JAL-98 round when formatting dec places

[jalview.git] / src / jalview / util / Format.java

diff --git a/src/jalview/util/Format.java b/src/jalview/util/Format.java
index a7b311b..20d228d 100755 (executable)
--- a/src/jalview/util/Format.java
+++ b/src/jalview/util/Format.java
@@ -1,6 +1,6 @@
 /*
- * Jalview - A Sequence Alignment Editor and Viewer (Version 2.8.2)
- * Copyright (C) 2014 The Jalview Authors
+ * Jalview - A Sequence Alignment Editor and Viewer ($$Version-Rel$$)
+ * Copyright (C) $$Year-Rel$$ The Jalview Authors
  * 
  * This file is part of Jalview.
  * 
@@ -54,6 +54,8 @@ public class Format
 
   private char fmt; // one of cdeEfgGiosxXos
 
+  private final String formatString;
+
   /**
    * Creates a new Format object.
    * 
@@ -62,6 +64,7 @@ public class Format
    */
   public Format(String s)
   {
+    formatString = s;
     width = 0;
     precision = -1;
     pre = "";
@@ -622,7 +625,7 @@ public class Format
   /**
    * Formats a character into a string (like sprintf in C)
    * 
-   * @param x
+   * @param debounceTrap
    *          the value to format
    * @return the formatted string
    */
@@ -641,7 +644,7 @@ public class Format
   /**
    * Formats a string into a larger string (like sprintf in C)
    * 
-   * @param x
+   * @param debounceTrap
    *          the value to format
    * @return the formatted string
    */
@@ -938,4 +941,55 @@ public class Format
 
     return f + p.substring(p.length() - 3, p.length());
   }
+
+  @Override
+  public String toString()
+  {
+    return formatString;
+  }
+
+  /**
+   * Bespoke method to format percentage float value to the specified number of
+   * decimal places. Avoids use of general-purpose format parsers as a
+   * processing hotspot.
+   * 
+   * @param sb
+   * @param value
+   * @param dp
+   */
+  public static void appendPercentage(StringBuilder sb, float value, int dp)
+  {
+    /*
+     * rounding first
+     */
+    double d = value;
+    long factor = 1L;
+    for (int i = 0; i < dp; i++)
+    {
+      factor *= 10;
+    }
+    d *= factor;
+    d += 0.5;
+
+    /*
+     * integer part
+     */
+    value = (float) (d / factor);
+    sb.append((long) value);
+
+    /*
+     * decimal places
+     */
+    if (dp > 0)
+    {
+      sb.append(".");
+      while (dp > 0)
+      {
+        value = value - (int) value;
+        value *= 10;
+        sb.append((int) value);
+        dp--;
+      }
+    }
+  }
 }