Add support for separating Tolk dependency for use on UWP.

Cargo.toml

@@ -7,10 +7,14 @@ edition = "2018"
 [lib]
 crate-type = ["staticlib", "cdylib"]
 
+[features]
+
+use_tolk = ["tolk", "tts/use_tolk"]
+
 [dependencies]
 env_logger = "0.7"
 gdnative = "0.9"
-tts = "0.9"
+tts = "0.10"
 
 [target.'cfg(windows)'.dependencies]
-tolk = ">= 0.2.1"
+tolk = { version = ">= 0.2.1", optional = true }

README.md

@@ -7,7 +7,7 @@ This addon was primarily developed for the [Godot Accessibility addon](https://g
 Text-to-speech is complicated, and some features may not work everywhere. Most optional features have an associated boolean property used to determine if the feature is available. Further, while I do attempt to ensure that this addon works as well as possible on all platforms, there may be bugs, and pull requests are welcome. Known supported platforms include:
 
 * Windows
-  * Screen readers/SAPI via Tolk
+  * Screen readers/SAPI via Tolk (requires `use_tolk` Cargo feature)
   * WinRT
 * Linux via [Speech Dispatcher](https://freebsoft.org/speechd)
 * MacOS

src/lib.rs

@@ -121,13 +121,19 @@ impl TTS {
             .done();
         builder
             .add_property("can_detect_screen_reader")
-            .with_getter(|_: &TTS, _| if cfg!(windows) { true } else { false })
+            .with_getter(|_: &TTS, _| {
+                if cfg!(all(windows, features = "use_tolk")) {
+                    true
+                } else {
+                    false
+                }
+            })
             .done();
         #[allow(unreachable_code)]
         builder
             .add_property("has_screen_reader")
             .with_getter(|_: &TTS, _| {
-                #[cfg(windows)]
+                #[cfg(all(windows, features = "use_tolk"))]
                 {
                     let tolk = tolk::Tolk::new();
                     return tolk.detect_screen_reader().is_some();