X-Git-Url: http://source.jalview.org/gitweb/?a=blobdiff_plain;f=src%2Fjalview%2Fviewmodel%2FViewportRanges.java;h=af75b2713e3e7a538f0cb8cb3d6d56f744836180;hb=14bfc6fb57f123b815f08dbf5b35544abd33b3af;hp=4f671da9ce899376397a2486c789ecd7aef84d1e;hpb=c0b77a767e71bffd8f55704f9a64f943f559e4f6;p=jalview.git

diff --git a/src/jalview/viewmodel/ViewportRanges.java b/src/jalview/viewmodel/ViewportRanges.java
index 4f671da..af75b27 100644
--- a/src/jalview/viewmodel/ViewportRanges.java
+++ b/src/jalview/viewmodel/ViewportRanges.java
@@ -137,11 +137,20 @@ public class ViewportRanges extends ViewportProperties
     int oldstartres = oldvalues[0];
     int oldendres = oldvalues[1];
 
+    if (oldstartres == startRes && oldendres == endRes)
+    {
+      return; // BH 2019.07.27 standard check for no changes
+    }
+
+    // "STARTRES" is a misnomer here -- really "STARTORENDRES"
+    // note that this could be "no change" if the range is just being expanded
     changeSupport.firePropertyChange(STARTRES, oldstartres, startRes);
     if (oldstartres == startRes)
     {
-      // event won't be fired if start positions are same
-      // fire an event for the end positions in case they changed
+      // No listener cares about this
+      // "ENDRES" is a misnomer here -- really "ENDONLYRES"
+      // BH 2019.07.27 adds end change check
+      // fire only if only the end is changed
       changeSupport.firePropertyChange(ENDRES, oldendres, endRes);
     }
   }
@@ -203,12 +212,13 @@ public class ViewportRanges extends ViewportProperties
    */
   public void setStartSeq(int seq)
   {
-    int startseq = seq;
     int height = getViewportHeight();
-    if (startseq + height - 1 > getVisibleAlignmentHeight() - 1)
-    {
-      startseq = getVisibleAlignmentHeight() - height;
-    }
+    int startseq = Math.min(seq, getVisibleAlignmentHeight() - height);
+    // BH 2019.07.27 cosmetic only -- was:
+    // if (startseq + height - 1 > getVisibleAlignmentHeight() - 1)
+    // {
+    // startseq = getVisibleAlignmentHeight() - height;
+    // }
     setStartEndSeq(startseq, startseq + height - 1);
   }
 
@@ -229,11 +239,19 @@ public class ViewportRanges extends ViewportProperties
     int oldstartseq = oldvalues[0];
     int oldendseq = oldvalues[1];
 
+    if (oldstartseq == startSeq && oldendseq == endSeq)
+    {
+      return; // BH 2019.07.27 standard check for no changes
+    }
+
+    // "STARTSEQ" is a misnomer here -- really "STARTORENDSEQ"
     changeSupport.firePropertyChange(STARTSEQ, oldstartseq, startSeq);
     if (oldstartseq == startSeq)
     {
-      // event won't be fired if start positions are the same
-      // fire in case the end positions changed
+      // Note that all listeners ignore this - could be removed, or there is a
+      // bug.
+      // "ENDSEQ" is a misnomer here -- really "ENDONLYSEQ"
+      // additional fire, only if only the end is changed
       changeSupport.firePropertyChange(ENDSEQ, oldendseq, endSeq);
     }
   }
@@ -317,9 +335,9 @@ public class ViewportRanges extends ViewportProperties
     }
     int[] oldseqvalues = updateStartEndSeq(startseq, startseq + height - 1);
 
-    int[] old = new int[] { oldresvalues[0], oldseqvalues[0] };
-    int[] newresseq = new int[] { startRes, startSeq };
-    changeSupport.firePropertyChange(STARTRESANDSEQ, old, newresseq);
+    int[] oldvalues = new int[] { oldresvalues[0], oldseqvalues[0] };
+    int[] newvalues = new int[] { startRes, startSeq };
+    changeSupport.firePropertyChange(STARTRESANDSEQ, oldvalues, newvalues);
   }
 
   /**
@@ -438,8 +456,6 @@ public class ViewportRanges extends ViewportProperties
     {
       vpstart = visHeight - h;
     }
-    // System.out.println("ViewportRanges setviewportStartAndHeight " + vpstart
-    // + " " + start + " " + h + " " + getVisibleAlignmentHeight());
 
     setStartEndSeq(vpstart, vpstart + h - 1);
   }
@@ -797,4 +813,11 @@ public class ViewportRanges extends ViewportProperties
 
     return maxScroll;
   }
+
+  @Override
+  public String toString()
+  {
+    return "[ViewportRange startRes=" + startRes + " endRes=" + endRes
+            + " startSeq=" + startSeq + " endSeq=" + endSeq + "]";
+  }
 }