X-Git-Url: http://gitweb.fperrin.net/?a=blobdiff_plain;f=tim%2Fprune%2Fjpeg%2FExifGateway.java;h=9fefadf33c78003248e12e119481346c667166d6;hb=f35b6d628f68e3b5ef19965ad8988d0dd1eb8efa;hp=5420ea6762fe9d0c534e2a7aa72a8f7dc4c43561;hpb=c0387c124840c9407e040600fda88f3c3e8f6aa6;p=GpsPrune.git

diff --git a/tim/prune/jpeg/ExifGateway.java b/tim/prune/jpeg/ExifGateway.java
index 5420ea6..9fefadf 100644
--- a/tim/prune/jpeg/ExifGateway.java
+++ b/tim/prune/jpeg/ExifGateway.java
@@ -1,9 +1,7 @@
 package tim.prune.jpeg;
 
 import java.io.File;
-
 import javax.swing.JOptionPane;
-
 import tim.prune.I18nManager;
 
 /**
@@ -12,19 +10,11 @@ import tim.prune.I18nManager;
  * to the external libmetadata-extractor-java library
  * instead of the included modified routines.
  *
- * To use the internal routines, set the USE_INTERNAL_LIBRARY flag to true
- * and include the internal classes in the compiled jar.
- * To use the external library, set the USE_INTERNAL_LIBRARY flag to false
- * and do not export the internal classes.
+ * Switching between internal and external libraries is
+ * handled by the ExifLibrarySwitch
  */
 public abstract class ExifGateway
 {
-	// *********************************************************
-	// TODO: Check this exif library flag before releasing!
-	/** Flag to specify internal or external library */
-	private static final boolean USE_INTERNAL_LIBRARY = true;
-	// *********************************************************
-
 	/** Library object to call */
 	private static ExifLibrary _exifLibrary = null;
 	/** Flag to set whether failure warning has already been shown */
@@ -33,7 +23,7 @@ public abstract class ExifGateway
 	/** Static block to initialise library */
 	static
 	{
-		String libraryClass = USE_INTERNAL_LIBRARY?"InternalExifLibrary":"ExternalExifLibrary";
+		String libraryClass = ExifLibrarySwitch.USE_INTERNAL_LIBRARY?"InternalExifLibrary":"ExternalExifLibrary";
 		try
 		{
 			_exifLibrary = (ExifLibrary) Class.forName("tim.prune.jpeg." + libraryClass).newInstance();
@@ -73,8 +63,29 @@ public abstract class ExifGateway
 	 */
 	public static String getDescriptionKey()
 	{
-		String key = USE_INTERNAL_LIBRARY?"internal":"external";
+		String key = ExifLibrarySwitch.USE_INTERNAL_LIBRARY?"internal":"external";
 		if (_exifLibrary == null || !_exifLibrary.looksOK()) {key = key + ".failed";}
 		return key;
 	}
+
+
+
+	/**
+	 * @param inNumerator numerator from Rational
+	 * @param inDenominator denominator from Rational
+	 * @return the value of the specified number as a positive <code>double</code>.
+	 * Prevents interpretation of 32 bit numbers as negative, and forces a positive answer
+	 */
+	public static final double convertToPositiveValue(int inNumerator, int inDenominator)
+	{
+		if (inDenominator == 0) return 0.0;
+		double numeratorDbl = inNumerator;
+		double denomDbl = inDenominator;
+		if (inNumerator >= 0)
+			return numeratorDbl / denomDbl;
+		final double correction = Math.pow(2.0, 32);
+		numeratorDbl += correction;
+		if (inDenominator < 0) denomDbl += correction;
+		return numeratorDbl / denomDbl;
+	}
 }