From 4088eb12a172a70e581f5fb627e505bacbe34029 Mon Sep 17 00:00:00 2001
From: Nolan Darilek <nolan@thewordnerd.info>
Date: Tue, 11 May 2021 19:37:56 -0500
Subject: [PATCH] Add ability to detect screen readers. Windows-only for now,
 and requires the `tolk` feature.

---
 examples/hello_world.rs |  5 +++++
 src/lib.rs              | 17 +++++++++++++++++
 2 files changed, 22 insertions(+)

diff --git a/examples/hello_world.rs b/examples/hello_world.rs
index f737f3f..1db3ed3 100644
--- a/examples/hello_world.rs
+++ b/examples/hello_world.rs
@@ -12,6 +12,11 @@ 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,
         ..
diff --git a/src/lib.rs b/src/lib.rs
index 1901556..50af8ac 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -527,6 +527,23 @@ impl Tts {
             Err(Error::UnsupportedFeature)
         }
     }
+
+    /*
+     * Returns `true` if a screen reader is available to provide speech.
+     */
+    pub fn screen_reader_available() -> bool {
+        if cfg!(target_os = "windows") {
+            #[cfg(feature = "tolk")]
+            {
+                let tolk = tolk::Tolk::new();
+                return tolk.detect_screen_reader().is_some();
+            }
+            #[cfg(not(feature = "tolk"))]
+            return false;
+        } else {
+            false
+        }
+    }
 }
 
 impl Drop for Tts {