altosui: Add AltosVoice.drain() to wait for queued speech to finish

drain() blocks until all pending phrases have been processed, allowing
the UI code to avoid pending data that will end up stale by the time
it is emitted.

Signed-off-by: Keith Packard <keithp@keithp.com>

1 files changed, 19 insertions, 2 deletions

diff --git a/ao-tools/altosui/AltosVoice.java b/ao-tools/altosui/AltosVoice.java
index ebe9d5a8..ac13ee14 100644
--- a/ao-tools/altosui/AltosVoice.java
+++ b/ao-tools/altosui/AltosVoice.java
@@ -27,6 +27,7 @@ public class AltosVoice implements Runnable {
 	Voice				voice;
 	LinkedBlockingQueue<String>	phrases;
 	Thread				thread;
+	boolean				busy;
 
 	final static String voice_name = "kevin16";
 
@@ -35,15 +36,30 @@ public class AltosVoice implements Runnable {
 			for (;;) {
 				String s = phrases.take();
 				voice.speak(s);
+				synchronized(this) {
+					if (phrases.isEmpty()) {
+						busy = false;
+						notifyAll();
+					}
+				}
 			}
 		} catch (InterruptedException e) {
 		}
 	}
 
+	public synchronized void drain() throws InterruptedException {
+		while (busy)
+			wait();
+	}
+
 	public void speak_always(String s) {
 		try {
-			if (voice != null)
-				phrases.put(s);
+			if (voice != null) {
+				synchronized(this) {
+					busy = true;
+					phrases.put(s);
+				}
+			}
 		} catch (InterruptedException e) {
 		}
 	}
@@ -58,6 +74,7 @@ public class AltosVoice implements Runnable {
 	}
 
 	public AltosVoice () {
+		busy = false;
 		voice_manager = VoiceManager.getInstance();
 		voice = voice_manager.getVoice(voice_name);
 		if (voice != null) {