X-Git-Url: http://source.jalview.org/gitweb/?a=blobdiff_plain;f=src%2Fjalview%2Fgui%2FSeqPanel.java;h=e99e5774dc47d606815fd01e330aaee483da32dc;hb=8e640547def8e151db1fafafe93a2a0bb8078369;hp=203dc4b549fe9df9a72c94ed992f33d131bea85c;hpb=2dd39c36211f947fda099c550e711ef5905efefd;p=jalview.git

diff --git a/src/jalview/gui/SeqPanel.java b/src/jalview/gui/SeqPanel.java
index 203dc4b..e99e577 100644
--- a/src/jalview/gui/SeqPanel.java
+++ b/src/jalview/gui/SeqPanel.java
@@ -1111,7 +1111,7 @@ public class SeqPanel extends JPanel
     }
 
     mouseDragging = true;
-    if (scrollThread != null)
+    if ((scrollThread != null) && (scrollThread.isRunning()))
     {
       scrollThread.setEvent(evt);
     }
@@ -1537,9 +1537,9 @@ public class SeqPanel extends JPanel
       oldSeq = 0;
     }
 
-    if (scrollThread != null)
+    if ((scrollThread != null) && (scrollThread.isRunning()))
     {
-      scrollThread.running = false;
+      scrollThread.stopScrolling();
       scrollThread = null;
     }
   }
@@ -1558,7 +1558,7 @@ public class SeqPanel extends JPanel
       return;
     }
 
-    if (mouseDragging)
+    if (mouseDragging && scrollThread == null)
     {
       scrollThread = new ScrollThread();
     }
@@ -1959,7 +1959,7 @@ public class SeqPanel extends JPanel
 
     mouseDragging = true;
 
-    if (scrollThread != null)
+    if ((scrollThread != null) && (scrollThread.isRunning()))
     {
       scrollThread.setEvent(evt);
     }
@@ -1969,9 +1969,9 @@ public class SeqPanel extends JPanel
   {
     if (evt == null)
     {
-      if (scrollThread != null)
+      if ((scrollThread != null) && (scrollThread.isRunning()))
       {
-        scrollThread.running = false;
+        scrollThread.stopScrolling();
         scrollThread = null;
       }
       mouseDragging = false;
@@ -1994,7 +1994,7 @@ public class SeqPanel extends JPanel
   {
     MouseEvent evt;
 
-    boolean running = false;
+    private volatile boolean threadRunning = true;
 
     public ScrollThread()
     {
@@ -2008,37 +2008,40 @@ public class SeqPanel extends JPanel
 
     public void stopScrolling()
     {
-      running = false;
+      threadRunning = false;
+    }
+
+    public boolean isRunning()
+    {
+      return threadRunning;
     }
 
     @Override
     public void run()
     {
-      running = true;
-
-      while (running)
+      while (threadRunning)
       {
         if (evt != null)
         {
           if (mouseDragging && (evt.getY() < 0)
                   && (av.getRanges().getStartSeq() > 0))
           {
-            running = av.getRanges().scrollUp(true);
+            av.getRanges().scrollUp(true);
           }
 
           if (mouseDragging && (evt.getY() >= getHeight()) && (av
                   .getAlignment().getHeight() > av.getRanges().getEndSeq()))
           {
-            running = av.getRanges().scrollUp(false);
+            av.getRanges().scrollUp(false);
           }
 
           if (mouseDragging && (evt.getX() < 0))
           {
-            running = av.getRanges().scrollRight(false);
+            av.getRanges().scrollRight(false);
           }
           else if (mouseDragging && (evt.getX() >= getWidth()))
           {
-            running = av.getRanges().scrollRight(true);
+            av.getRanges().scrollRight(true);
           }
         }