Adds a split option to disregard the last unit size

gradle.properties

@@ -4,4 +4,4 @@ repositoryRevision=N/A
 repositoryURL=https://github.com/brailleapps/dotify.common
 repositorySCM=scm:git:https://github.com/brailleapps/dotify.common.git
 moduleName=org.daisy.dotify.common
-version=4.0.1-SNAPSHOT
+version=4.1.0-SNAPSHOT

src/org/daisy/dotify/common/splitter/SizeStep.java

@@ -9,11 +9,13 @@ class SizeStep<T extends SplitPointUnit> implements StepForward<T> {
 	private final Supplements<T> map;
 	private final Set<String> ids;
 	private final float breakPoint;
+	private final boolean useLastUnitSize;
 	private T lastUnit;
 	private boolean hasSupplements;
 
-	SizeStep(float breakPoint, Supplements<T> map) {
+	SizeStep(float breakPoint, Supplements<T> map, boolean useLastUnitSize) {
 		this.breakPoint = breakPoint;
+		this.useLastUnitSize = useLastUnitSize;
 		this.map = map;
 		this.ids = new HashSet<>();
 		this.hasSupplements = false;
@@ -48,7 +50,7 @@ public boolean overflows(T buffer) {
 		return size+(
 				buffer!=null?
 						lastUnitSize(buffer) + (lastUnit!=null?lastUnit.getUnitSize():0):
-						lastUnit!=null?lastUnit.getLastUnitSize():0
+						lastUnit!=null?(useLastUnitSize?lastUnit.getLastUnitSize():lastUnit.getUnitSize()):0
 					)>breakPoint;
 	}
 
@@ -70,7 +72,7 @@ private float lastUnitSize(T b) {
 				}
 			}
 		}
-		ret += b.getLastUnitSize();
+		ret += useLastUnitSize?b.getLastUnitSize():b.getUnitSize();
 		return ret;
 	}
 

src/org/daisy/dotify/common/splitter/SplitPointHandler.java

@@ -172,10 +172,10 @@ public SplitPointSpecification find(float breakPoint, U data, SplitPointCost<T>
 			return SplitPointSpecification.empty();
 		} else if (breakPoint<=0) {
 			return SplitPointSpecification.none();
-		} else if (fits(data, breakPoint)) {
+		} else if (fits(data, breakPoint, opts.useLastUnitSize)) {
 			return SplitPointSpecification.all();
 		} else {
-			int startPos = findCollapse(data, new SizeStep<>(breakPoint, data.getSupplements()));
+			int startPos = findCollapse(data, new SizeStep<>(breakPoint, data.getSupplements(), opts.useLastUnitSize));
 			// If no units are returned here it's because even the first unit doesn't fit.
 			// Therefore, force will not help.
 			if (startPos<0) {
@@ -189,13 +189,16 @@ public SplitPointSpecification find(float breakPoint, U data, SplitPointCost<T>
 	private static class SplitOptions {
 		boolean useForce = false;
 		boolean trimTrailing = true;
+		boolean useLastUnitSize = true;
 		static SplitOptions parse(SplitOption ... opts) {
 			SplitOptions result = new SplitOptions();
 			for (SplitOption option : opts) {
 				if (option==StandardSplitOption.ALLOW_FORCE) {
 					result.useForce = true;
 				} else if (option==StandardSplitOption.RETAIN_TRAILING) {
 					result.trimTrailing = false;
+				} else if (option==StandardSplitOption.NO_LAST_UNIT_SIZE) {
+					result.useLastUnitSize = false; 
 				} else if (option == null) {
                    //no-op
 				} else {
@@ -445,8 +448,8 @@ private static class BreakPointScannerResult {
 	 * @param limit the maximum width that is relevant to calculate
 	 * @return returns the size 
 	 */
-	static <T extends SplitPointUnit, U extends SplitPointDataSource<T, U>> boolean fits(U data, float limit) {
-		return totalSize(data, limit)<=limit;
+	static <T extends SplitPointUnit, U extends SplitPointDataSource<T, U>> boolean fits(U data, float limit, boolean useLastUnitSize) {
+		return totalSize(data, limit, useLastUnitSize)<=limit;
 	}
 	/**
 	 * If the total size is less than the limit, the size is returned, otherwise a value greater
@@ -456,7 +459,7 @@ static <T extends SplitPointUnit, U extends SplitPointDataSource<T, U>> boolean
 	 * @param limit the maximum width that is relevant to calculate
 	 * @return returns the size 
 	 */
-	static <T extends SplitPointUnit, U extends SplitPointDataSource<T, U>> float totalSize(U data, float limit) {
+	static <T extends SplitPointUnit, U extends SplitPointDataSource<T, U>> float totalSize(U data, float limit, boolean useLastUnitSize) {
 		float ret = 0;
 		Set<String> ids = new HashSet<>();
 		Supplements<T> map = data.getSupplements();
@@ -480,7 +483,7 @@ static <T extends SplitPointUnit, U extends SplitPointDataSource<T, U>> float to
 				}
 			}
 			//last unit?
-			if (!data.hasElementAt(i+1)) {
+			if (useLastUnitSize && !data.hasElementAt(i+1)) {
 				ret += unit.getLastUnitSize();
 			} else {
 				ret += unit.getUnitSize();

src/org/daisy/dotify/common/splitter/StandardSplitOption.java

@@ -14,5 +14,9 @@ public enum StandardSplitOption implements SplitOption {
 	/**
 	 * Retain trailing skippable units
 	 */
-	RETAIN_TRAILING;
+	RETAIN_TRAILING,
+	/**
+	 * Treats the last unit as a regular unit.
+	 */
+	NO_LAST_UNIT_SIZE;
 }

test/org/daisy/dotify/common/splitter/SplitPointHandlerTest.java

@@ -349,7 +349,7 @@ public void testTotalSize_01() {
 		final DummySplitPoint s1 = new DummySplitPoint.Builder().breakable(true).skippable(false).size(1).minSize(0.5f).build();
 		final DummySplitPoint s2 = new DummySplitPoint.Builder().breakable(true).skippable(false).size(1).minSize(0.5f).build();
 		final DummySplitPoint s3 = new DummySplitPoint.Builder().breakable(true).skippable(false).size(1).minSize(0.5f).build();
-		float res = SplitPointHandler.totalSize(new SplitPointDataList<DummySplitPoint>(Arrays.asList(s1, s2, s3)), 3);
+		float res = SplitPointHandler.totalSize(new SplitPointDataList<DummySplitPoint>(Arrays.asList(s1, s2, s3)), 3, true);
 		assertEquals(2.5, res, 0);
 	}