updates for 0.9.3

[debian/openrocket] / src / net / sf / openrocket / util / TextUtil.java

diff --git a/src/net/sf/openrocket/util/TextUtil.java b/src/net/sf/openrocket/util/TextUtil.java
index fdbf99128a4cde2e20d8fe1c7cccd1b3143f8469..7d2ee85355bd6d85c4534fea0802771f3c55891c 100644 (file)
--- a/src/net/sf/openrocket/util/TextUtil.java
+++ b/src/net/sf/openrocket/util/TextUtil.java
@@ -1,16 +1,13 @@
 package net.sf.openrocket.util;
 
-import java.util.Locale;
 
 public class TextUtil {
 
        /**
-        * Return a string of the double value with suitable precision.
+        * Return a string of the double value with suitable precision (5 digits).
         * The string is the shortest representation of the value including the
         * required precision.
         * 
-        * TODO: MEDIUM: Extra zeros are added unnecessarily to the end of the string.
-        * 
         * @param d             the value to present.
         * @return              a representation with suitable precision.
         */
@@ -31,46 +28,106 @@ public class TextUtil {
                }
                
                
+               final String sign = (d < 0) ? "-" : "";
                double abs = Math.abs(d);
                
-               if (abs < 0.001) {
-                       // Compact exponential notation
-                       int exp = 0;
-                       
-                       while (abs < 1.0) {
-                               abs *= 10;
-                               exp++;
-                       }
-                       
-                       String sign = (d < 0) ? "-" : "";
-                       return sign + String.format((Locale)null, "%.4fe-%d", abs, exp);
+               // Small and large values always in exponential notation
+               if (abs < 0.001 || abs >= 100000000) {
+                       return sign + exponentialFormat(abs);
                }
-               if (abs < 0.01)
-                       return String.format((Locale)null, "%.7f", d);
-               if (abs < 0.1)
-                       return String.format((Locale)null, "%.6f", d);
-               if (abs < 1)
-                       return String.format((Locale)null, "%.5f", d);
-               if (abs < 10)
-                       return String.format((Locale)null, "%.4f", d);
-               if (abs < 100)
-                       return String.format((Locale)null, "%.3f", d);
-               if (abs < 1000)
-                       return String.format((Locale)null, "%.2f", d);
-               if (abs < 10000)
-                       return String.format((Locale)null, "%.1f", d);
-               if (abs < 100000000.0)
-                       return String.format((Locale)null, "%.0f", d);
-                       
-               // Compact exponential notation
-               int exp = 0;
-               while (abs >= 10.0) {
-                       abs /= 10;
+               
+               // Check whether decimal or exponential notation is shorter
+               
+               String exp = exponentialFormat(abs);
+               String dec = decimalFormat(abs);
+               
+               if (dec.length() <= exp.length())
+                       return sign + dec;
+               else
+                       return sign + exp;
+       }
+       
+       
+       /*
+        * value must be positive and not zero!
+        */
+       private static String exponentialFormat(double value) {
+               int exp;
+               
+               exp = 0;
+               while (value < 1.0) {
+                       value *= 10;
+                       exp--;
+               }
+               while (value >= 10.0) {
+                       value /= 10;
                        exp++;
                }
                
-               String sign = (d < 0) ? "-" : "";
-               return sign + String.format((Locale)null, "%.4fe%d", abs, exp);
+               return shortDecimal(value, 4) + "e" + exp;
+       }
+       
+       
+       /*
+        * value must be positive and not zero!
+        */
+       private static String decimalFormat(double value) {
+               if (value >= 10000)
+                       return "" + (int)(value + 0.5);
+               
+               int decimals = 1;
+               double v = value;
+               while (v < 1000) {
+                       v *= 10;
+                       decimals++;
+               }
+               
+               return shortDecimal(value, decimals);
+       }
+       
+       
+       
+       
+       /*
+        * value must be positive!
+        */
+       private static String shortDecimal(double value, int decimals) {
+               
+               int whole = (int)value;
+               value -= whole;
+               
+               // Calculate limit, return when remaining value less than this
+               double limit;
+               limit = 0.5;
+               for (int i=0; i<decimals; i++)
+                       limit /= 10;
+               
+               
+               if (value < limit)
+                       return "" + whole; 
+               limit *= 10;
+
+               StringBuilder sb = new StringBuilder();
+               sb.append("" + whole);
+               sb.append('.');
+
+               
+               for (int i = 0; i<decimals; i++) {
+                       
+                       value *= 10;
+                       if (i == decimals-1)
+                               value += 0.5;
+                       whole = (int)value;
+                       value -= whole;
+                       sb.append((char)('0' + whole));
+                       
+                       if (value < limit)
+                               return sb.toString();
+                       limit *= 10;
+
+               }
+
+               return sb.toString();
        }
 
 }