Fix DateUtils.formatElapsedTime.

More reuse of StringBuilders, less broken home-grown formatting code.

Long-term, we should hand this over to icu4c, but they're not ready yet.

Bug: http://code.google.com/p/android/issues/detail?id=41401
Bug: 7736688
Change-Id: Ib3c1e1aad05827df646aa18645cce19dffb7551f

1 files changed, 18 insertions, 71 deletions

diff --git a/core/java/android/text/format/DateUtils.java b/core/java/android/text/format/DateUtils.java
index 1060bd8..ddd62a8 100644
--- a/core/java/android/text/format/DateUtils.java
+++ b/core/java/android/text/format/DateUtils.java
@@ -43,11 +43,6 @@ public class DateUtils
     private static String sElapsedFormatMMSS;
     private static String sElapsedFormatHMMSS;
 
-    private static final String FAST_FORMAT_HMMSS = "%1$d:%2$02d:%3$02d";
-    private static final String FAST_FORMAT_MMSS = "%1$02d:%2$02d";
-    private static final char TIME_SEPARATOR = ':';
-
-
     public static final long SECOND_IN_MILLIS = 1000;
     public static final long MINUTE_IN_MILLIS = SECOND_IN_MILLIS * 60;
     public static final long HOUR_IN_MILLIS = MINUTE_IN_MILLIS * 60;
@@ -616,19 +611,18 @@ public class DateUtils
     }
 
     /**
-     * Formats an elapsed time in the form "MM:SS" or "H:MM:SS"
-     * for display on the call-in-progress screen.
+     * Formats an elapsed time in a format like "MM:SS" or "H:MM:SS" (using a form
+     * suited to the current locale), similar to that used on the call-in-progress
+     * screen.
      *
-     * @param recycle {@link StringBuilder} to recycle, if possible
+     * @param recycle {@link StringBuilder} to recycle, or null to use a temporary one.
      * @param elapsedSeconds the elapsed time in seconds.
      */
     public static String formatElapsedTime(StringBuilder recycle, long elapsedSeconds) {
-        initFormatStrings();
-
+        // Break the elapsed seconds into hours, minutes, and seconds.
         long hours = 0;
         long minutes = 0;
         long seconds = 0;
-
         if (elapsedSeconds >= 3600) {
             hours = elapsedSeconds / 3600;
             elapsedSeconds -= hours * 3600;
@@ -639,70 +633,23 @@ public class DateUtils
         }
         seconds = elapsedSeconds;
 
-        String result;
-        if (hours > 0) {
-            return formatElapsedTime(recycle, sElapsedFormatHMMSS, hours, minutes, seconds);
+        // Create a StringBuilder if we weren't given one to recycle.
+        // TODO: if we cared, we could have a thread-local temporary StringBuilder.
+        StringBuilder sb = recycle;
+        if (sb == null) {
+            sb = new StringBuilder(8);
         } else {
-            return formatElapsedTime(recycle, sElapsedFormatMMSS, minutes, seconds);
+            sb.setLength(0);
         }
-    }
-
-    private static void append(StringBuilder sb, long value, boolean pad, char zeroDigit) {
-        if (value < 10) {
-            if (pad) {
-                sb.append(zeroDigit);
-            }
-        } else {
-            sb.append((char) (zeroDigit + (value / 10)));
-        }
-        sb.append((char) (zeroDigit + (value % 10)));
-    }
 
-    /**
-     * Fast formatting of h:mm:ss.
-     */
-    private static String formatElapsedTime(StringBuilder recycle, String format, long hours,
-            long minutes, long seconds) {
-        if (FAST_FORMAT_HMMSS.equals(format)) {
-            char zeroDigit = LocaleData.get(Locale.getDefault()).zeroDigit;
-
-            StringBuilder sb = recycle;
-            if (sb == null) {
-                sb = new StringBuilder(8);
-            } else {
-                sb.setLength(0);
-            }
-            append(sb, hours, false, zeroDigit);
-            sb.append(TIME_SEPARATOR);
-            append(sb, minutes, true, zeroDigit);
-            sb.append(TIME_SEPARATOR);
-            append(sb, seconds, true, zeroDigit);
-            return sb.toString();
-        } else {
-            return String.format(format, hours, minutes, seconds);
-        }
-    }
-
-    /**
-     * Fast formatting of mm:ss.
-     */
-    private static String formatElapsedTime(StringBuilder recycle, String format, long minutes,
-            long seconds) {
-        if (FAST_FORMAT_MMSS.equals(format)) {
-            char zeroDigit = LocaleData.get(Locale.getDefault()).zeroDigit;
-
-            StringBuilder sb = recycle;
-            if (sb == null) {
-                sb = new StringBuilder(8);
-            } else {
-                sb.setLength(0);
-            }
-            append(sb, minutes, false, zeroDigit);
-            sb.append(TIME_SEPARATOR);
-            append(sb, seconds, true, zeroDigit);
-            return sb.toString();
+        // Format the broken-down time in a locale-appropriate way.
+        // TODO: use icu4c when http://unicode.org/cldr/trac/ticket/3407 is fixed.
+        Formatter f = new Formatter(sb, Locale.getDefault());
+        initFormatStrings();
+        if (hours > 0) {
+            return f.format(sElapsedFormatHMMSS, hours, minutes, seconds).toString();
         } else {
-            return String.format(format, minutes, seconds);
+            return f.format(sElapsedFormatMMSS, minutes, seconds).toString();
         }
     }