Added checks for X mouse coordinate being >= 0 and a test for JAL-2750

[jalview.git] / src / jalview / gui / ScalePanel.java

diff --git a/src/jalview/gui/ScalePanel.java b/src/jalview/gui/ScalePanel.java
index 1db4051..ef2392c 100755 (executable)
--- a/src/jalview/gui/ScalePanel.java
+++ b/src/jalview/gui/ScalePanel.java
@@ -275,7 +275,9 @@ public class ScalePanel extends JPanel
   {
     mouseDragging = false;
 
-    int res = (evt.getX() / av.getCharWidth())
+    int xCords = Math.max(0, evt.getX()); // prevent negative X coordinates
+
+    int res = (xCords / av.getCharWidth())
             + av.getRanges().getStartRes();
 
     if (av.hasHiddenColumns())