Improve the Priority constants

This addresses two issues:

1. They were redundantly named. Now e.g. Priority.LOW reads more nicely.
2. The FIRST and LAST constants were set to +Infinity and -Infinity,
   which meant it was mathematically to inject anything before or after,
   e.g. for testing or workaround purposes. The new FIRST and LAST
   constants are set to +1e300 and -1e300 respectively, so that it is
   still possible to bypass them in the rare cases where that is needed.

Author: ctrueden

src/main/java/org/scijava/AbstractUIDetails.java

@@ -51,7 +51,7 @@ public abstract class AbstractUIDetails extends AbstractBasicDetails implements
 	private String iconPath;
 
 	/** Sort priority of the object. */
-	private double priority = Priority.NORMAL_PRIORITY;
+	private double priority = Priority.NORMAL;
 
 	/** Whether the object can be selected in the user interface. */
 	private boolean selectable;

src/main/java/org/scijava/Priority.java

@@ -46,26 +46,45 @@ private Priority() {
 		// prevent instantiation of utility class
 	}
 
-	/** Priority for items that must be sorted first. */
-	public static final double FIRST_PRIORITY = Double.POSITIVE_INFINITY;
+	/**
+	 * Priority for items that must be sorted first.
+	 * <p>
+	 * Note that it <em>is</em> still possible to prioritize something earlier
+	 * than this value (e.g., for testing purposes), although doing so strongly
+	 * discouraged in production.
+	 * </p>
+	 */
+	public static final double FIRST = +1e300;
+
+	/** Priority for items that very strongly prefer to be sorted early. */
+	public static final double EXTREMELY_HIGH = +1000000;
 
 	/** Priority for items that strongly prefer to be sorted early. */
-	public static final double VERY_HIGH_PRIORITY = +10000;
+	public static final double VERY_HIGH = +10000;
 
 	/** Priority for items that prefer to be sorted earlier. */
-	public static final double HIGH_PRIORITY = +100;
+	public static final double HIGH = +100;
 
 	/** Default priority for items. */
-	public static final double NORMAL_PRIORITY = 0;
+	public static final double NORMAL = 0;
 
 	/** Priority for items that prefer to be sorted later. */
-	public static final double LOW_PRIORITY = -100;
+	public static final double LOW = -100;
 
 	/** Priority for items that strongly prefer to be sorted late. */
-	public static final double VERY_LOW_PRIORITY = -10000;
+	public static final double VERY_LOW = -10000;
 
-	/** Priority for items that must be sorted last. */
-	public static final double LAST_PRIORITY = Double.NEGATIVE_INFINITY;
+	/** Priority for items that very strongly prefer to be sorted late. */
+	public static final double EXTREMELY_LOW = -1000000;
+
+	/** Priority for items that must be sorted last.
+	 * <p>
+	 * Note that it <em>is</em> still possible to prioritize something later
+	 * than this value (e.g., for testing purposes), although doing so strongly
+	 * discouraged in production.
+	 * </p>
+	 */
+	public static final double LAST = -1e300;
 
 	/**
 	 * Compares two {@link Prioritized} objects.
@@ -109,4 +128,33 @@ public static boolean inject(final Object o, final double priority) {
 		return true;
 	}
 
+	// -- Deprecated --
+
+	/** @deprecated Use {@link #FIRST} instead. */
+	@Deprecated
+	public static final double FIRST_PRIORITY = Double.POSITIVE_INFINITY;
+
+	/** @deprecated Use {@link #VERY_HIGH} instead. */
+	@Deprecated
+	public static final double VERY_HIGH_PRIORITY = +10000;
+
+	/** @deprecated Use {@link #HIGH} instead. */
+	@Deprecated
+	public static final double HIGH_PRIORITY = +100;
+
+	/** @deprecated Use {@link #NORMAL} instead. */
+	@Deprecated
+	public static final double NORMAL_PRIORITY = 0;
+
+	/** @deprecated Use {@link #LOW} instead. */
+	@Deprecated
+	public static final double LOW_PRIORITY = -100;
+
+	/** @deprecated Use {@link #VERY_LOW} instead. */
+	@Deprecated
+	public static final double VERY_LOW_PRIORITY = -10000;
+
+	/** @deprecated Use {@link #LAST} instead. */
+	@Deprecated
+	public static final double LAST_PRIORITY = Double.NEGATIVE_INFINITY;
 }

src/main/java/org/scijava/app/SciJavaApp.java

@@ -42,7 +42,7 @@
  * @see AppService
  */
 @Plugin(type = App.class, name = SciJavaApp.NAME,
-	priority = Priority.LOW_PRIORITY)
+	priority = Priority.LOW)
 public class SciJavaApp extends AbstractApp {
 
 	public static final String NAME = "SciJava";

src/main/java/org/scijava/cache/DefaultCacheService.java

@@ -43,7 +43,7 @@
 /**
  * Trivial {@link CacheService} implementation. Wraps a {@link WeakHashMap}
  */
-@Plugin(type = Service.class, priority = Priority.VERY_LOW_PRIORITY)
+@Plugin(type = Service.class, priority = Priority.VERY_LOW)
 public class DefaultCacheService extends AbstractService implements
 	CacheService
 {

src/main/java/org/scijava/convert/ArrayConverters.java

@@ -54,7 +54,7 @@ public class ArrayConverters {
 
 	// -- Integer array converters --
 
-	@Plugin(type = Converter.class, priority = Priority.HIGH_PRIORITY)
+	@Plugin(type = Converter.class, priority = Priority.HIGH)
 	public static class IntArrayWrapper extends
 		PrimitiveArrayWrapper<int[], Integer, IntArray>
 	{
@@ -70,7 +70,7 @@ public Class<int[]> getInputType() {
 		}
 	}
 
-	@Plugin(type = Converter.class, priority = Priority.HIGH_PRIORITY)
+	@Plugin(type = Converter.class, priority = Priority.HIGH)
 	public static class IntArrayUnwrapper extends
 		PrimitiveArrayUnwrapper<int[], Integer, IntArray>
 	{
@@ -88,7 +88,7 @@ public Class<IntArray> getInputType() {
 
 	// -- Byte array converters --
 
-	@Plugin(type = Converter.class, priority = Priority.HIGH_PRIORITY)
+	@Plugin(type = Converter.class, priority = Priority.HIGH)
 	public static class ByteArrayWrapper extends
 		PrimitiveArrayWrapper<byte[], Byte, ByteArray>
 	{
@@ -104,7 +104,7 @@ public Class<byte[]> getInputType() {
 		}
 	}
 
-	@Plugin(type = Converter.class, priority = Priority.HIGH_PRIORITY)
+	@Plugin(type = Converter.class, priority = Priority.HIGH)
 	public static class ByteArrayUnwrapper extends
 		PrimitiveArrayUnwrapper<byte[], Byte, ByteArray>
 	{
@@ -122,7 +122,7 @@ public Class<ByteArray> getInputType() {
 
 	// -- Bool array converters --
 
-	@Plugin(type = Converter.class, priority = Priority.HIGH_PRIORITY)
+	@Plugin(type = Converter.class, priority = Priority.HIGH)
 	public static class BoolArrayWrapper extends
 		PrimitiveArrayWrapper<boolean[], Boolean, BoolArray>
 	{
@@ -138,7 +138,7 @@ public Class<boolean[]> getInputType() {
 		}
 	}
 
-	@Plugin(type = Converter.class, priority = Priority.HIGH_PRIORITY)
+	@Plugin(type = Converter.class, priority = Priority.HIGH)
 	public static class BoolArrayUnwrapper extends
 		PrimitiveArrayUnwrapper<boolean[], Boolean, BoolArray>
 	{
@@ -156,7 +156,7 @@ public Class<BoolArray> getInputType() {
 
 	// -- Char array converters --
 
-	@Plugin(type = Converter.class, priority = Priority.HIGH_PRIORITY)
+	@Plugin(type = Converter.class, priority = Priority.HIGH)
 	public static class CharArrayWrapper extends
 		PrimitiveArrayWrapper<char[], Character, CharArray>
 	{
@@ -172,7 +172,7 @@ public Class<char[]> getInputType() {
 		}
 	}
 
-	@Plugin(type = Converter.class, priority = Priority.HIGH_PRIORITY)
+	@Plugin(type = Converter.class, priority = Priority.HIGH)
 	public static class CharArrayUnwrapper extends
 		PrimitiveArrayUnwrapper<char[], Character, CharArray>
 	{
@@ -190,7 +190,7 @@ public Class<CharArray> getInputType() {
 
 	// -- Short array converters --
 
-	@Plugin(type = Converter.class, priority = Priority.HIGH_PRIORITY)
+	@Plugin(type = Converter.class, priority = Priority.HIGH)
 	public static class ShortArrayWrapper extends
 		PrimitiveArrayWrapper<short[], Short, ShortArray>
 	{
@@ -206,7 +206,7 @@ public Class<short[]> getInputType() {
 		}
 	}
 
-	@Plugin(type = Converter.class, priority = Priority.HIGH_PRIORITY)
+	@Plugin(type = Converter.class, priority = Priority.HIGH)
 	public static class ShortArrayUnwrapper extends
 		PrimitiveArrayUnwrapper<short[], Short, ShortArray>
 	{
@@ -224,7 +224,7 @@ public Class<ShortArray> getInputType() {
 
 	// -- Float array converters --
 
-	@Plugin(type = Converter.class, priority = Priority.HIGH_PRIORITY)
+	@Plugin(type = Converter.class, priority = Priority.HIGH)
 	public static class FloatArrayWrapper extends
 		PrimitiveArrayWrapper<float[], Float, FloatArray>
 	{
@@ -240,7 +240,7 @@ public Class<float[]> getInputType() {
 		}
 	}
 
-	@Plugin(type = Converter.class, priority = Priority.HIGH_PRIORITY)
+	@Plugin(type = Converter.class, priority = Priority.HIGH)
 	public static class FloatArrayUnwrapper extends
 		PrimitiveArrayUnwrapper<float[], Float, FloatArray>
 	{
@@ -258,7 +258,7 @@ public Class<FloatArray> getInputType() {
 
 	// -- Double array converters --
 
-	@Plugin(type = Converter.class, priority = Priority.HIGH_PRIORITY)
+	@Plugin(type = Converter.class, priority = Priority.HIGH)
 	public static class DoubleArrayWrapper extends
 		PrimitiveArrayWrapper<double[], Double, DoubleArray>
 	{
@@ -274,7 +274,7 @@ public Class<double[]> getInputType() {
 		}
 	}
 
-	@Plugin(type = Converter.class, priority = Priority.HIGH_PRIORITY)
+	@Plugin(type = Converter.class, priority = Priority.HIGH)
 	public static class DoubleArrayUnwrapper extends
 		PrimitiveArrayUnwrapper<double[], Double, DoubleArray>
 	{
@@ -292,7 +292,7 @@ public Class<DoubleArray> getInputType() {
 
 	// -- Long array converters --
 
-	@Plugin(type = Converter.class, priority = Priority.HIGH_PRIORITY)
+	@Plugin(type = Converter.class, priority = Priority.HIGH)
 	public static class LongArrayWrapper extends
 		PrimitiveArrayWrapper<long[], Long, LongArray>
 	{
@@ -308,7 +308,7 @@ public Class<long[]> getInputType() {
 		}
 	}
 
-	@Plugin(type = Converter.class, priority = Priority.HIGH_PRIORITY)
+	@Plugin(type = Converter.class, priority = Priority.HIGH)
 	public static class LongArrayUnwrapper extends
 		PrimitiveArrayUnwrapper<long[], Long, LongArray>
 	{

src/main/java/org/scijava/convert/CastingConverter.java

@@ -42,7 +42,7 @@
  *
  * @author Mark Hiner
  */
-@Plugin(type = Converter.class, priority = Priority.FIRST_PRIORITY)
+@Plugin(type = Converter.class, priority = Priority.FIRST)
 public class CastingConverter extends AbstractConverter<Object, Object> {
 
 	@SuppressWarnings("deprecation")

src/main/java/org/scijava/convert/NullConverter.java

@@ -43,7 +43,7 @@
  * basic casting when given a {@code null} source and returns {@code} null
  * directly when given a {@code} null destination.
  * <p>
- * By running at {@link Priority#FIRST_PRIORITY}, other converters should
+ * By running at {@link Priority#FIRST}, other converters should
  * not need to worry about {@code null} source or destination parameters.
  * </p>
  * <p>
@@ -54,7 +54,7 @@
  *
  * @author Mark Hiner
  */
-@Plugin(type = Converter.class, priority = Priority.FIRST_PRIORITY)
+@Plugin(type = Converter.class, priority = Priority.FIRST)
 public class NullConverter extends AbstractConverter<Object, Object> {
 
 	@Override

src/main/java/org/scijava/display/ActiveDisplayPreprocessor.java

@@ -54,7 +54,7 @@
  * @author Curtis Rueden
  */
 @Plugin(type = PreprocessorPlugin.class,
-	priority = Priority.VERY_HIGH_PRIORITY)
+	priority = Priority.VERY_HIGH)
 public class ActiveDisplayPreprocessor extends AbstractPreprocessorPlugin {
 
 	@Parameter(required = false)

src/main/java/org/scijava/display/DefaultDisplay.java

@@ -39,7 +39,7 @@
 // using Object#toString()), but until it exists, discovery of this display
 // merely causes the UIService to eventually issue some warnings anyway
 // ("No suitable viewer found for display" and "No viewer found for display").
-//@Plugin(type = Display.class, priority = Priority.VERY_LOW_PRIORITY)
+//@Plugin(type = Display.class, priority = Priority.VERY_LOW)
 /**
  * Default display for objects, when no other displays are available.
  * 

src/main/java/org/scijava/display/DefaultTextDisplay.java

@@ -40,7 +40,7 @@
  * 
  * @author Curtis Rueden
  */
-@Plugin(type = Display.class, priority = Priority.LOW_PRIORITY)
+@Plugin(type = Display.class, priority = Priority.LOW)
 public class DefaultTextDisplay extends AbstractDisplay<String> implements
 	TextDisplay
 {