Move external processing to worker threads

src/uk/co/majenko/audiobookrecorder/AudiobookRecorder.java

@@ -1429,7 +1429,7 @@ public class AudiobookRecorder extends JFrame implements DocumentListener {
                             Debug.trace();
                             JMenuObject o = (JMenuObject)e.getSource();
                             Sentence s = (Sentence)o.getObject();
-                            s.runExternalProcessor(Utils.s2i(o.getActionCommand()));
+                            queueJob(new SentenceExternalJob(s, Utils.s2i(o.getActionCommand())));
                         }
                     });
                     ob.setActionCommand(Integer.toString(i));
@@ -1725,7 +1725,7 @@ public class AudiobookRecorder extends JFrame implements DocumentListener {
                             for (Enumeration s = c.children(); s.hasMoreElements();) {
                                 Sentence snt = (Sentence)s.nextElement();
                                 if (!snt.isLocked()) {
-                                    snt.runExternalProcessor(Utils.s2i(o.getActionCommand()));
+                                    queueJob(new SentenceExternalJob(snt, Utils.s2i(o.getActionCommand())));
                                 }
                             }
                         }

src/uk/co/majenko/audiobookrecorder/Sentence.java

@@ -956,8 +956,7 @@ public class Sentence extends BookTreeNode implements Cacheable {
     public void openInExternalEditor() {
         Debug.trace();
         ExternalEditor ed = new ExternalEditor(this);
-        Thread t = new Thread(ed);
-        t.start();
+        ed.run();
     }
 
     public void backup() throws IOException {
@@ -1051,8 +1050,7 @@ public class Sentence extends BookTreeNode implements Cacheable {
         Debug.trace();
         if (isLocked()) return;
         ExternalProcessor ed = new ExternalProcessor(this, num);
-        Thread t = new Thread(ed);
-        t.start();
+        ed.run();
     }
 
     public void undo() {

src/uk/co/majenko/audiobookrecorder/SentenceExternalJob.java

@@ -0,0 +1,17 @@
+package uk.co.majenko.audiobookrecorder;
+
+import java.lang.Runnable;
+
+public class SentenceExternalJob extends SentenceJob {
+    protected int command;
+
+    public SentenceExternalJob(Sentence s, int c) {
+        super(s);
+        command = c;
+    }
+
+    @Override
+    public void run() {
+        sentence.runExternalProcessor(command);
+    }
+}