Author: desruisseaux
Date: Sun Feb 10 19:50:48 2013
New Revision: 1444592
URL: http://svn.apache.org/r1444592
Log:
Added 'subtract' implementation.
Modified:
sis/branches/JDK7/sis-utility/src/main/java/org/apache/sis/measure/Range.java
Modified:
sis/branches/JDK7/sis-utility/src/main/java/org/apache/sis/measure/Range.java
URL:
http://svn.apache.org/viewvc/sis/branches/JDK7/sis-utility/src/main/java/org/apache/sis/measure/Range.java?rev=1444592&r1=1444591&r2=1444592&view=diff
==============================================================================
---
sis/branches/JDK7/sis-utility/src/main/java/org/apache/sis/measure/Range.java
(original)
+++
sis/branches/JDK7/sis-utility/src/main/java/org/apache/sis/measure/Range.java
Sun Feb 10 19:50:48 2013
@@ -127,6 +127,15 @@ public class Range<T extends Comparable<
}
/**
+ * Returns an initially empty array of the given length. To be overridden
+ * by subclasses in order to create arrays of more specific type.
+ */
+ @SuppressWarnings({"unchecked","rawtypes"}) // Generic array creation.
+ Range<T>[] newArray(final int length) {
+ return new Range[length];
+ }
+
+ /**
* Ensures that the given range uses the same element class than this
range,
* then return the casted argument value.
*
@@ -429,13 +438,59 @@ public class Range<T extends Comparable<
return union;
}
- //TODO: implement this
- public Range<T>[] subtract(final Range<T> value) throws
IllegalArgumentException
- {
- ensureCompatible(value);
- Range<T>[] ranges = new Range[1];
- ranges[0] = null;
- return ranges;
+ /**
+ * Returns the range of values that are in this range but not in the given
range.
+ * This method returns an array of length 0, 1 or 2:
+ *
+ * <ul>
+ * <li>If the given range contains fully this range, returns an array of
length 0.</li>
+ * <li>If the given range is in the middle of this range, then the
subtraction results in
+ * two disjoint ranges which will be returned as two elements in the
array.</li>
+ * <li>Otherwise returns an array of length 1.</li>
+ * </ul>
+ *
+ * @param range The range to subtract.
+ * @return This range without the given range.
+ * @throws IllegalArgumentException is the given range can not be
converted to a valid type
+ * through widening conversion, or if the units of measurement are
not convertible.
+ */
+ public Range<?>[] subtract(final Range<?> range) throws
IllegalArgumentException {
+ return subtractNC(ensureCompatible(range));
+ }
+
+ /**
+ * Implementation of {@link #subtract(Range)} to be invoked directly by
subclasses.
+ * "NC" stands for "No Cast" - this method do not try to cast the value to
a compatible type.
+ */
+ final Range<T>[] subtractNC(final Range<? extends T> range) throws
IllegalArgumentException {
+ final Range<T> subtract;
+ if (!intersects(range)) {
+ subtract = this;
+ } else {
+ final boolean clipMin = compareMinTo(range.minValue,
range.isMinIncluded ? 0 : -1) >= 0;
+ final boolean clipMax = compareMaxTo(range.maxValue,
range.isMaxIncluded ? 0 : +1) <= 0;
+ if (clipMin) {
+ if (clipMax) {
+ // The given range contains fully this range.
+ assert range.contains(this) : range;
+ return newArray(0);
+ }
+ subtract = create(range.maxValue, !range.isMaxIncluded,
maxValue, isMaxIncluded);
+ } else {
+ if (!clipMax) {
+ final Range<T>[] array = newArray(2);
+ array[0] = create(minValue, isMinIncluded, range.minValue,
!range.isMinIncluded);
+ array[1] = create(range.maxValue, !range.isMaxIncluded,
maxValue, isMaxIncluded);
+ return array;
+ }
+ subtract = create(minValue, isMinIncluded, range.minValue,
!range.isMinIncluded);
+ }
+ }
+ assert contains(subtract) : subtract;
+ assert !subtract.intersects(range) : subtract;
+ final Range<T>[] array = newArray(1);
+ array[0] = subtract;
+ return array;
}
/**
