Adds support for volume-keep-priority

build.gradle

@@ -12,7 +12,7 @@ repositories {
 dependencies {
     provided group: "biz.aQute.bnd", name: "annotation", version: "2.3.0"
     compile "org.daisy.dotify:dotify.api:2.9.0"
-    compile "org.daisy.dotify:dotify.common:2.0.2"
+    compile "org.daisy.dotify:dotify.common:2.1.0"
     compile (group: 'org.daisy.libs', name: 'saxon-he', version: '9.5.1.5') {
 		exclude module: 'Saxon-HE'
 	}

src/org/daisy/dotify/formatter/impl/AncestorContext.java

@@ -4,16 +4,21 @@
 
 class AncestorContext {
 	private final BlockProperties blockProperties;
+	private final Integer volumeKeepPriority;
 	private int listIterator;
 
-	AncestorContext(BlockProperties props) {
+	AncestorContext(BlockProperties props, Integer volumeKeep) {
 		this.blockProperties = props;
+		this.volumeKeepPriority = volumeKeep;
 		this.listIterator = 0;
 	}
 	public BlockProperties getBlockProperties() {
 		return blockProperties;
 	}
 
+	public Integer getVolumeKeepPriority() {
+		return volumeKeepPriority;
+	}
 	public int nextListNumber() {
 		listIterator++;
 		return listIterator;

src/org/daisy/dotify/formatter/impl/Block.java

@@ -25,6 +25,8 @@ abstract class Block implements Cloneable {
 	private int keepWithNext;
 	private int keepWithPreviousSheets;
 	private int keepWithNextSheets;
+	private Integer avoidVolumeBreakInsidePriority;
+	private Integer avoidVolumeBreakAfterPriority;
 	private String id;
 	protected final Stack<Segment> segments;
 	protected RowDataProperties rdp;
@@ -42,6 +44,8 @@ abstract class Block implements Cloneable {
 		this.keepWithNext = 0;
 		this.keepWithPreviousSheets = 0;
 		this.keepWithNextSheets = 0;
+		this.avoidVolumeBreakInsidePriority = null;
+		this.avoidVolumeBreakAfterPriority = null;
 		this.id = "";
 		this.blockId = blockId;
 		this.segments = new Stack<>();
@@ -75,6 +79,14 @@ public int getKeepWithNextSheets() {
 		return keepWithNextSheets;
 	}
 
+	public Integer getVolumeKeepInsidePriority() {
+		return avoidVolumeBreakInsidePriority;
+	}
+
+	public Integer getVolumeKeepAfterPriority() {
+		return avoidVolumeBreakAfterPriority;
+	}
+
 	public String getIdentifier() {
 		return id;
 	}
@@ -103,6 +115,14 @@ public void setKeepWithNextSheets(int keepWithNextSheets) {
 		this.keepWithNextSheets = keepWithNextSheets;
 	}
 
+	public void setVolumeKeepInsidePriority(Integer priority) {
+		this.avoidVolumeBreakInsidePriority = priority;
+	}
+
+	public void setVolumeKeepAfterPriority(Integer priority) {
+		this.avoidVolumeBreakAfterPriority = priority;
+	}
+
 	public void setIdentifier(String id) {
 		this.id = id;
 	}
@@ -152,6 +172,15 @@ public void setRowDataProperties(RowDataProperties value) {
 	RenderingScenario getRenderingScenario() {
 		return rs;
 	}
+
+	Integer getAvoidVolumeBreakAfterPriority() {
+		return avoidVolumeBreakAfterPriority;
+	}
+
+	Integer getAvoidVolumeBreakInsidePriority() {
+		return avoidVolumeBreakInsidePriority;
+	}
+
 
 	@Override
 	public Object clone() {

src/org/daisy/dotify/formatter/impl/FormatterCoreImpl.java

@@ -54,6 +54,8 @@ class FormatterCoreImpl extends Stack<Block> implements FormatterCore, BlockGrou
 	private Table table;
 	protected final FormatterCoreContext fc;
 	private MarkerProcessor mp;
+	//The code where this variable is used is not very nice, but it will do to get the feature running
+	private Boolean endStart = null;
 	// TODO: fix recursive keep problem
 	// TODO: Implement floating elements
 	public FormatterCoreImpl(FormatterCoreContext fc) {
@@ -84,6 +86,10 @@ public void startBlock(BlockProperties p, String blockId) {
 		if (table!=null) {
 			throw new IllegalStateException("A table is open.");
 		}
+		if (endStart!=null && endStart == true) {
+			getCurrentBlock().setVolumeKeepAfterPriority(getCurrentVolumeKeepPriority());
+		}
+		endStart = null;
 		String lb = "";
 		String rb = "";
 		if (p.getTextBorderStyle()!=null) {
@@ -137,7 +143,11 @@ public void startBlock(BlockProperties p, String blockId) {
 		}
 		c.setKeepWithNextSheets(p.getKeepWithNextSheets());
 		c.setVerticalPosition(p.getVerticalPosition());
-		propsContext.push(new AncestorContext(p));
+		AncestorContext ac = new AncestorContext(p, inheritVolumeKeepPriority(p.getVolumeKeepPriority()));
+		// We don't get the volume keep priority from block properties, because it could have been inherited from an ancestor
+		c.setVolumeKeepInsidePriority(ac.getVolumeKeepPriority());
+		c.setVolumeKeepAfterPriority(ac.getVolumeKeepPriority());
+		propsContext.push(ac);
 		Block bi = getCurrentBlock();
 		RowDataProperties.Builder builder = new RowDataProperties.Builder(bi.getRowDataProperties());
 		if (p.getTextBorderStyle()!=null) {
@@ -150,6 +160,18 @@ public void startBlock(BlockProperties p, String blockId) {
 		bi.setRowDataProperties(builder.build());
 		//firstRow = true;
 	}
+
+	private Integer inheritVolumeKeepPriority(Integer value) {
+		return (value==null?getCurrentVolumeKeepPriority():value);
+	}
+
+	private Integer getCurrentVolumeKeepPriority() {
+		return propsContext.isEmpty()?null:propsContext.peek().getVolumeKeepPriority();
+	}
+
+	private Integer getParentVolumeKeepPriority() {
+		return propsContext.size()<2?null:propsContext.get(propsContext.size()-2).getVolumeKeepPriority();
+	}
 
 	@Override
 	public void endBlock() {
@@ -159,8 +181,14 @@ public void endBlock() {
 		if (listItem!=null) {
 			addChars("", new TextProperties.Builder(null).build());
 		}
+		if (endStart == null) {
+			endStart = true;
+		} else {
+			endStart = false;
+		}
 		{
-		BlockProperties p = propsContext.pop().getBlockProperties();
+		AncestorContext ac = propsContext.pop();
+		BlockProperties p = ac.getBlockProperties();
 		Block bi = getCurrentBlock();
 		RowDataProperties.Builder builder = new RowDataProperties.Builder(bi.getRowDataProperties());
 		if (p.getTextBorderStyle()!=null) {
@@ -173,11 +201,14 @@ public void endBlock() {
 			outerSpaceAfter(bi.getRowDataProperties().getOuterSpaceAfter()+p.getMargin().getBottomSpacing());
 		bi.setKeepWithPreviousSheets(p.getKeepWithPreviousSheets());
 		bi.setRowDataProperties(builder.build());
+		//set the volume keep after for the closing block to the parent priority 
+		bi.setVolumeKeepAfterPriority(getCurrentVolumeKeepPriority());
 		}
 		leftMargin.pop();
 		rightMargin.pop();
 		if (propsContext.size()>0) {
-			BlockProperties p = propsContext.peek().getBlockProperties();
+			AncestorContext ac = propsContext.peek(); 
+			BlockProperties p = ac.getBlockProperties();
 			Keep keep = p.getKeepType();
 			int next = p.getKeepWithNext();
 			subtractFromBlockIndent(p.getBlockIndent());
@@ -198,6 +229,9 @@ public void endBlock() {
 			Block c = newBlock(null, rdp.build());
 			c.setKeepType(keep);
 			c.setKeepWithNext(next);
+			// We don't get the volume keep priority from the BlockProperties, as it could have been inherited from an ancestor
+			c.setVolumeKeepInsidePriority(getCurrentVolumeKeepPriority());
+			c.setVolumeKeepAfterPriority(getParentVolumeKeepPriority());
 		}
 		//firstRow = true;
 	}

src/org/daisy/dotify/formatter/impl/PageImpl.java

@@ -49,6 +49,7 @@ class PageImpl implements Page {
 	private boolean isVolBreak;
 	private boolean isVolBreakAllowed;
 	private int keepPreviousSheets;
+	private Integer volumeBreakAfterPriority;
 	private int volumeNumber;
 
 
@@ -74,6 +75,7 @@ public PageImpl(LayoutMaster master, FormatterContext fcontext, int pageIndex, L
 		this.isVolBreak = false;
 		this.isVolBreakAllowed = true;
 		this.keepPreviousSheets = 0;
+		this.volumeBreakAfterPriority = null;
 		this.volumeNumber = 0;
 	}
 
@@ -708,5 +710,13 @@ int getVolumeNumber() {
 	void setVolumeNumber(int volumeNumber) {
 		this.volumeNumber = volumeNumber;
 	}
+
+	Integer getAvoidVolumeBreakAfter() {
+		return volumeBreakAfterPriority;
+	}
+
+	void setAvoidVolumeBreakAfter(Integer value) {
+		this.volumeBreakAfterPriority = value;
+	}
 
 }

src/org/daisy/dotify/formatter/impl/PageSequenceBuilder2.java

@@ -162,7 +162,8 @@ PageImpl nextPage() throws PaginatorException, RestartPaginationException {
 				}
 				force = res.getHead().size()==0;
 				data = res.getTail();
-				for (RowGroup rg : res.getHead()) {
+				List<RowGroup> head = res.getHead();
+				for (RowGroup rg : head) {
 					addProperties(rg);
 					for (RowImpl r : rg.getRows()) { 
 						if (r.shouldAdjustForMargin()) {
@@ -178,6 +179,12 @@ PageImpl nextPage() throws PaginatorException, RestartPaginationException {
 						currentPage().newRow(r);
 					}
 				}
+				Integer lastPriority = getLastPriority(head);
+				if (!res.getDiscarded().isEmpty()) {
+					//override if not empty
+					lastPriority = getLastPriority(res.getDiscarded());
+				}
+				currentPage().setAvoidVolumeBreakAfter(lastPriority);
 				for (RowGroup rg : res.getDiscarded()) {
 					addProperties(rg);
 				}
@@ -199,6 +206,14 @@ PageImpl nextPage() throws PaginatorException, RestartPaginationException {
 		return ret;
 	}
 
+	private static Integer getLastPriority(List<RowGroup> list) {
+		if (!list.isEmpty()) {
+			return list.get(list.size()-1).getAvoidVolumeBreakAfterPriority();
+		} else {
+			return null;
+		}
+	}
+
 	private boolean firstUnitHasSupplements(SplitPointData<RowGroup> spd) {
 		return !spd.getUnits().isEmpty() && !spd.getUnits().get(0).getSupplementaryIDs().isEmpty();
 	}

src/org/daisy/dotify/formatter/impl/PageSequenceRecorder.java

@@ -149,6 +149,10 @@ boolean isDataEmpty() {
 		return data.isDataEmpty();
 	}
 
+	RowGroupSequence currentSequence() {
+		return data.dataGroups.peek();
+	}
+
 	void addRowGroup(RowGroup rg) {
 		data.addRowGroup(rg); 
 	}

src/org/daisy/dotify/formatter/impl/PageStructBuilder.java

@@ -45,14 +45,21 @@ List<Sheet> paginate(DefaultContext rcontext) throws PaginatorException {
 							si = new SheetIdentity(rcontext.getSpace(), rcontext.getCurrentVolume()==null?0:rcontext.getCurrentVolume(), ret.size());
 							sheetIndex++;
 						}
+						s.avoidVolumeBreakAfterPriority(p.getAvoidVolumeBreakAfter());
 						if (sheetIndex==1 && bs.getSequenceProperties().getBreakBeforeType()==SequenceBreakBefore.VOLUME) {
 							s.startNewVolume(true);
 						}
 						if (pageIndex==pages.size()-1) {
+							s.avoidVolumeBreakAfterPriority(null);
 							//Don't get or store this value in crh as it is transient and not a property of the sheet context
 							s.breakable(true);
 						} else {
-							s.breakable(crh.getBreakable(si));
+							boolean br = crh.getBreakable(si);
+							//TODO: the following is a low effort way of giving existing uses of non-breakable units a high priority, but it probably shouldn't be done this way
+							if (!br) {
+								s.avoidVolumeBreakAfterPriority(1);
+							}
+							s.breakable(br);
 						}
 
 						setPreviousSheet(si.getSheetIndex()-1, Math.min(p.keepPreviousSheets(), sheetIndex-1), rcontext);
@@ -63,6 +70,7 @@ List<Sheet> paginate(DefaultContext rcontext) throws PaginatorException {
 						s.add(p);
 					}
 					if (s!=null) {
+						//Last page in the sequence doesn't need volume keep priority
 						ret.add(s.build());
 					}
 				} catch (RestartPaginationException e) {

src/org/daisy/dotify/formatter/impl/RowGroup.java

@@ -18,6 +18,7 @@ class RowGroup implements SplitPointUnit {
 	private final List<String> ids;
 	private final String identifier;
 	private final int keepWithNextSheets, keepWithPreviousSheets;
+	private Integer avoidVolumeBreakAfterPriority = null;
 
 	static class Builder {
 		private final List<RowImpl> rows;
@@ -135,6 +136,7 @@ private RowGroup(Builder builder) {
 		this.identifier = template.identifier;
 		this.keepWithNextSheets = template.keepWithNextSheets;
 		this.keepWithPreviousSheets = template.keepWithPreviousSheets;
+		this.avoidVolumeBreakAfterPriority = template.avoidVolumeBreakAfterPriority;
 	}
 
 	private static float getRowSpacing(float rowDefault, RowImpl r) {
@@ -249,4 +251,12 @@ public int getKeepWithPreviousSheets() {
 		return keepWithPreviousSheets;
 	}
 
+	public Integer getAvoidVolumeBreakAfterPriority() {
+		return avoidVolumeBreakAfterPriority;
+	}
+
+	void setAvoidVolumeBreakAfterPriority(Integer value) {
+		this.avoidVolumeBreakAfterPriority = value;
+	}
+
 }