JAL-2069 cache colours generated from labels

diff --git a/src/jalview/util/ColorUtils.java b/src/jalview/util/ColorUtils.java
index d4be322..60129fb 100644 (file)
--- a/src/jalview/util/ColorUtils.java
+++ b/src/jalview/util/ColorUtils.java
@@ -25,10 +25,17 @@
 package jalview.util;
 
 import java.awt.Color;
+import java.util.HashMap;
+import java.util.Map;
 import java.util.Random;
 
 public class ColorUtils
 {
+  private static final int MAX_CACHE_SIZE = 1729;
+  /*
+   * a cache for colours generated from text strings
+   */
+  static Map<String, Color> myColours = new HashMap<>();
 
   /**
    * Generates a random color, will mix with input color. Code taken from
@@ -260,6 +267,10 @@ public class ColorUtils
     {
       return Color.white;
     }
+    if (myColours.containsKey(name))
+    {
+      return myColours.get(name);
+    }
     int lsize = name.length();
     int start = 0;
     int end = lsize / 3;
@@ -291,6 +302,11 @@ public class ColorUtils
 
     Color color = new Color(r, g, b);
 
+    if (myColours.size() < MAX_CACHE_SIZE)
+    {
+      myColours.put(name, color);
+    }
+
     return color;
   }