        Features {
            stop: true,
@ -152,83 +52,36 @@ impl Backend for WinRt {
            pitch: true,
            volume: true,
            is_speaking: true,
-            voice: true,
-            get_voice: true,
-            utterance_callbacks: true,
        }
    }

-    fn speak(
-        &mut self,
-        text: &str,
-        interrupt: bool,
-    ) -> std::result::Result<Option<UtteranceId>, Error> {
-        if interrupt && self.is_speaking()? {
+    fn speak(&mut self, text: &str, interrupt: bool) -> std::result::Result<(), Error> {
+        trace!("speak({}, {})", text, interrupt);
+        if interrupt {
            self.stop()?;
        }
-        let utterance_id = {
-            let mut uid = NEXT_UTTERANCE_ID.lock().unwrap();
-            let utterance_id = UtteranceId::WinRt(*uid);
-            *uid += 1;
-            utterance_id
-        };
-        let mut no_utterances = false;
-        {
-            let mut utterances = UTTERANCES.lock().unwrap();
-            if let Some(utterances) = utterances.get_mut(&self.id) {
-                no_utterances = utterances.is_empty();
-                let utterance = Utterance {
-                    id: utterance_id,
-                    text: text.into(),
-                    rate: self.rate,
-                    pitch: self.pitch,
-                    volume: self.volume,
-                    voice: self.voice.clone(),
-                };
-                utterances.push_back(utterance);
+        let stream = self.synth.synthesize_text_to_stream_async(text)?.get()?;
+        let content_type = stream.content_type()?;
+        let source = MediaSource::create_from_stream(stream, content_type)?;
+        let item = MediaPlaybackItem::create(source)?;
+        let state = self.player.playback_session()?.playback_state()?;
+        if state == MediaPlaybackState::Paused {
+            let index = self.playback_list.current_item_index()?;
+            let total = self.playback_list.items()?.size()?;
+            if total != 0 && index == total - 1 {
+                self.reinit_player()?;
            }
        }
-        if no_utterances {
-            self.synth.Options()?.SetSpeakingRate(self.rate.into())?;
-            self.synth.Options()?.SetAudioPitch(self.pitch.into())?;
-            self.synth.Options()?.SetAudioVolume(self.volume.into())?;
-            self.synth.SetVoice(&self.voice)?;
-            let stream = self
-                .synth
-                .SynthesizeTextToStreamAsync(&text.into())?
-                .get()?;
-            let content_type = stream.ContentType()?;
-            let source = MediaSource::CreateFromStream(&stream, &content_type)?;
-            self.player.SetSource(&source)?;
-            self.player.Play()?;
-            let mut callbacks = CALLBACKS.lock().unwrap();
-            let callbacks = callbacks.get_mut(&self.id).unwrap();
-            if let Some(callback) = callbacks.utterance_begin.as_mut() {
-                callback(utterance_id);
-            }
+        self.playback_list.items()?.append(item)?;
+        if !self.is_speaking()? {
+            self.player.play()?;
        }
-        Ok(Some(utterance_id))
+        Ok(())
    }

    fn stop(&mut self) -> std::result::Result<(), Error> {
        trace!("stop()");
-        if !self.is_speaking()? {
-            return Ok(());
-        }
-        let mut utterances = UTTERANCES.lock().unwrap();
-        if let Some(utterances) = utterances.get(&self.id) {
-            let mut callbacks = CALLBACKS.lock().unwrap();
-            let callbacks = callbacks.get_mut(&self.id).unwrap();
-            if let Some(callback) = callbacks.utterance_stop.as_mut() {
-                for utterance in utterances {
-                    callback(utterance.id);
-                }
-            }
-        }
-        if let Some(utterances) = utterances.get_mut(&self.id) {
-            utterances.clear();
-        }
-        self.player.Pause()?;
+        self.reinit_player()?;
        Ok(())
    }

@ -245,12 +98,12 @@ impl Backend for WinRt {
    }

    fn get_rate(&self) -> std::result::Result<f32, Error> {
-        let rate = self.synth.Options()?.SpeakingRate()?;
+        let rate = self.synth.options()?.speaking_rate()?;
        Ok(rate as f32)
    }

    fn set_rate(&mut self, rate: f32) -> std::result::Result<(), Error> {
-        self.rate = rate;
+        self.synth.options()?.set_speaking_rate(rate.into())?;
        Ok(())
    }

@ -267,12 +120,12 @@ impl Backend for WinRt {
    }

    fn get_pitch(&self) -> std::result::Result<f32, Error> {
-        let pitch = self.synth.Options()?.AudioPitch()?;
+        let pitch = self.synth.options()?.audio_pitch()?;
        Ok(pitch as f32)
    }

    fn set_pitch(&mut self, pitch: f32) -> std::result::Result<(), Error> {
-        self.pitch = pitch;
+        self.synth.options()?.set_audio_pitch(pitch.into())?;
        Ok(())
    }

@ -289,76 +142,18 @@ impl Backend for WinRt {
    }

    fn get_volume(&self) -> std::result::Result<f32, Error> {
-        let volume = self.synth.Options()?.AudioVolume()?;
+        let volume = self.synth.options()?.audio_volume()?;
        Ok(volume as f32)
    }

    fn set_volume(&mut self, volume: f32) -> std::result::Result<(), Error> {
-        self.volume = volume;
+        self.synth.options()?.set_audio_volume(volume.into())?;
        Ok(())
    }

    fn is_speaking(&self) -> std::result::Result<bool, Error> {
-        let utterances = UTTERANCES.lock().unwrap();
-        let utterances = utterances.get(&self.id).unwrap();
-        Ok(!utterances.is_empty())
-    }
-
-    fn voice(&self) -> Result<Option<Voice>, Error> {
-        let voice = self.synth.Voice()?;
-        let voice = voice.try_into()?;
-        Ok(Some(voice))
-    }
-
-    fn voices(&self) -> Result<Vec<Voice>, Error> {
-        let mut rv: Vec<Voice> = vec![];
-        for voice in SpeechSynthesizer::AllVoices()? {
-            rv.push(voice.try_into()?);
-        }
-        Ok(rv)
-    }
-
-    fn set_voice(&mut self, voice: &Voice) -> Result<(), Error> {
-        for v in SpeechSynthesizer::AllVoices()? {
-            let vid: String = v.Id()?.try_into()?;
-            if vid == voice.id {
-                self.voice = v;
-                return Ok(());
-            }
-        }
-        Err(Error::OperationFailed)
-    }
-}
-
-impl Drop for WinRt {
-    fn drop(&mut self) {
-        let id = self.id;
-        let mut backend_to_media_player = BACKEND_TO_MEDIA_PLAYER.lock().unwrap();
-        backend_to_media_player.remove(&id);
-        let mut backend_to_speech_synthesizer = BACKEND_TO_SPEECH_SYNTHESIZER.lock().unwrap();
-        backend_to_speech_synthesizer.remove(&id);
-        let mut utterances = UTTERANCES.lock().unwrap();
-        utterances.remove(&id);
-    }
-}
-
-impl TryInto<Voice> for VoiceInformation {
-    type Error = Error;
-
-    fn try_into(self) -> Result<Voice, Self::Error> {
-        let gender = self.Gender()?;
-        let gender = if gender == VoiceGender::Male {
-            Gender::Male
-        } else {
-            Gender::Female
-        };
-        let language: String = self.Language()?.try_into()?;
-        let language = LanguageTag::parse(language).unwrap();
-        Ok(Voice {
-            id: self.Id()?.try_into()?,
-            name: self.DisplayName()?.try_into()?,
-            gender: Some(gender),
-            language,
-        })
+        let state = self.player.playback_session()?.playback_state()?;
+        let playing = state == MediaPlaybackState::Opening || state == MediaPlaybackState::Playing;
+        Ok(playing)
    }
 }
--- a/src/lib.rs
+++ b/src/lib.rs
@ -1,223 +1,74 @@
-//! * a Text-To-Speech (TTS) library providing high-level interfaces to a variety of backends.
-//!  * Currently supported backends are:
-//!  * * Windows
-//!  *   * Screen readers/SAPI via Tolk (requires `tolk` Cargo feature)
-//!  *   * WinRT
-//!  * * Linux via [Speech Dispatcher](https://freebsoft.org/speechd)
-//!  * * MacOS/iOS
-//!  *   * AppKit on MacOS 10.13 and below
-//!  *   * AVFoundation on MacOS 10.14 and above, and iOS
-//!  * * Android
-//!  * * WebAssembly
+/*!
+ * a Text-To-Speech (TTS) library providing high-level interfaces to a variety of backends.
+ * Currently supported backends are:
+ * * Windows
+ *   * Screen readers/SAPI via Tolk
+ *   * WinRT
+ * * Linux via [Speech Dispatcher](https://freebsoft.org/speechd)
+ * * MacOS
+ *   * AppKit on MacOS 10.13 and below
+ *   * AVFoundation on MacOS 10.14 and above, and iOS
+ * * WebAssembly
+ */

-use std::collections::HashMap;
+use std::boxed::Box;
 #[cfg(target_os = "macos")]
 use std::ffi::CStr;
-use std::fmt;
-use std::rc::Rc;
-#[cfg(windows)]
-use std::string::FromUtf16Error;
-use std::sync::Mutex;
-use std::{boxed::Box, sync::RwLock};

-#[cfg(any(target_os = "macos", target_os = "ios"))]
+#[cfg(target_os = "macos")]
 use cocoa_foundation::base::id;
-use dyn_clonable::*;
-use lazy_static::lazy_static;
 #[cfg(target_os = "macos")]
 use libc::c_char;
 #[cfg(target_os = "macos")]
 use objc::{class, msg_send, sel, sel_impl};
-pub use oxilangtag::LanguageTag;
-#[cfg(target_os = "linux")]
-use speech_dispatcher::Error as SpeechDispatcherError;
 use thiserror::Error;
-#[cfg(all(windows, feature = "tolk"))]
-use tolk::Tolk;

 mod backends;

-#[derive(Clone, Copy, Debug, Eq, Hash, PartialEq, PartialOrd, Ord)]
-#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
 pub enum Backends {
-    #[cfg(target_os = "android")]
-    Android,
+    #[cfg(target_os = "linux")]
+    SpeechDispatcher,
+    #[cfg(target_arch = "wasm32")]
+    Web,
+    #[cfg(windows)]
+    Tolk,
+    #[cfg(windows)]
+    WinRT,
    #[cfg(target_os = "macos")]
    AppKit,
    #[cfg(any(target_os = "macos", target_os = "ios"))]
    AvFoundation,
-    #[cfg(target_os = "linux")]
-    SpeechDispatcher,
-    #[cfg(all(windows, feature = "tolk"))]
-    Tolk,
-    #[cfg(target_arch = "wasm32")]
-    Web,
-    #[cfg(windows)]
-    WinRt,
 }

-impl fmt::Display for Backends {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> Result<(), fmt::Error> {
-        match self {
-            #[cfg(target_os = "android")]
-            Backends::Android => writeln!(f, "Android"),
-            #[cfg(target_os = "macos")]
-            Backends::AppKit => writeln!(f, "AppKit"),
-            #[cfg(any(target_os = "macos", target_os = "ios"))]
-            Backends::AvFoundation => writeln!(f, "AVFoundation"),
-            #[cfg(target_os = "linux")]
-            Backends::SpeechDispatcher => writeln!(f, "Speech Dispatcher"),
-            #[cfg(all(windows, feature = "tolk"))]
-            Backends::Tolk => writeln!(f, "Tolk"),
-            #[cfg(target_arch = "wasm32")]
-            Backends::Web => writeln!(f, "Web"),
-            #[cfg(windows)]
-            Backends::WinRt => writeln!(f, "Windows Runtime"),
-        }
-    }
-}
-
-#[derive(Clone, Copy, Debug, Eq, Hash, PartialEq, PartialOrd, Ord)]
-#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
-pub enum BackendId {
-    #[cfg(target_os = "android")]
-    Android(u64),
-    #[cfg(any(target_os = "macos", target_os = "ios"))]
-    AvFoundation(u64),
-    #[cfg(target_os = "linux")]
-    SpeechDispatcher(usize),
-    #[cfg(target_arch = "wasm32")]
-    Web(u64),
-    #[cfg(windows)]
-    WinRt(u64),
-}
-
-impl fmt::Display for BackendId {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> Result<(), fmt::Error> {
-        match self {
-            #[cfg(target_os = "android")]
-            BackendId::Android(id) => writeln!(f, "Android({id})"),
-            #[cfg(any(target_os = "macos", target_os = "ios"))]
-            BackendId::AvFoundation(id) => writeln!(f, "AvFoundation({id})"),
-            #[cfg(target_os = "linux")]
-            BackendId::SpeechDispatcher(id) => writeln!(f, "SpeechDispatcher({id})"),
-            #[cfg(target_arch = "wasm32")]
-            BackendId::Web(id) => writeln!(f, "Web({id})"),
-            #[cfg(windows)]
-            BackendId::WinRt(id) => writeln!(f, "WinRT({id})"),
-        }
-    }
-}
-
-// # Note
-//
-// Most trait implementations are blocked by cocoa_foundation::base::id;
-// which is a type alias for objc::runtime::Object, which only implements Debug.
-#[derive(Debug)]
-#[cfg_attr(
-    not(any(target_os = "macos", target_os = "ios")),
-    derive(Clone, Copy, Eq, Hash, PartialEq, PartialOrd, Ord)
-)]
-#[cfg_attr(
-    all(feature = "serde", not(any(target_os = "macos", target_os = "ios"))),
-    derive(serde::Serialize, serde::Deserialize)
-)]
-pub enum UtteranceId {
-    #[cfg(target_os = "android")]
-    Android(u64),
-    #[cfg(any(target_os = "macos", target_os = "ios"))]
-    AvFoundation(id),
-    #[cfg(target_os = "linux")]
-    SpeechDispatcher(u64),
-    #[cfg(target_arch = "wasm32")]
-    Web(u64),
-    #[cfg(windows)]
-    WinRt(u64),
-}
-
-// # Note
-//
-// Display is not implemented by cocoa_foundation::base::id;
-// which is a type alias for objc::runtime::Object, which only implements Debug.
-#[cfg(not(any(target_os = "macos", target_os = "ios")))]
-impl fmt::Display for UtteranceId {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> Result<(), fmt::Error> {
-        match self {
-            #[cfg(target_os = "android")]
-            UtteranceId::Android(id) => writeln!(f, "Android({id})"),
-            #[cfg(target_os = "linux")]
-            UtteranceId::SpeechDispatcher(id) => writeln!(f, "SpeechDispatcher({id})"),
-            #[cfg(target_arch = "wasm32")]
-            UtteranceId::Web(id) => writeln!(f, "Web({})", id),
-            #[cfg(windows)]
-            UtteranceId::WinRt(id) => writeln!(f, "WinRt({id})"),
-        }
-    }
-}
-
-unsafe impl Send for UtteranceId {}
-
-unsafe impl Sync for UtteranceId {}
-
-#[derive(Clone, Copy, Debug, Default, Eq, Hash, PartialEq, PartialOrd, Ord)]
-#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
 pub struct Features {
-    pub is_speaking: bool,
-    pub pitch: bool,
-    pub rate: bool,
    pub stop: bool,
-    pub utterance_callbacks: bool,
-    pub voice: bool,
-    pub get_voice: bool,
+    pub rate: bool,
+    pub pitch: bool,
    pub volume: bool,
-}
-
-impl fmt::Display for Features {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> Result<(), fmt::Error> {
-        writeln!(f, "{self:#?}")
-    }
-}
-
-impl Features {
-    pub fn new() -> Self {
-        Self::default()
-    }
+    pub is_speaking: bool,
 }

 #[derive(Debug, Error)]
 pub enum Error {
    #[error("IO error: {0}")]
-    Io(#[from] std::io::Error),
+    IO(#[from] std::io::Error),
    #[error("Value not received")]
    NoneError,
-    #[error("Operation failed")]
-    OperationFailed,
    #[cfg(target_arch = "wasm32")]
-    #[error("JavaScript error: [0]")]
+    #[error("JavaScript error: [0])]")]
    JavaScriptError(wasm_bindgen::JsValue),
-    #[cfg(target_os = "linux")]
-    #[error("Speech Dispatcher error: {0}")]
-    SpeechDispatcher(#[from] SpeechDispatcherError),
    #[cfg(windows)]
    #[error("WinRT error")]
-    WinRt(windows::core::Error),
-    #[cfg(windows)]
-    #[error("UTF string conversion failed")]
-    UtfStringConversionFailed(#[from] FromUtf16Error),
+    WinRT(winrt::Error),
    #[error("Unsupported feature")]
    UnsupportedFeature,
    #[error("Out of range")]
    OutOfRange,
-    #[cfg(target_os = "android")]
-    #[error("JNI error: [0])]")]
-    JNI(#[from] jni::errors::Error),
 }

-#[clonable]
-pub trait Backend: Clone {
-    fn id(&self) -> Option<BackendId>;
+pub trait Backend {
    fn supported_features(&self) -> Features;
-    fn speak(&mut self, text: &str, interrupt: bool) -> Result<Option<UtteranceId>, Error>;
+    fn speak(&mut self, text: &str, interrupt: bool) -> Result<(), Error>;
    fn stop(&mut self) -> Result<(), Error>;
    fn min_rate(&self) -> f32;
    fn max_rate(&self) -> f32;
@ -235,103 +86,59 @@ pub trait Backend: Clone {
    fn get_volume(&self) -> Result<f32, Error>;
    fn set_volume(&mut self, volume: f32) -> Result<(), Error>;
    fn is_speaking(&self) -> Result<bool, Error>;
-    fn voices(&self) -> Result<Vec<Voice>, Error>;
-    fn voice(&self) -> Result<Option<Voice>, Error>;
-    fn set_voice(&mut self, voice: &Voice) -> Result<(), Error>;
 }

-#[derive(Default)]
-struct Callbacks {
-    utterance_begin: Option<Box<dyn FnMut(UtteranceId)>>,
-    utterance_end: Option<Box<dyn FnMut(UtteranceId)>>,
-    utterance_stop: Option<Box<dyn FnMut(UtteranceId)>>,
-}
+pub struct TTS(Box<dyn Backend>);

-unsafe impl Send for Callbacks {}
+unsafe impl std::marker::Send for TTS {}

-unsafe impl Sync for Callbacks {}
+unsafe impl std::marker::Sync for TTS {}

-lazy_static! {
-    static ref CALLBACKS: Mutex<HashMap<BackendId, Callbacks>> = {
-        let m: HashMap<BackendId, Callbacks> = HashMap::new();
-        Mutex::new(m)
-    };
-}
-
-#[derive(Clone)]
-pub struct Tts(Rc<RwLock<Box<dyn Backend>>>);
-
-unsafe impl Send for Tts {}
-
-unsafe impl Sync for Tts {}
-
-impl Tts {
-    /// Create a new `TTS` instance with the specified backend.
-    pub fn new(backend: Backends) -> Result<Tts, Error> {
-        let backend = match backend {
+impl TTS {
+    /**
+     * Create a new `TTS` instance with the specified backend.
+     */
+    pub fn new(backend: Backends) -> Result<TTS, Error> {
+        match backend {
            #[cfg(target_os = "linux")]
-            Backends::SpeechDispatcher => {
-                let tts = backends::SpeechDispatcher::new()?;
-                Ok(Tts(Rc::new(RwLock::new(Box::new(tts)))))
-            }
+            Backends::SpeechDispatcher => Ok(TTS(Box::new(backends::SpeechDispatcher::new()))),
            #[cfg(target_arch = "wasm32")]
            Backends::Web => {
                let tts = backends::Web::new()?;
-                Ok(Tts(Rc::new(RwLock::new(Box::new(tts)))))
+                Ok(TTS(Box::new(tts)))
            }
-            #[cfg(all(windows, feature = "tolk"))]
+            #[cfg(windows)]
            Backends::Tolk => {
                let tts = backends::Tolk::new();
                if let Some(tts) = tts {
-                    Ok(Tts(Rc::new(RwLock::new(Box::new(tts)))))
+                    Ok(TTS(Box::new(tts)))
                } else {
                    Err(Error::NoneError)
                }
            }
            #[cfg(windows)]
-            Backends::WinRt => {
-                let tts = backends::WinRt::new()?;
-                Ok(Tts(Rc::new(RwLock::new(Box::new(tts)))))
+            Backends::WinRT => {
+                let tts = backends::winrt::WinRT::new()?;
+                Ok(TTS(Box::new(tts)))
            }
            #[cfg(target_os = "macos")]
-            Backends::AppKit => Ok(Tts(Rc::new(RwLock::new(
-                Box::new(backends::AppKit::new()?),
-            )))),
+            Backends::AppKit => Ok(TTS(Box::new(backends::AppKit::new()))),
            #[cfg(any(target_os = "macos", target_os = "ios"))]
-            Backends::AvFoundation => Ok(Tts(Rc::new(RwLock::new(Box::new(
-                backends::AvFoundation::new()?,
-            ))))),
-            #[cfg(target_os = "android")]
-            Backends::Android => {
-                let tts = backends::Android::new()?;
-                Ok(Tts(Rc::new(RwLock::new(Box::new(tts)))))
-            }
-        };
-        if let Ok(backend) = backend {
-            if let Some(id) = backend.0.read().unwrap().id() {
-                let mut callbacks = CALLBACKS.lock().unwrap();
-                callbacks.insert(id, Callbacks::default());
-            }
-            Ok(backend)
-        } else {
-            backend
+            Backends::AvFoundation => Ok(TTS(Box::new(backends::AvFoundation::new()))),
        }
    }

-    #[allow(clippy::should_implement_trait)]
-    pub fn default() -> Result<Tts, Error> {
+    pub fn default() -> Result<TTS, Error> {
        #[cfg(target_os = "linux")]
-        let tts = Tts::new(Backends::SpeechDispatcher);
-        #[cfg(all(windows, feature = "tolk"))]
-        let tts = if let Ok(tts) = Tts::new(Backends::Tolk) {
+        let tts = TTS::new(Backends::SpeechDispatcher);
+        #[cfg(windows)]
+        let tts = if let Some(tts) = TTS::new(Backends::Tolk).ok() {
            Ok(tts)
        } else {
-            Tts::new(Backends::WinRt)
+            TTS::new(Backends::WinRT)
        };
-        #[cfg(all(windows, not(feature = "tolk")))]
-        let tts = Tts::new(Backends::WinRt);
        #[cfg(target_arch = "wasm32")]
-        let tts = Tts::new(Backends::Web);
+        let tts = TTS::new(Backends::Web);
        #[cfg(target_os = "macos")]
        let tts = unsafe {
            // Needed because the Rust NSProcessInfo structs report bogus values, and I don't want to pull in a full bindgen stack.
@ -340,88 +147,94 @@ impl Tts {
            let str: *const c_char = msg_send![version, UTF8String];
            let str = CStr::from_ptr(str);
            let str = str.to_string_lossy();
-            let version: Vec<&str> = str.split(' ').collect();
+            let version: Vec<&str> = str.split(" ").collect();
            let version = version[1];
-            let version_parts: Vec<&str> = version.split('.').collect();
-            let major_version: i8 = version_parts[0].parse().unwrap();
+            let version_parts: Vec<&str> = version.split(".").collect();
            let minor_version: i8 = version_parts[1].parse().unwrap();
-            if major_version >= 11 || minor_version >= 14 {
-                Tts::new(Backends::AvFoundation)
+            if minor_version >= 14 {
+                TTS::new(Backends::AvFoundation)
            } else {
-                Tts::new(Backends::AppKit)
+                TTS::new(Backends::AppKit)
            }
        };
        #[cfg(target_os = "ios")]
-        let tts = Tts::new(Backends::AvFoundation);
-        #[cfg(target_os = "android")]
-        let tts = Tts::new(Backends::Android);
+        let tts = TTS::new(Backends::AvFoundation);
        tts
    }

-    /// Returns the features supported by this TTS engine
+    /**
+     * Returns the features supported by this TTS engine
+     */
    pub fn supported_features(&self) -> Features {
-        self.0.read().unwrap().supported_features()
+        self.0.supported_features()
    }

-    /// Speaks the specified text, optionally interrupting current speech.
-    pub fn speak<S: Into<String>>(
-        &mut self,
-        text: S,
-        interrupt: bool,
-    ) -> Result<Option<UtteranceId>, Error> {
-        self.0
-            .write()
-            .unwrap()
-            .speak(text.into().as_str(), interrupt)
+    /**
+     * Speaks the specified text, optionally interrupting current speech.
+     */
+    pub fn speak<S: Into<String>>(&mut self, text: S, interrupt: bool) -> Result<&Self, Error> {
+        self.0.speak(text.into().as_str(), interrupt)?;
+        Ok(self)
    }

-    /// Stops current speech.
+    /**
+     * Stops current speech.
+     */
    pub fn stop(&mut self) -> Result<&Self, Error> {
        let Features { stop, .. } = self.supported_features();
        if stop {
-            self.0.write().unwrap().stop()?;
+            self.0.stop()?;
            Ok(self)
        } else {
            Err(Error::UnsupportedFeature)
        }
    }

-    /// Returns the minimum rate for this speech synthesizer.
+    /**
+     * Returns the minimum rate for this speech synthesizer.
+     */
    pub fn min_rate(&self) -> f32 {
-        self.0.read().unwrap().min_rate()
+        self.0.min_rate()
    }

-    /// Returns the maximum rate for this speech synthesizer.
+    /**
+     * Returns the maximum rate for this speech synthesizer.
+     */
    pub fn max_rate(&self) -> f32 {
-        self.0.read().unwrap().max_rate()
+        self.0.max_rate()
    }

-    /// Returns the normal rate for this speech synthesizer.
+    /**
+     * Returns the normal rate for this speech synthesizer.
+     */
    pub fn normal_rate(&self) -> f32 {
-        self.0.read().unwrap().normal_rate()
+        self.0.normal_rate()
    }

-    /// Gets the current speech rate.
+    /**
+     * Gets the current speech rate.
+     */
    pub fn get_rate(&self) -> Result<f32, Error> {
        let Features { rate, .. } = self.supported_features();
        if rate {
-            self.0.read().unwrap().get_rate()
+            self.0.get_rate()
        } else {
            Err(Error::UnsupportedFeature)
        }
    }

-    /// Sets the desired speech rate.
+    /**
+     * Sets the desired speech rate.
+     */
    pub fn set_rate(&mut self, rate: f32) -> Result<&Self, Error> {
        let Features {
            rate: rate_feature, ..
        } = self.supported_features();
        if rate_feature {
-            let mut backend = self.0.write().unwrap();
-            if rate < backend.min_rate() || rate > backend.max_rate() {
+            if rate < self.0.min_rate() || rate > self.0.max_rate() {
                Err(Error::OutOfRange)
            } else {
-                backend.set_rate(rate)?;
+                self.0.set_rate(rate)?;
                Ok(self)
            }
        } else {
@ -429,43 +242,52 @@ impl Tts {
        }
    }

-    /// Returns the minimum pitch for this speech synthesizer.
+    /**
+     * Returns the minimum pitch for this speech synthesizer.
+     */
    pub fn min_pitch(&self) -> f32 {
-        self.0.read().unwrap().min_pitch()
+        self.0.min_pitch()
    }

-    /// Returns the maximum pitch for this speech synthesizer.
+    /**
+     * Returns the maximum pitch for this speech synthesizer.
+     */
    pub fn max_pitch(&self) -> f32 {
-        self.0.read().unwrap().max_pitch()
+        self.0.max_pitch()
    }

-    /// Returns the normal pitch for this speech synthesizer.
+    /**
+     * Returns the normal pitch for this speech synthesizer.
+     */
    pub fn normal_pitch(&self) -> f32 {
-        self.0.read().unwrap().normal_pitch()
+        self.0.normal_pitch()
    }

-    /// Gets the current speech pitch.
+    /**
+     * Gets the current speech pitch.
+     */
    pub fn get_pitch(&self) -> Result<f32, Error> {
        let Features { pitch, .. } = self.supported_features();
        if pitch {
-            self.0.read().unwrap().get_pitch()
+            self.0.get_pitch()
        } else {
            Err(Error::UnsupportedFeature)
        }
    }

-    /// Sets the desired speech pitch.
+    /**
+     * Sets the desired speech pitch.
+     */
    pub fn set_pitch(&mut self, pitch: f32) -> Result<&Self, Error> {
        let Features {
            pitch: pitch_feature,
            ..
        } = self.supported_features();
        if pitch_feature {
-            let mut backend = self.0.write().unwrap();
-            if pitch < backend.min_pitch() || pitch > backend.max_pitch() {
+            if pitch < self.0.min_pitch() || pitch > self.0.max_pitch() {
                Err(Error::OutOfRange)
            } else {
-                backend.set_pitch(pitch)?;
+                self.0.set_pitch(pitch)?;
                Ok(self)
            }
        } else {
@ -473,43 +295,52 @@ impl Tts {
        }
    }

-    /// Returns the minimum volume for this speech synthesizer.
+    /**
+     * Returns the minimum volume for this speech synthesizer.
+     */
    pub fn min_volume(&self) -> f32 {
-        self.0.read().unwrap().min_volume()
+        self.0.min_volume()
    }

-    /// Returns the maximum volume for this speech synthesizer.
+    /**
+     * Returns the maximum volume for this speech synthesizer.
+     */
    pub fn max_volume(&self) -> f32 {
-        self.0.read().unwrap().max_volume()
+        self.0.max_volume()
    }

-    /// Returns the normal volume for this speech synthesizer.
+    /**
+     * Returns the normal volume for this speech synthesizer.
+     */
    pub fn normal_volume(&self) -> f32 {
-        self.0.read().unwrap().normal_volume()
+        self.0.normal_volume()
    }

-    /// Gets the current speech volume.
+    /**
+     * Gets the current speech volume.
+     */
    pub fn get_volume(&self) -> Result<f32, Error> {
        let Features { volume, .. } = self.supported_features();
        if volume {
-            self.0.read().unwrap().get_volume()
+            self.0.get_volume()
        } else {
            Err(Error::UnsupportedFeature)
        }
    }

-    /// Sets the desired speech volume.
+    /**
+     * Sets the desired speech volume.
+     */
    pub fn set_volume(&mut self, volume: f32) -> Result<&Self, Error> {
        let Features {
            volume: volume_feature,
            ..
        } = self.supported_features();
        if volume_feature {
-            let mut backend = self.0.write().unwrap();
-            if volume < backend.min_volume() || volume > backend.max_volume() {
+            if volume < self.0.min_volume() || volume > self.0.max_volume() {
                Err(Error::OutOfRange)
            } else {
-                backend.set_volume(volume)?;
+                self.0.set_volume(volume)?;
                Ok(self)
            }
        } else {
@ -517,167 +348,15 @@ impl Tts {
        }
    }

-    /// Returns whether this speech synthesizer is speaking.
+    /**
+     * Returns whether this speech synthesizer is speaking.
+     */
    pub fn is_speaking(&self) -> Result<bool, Error> {
        let Features { is_speaking, .. } = self.supported_features();
        if is_speaking {
-            self.0.read().unwrap().is_speaking()
+            self.0.is_speaking()
        } else {
            Err(Error::UnsupportedFeature)
        }
    }
-
-    /// Returns list of available voices.
-    pub fn voices(&self) -> Result<Vec<Voice>, Error> {
-        let Features { voice, .. } = self.supported_features();
-        if voice {
-            self.0.read().unwrap().voices()
-        } else {
-            Err(Error::UnsupportedFeature)
-        }
-    }
-
-    /// Return the current speaking voice.
-    pub fn voice(&self) -> Result<Option<Voice>, Error> {
-        let Features { get_voice, .. } = self.supported_features();
-        if get_voice {
-            self.0.read().unwrap().voice()
-        } else {
-            Err(Error::UnsupportedFeature)
-        }
-    }
-
-    /// Set speaking voice.
-    pub fn set_voice(&mut self, voice: &Voice) -> Result<(), Error> {
-        let Features {
-            voice: voice_feature,
-            ..
-        } = self.supported_features();
-        if voice_feature {
-            self.0.write().unwrap().set_voice(voice)
-        } else {
-            Err(Error::UnsupportedFeature)
-        }
-    }
-
-    /// Called when this speech synthesizer begins speaking an utterance.
-    pub fn on_utterance_begin(
-        &self,
-        callback: Option<Box<dyn FnMut(UtteranceId)>>,
-    ) -> Result<(), Error> {
-        let Features {
-            utterance_callbacks,
-            ..
-        } = self.supported_features();
-        if utterance_callbacks {
-            let mut callbacks = CALLBACKS.lock().unwrap();
-            let id = self.0.read().unwrap().id().unwrap();
-            let callbacks = callbacks.get_mut(&id).unwrap();
-            callbacks.utterance_begin = callback;
-            Ok(())
-        } else {
-            Err(Error::UnsupportedFeature)
-        }
-    }
-
-    /// Called when this speech synthesizer finishes speaking an utterance.
-    pub fn on_utterance_end(
-        &self,
-        callback: Option<Box<dyn FnMut(UtteranceId)>>,
-    ) -> Result<(), Error> {
-        let Features {
-            utterance_callbacks,
-            ..
-        } = self.supported_features();
-        if utterance_callbacks {
-            let mut callbacks = CALLBACKS.lock().unwrap();
-            let id = self.0.read().unwrap().id().unwrap();
-            let callbacks = callbacks.get_mut(&id).unwrap();
-            callbacks.utterance_end = callback;
-            Ok(())
-        } else {
-            Err(Error::UnsupportedFeature)
-        }
-    }
-
-    /// Called when this speech synthesizer is stopped and still has utterances in its queue.
-    pub fn on_utterance_stop(
-        &self,
-        callback: Option<Box<dyn FnMut(UtteranceId)>>,
-    ) -> Result<(), Error> {
-        let Features {
-            utterance_callbacks,
-            ..
-        } = self.supported_features();
-        if utterance_callbacks {
-            let mut callbacks = CALLBACKS.lock().unwrap();
-            let id = self.0.read().unwrap().id().unwrap();
-            let callbacks = callbacks.get_mut(&id).unwrap();
-            callbacks.utterance_stop = callback;
-            Ok(())
-        } else {
-            Err(Error::UnsupportedFeature)
-        }
-    }
-
-    /*
-     * Returns `true` if a screen reader is available to provide speech.
-     */
-    #[allow(unreachable_code)]
-    pub fn screen_reader_available() -> bool {
-        #[cfg(target_os = "windows")]
-        {
-            #[cfg(feature = "tolk")]
-            {
-                let tolk = Tolk::new();
-                return tolk.detect_screen_reader().is_some();
-            }
-            #[cfg(not(feature = "tolk"))]
-            return false;
-        }
-        false
-    }
-}
-
-impl Drop for Tts {
-    fn drop(&mut self) {
-        if Rc::strong_count(&self.0) <= 1 {
-            if let Some(id) = self.0.read().unwrap().id() {
-                let mut callbacks = CALLBACKS.lock().unwrap();
-                callbacks.remove(&id);
-            }
-        }
-    }
-}
-
-#[derive(Clone, Copy, Debug, PartialEq, Eq, PartialOrd, Ord, Hash)]
-pub enum Gender {
-    Male,
-    Female,
-}
-
-#[derive(Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash)]
-pub struct Voice {
-    pub(crate) id: String,
-    pub(crate) name: String,
-    pub(crate) gender: Option<Gender>,
-    pub(crate) language: LanguageTag<String>,
-}
-
-impl Voice {
-    pub fn id(&self) -> String {
-        self.id.clone()
-    }
-
-    pub fn name(&self) -> String {
-        self.name.clone()
-    }
-
-    pub fn gender(&self) -> Option<Gender> {
-        self.gender
-    }
-
-    pub fn language(&self) -> LanguageTag<String> {
-        self.language.clone()
-    }
 }
--- a/winrt_bindings/Cargo.toml
+++ b/winrt_bindings/Cargo.toml
@ -0,0 +1,13 @@
+[package]
+name = "tts_winrt_bindings"
+version = "0.1.0"
+authors = ["Nolan Darilek <nolan@thewordnerd.info>"]
+description = "Internal crate used by `tts`"
+license = "MIT"
+edition = "2018"
+
+[dependencies]
+winrt = "0.7"
+
+[build-dependencies]
+winrt = "0.7"
--- a/winrt_bindings/build.rs
+++ b/winrt_bindings/build.rs
@ -0,0 +1,12 @@
+winrt::build!(
+    dependencies
+        os
+    types
+        windows::media::core::MediaSource
+        windows::media::playback::{MediaPlaybackItem, MediaPlaybackList, MediaPlaybackState, MediaPlayer}
+        windows::media::speech_synthesis::SpeechSynthesizer
+);
+
+fn main() {
+    build();
+}
--- a/winrt_bindings/src/lib.rs
+++ b/winrt_bindings/src/lib.rs
@ -0,0 +1 @@
+include!(concat!(env!("OUT_DIR"), "/winrt.rs"));
				`@ -0,0 +1 @@`
				`include!(concat!(env!("OUT_DIR"), "/winrt.rs"));`