X-Git-Url: http://source.jalview.org/gitweb/?a=blobdiff_plain;f=src%2Fjalview%2Fviewmodel%2FOverviewDimensions.java;h=12512074a4f9e121ee9ae4a8807faea51d402e46;hb=aa08cfe91eda60027de76aafb0bcdbfc6481a1d9;hp=d7f2e61b641b1853a5dec85ffa270a83ffa11985;hpb=c526a787880d475c11bbc9124052fd5b7d120405;p=jalview.git

diff --git a/src/jalview/viewmodel/OverviewDimensions.java b/src/jalview/viewmodel/OverviewDimensions.java
index d7f2e61..1251207 100644
--- a/src/jalview/viewmodel/OverviewDimensions.java
+++ b/src/jalview/viewmodel/OverviewDimensions.java
@@ -20,14 +20,14 @@
  */
 package jalview.viewmodel;
 
+import java.awt.Graphics;
+
 import jalview.api.AlignmentColsCollectionI;
 import jalview.api.AlignmentRowsCollectionI;
 import jalview.datamodel.AlignmentI;
 import jalview.datamodel.HiddenColumns;
 import jalview.datamodel.HiddenSequences;
 
-import java.awt.Graphics;
-
 public abstract class OverviewDimensions
 {
   protected static final int MAX_WIDTH = 400;
@@ -161,23 +161,25 @@ public abstract class OverviewDimensions
   public float getPixelsPerCol()
   {
     resetAlignmentDims();
-    return (float) width / alwidth;
+    return 1 / widthRatio;
   }
 
   public float getPixelsPerSeq()
   {
     resetAlignmentDims();
-    return (float) sequencesHeight / alheight;
+    return 1 / heightRatio;
   }
 
   public void setWidth(int w)
   {
-    width = w;
+    width = w < 1 ? 1 : w;
+    widthRatio = (float) alwidth / width;
   }
 
   public void setHeight(int h)
   {
-    sequencesHeight = h - graphHeight;
+    sequencesHeight = (h < 1 ? 1 : h) - graphHeight;
+    heightRatio = (float) alheight / sequencesHeight;
   }
 
   /**
@@ -277,14 +279,14 @@ public abstract class OverviewDimensions
 
     // boxX, boxY is the x,y location equivalent to startRes, startSeq
     int xPos = Math.min(startRes, alwidth - vpwidth + 1);
-    boxX = Math.round((float) xPos * width / alwidth);
-    boxY = Math.round((float) startSeq * sequencesHeight / alheight);
+    boxX = Math.round(xPos / widthRatio);
+    boxY = Math.round(startSeq / heightRatio);
 
     // boxWidth is the width in residues translated to pixels
-    boxWidth = Math.round((float) vpwidth * width / alwidth);
+    boxWidth = Math.round(vpwidth / widthRatio);
 
     // boxHeight is the height in sequences translated to pixels
-    boxHeight = Math.round((float) vpheight * sequencesHeight / alheight);
+    boxHeight = Math.round(vpheight / heightRatio);
   }
 
   /**