X-Git-Url: http://source.jalview.org/gitweb/?a=blobdiff_plain;f=src%2Fjalview%2Futil%2FColorUtils.java;h=9ed98bd129a9499ea7f02ee2dd6b943225866273;hb=eb3e681d6e82ccdd5d312d1981dfb306e7f479f0;hp=525bfdbce880941c4c9276d63d9bdff1e3dbac04;hpb=04a1f49daf769f0cb827dbf8f4872e65d65cd1cb;p=jalview.git

diff --git a/src/jalview/util/ColorUtils.java b/src/jalview/util/ColorUtils.java
index 525bfdb..9ed98bd 100644
--- a/src/jalview/util/ColorUtils.java
+++ b/src/jalview/util/ColorUtils.java
@@ -24,11 +24,21 @@
 
 package jalview.util;
 
+import java.util.Locale;
+
 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
@@ -60,6 +70,18 @@ public class ColorUtils
   }
 
   /**
+   * 
+   * @return random color
+   */
+  public static final Color getARandomColor()
+  {
+
+    Color col = new Color((int) (Math.random() * 255),
+            (int) (Math.random() * 255), (int) (Math.random() * 255));
+    return col;
+  }
+
+  /**
    * Convert to Tk colour code format
    * 
    * @param colour
@@ -134,12 +156,12 @@ public class ColorUtils
      * prop = proportion of the way value is from minValue to maxValue
      */
     float prop = (value - minValue) / (maxValue - minValue);
-    float r = minColour.getRed() + prop
-            * (maxColour.getRed() - minColour.getRed());
-    float g = minColour.getGreen() + prop
-            * (maxColour.getGreen() - minColour.getGreen());
-    float b = minColour.getBlue() + prop
-            * (maxColour.getBlue() - minColour.getBlue());
+    float r = minColour.getRed()
+            + prop * (maxColour.getRed() - minColour.getRed());
+    float g = minColour.getGreen()
+            + prop * (maxColour.getGreen() - minColour.getGreen());
+    float b = minColour.getBlue()
+            + prop * (maxColour.getBlue() - minColour.getBlue());
     return new Color(r / 255, g / 255, b / 255);
   }
 
@@ -191,4 +213,178 @@ public class ColorUtils
       return new Color(red, green, blue);
     }
   }
+
+  /**
+   * Parses a string into a Color, where the accepted formats are
+   * <ul>
+   * <li>an AWT colour name e.g. white</li>
+   * <li>a hex colour value (without prefix) e.g. ff0000</li>
+   * <li>an rgb triple e.g. 100,50,150</li>
+   * </ul>
+   * 
+   * @param colour
+   * @return the parsed colour, or null if parsing fails
+   */
+  public static Color parseColourString(String colour)
+  {
+    if (colour == null)
+    {
+      return null;
+    }
+    colour = colour.trim();
+
+    Color col = null;
+    try
+    {
+      int value = Integer.parseInt(colour, 16);
+      col = new Color(value);
+    } catch (NumberFormatException ex)
+    {
+    }
+
+    if (col == null)
+    {
+      col = ColorUtils.getAWTColorFromName(colour);
+    }
+
+    if (col == null)
+    {
+      try
+      {
+        String[] tokens = colour.split(",");
+        if (tokens.length == 3)
+        {
+          int r = Integer.parseInt(tokens[0].trim());
+          int g = Integer.parseInt(tokens[1].trim());
+          int b = Integer.parseInt(tokens[2].trim());
+          col = new Color(r, g, b);
+        }
+      } catch (Exception ex)
+      {
+        // non-numeric token or out of 0-255 range
+      }
+    }
+
+    return col;
+  }
+
+  /**
+   * Constructs a colour from a text string. The hashcode of the whole string is
+   * scaled to the range 0-135. This is added to RGB values made from the
+   * hashcode of each third of the string, and scaled to the range 20-229.
+   * 
+   * @param name
+   * @return
+   */
+  public static Color createColourFromName(String name)
+  {
+    if (name == null)
+    {
+      return Color.white;
+    }
+    if (myColours.containsKey(name))
+    {
+      return myColours.get(name);
+    }
+    int lsize = name.length();
+    int start = 0;
+    int end = lsize / 3;
+
+    int rgbOffset = Math.abs(name.hashCode() % 10) * 15; // 0-135
+
+    /*
+     * red: first third
+     */
+    int r = Math.abs(name.substring(start, end).hashCode() + rgbOffset)
+            % 210 + 20;
+    start = end;
+    end += lsize / 3;
+    if (end > lsize)
+    {
+      end = lsize;
+    }
+
+    /*
+     * green: second third
+     */
+    int g = Math.abs(name.substring(start, end).hashCode() + rgbOffset)
+            % 210 + 20;
+
+    /*
+     * blue: third third
+     */
+    int b = Math.abs(name.substring(end).hashCode() + rgbOffset) % 210 + 20;
+
+    Color color = new Color(r, g, b);
+
+    if (myColours.size() < MAX_CACHE_SIZE)
+    {
+      myColours.put(name, color);
+    }
+
+    return color;
+  }
+
+  /**
+   * Returns the Color constant for a given colour name e.g. "pink", or null if
+   * the name is not recognised
+   * 
+   * @param name
+   * @return
+   */
+  public static Color getAWTColorFromName(String name)
+  {
+    if (name == null)
+    {
+      return null;
+    }
+    Color col = null;
+    name = name.toLowerCase(Locale.ROOT);
+
+    // or make a static map; or use reflection on the field name
+    switch (name)
+    {
+    case "black":
+      col = Color.black;
+      break;
+    case "blue":
+      col = Color.blue;
+      break;
+    case "cyan":
+      col = Color.cyan;
+      break;
+    case "darkgray":
+      col = Color.darkGray;
+      break;
+    case "gray":
+      col = Color.gray;
+      break;
+    case "green":
+      col = Color.green;
+      break;
+    case "lightgray":
+      col = Color.lightGray;
+      break;
+    case "magenta":
+      col = Color.magenta;
+      break;
+    case "orange":
+      col = Color.orange;
+      break;
+    case "pink":
+      col = Color.pink;
+      break;
+    case "red":
+      col = Color.red;
+      break;
+    case "white":
+      col = Color.white;
+      break;
+    case "yellow":
+      col = Color.yellow;
+      break;
+    }
+
+    return col;
+  }
 }