Exploration: Make Locale configurable for formatting of tags (not to be merged)

Source/com/drew/imaging/jpeg/JpegMetadataReader.java

@@ -24,6 +24,7 @@
 import com.drew.lang.annotations.NotNull;
 import com.drew.lang.annotations.Nullable;
 import com.drew.metadata.Metadata;
+import com.drew.metadata.MetadataContext;
 import com.drew.metadata.adobe.AdobeJpegReader;
 import com.drew.metadata.exif.ExifReader;
 import com.drew.metadata.file.FileSystemMetadataReader;
@@ -71,45 +72,80 @@ public class JpegMetadataReader
     );
 
     @NotNull
-    public static Metadata readMetadata(@NotNull InputStream inputStream, @Nullable Iterable<JpegSegmentMetadataReader> readers) throws JpegProcessingException, IOException
+    public static Metadata readMetadata(@NotNull InputStream inputStream, @Nullable Iterable<JpegSegmentMetadataReader> readers, @NotNull MetadataContext context) throws JpegProcessingException, IOException
     {
         Metadata metadata = new Metadata();
-        process(metadata, inputStream, readers);
+        process(metadata, inputStream, readers, context);
         return metadata;
     }
 
+    @NotNull
+    public static Metadata readMetadata(@NotNull InputStream inputStream, @Nullable Iterable<JpegSegmentMetadataReader> readers) throws JpegProcessingException, IOException
+    {
+        return readMetadata(inputStream, readers, null);
+    }
+
+    @NotNull
+    public static Metadata readMetadata(@NotNull InputStream inputStream, @NotNull MetadataContext context) throws JpegProcessingException, IOException
+    {
+        return readMetadata(inputStream, null, context);
+    }
+
     @NotNull
     public static Metadata readMetadata(@NotNull InputStream inputStream) throws JpegProcessingException, IOException
     {
-        return readMetadata(inputStream, null);
+        // TODO document this default context?
+        return readMetadata(inputStream, null, new MetadataContext());
     }
 
     @NotNull
-    public static Metadata readMetadata(@NotNull File file, @Nullable Iterable<JpegSegmentMetadataReader> readers) throws JpegProcessingException, IOException
+    public static Metadata readMetadata(@NotNull File file, @Nullable Iterable<JpegSegmentMetadataReader> readers, @NotNull MetadataContext context) throws JpegProcessingException, IOException
     {
         InputStream inputStream = new FileInputStream(file);
         Metadata metadata;
         try {
-            metadata = readMetadata(inputStream, readers);
+            metadata = readMetadata(inputStream, readers, context);
         } finally {
             inputStream.close();
         }
+        // TODO pass locale?
         new FileSystemMetadataReader().read(file, metadata);
         return metadata;
     }
 
+    @NotNull
+    public static Metadata readMetadata(@NotNull File file, @Nullable Iterable<JpegSegmentMetadataReader> readers) throws JpegProcessingException, IOException
+    {
+        // TODO document this default context?
+        return readMetadata(file, readers, new MetadataContext());
+    }
+
+    @NotNull
+    public static Metadata readMetadata(@NotNull File file, @NotNull MetadataContext context) throws JpegProcessingException, IOException
+    {
+        return readMetadata(file, null, context);
+    }
+
     @NotNull
     public static Metadata readMetadata(@NotNull File file) throws JpegProcessingException, IOException
     {
-        return readMetadata(file, null);
+        // TODO document this default context?
+        return readMetadata(file, null, new MetadataContext());
     }
 
     public static void process(@NotNull Metadata metadata, @NotNull InputStream inputStream) throws JpegProcessingException, IOException
     {
-        process(metadata, inputStream, null);
+        // TODO document this default context?
+        process(metadata, inputStream, null, new MetadataContext());
     }
 
     public static void process(@NotNull Metadata metadata, @NotNull InputStream inputStream, @Nullable Iterable<JpegSegmentMetadataReader> readers) throws JpegProcessingException, IOException
+    {
+        // TODO document this default context?
+        process(metadata, inputStream, readers, new MetadataContext());
+    }
+
+    public static void process(@NotNull Metadata metadata, @NotNull InputStream inputStream, @Nullable Iterable<JpegSegmentMetadataReader> readers, @NotNull MetadataContext context) throws JpegProcessingException, IOException
     {
         if (readers == null)
             readers = ALL_READERS;
@@ -123,15 +159,16 @@ public static void process(@NotNull Metadata metadata, @NotNull InputStream inpu
 
         JpegSegmentData segmentData = JpegSegmentReader.readSegments(new StreamReader(inputStream), segmentTypes);
 
-        processJpegSegmentData(metadata, readers, segmentData);
+        processJpegSegmentData(metadata, readers, segmentData, context);
     }
 
-    public static void processJpegSegmentData(Metadata metadata, Iterable<JpegSegmentMetadataReader> readers, JpegSegmentData segmentData)
+    // TODO create method with original signature for backwards compatibility
+    public static void processJpegSegmentData(@NotNull Metadata metadata, @NotNull Iterable<JpegSegmentMetadataReader> readers, @NotNull JpegSegmentData segmentData, @NotNull MetadataContext context)
     {
         // Pass the appropriate byte arrays to each reader.
         for (JpegSegmentMetadataReader reader : readers) {
             for (JpegSegmentType segmentType : reader.getSegmentTypes()) {
-                reader.readJpegSegments(segmentData.getSegments(segmentType), metadata, segmentType);
+                reader.readJpegSegments(segmentData.getSegments(segmentType), metadata, segmentType, context);
             }
         }
     }

Source/com/drew/imaging/jpeg/JpegSegmentMetadataReader.java

@@ -2,6 +2,7 @@
 
 import com.drew.lang.annotations.NotNull;
 import com.drew.metadata.Metadata;
+import com.drew.metadata.MetadataContext;
 
 /**
  * Defines an object that extracts metadata from in JPEG segments.
@@ -21,6 +22,7 @@ public interface JpegSegmentMetadataReader
      *                 encountered in the original file.
      * @param metadata The {@link Metadata} object into which extracted values should be merged.
      * @param segmentType The {@link JpegSegmentType} being read.
+     * @param context The {@link MetadataContext} to use for parsing and formatting.
      */
-    void readJpegSegments(@NotNull final Iterable<byte[]> segments, @NotNull final Metadata metadata, @NotNull final JpegSegmentType segmentType);
+    void readJpegSegments(@NotNull final Iterable<byte[]> segments, @NotNull final Metadata metadata, @NotNull final JpegSegmentType segmentType, @NotNull MetadataContext context);
 }

Source/com/drew/lang/GeoLocation.java

@@ -25,6 +25,8 @@
 import com.drew.lang.annotations.Nullable;
 
 import java.text.DecimalFormat;
+import java.text.DecimalFormatSymbols;
+import java.util.Locale;
 
 /**
  * Represents a latitude and longitude pair, giving a position on earth in spherical coordinates.
@@ -37,17 +39,20 @@ public final class GeoLocation
 {
     private final double _latitude;
     private final double _longitude;
+    private final Locale _locale;
 
     /**
      * Instantiates a new instance of {@link GeoLocation}.
      *
      * @param latitude the latitude, in degrees
      * @param longitude the longitude, in degrees
+     * @param locale the locale to use
      */
-    public GeoLocation(double latitude, double longitude)
+    public GeoLocation(double latitude, double longitude, Locale locale)
     {
         _latitude = latitude;
         _longitude = longitude;
+        _locale = locale;
     }
 
     /**
@@ -77,12 +82,26 @@ public boolean isZero()
     /**
      * Converts a decimal degree angle into its corresponding DMS (degrees-minutes-seconds) representation as a string,
      * of format: {@code -1° 23' 4.56"}
+     *
+     * @deprecated Use {@link #decimalToDegreesMinutesSecondsString(double, Locale)} instead
      */
     @NotNull
+    @Deprecated
     public static String decimalToDegreesMinutesSecondsString(double decimal)
+    {
+        return decimalToDegreesMinutesSecondsString(decimal, null);
+    }
+
+    /**
+     * Converts a decimal degree angle into its corresponding DMS (degrees-minutes-seconds) representation as a string,
+     * of format: {@code -1° 23' 4.56"}
+     */
+    @NotNull
+    public static String decimalToDegreesMinutesSecondsString(double decimal, Locale locale)
     {
         double[] dms = decimalToDegreesMinutesSeconds(decimal);
-        DecimalFormat format = new DecimalFormat("0.##");
+        DecimalFormatSymbols symbols = locale == null ? DecimalFormatSymbols.getInstance() : DecimalFormatSymbols.getInstance(locale);
+        DecimalFormat format = new DecimalFormat("0.##", symbols);
         return String.format("%s\u00B0 %s' %s\"", format.format(dms[0]), format.format(dms[1]), format.format(dms[2]));
     }
 
@@ -158,6 +177,8 @@ public String toString()
     @NotNull
     public String toDMSString()
     {
-        return decimalToDegreesMinutesSecondsString(_latitude) + ", " + decimalToDegreesMinutesSecondsString(_longitude);
+        return decimalToDegreesMinutesSecondsString(_latitude, _locale)
+            + ", "
+            + decimalToDegreesMinutesSecondsString(_longitude, _locale);
     }
 }

Source/com/drew/metadata/Directory.java

@@ -29,6 +29,7 @@
 import java.lang.reflect.Array;
 import java.text.DateFormat;
 import java.text.DecimalFormat;
+import java.text.DecimalFormatSymbols;
 import java.text.ParseException;
 import java.text.SimpleDateFormat;
 import java.util.*;
@@ -192,6 +193,12 @@ public void setParent(@NotNull Directory parent)
         _parent = parent;
     }
 
+    protected Locale getLocale()
+    {
+        // TODO discuss: is it acceptable to use a default here?
+        return _descriptor != null ? _descriptor.getContext().locale() : new MetadataContext().locale();
+    }
+
 // TAG SETTERS
 
     /**
@@ -1024,15 +1031,15 @@ public String getString(int tagType)
                     string.append(Array.getLong(o, i));
                 }
             } else if (componentType.getName().equals("float")) {
-                DecimalFormat format = new DecimalFormat(_floatFormatPattern);
+                DecimalFormat format = getFloatFormat();
                 for (int i = 0; i < arrayLength; i++) {
                     if (i != 0)
                         string.append(' ');
                     String s = format.format(Array.getFloat(o, i));
                     string.append(s.equals("-0") ? "0" : s);
                 }
             } else if (componentType.getName().equals("double")) {
-                DecimalFormat format = new DecimalFormat(_floatFormatPattern);
+                DecimalFormat format = getFloatFormat();
                 for (int i = 0; i < arrayLength; i++) {
                     if (i != 0)
                         string.append(' ');
@@ -1053,10 +1060,10 @@ public String getString(int tagType)
         }
 
         if (o instanceof Double)
-            return new DecimalFormat(_floatFormatPattern).format(((Double)o).doubleValue());
+            return getFloatFormat().format(((Double) o).doubleValue());
 
         if (o instanceof Float)
-            return new DecimalFormat(_floatFormatPattern).format(((Float)o).floatValue());
+            return getFloatFormat().format(((Float) o).floatValue());
 
         // Note that several cameras leave trailing spaces (Olympus, Nikon) but this library is intended to show
         // the actual data within the file.  It is not inconceivable that whitespace may be significant here, so we
@@ -1065,6 +1072,12 @@ public String getString(int tagType)
         return o.toString();
     }
 
+    private DecimalFormat getFloatFormat()
+    {
+        DecimalFormatSymbols symbols = DecimalFormatSymbols.getInstance(getLocale());
+        return new DecimalFormat(_floatFormatPattern, symbols);
+    }
+
     @Nullable
     public String getString(int tagType, String charset)
     {
@@ -1150,7 +1163,8 @@ public String getDescription(int tagType)
     @Override
     public String toString()
     {
-        return String.format("%s Directory (%d %s)",
+        return String.format(getLocale(),
+            "%s Directory (%d %s)",
             getName(),
             _tagMap.size(),
             _tagMap.size() == 1

Source/com/drew/metadata/MetadataContext.java

@@ -0,0 +1,49 @@
+package com.drew.metadata;
+
+import com.drew.lang.annotations.NotNull;
+
+import java.util.Locale;
+
+/**
+ * Context class for metadata. Contains settings used while extracting and formatting metadata.
+ *
+ * @author Roel van Dijk
+ */
+public class MetadataContext
+{
+    /**
+     * Locale used to format metadata.
+     */
+    private Locale _locale;
+
+    /**
+     * Initialize a context using the system default {@link Locale}.
+     */
+    public MetadataContext()
+    {
+        _locale = Locale.getDefault();
+    }
+
+    /**
+     * Gets the configured {@link Locale}.
+     *
+     * @return the configured locale.
+     */
+    public Locale locale()
+    {
+        return _locale;
+    }
+
+    /**
+     * Configure the {@link Locale} to use for extracting and formatting metadata.
+     *
+     * @param locale the locale to use
+     * @return this context
+     */
+    public MetadataContext locale(@NotNull final Locale locale)
+    {
+        _locale = locale;
+        return this;
+    }
+
+}