Bugzilla 46905: Added basic implementation for column-level keeps.

Also added one disabled-testcase for a remaining issue with page-level
keeps in multi-column layout.


git-svn-id: https://svn.apache.org/repos/asf/xmlgraphics/fop/trunk@807014 13f79535-47bb-0310-9956-ffa450edef68

src/java/org/apache/fop/fo/flow/table/EffRow.java

@@ -23,8 +23,7 @@ import java.util.Iterator;
 import java.util.List;
 
 import org.apache.fop.fo.Constants;
-import org.apache.fop.layoutmgr.BlockLevelLayoutManager;
-import org.apache.fop.layoutmgr.KeepUtil;
+import org.apache.fop.layoutmgr.Keep;
 import org.apache.fop.layoutmgr.table.TableRowIterator;
 import org.apache.fop.traits.MinOptMax;
 import org.apache.fop.util.BreakUtil;
@@ -170,20 +169,19 @@ public class EffRow {
      *
      * @return the strength of the keep-with-previous constraint
      */
-    public int getKeepWithPreviousStrength() {
-        int strength = BlockLevelLayoutManager.KEEP_AUTO;
+    public Keep getKeepWithPrevious() {
+        Keep keep = Keep.KEEP_AUTO;
         TableRow row = getTableRow();
         if (row != null) {
-            strength = Math.max(strength,
-                    KeepUtil.getCombinedBlockLevelKeepStrength(row.getKeepWithPrevious()));
+            keep = Keep.getKeep(row.getKeepWithPrevious());
         }
         for (Iterator iter = gridUnits.iterator(); iter.hasNext();) {
             GridUnit gu = (GridUnit) iter.next();
             if (gu.isPrimary()) {
-                strength = Math.max(strength, gu.getPrimary().getKeepWithPreviousStrength());
+                keep = keep.compare(gu.getPrimary().getKeepWithPrevious());
             }
         }
-        return strength;
+        return keep;
     }
 
     /**
@@ -192,20 +190,19 @@ public class EffRow {
      *
      * @return the strength of the keep-with-next constraint
      */
-    public int getKeepWithNextStrength() {
-        int strength = BlockLevelLayoutManager.KEEP_AUTO;
+    public Keep getKeepWithNext() {
+        Keep keep = Keep.KEEP_AUTO;
         TableRow row = getTableRow();
         if (row != null) {
-            strength = Math.max(strength,
-                    KeepUtil.getCombinedBlockLevelKeepStrength(row.getKeepWithNext()));
+            keep = Keep.getKeep(row.getKeepWithNext());
         }
         for (Iterator iter = gridUnits.iterator(); iter.hasNext();) {
             GridUnit gu = (GridUnit) iter.next();
             if (!gu.isEmpty() && gu.getColSpanIndex() == 0 && gu.isLastGridUnitRowSpan()) {
-                strength = Math.max(strength, gu.getPrimary().getKeepWithNextStrength());
+                keep = keep.compare(gu.getPrimary().getKeepWithNext());
             }
         }
-        return strength;
+        return keep;
     }
 
     /**
@@ -213,16 +210,13 @@ public class EffRow {
      * not take the parent table's keeps into account!
      * @return the keep-together strength
      */
-    public int getKeepTogetherStrength() {
+    public Keep getKeepTogether() {
         TableRow row = getTableRow();
-        int strength = BlockLevelLayoutManager.KEEP_AUTO;
+        Keep keep = Keep.KEEP_AUTO;
         if (row != null) {
-            strength = Math.max(strength, KeepUtil.getKeepStrength(
-                    row.getKeepTogether().getWithinPage()));
-            strength = Math.max(strength, KeepUtil.getKeepStrength(
-                    row.getKeepTogether().getWithinColumn()));
+            keep = Keep.getKeep(row.getKeepTogether());
         }
-        return strength;
+        return keep;
     }
 
     /**

src/java/org/apache/fop/fo/flow/table/PrimaryGridUnit.java

@@ -19,14 +19,13 @@
 
 package org.apache.fop.fo.flow.table;
 
-import java.util.LinkedList;
 import java.util.List;
 
 import org.apache.fop.fo.Constants;
 import org.apache.fop.fo.FONode;
 import org.apache.fop.fo.properties.CommonBorderPaddingBackground;
-import org.apache.fop.layoutmgr.BlockLevelLayoutManager;
 import org.apache.fop.layoutmgr.ElementListUtils;
+import org.apache.fop.layoutmgr.Keep;
 import org.apache.fop.layoutmgr.table.TableCellLayoutManager;
 
 /**
@@ -54,8 +53,8 @@ public class PrimaryGridUnit extends GridUnit {
     private boolean isSeparateBorderModel;
     private int halfBorderSeparationBPD;
 
-    private int keepWithPrevious = BlockLevelLayoutManager.KEEP_AUTO;
-    private int keepWithNext = BlockLevelLayoutManager.KEEP_AUTO;
+    private Keep keepWithPrevious = Keep.KEEP_AUTO;
+    private Keep keepWithNext = Keep.KEEP_AUTO;
     private int breakBefore = Constants.EN_AUTO;
     private int breakAfter = Constants.EN_AUTO;
 
@@ -334,16 +333,16 @@ public class PrimaryGridUnit extends GridUnit {
      *
      * @return the keep-with-previous strength
      */
-    public int getKeepWithPreviousStrength() {
+    public Keep getKeepWithPrevious() {
         return keepWithPrevious;
     }
 
     /**
      * Don't use, reserved for TableCellLM. TODO
-     * @param strength the keep strength
+     * @param keep the keep strength
      */
-    public void setKeepWithPreviousStrength(int strength) {
-        this.keepWithPrevious = strength;
+    public void setKeepWithPrevious(Keep keep) {
+        this.keepWithPrevious = keep;
     }
 
     /**
@@ -352,16 +351,16 @@ public class PrimaryGridUnit extends GridUnit {
      *
      * @return the keep-with-next strength
      */
-    public int getKeepWithNextStrength() {
+    public Keep getKeepWithNext() {
         return keepWithNext;
     }
 
     /**
      * Don't use, reserved for TableCellLM. TODO
-     * @param strength the keep strength
+     * @param keep the keep strength
      */
-    public void setKeepWithNextStrength(int strength) {
-        this.keepWithNext = strength;
+    public void setKeepWithNext(Keep keep) {
+        this.keepWithNext = keep;
     }
 
     /**

src/java/org/apache/fop/layoutmgr/BlockContainerLayoutManager.java

@@ -37,6 +37,7 @@ import org.apache.fop.datatypes.FODimension;
 import org.apache.fop.datatypes.Length;
 import org.apache.fop.fo.flow.BlockContainer;
 import org.apache.fop.fo.properties.CommonAbsolutePosition;
+import org.apache.fop.fo.properties.KeepProperty;
 import org.apache.fop.traits.MinOptMax;
 import org.apache.fop.traits.SpaceVal;
 import org.apache.fop.util.ListUtil;
@@ -261,7 +262,7 @@ public class BlockContainerLayoutManager extends BlockStackingLayoutManager
 
         if (!firstVisibleMarkServed) {
             addKnuthElementsForSpaceBefore(returnList, alignment);
-            context.updateKeepWithPreviousPending(getKeepWithPreviousStrength());
+            context.updateKeepWithPreviousPending(getKeepWithPrevious());
         }
 
         addKnuthElementsForBorderPaddingBefore(returnList, !firstVisibleMarkServed);
@@ -271,9 +272,9 @@ public class BlockContainerLayoutManager extends BlockStackingLayoutManager
             //Spaces, border and padding to be repeated at each break
             addPendingMarks(context);
 
-            BlockLevelLayoutManager curLM; // currently active LM
-            BlockLevelLayoutManager prevLM = null; // previously active LM
-            while ((curLM = (BlockLevelLayoutManager) getChildLM()) != null) {
+            LayoutManager curLM; // currently active LM
+            LayoutManager prevLM = null; // previously active LM
+            while ((curLM = getChildLM()) != null) {
                 LayoutContext childLC = new LayoutContext(0);
                 childLC.copyPendingMarksFrom(context);
                 // curLM is a ?
@@ -323,8 +324,7 @@ public class BlockContainerLayoutManager extends BlockStackingLayoutManager
                         //Avoid NoSuchElementException below (happens with empty blocks)
                         continue;
                     }
-                    if (((ListElement) ListUtil.getLast(returnedList))
-                            .isForcedBreak()) {
+                    if (ElementListUtils.endsWithForcedBreak(returnedList)) {
                         // a descendant of this block has break-after
                         if (curLM.isFinished()) {
                             // there is no other content in this block;
@@ -391,7 +391,7 @@ public class BlockContainerLayoutManager extends BlockStackingLayoutManager
         context.clearPendingMarks();
         addKnuthElementsForBreakAfter(returnList, context);
 
-        context.updateKeepWithNextPending(getKeepWithNextStrength());
+        context.updateKeepWithNextPending(getKeepWithNext());
 
         setFinished(true);
         return returnList;
@@ -1011,23 +1011,18 @@ public class BlockContainerLayoutManager extends BlockStackingLayoutManager
     }
 
     /** {@inheritDoc} */
-    public int getKeepTogetherStrength() {
-        int strength = KeepUtil.getCombinedBlockLevelKeepStrength(
-                getBlockContainerFO().getKeepTogether());
-        strength = Math.max(strength, getParentKeepTogetherStrength());
-        return strength;
+    public KeepProperty getKeepTogetherProperty() {
+        return getBlockContainerFO().getKeepTogether();
     }
 
     /** {@inheritDoc} */
-    public int getKeepWithNextStrength() {
-        return KeepUtil.getCombinedBlockLevelKeepStrength(
-                getBlockContainerFO().getKeepWithNext());
+    public KeepProperty getKeepWithPreviousProperty() {
+        return getBlockContainerFO().getKeepWithPrevious();
     }
 
     /** {@inheritDoc} */
-    public int getKeepWithPreviousStrength() {
-        return KeepUtil.getCombinedBlockLevelKeepStrength(
-                getBlockContainerFO().getKeepWithPrevious());
+    public KeepProperty getKeepWithNextProperty() {
+        return getBlockContainerFO().getKeepWithNext();
     }
 
     /**

src/java/org/apache/fop/layoutmgr/BlockLayoutManager.java

@@ -207,21 +207,18 @@ public class BlockLayoutManager extends BlockStackingLayoutManager
     }
 
     /** {@inheritDoc} */
-    public int getKeepTogetherStrength() {
-        KeepProperty keep = getBlockFO().getKeepTogether();
-        int strength = KeepUtil.getCombinedBlockLevelKeepStrength(keep);
-        strength = Math.max(strength, getParentKeepTogetherStrength());
-        return strength;
+    public KeepProperty getKeepTogetherProperty() {
+        return getBlockFO().getKeepTogether();
     }
 
     /** {@inheritDoc} */
-    public int getKeepWithNextStrength() {
-        return KeepUtil.getCombinedBlockLevelKeepStrength(getBlockFO().getKeepWithNext());
+    public KeepProperty getKeepWithPreviousProperty() {
+        return getBlockFO().getKeepWithPrevious();
     }
 
     /** {@inheritDoc} */
-    public int getKeepWithPreviousStrength() {
-        return KeepUtil.getCombinedBlockLevelKeepStrength(getBlockFO().getKeepWithPrevious());
+    public KeepProperty getKeepWithNextProperty() {
+        return getBlockFO().getKeepWithNext();
     }
 
     /** {@inheritDoc} */

src/java/org/apache/fop/layoutmgr/BlockLevelLayoutManager.java

@@ -19,6 +19,8 @@
 
 package org.apache.fop.layoutmgr;
 
+import org.apache.fop.fo.properties.KeepProperty;
+
 /**
  * The interface for LayoutManagers which generate block areas
  */
@@ -35,11 +37,6 @@ public interface BlockLevelLayoutManager extends LayoutManager {
     /** Adjustment class: adjustment for line height */
     int LINE_HEIGHT_ADJUSTMENT = 3;
 
-    /** The integer value for "auto" keep strength */
-    int KEEP_AUTO = Integer.MIN_VALUE;
-    /** The integer value for "always" keep strength */
-    int KEEP_ALWAYS = Integer.MAX_VALUE;
-
     int negotiateBPDAdjustment(int adj, KnuthElement lastElement);
 
     void discardSpace(KnuthGlue spaceGlue);
@@ -48,7 +45,7 @@ public interface BlockLevelLayoutManager extends LayoutManager {
      * Returns the keep-together strength for this element.
      * @return the keep-together strength
      */
-    int getKeepTogetherStrength();
+    Keep getKeepTogether();
 
     /**
      * @return true if this element must be kept together
@@ -59,7 +56,7 @@ public interface BlockLevelLayoutManager extends LayoutManager {
      * Returns the keep-with-previous strength for this element.
      * @return the keep-with-previous strength
      */
-    int getKeepWithPreviousStrength();
+    Keep getKeepWithPrevious();
 
     /**
      * @return true if this element must be kept with the previous element.
@@ -70,11 +67,28 @@ public interface BlockLevelLayoutManager extends LayoutManager {
      * Returns the keep-with-next strength for this element.
      * @return the keep-with-next strength
      */
-    int getKeepWithNextStrength();
+    Keep getKeepWithNext();
 
     /**
      * @return true if this element must be kept with the next element.
      */
     boolean mustKeepWithNext();
 
+    /**
+     * Returns the keep-together property specified on the FObj.
+     * @return the keep-together property
+     */
+    KeepProperty getKeepTogetherProperty();
+
+    /**
+     * Returns the keep-with-previous property specified on the FObj.
+     * @return the keep-together property
+     */
+    KeepProperty getKeepWithPreviousProperty();
+
+    /**
+     * Returns the keep-with-next property specified on the FObj.
+     * @return the keep-together property
+     */
+    KeepProperty getKeepWithNextProperty();
 }

src/java/org/apache/fop/layoutmgr/BlockStackingLayoutManager.java

@@ -31,9 +31,11 @@ import org.apache.fop.area.Area;
 import org.apache.fop.area.Block;
 import org.apache.fop.area.BlockParent;
 import org.apache.fop.fo.FObj;
+import org.apache.fop.fo.Constants;
 import org.apache.fop.fo.properties.BreakPropertySet;
 import org.apache.fop.fo.properties.CommonBorderPaddingBackground;
 import org.apache.fop.fo.properties.SpaceProperty;
+import org.apache.fop.fo.properties.KeepProperty;
 import org.apache.fop.layoutmgr.inline.InlineLayoutManager;
 import org.apache.fop.layoutmgr.inline.LineLayoutManager;
 import org.apache.fop.traits.MinOptMax;
@@ -258,7 +260,7 @@ public abstract class BlockStackingLayoutManager extends AbstractLayoutManager
 
         if (!firstVisibleMarkServed) {
             addKnuthElementsForSpaceBefore(elements, alignment);
-            context.updateKeepWithPreviousPending(getKeepWithPreviousStrength());
+            context.updateKeepWithPreviousPending(getKeepWithPrevious());
         }
 
         addKnuthElementsForBorderPaddingBefore(elements, !firstVisibleMarkServed);
@@ -349,7 +351,7 @@ public abstract class BlockStackingLayoutManager extends AbstractLayoutManager
             elements.add(forcedBreakAfterLast);
         }
 
-        context.updateKeepWithNextPending(getKeepWithNextStrength());
+        context.updateKeepWithNextPending(getKeepWithNext());
 
         setFinished(true);
 
@@ -375,31 +377,31 @@ public abstract class BlockStackingLayoutManager extends AbstractLayoutManager
 
     /**
      * Adds a break element to the content list between individual child elements.
-     * @param contentList the content list to populate
-     * @param context the current layout context
+     * @param contentList
+     * @param parentLC
      * @param childLC the currently active child layout context
      */
-    protected void addInBetweenBreak(List contentList, LayoutContext context,
-            LayoutContext childLC) {
+    protected void addInBetweenBreak(List contentList, LayoutContext parentLC,
+                                     LayoutContext childLC) {
+
         if (mustKeepTogether()
-                || context.isKeepWithNextPending()
+                || parentLC.isKeepWithNextPending()
                 || childLC.isKeepWithPreviousPending()) {
 
-            int strength = getKeepTogetherStrength();
+            Keep keep = getKeepTogether();
 
             //Handle pending keep-with-next
-            strength = Math.max(strength, context.getKeepWithNextPending());
-            context.clearKeepWithNextPending();
+            keep = keep.compare(parentLC.getKeepWithNextPending());
+            parentLC.clearKeepWithNextPending();
 
             //Handle pending keep-with-previous from child LM
-            strength = Math.max(strength, childLC.getKeepWithPreviousPending());
+            keep = keep.compare(childLC.getKeepWithPreviousPending());
             childLC.clearKeepWithPreviousPending();
 
-            int penalty = KeepUtil.getPenaltyForKeep(strength);
-
             // add a penalty to forbid or discourage a break between blocks
             contentList.add(new BreakElement(
-                    new Position(this), penalty, context));
+                    new Position(this), keep.getPenalty(),
+                    keep.getContext(), parentLC));
             return;
         }
 
@@ -430,7 +432,7 @@ public abstract class BlockStackingLayoutManager extends AbstractLayoutManager
 
             // add a null penalty to allow a break between blocks
             contentList.add(new BreakElement(
-                    new Position(this), 0, context));
+                    new Position(this), 0, Constants.EN_AUTO, parentLC));
         }
     }
 
@@ -766,33 +768,77 @@ public abstract class BlockStackingLayoutManager extends AbstractLayoutManager
      * Retrieves and returns the keep-together strength from the parent element.
      * @return the keep-together strength
      */
-    protected int getParentKeepTogetherStrength() {
-        int strength = KEEP_AUTO;
+    protected Keep getParentKeepTogether() {
+        Keep keep = Keep.KEEP_AUTO;
         if (getParent() instanceof BlockLevelLayoutManager) {
-            strength = ((BlockLevelLayoutManager)getParent()).getKeepTogetherStrength();
+            keep = ((BlockLevelLayoutManager)getParent()).getKeepTogether();
         } else if (getParent() instanceof InlineLayoutManager) {
             if (((InlineLayoutManager) getParent()).mustKeepTogether()) {
-                strength = KEEP_ALWAYS;
+                keep = Keep.KEEP_ALWAYS;
             }
             //TODO Fix me
             //strength = ((InlineLayoutManager) getParent()).getKeepTogetherStrength();
         }
-        return strength;
+        return keep;
     }
 
     /** {@inheritDoc} */
     public boolean mustKeepTogether() {
-        return getKeepTogetherStrength() > KEEP_AUTO;
+        return !getKeepTogether().isAuto();
     }
 
     /** {@inheritDoc} */
     public boolean mustKeepWithPrevious() {
-        return getKeepWithPreviousStrength() > KEEP_AUTO;
+        return !getKeepWithPrevious().isAuto();
     }
 
     /** {@inheritDoc} */
     public boolean mustKeepWithNext() {
-        return getKeepWithNextStrength() > KEEP_AUTO;
+        return !getKeepWithNext().isAuto();
+    }
+
+    /** {@inheritDoc} */
+    public Keep getKeepTogether() {
+        Keep keep = Keep.getKeep(getKeepTogetherProperty());
+        keep = keep.compare(getParentKeepTogether());
+        return keep;
+    }
+
+    /** {@inheritDoc} */
+    public Keep getKeepWithPrevious() {
+        return Keep.getKeep(getKeepWithPreviousProperty());
+    }
+
+    /** {@inheritDoc} */
+    public Keep getKeepWithNext() {
+        return Keep.getKeep(getKeepWithNextProperty());
+    }
+
+    /**
+     * {@inheritDoc}
+     * Default implementation throws {@code IllegalStateException}
+     * Must be implemented by the subclass, if applicable.
+     */
+    public KeepProperty getKeepTogetherProperty() {
+        throw new IllegalStateException();
+    }
+
+    /**
+     * {@inheritDoc}
+     * Default implementation throws {@code IllegalStateException}
+     * Must be implemented by the subclass, if applicable.
+     */
+    public KeepProperty getKeepWithPreviousProperty() {
+        throw new IllegalStateException();
+    }
+
+    /**
+     * {@inheritDoc}
+     * Default implementation throws {@code IllegalStateException}
+     * Must be implemented by the subclass, if applicable.
+     */
+    public KeepProperty getKeepWithNextProperty() {
+        throw new IllegalStateException();
     }
 
     /**

src/java/org/apache/fop/layoutmgr/BreakElement.java

@@ -41,7 +41,22 @@ public class BreakElement extends UnresolvedListElement {
      * @param context the layout context which contains the pending conditional elements
      */
     public BreakElement(Position position, int penaltyValue, LayoutContext context) {
-        this(position, 0, penaltyValue, -1, context);
+        this(position, penaltyValue, -1, context);
+    }
+
+    /**
+     * Create a new BreakElement for the given {@code position}, {@code penaltyValue}
+     * and {@code breakClass}. (Used principally to generate break-possibilities in
+     * ranges of content that must be kept together within the context corresponding
+     * to the {@code breakClass}; expected to be one of {@link Constants#EN_AUTO},
+     * {@link Constants#EN_LINE}, {@link Constants#EN_COLUMN} or {@link Constants#EN_PAGE})
+     * @param position  the corresponding {@link Position}
+     * @param penaltyValue  the penalty value
+     * @param breakClass    the break class
+     * @param context       the {@link LayoutContext}
+     */
+    public BreakElement(Position position, int penaltyValue, int breakClass, LayoutContext context) {
+        this(position, 0, penaltyValue, breakClass, context);
     }
 
     /**
@@ -65,6 +80,10 @@ public class BreakElement extends UnresolvedListElement {
         this.pendingAfterMarks = context.getPendingAfterMarks();
     }
 
+    private static String getBreakClassName(int breakClass) {
+        return AbstractBreaker.getBreakClassName(breakClass);
+    }
+
     /** {@inheritDoc} */
     public boolean isConditional() {
         return false; //Does not really apply here
@@ -143,27 +162,17 @@ public class BreakElement extends UnresolvedListElement {
 
     /** {@inheritDoc} */
     public String toString() {
-        StringBuffer sb = new StringBuffer();
+        StringBuffer sb = new StringBuffer(64);
         sb.append("BreakPossibility[p:");
-        sb.append(this.penaltyValue);
+        sb.append(KnuthPenalty.valueOf(this.penaltyValue));
         if (isForcedBreak()) {
-            sb.append(" (forced break");
-            switch (getBreakClass()) {
-            case Constants.EN_PAGE:
-                sb.append(", page");
-                break;
-            case Constants.EN_COLUMN:
-                sb.append(", column");
-                break;
-            case Constants.EN_EVEN_PAGE:
-                sb.append(", even page");
-                break;
-            case Constants.EN_ODD_PAGE:
-                sb.append(", odd page");
-                break;
-            default:
-            }
-            sb.append(")");
+            sb.append(" (forced break, ")
+                    .append(getBreakClassName(this.breakClass))
+                    .append(")");
+        } else if (this.penaltyValue >= 0 && this.breakClass != -1) {
+            sb.append(" (keep constraint, ")
+                    .append(getBreakClassName(this.breakClass))
+                    .append(")");
         }
         sb.append("; w:");
         sb.append(penaltyWidth);

src/java/org/apache/fop/layoutmgr/BreakingAlgorithm.java

@@ -610,6 +610,14 @@ public abstract class BreakingAlgorithm {
                              best.getNode(fitness));
     }
 
+    /**
+     * Return the last node that yielded a too short line.
+     * @return  the node corresponding to the last too short line
+     */
+    protected final KnuthNode getLastTooShort() {
+        return this.lastTooShort;
+    }
+
     /**
      * Generic handler for a {@link KnuthElement} at the given {@code position},
      * taking into account whether the preceding element was a box, and which
@@ -647,7 +655,7 @@ public abstract class BreakingAlgorithm {
 
     /**
      * Handle a {@link KnuthBox}.
-     * <em>Note: default implementation just adds the box's width
+     * <br/><em>Note: default implementation just adds the box's width
      * to the total content width. Subclasses that do not keep track
      * of this themselves, but override this method, should remember
      * to call {@code super.handleBox(box)} to avoid unwanted side-effects.</em>
@@ -808,14 +816,16 @@ public abstract class BreakingAlgorithm {
         lastDeactivated = null;
         lastTooLong = null;
         for (int line = startLine; line < endLine; line++) {
-            if (!elementCanEndLine(element, line)) {
-                continue;
-            }
             for (KnuthNode node = getNode(line); node != null; node = node.next) {
                 if (node.position == elementIdx) {
                     continue;
                 }
                 int difference = computeDifference(node, element, elementIdx);
+                if (!elementCanEndLine(element, endLine, difference)) {
+                    log.trace("Skipping legal break");
+                    break;
+                }
+
                 double r = computeAdjustmentRatio(node, difference);
                 int availableShrink = totalShrink - node.totalShrink;
                 int availableStretch = totalStretch - node.totalStretch;
@@ -854,9 +864,10 @@ public abstract class BreakingAlgorithm {
      * number.
      * @param element   the element
      * @param line      the line number
+     * @param difference
      * @return  {@code true} if the element can end the line
      */
-    protected boolean elementCanEndLine(KnuthElement element, int line) {
+    protected boolean elementCanEndLine(KnuthElement element, int line, int difference) {
         return (!element.isPenalty()
                 || element.getP() < KnuthElement.INFINITE);
     }

src/java/org/apache/fop/layoutmgr/FlowLayoutManager.java

@@ -181,18 +181,18 @@ public class FlowLayoutManager extends BlockStackingLayoutManager
     }
 
     /** {@inheritDoc} */
-    public int getKeepTogetherStrength() {
-        return KEEP_AUTO;
+    public Keep getKeepTogether() {
+        return Keep.KEEP_AUTO;
     }
 
     /** {@inheritDoc} */
-    public int getKeepWithNextStrength() {
-        return KEEP_AUTO;
+    public Keep getKeepWithNext() {
+        return Keep.KEEP_AUTO;
     }
 
     /** {@inheritDoc} */
-    public int getKeepWithPreviousStrength() {
-        return KEEP_AUTO;
+    public Keep getKeepWithPrevious() {
+        return Keep.KEEP_AUTO;
     }
 
     /** {@inheritDoc} */

src/java/org/apache/fop/layoutmgr/FootnoteBodyLayoutManager.java

@@ -92,18 +92,18 @@ public class FootnoteBodyLayoutManager extends BlockStackingLayoutManager {
     }
 
     /** {@inheritDoc} */
-    public int getKeepTogetherStrength() {
-        return getParentKeepTogetherStrength();
+    public Keep getKeepTogether() {
+        return getParentKeepTogether();
     }
 
     /** {@inheritDoc} */
-    public int getKeepWithNextStrength() {
-        return KEEP_AUTO;
+    public Keep getKeepWithNext() {
+        return Keep.KEEP_AUTO;
     }
 
     /** {@inheritDoc} */
-    public int getKeepWithPreviousStrength() {
-        return KEEP_AUTO;
+    public Keep getKeepWithPrevious() {
+        return Keep.KEEP_AUTO;
     }
 
 }

src/java/org/apache/fop/layoutmgr/Keep.java

@@ -0,0 +1,152 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more contributor license
+ * agreements. See the NOTICE file distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file to You under the Apache
+ * License, Version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under
+ * the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the specific language governing
+ * permissions and limitations under the License.
+ */
+
+/* $Id$ */
+
+package org.apache.fop.layoutmgr;
+
+import org.apache.fop.fo.Constants;
+import org.apache.fop.fo.properties.KeepProperty;
+import org.apache.fop.fo.properties.Property;
+
+/**
+ * Object representing a keep constraint, corresponding
+ * to the XSL-FO <a href="http://www.w3.org/TR/xsl/#d0e26492">keep properties</a>.
+ */
+public class Keep {
+
+    /** The integer value for "auto" keep strength. */
+    private static final int STRENGTH_AUTO = Integer.MIN_VALUE;
+
+    /** The integer value for "always" keep strength. */
+    private static final int STRENGTH_ALWAYS = Integer.MAX_VALUE;
+
+    public static final Keep KEEP_AUTO = new Keep(STRENGTH_AUTO, Constants.EN_AUTO);
+
+    public static final Keep KEEP_ALWAYS = new Keep(STRENGTH_ALWAYS, Constants.EN_LINE);
+
+    private int strength;
+
+    private int context;
+
+    private Keep(int strength, int context) {
+        this.strength = strength;
+        this.context = context;
+    }
+
+    private static int getKeepStrength(Property keep) {
+        if (keep.isAuto()) {
+            return STRENGTH_AUTO;
+        } else if (keep.getEnum() == Constants.EN_ALWAYS) {
+            return STRENGTH_ALWAYS;
+        } else {
+            return keep.getNumber().intValue();
+        }
+    }
+
+    /**
+     * Obtain a Keep instance corresponding to the given {@link KeepProperty}
+     *
+     * @param keepProperty  the {@link KeepProperty}
+     * @return  a new instance corresponding to the given property
+     */
+    public static Keep getKeep(KeepProperty keepProperty) {
+        Keep keep = new Keep(STRENGTH_AUTO, Constants.EN_AUTO);
+        keep.update(keepProperty.getWithinPage(),   Constants.EN_PAGE);
+        keep.update(keepProperty.getWithinColumn(), Constants.EN_COLUMN);
+        keep.update(keepProperty.getWithinLine(),   Constants.EN_LINE);
+        return keep;
+    }
+
+    private void update(Property keep, int context) {
+        if (!keep.isAuto()) {
+            this.strength = getKeepStrength(keep);
+            this.context = context;
+        }
+    }
+
+    /** @return {@code true} if the keep property was specified as "auto" */
+    public boolean isAuto() {
+        return strength == STRENGTH_AUTO;
+    }
+
+    /**
+     * Returns the context of this keep.
+     *
+     * @return one of {@link Constants#EN_LINE}, {@link Constants#EN_COLUMN} or
+     * {@link Constants#EN_PAGE}
+     */
+    public int getContext() {
+        return context;
+    }
+
+    /** @return the penalty value corresponding to the strength of this Keep */
+    public int getPenalty() {
+        if (strength == STRENGTH_AUTO) {
+            return 0;
+        } else if (strength == STRENGTH_ALWAYS) {
+            return KnuthElement.INFINITE;
+        } else {
+            return KnuthElement.INFINITE - 1;
+        }
+    }
+
+    private static int getKeepContextPriority(int context) {
+        switch (context) {
+        case Constants.EN_LINE:   return 0;
+        case Constants.EN_COLUMN: return 1;
+        case Constants.EN_PAGE:   return 2;
+        case Constants.EN_AUTO:   return 3;
+        default: throw new IllegalArgumentException();
+        }
+    }
+
+    /**
+     * Compare this Keep instance to another one, and return the
+     * stronger one if the context is the same
+     *
+     * @param other     the instance to compare to
+     * @return  the winning Keep instance
+     */
+    public Keep compare(Keep other) {
+
+        /* check strength "always" first, regardless of priority */
+        if (this.strength == STRENGTH_ALWAYS
+                && this.strength > other.strength) {
+            return this;
+        } else if (other.strength == STRENGTH_ALWAYS
+                && other.strength > this.strength) {
+            return other;
+        }
+
+        int pThis = getKeepContextPriority(this.context);
+        int pOther = getKeepContextPriority(other.context);
+
+        /* equal priority: strongest wins */
+        if (pThis == pOther) {
+            return (strength >= other.strength) ? this : other;
+        }
+
+        /* different priority: lowest priority wins */
+        return (pThis < pOther) ? this : other;
+    }
+
+    /** {@inheritDoc} */
+    public String toString() {
+        return (strength == STRENGTH_AUTO) ? "auto"
+                : (strength == STRENGTH_ALWAYS) ? "always"
+                        : Integer.toString(strength);
+    }
+}

src/java/org/apache/fop/layoutmgr/KeepUtil.java

@@ -1,109 +0,0 @@
-/*
- * Licensed to the Apache Software Foundation (ASF) under one or more
- * contributor license agreements.  See the NOTICE file distributed with
- * this work for additional information regarding copyright ownership.
- * The ASF licenses this file to You under the Apache License, Version 2.0
- * (the "License"); you may not use this file except in compliance with
- * the License.  You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-/* $Id$ */
-
-package org.apache.fop.layoutmgr;
-
-import org.apache.fop.fo.Constants;
-import org.apache.fop.fo.properties.KeepProperty;
-import org.apache.fop.fo.properties.Property;
-
-/**
- * Utility class for working with keeps.
- */
-public class KeepUtil {
-
-    /**
-     * Converts a keep property into an integer value.
-     * <p>
-     * Note: The conversion restricts the effectively available integer range by two values.
-     * Integer.MIN_VALUE is used to represent the value "auto" and
-     * Integer.MAX_VALUE is used to represebt the value "always".
-     * @param keep the keep property
-     * @return the keep value as an integer
-     */
-    public static int getKeepStrength(Property keep) {
-        if (keep.isAuto()) {
-            return BlockLevelLayoutManager.KEEP_AUTO;
-        } else if (keep.getEnum() == Constants.EN_ALWAYS) {
-            return BlockLevelLayoutManager.KEEP_ALWAYS;
-        } else {
-            return keep.getNumber().intValue();
-        }
-    }
-
-    /**
-     * Returns the combined block-level keep strength from a keep property.
-     * <p>
-     * Note: This is a temporary method to be used until it is possible to differentiate between
-     * page and column keeps!
-     * @param keep the keep property
-     * @return the combined keep strength
-     */
-    public static int getCombinedBlockLevelKeepStrength(KeepProperty keep) {
-        return Math.max(
-                getKeepStrength(keep.getWithinPage()),
-                getKeepStrength(keep.getWithinColumn()));
-    }
-
-    /**
-     * Indicates whether a keep strength indicates a keep constraint.
-     * @param strength the keep strength
-     * @return true if the keep is not "auto"
-     */
-    public static boolean hasKeep(int strength) {
-        return strength > BlockLevelLayoutManager.KEEP_AUTO;
-    }
-
-    /**
-     * Returns the penalty value to be used for a certain keep strength.
-     * <ul>
-     *   <li>"auto": returns 0</li>
-     *   <li>"always": returns KnuthElement.INFINITE</li>
-     *   <li>otherwise: returns KnuthElement.INFINITE - 1</li>
-     * </ul>
-     * @param keepStrength the keep strength
-     * @return the penalty value
-     */
-    public static int getPenaltyForKeep(int keepStrength) {
-        if (keepStrength == BlockLevelLayoutManager.KEEP_AUTO) {
-            return 0;
-        }
-        int penalty = KnuthElement.INFINITE;
-        if (keepStrength < BlockLevelLayoutManager.KEEP_ALWAYS) {
-            penalty--;
-        }
-        return penalty;
-    }
-
-    /**
-     * Returns a string representation of a keep strength value.
-     * @param keepStrength the keep strength
-     * @return the string representation
-     */
-    public static String keepStrengthToString(int keepStrength) {
-        if (keepStrength == BlockLevelLayoutManager.KEEP_AUTO) {
-            return "auto";
-        } else if (keepStrength == BlockLevelLayoutManager.KEEP_ALWAYS) {
-            return "always";
-        } else {
-            return Integer.toString(keepStrength);
-        }
-    }
-
-}

src/java/org/apache/fop/layoutmgr/KnuthPenalty.java

@@ -45,7 +45,7 @@ public class KnuthPenalty extends KnuthElement {
     public static final int FLAGGED_PENALTY = 50;
 
     private int penalty;
-    private boolean bFlagged;
+    private boolean isFlagged;
     private int breakClass = -1;
 
     /**
@@ -55,12 +55,12 @@ public class KnuthPenalty extends KnuthElement {
      * @param p the penalty value of this penalty
      * @param f is this penalty flagged?
      * @param pos the Position stored in this penalty
-     * @param bAux is this penalty auxiliary?
+     * @param isAuxiliary is this penalty auxiliary?
      */
-    public KnuthPenalty(int w, int p, boolean f, Position pos, boolean bAux) {
-        super(w, pos, bAux);
+    public KnuthPenalty(int w, int p, boolean f, Position pos, boolean isAuxiliary) {
+        super(w, pos, isAuxiliary);
         penalty = p;
-        bFlagged = f;
+        isFlagged = f;
     }
 
     /**
@@ -69,18 +69,37 @@ public class KnuthPenalty extends KnuthElement {
      * @param w the width of this penalty
      * @param p the penalty value of this penalty
      * @param f is this penalty flagged?
-     * @param iBreakClass the break class of this penalty (one of
+     * @param breakClass the break class of this penalty (one of
      * {@link Constants#EN_AUTO}, {@link Constants#EN_COLUMN}, {@link Constants#EN_PAGE},
      * {@link Constants#EN_EVEN_PAGE}, {@link Constants#EN_ODD_PAGE})
      * @param pos the Position stored in this penalty
-     * @param bAux is this penalty auxiliary?
+     * @param isAuxiliary is this penalty auxiliary?
      */
     public KnuthPenalty(int w, int p, boolean f,
-            int iBreakClass, Position pos, boolean bAux) {
-        super(w, pos, bAux);
-        penalty = p;
-        bFlagged = f;
-        breakClass = iBreakClass;
+            int breakClass, Position pos, boolean isAuxiliary) {
+        this(w, p, f, pos, isAuxiliary);
+        this.breakClass = breakClass;
+    }
+
+    private static String getBreakClassName(int breakClass) {
+        return AbstractBreaker.getBreakClassName(breakClass);
+    }
+
+    /**
+     * Get the penalty's value as a {@code java.lang.String}.
+     * (Mainly used in {@code toString()} methods, to improve readability
+     * of the trace logs.)
+     *
+     * @param penaltyValue  the penalty value
+     * @return  the penalty value as a {@code java.lang.String}
+     */
+    protected static String valueOf(int penaltyValue) {
+        String result = (penaltyValue < 0) ? "-" : "";
+        int tmpValue = Math.abs(penaltyValue);
+        result += (tmpValue == KnuthElement.INFINITE)
+                ? "INFINITE"
+                : String.valueOf(tmpValue);
+        return result;
     }
 
     /** {@inheritDoc} */
@@ -105,7 +124,7 @@ public class KnuthPenalty extends KnuthElement {
 
     /** @return true is this penalty is a flagged one. */
     public boolean isFlagged() {
-        return bFlagged;
+        return isFlagged;
     }
 
     /** {@inheritDoc} */
@@ -121,14 +140,6 @@ public class KnuthPenalty extends KnuthElement {
         return breakClass;
     }
 
-    /**
-     * Sets the break class for this penalty.
-     * @param cl the break class (EN_AUTO, EN_COLUMN, EN_PAGE, EN_EVEN_PAGE, EN_ODD_PAGE)
-     */
-    public void setBreakClass(int cl) {
-        this.breakClass = cl;
-    }
-
     /** {@inheritDoc} */
     public String toString() {
         StringBuffer sb = new StringBuffer(64);
@@ -137,39 +148,22 @@ public class KnuthPenalty extends KnuthElement {
         }
         sb.append("penalty");
         sb.append(" p=");
-        if (getP() < 0) {
-            sb.append("-");
-        }
-        if (Math.abs(getP()) == INFINITE) {
-            sb.append("INFINITE");
-        } else {
-            sb.append(getP());
-        }
-        if (isFlagged()) {
+        sb.append(valueOf(this.penalty));
+        if (this.isFlagged) {
             sb.append(" [flagged]");
         }
         sb.append(" w=");
         sb.append(getW());
         if (isForcedBreak()) {
-            sb.append(" (forced break");
-            switch (getBreakClass()) {
-            case Constants.EN_PAGE:
-                sb.append(", page");
-                break;
-            case Constants.EN_COLUMN:
-                sb.append(", column");
-                break;
-            case Constants.EN_EVEN_PAGE:
-                sb.append(", even page");
-                break;
-            case Constants.EN_ODD_PAGE:
-                sb.append(", odd page");
-                break;
-            default:
-            }
-            sb.append(")");
+            sb.append(" (forced break, ")
+                    .append(getBreakClassName(this.breakClass))
+                    .append(")");
+        } else if (this.penalty >= 0 && this.breakClass != -1) {
+            //penalty corresponding to a keep constraint
+            sb.append(" (keep constraint, ")
+                    .append(getBreakClassName(this.breakClass))
+                    .append(")");
         }
         return sb.toString();
     }
-
 }

src/java/org/apache/fop/layoutmgr/LayoutContext.java

@@ -136,8 +136,8 @@ public class LayoutContext {
     private int breakBefore;
     private int breakAfter;
 
-    private int pendingKeepWithNext = BlockLevelLayoutManager.KEEP_AUTO;
-    private int pendingKeepWithPrevious = BlockLevelLayoutManager.KEEP_AUTO;
+    private Keep pendingKeepWithNext = Keep.KEEP_AUTO;
+    private Keep pendingKeepWithPrevious = Keep.KEEP_AUTO;
 
     private int disableColumnBalancing;
 
@@ -227,7 +227,7 @@ public class LayoutContext {
      * Returns the strength of a keep-with-next currently pending.
      * @return the keep-with-next strength
      */
-    public int getKeepWithNextPending() {
+    public Keep getKeepWithNextPending() {
         return this.pendingKeepWithNext;
     }
 
@@ -235,7 +235,7 @@ public class LayoutContext {
      * Returns the strength of a keep-with-previous currently pending.
      * @return the keep-with-previous strength
      */
-    public int getKeepWithPreviousPending() {
+    public Keep getKeepWithPreviousPending() {
         return this.pendingKeepWithPrevious;
     }
 
@@ -243,14 +243,14 @@ public class LayoutContext {
      * Clears any pending keep-with-next strength.
      */
     public void clearKeepWithNextPending() {
-        this.pendingKeepWithNext = BlockLevelLayoutManager.KEEP_AUTO;
+        this.pendingKeepWithNext = Keep.KEEP_AUTO;
     }
 
     /**
      * Clears any pending keep-with-previous strength.
      */
     public void clearKeepWithPreviousPending() {
-        this.pendingKeepWithPrevious = BlockLevelLayoutManager.KEEP_AUTO;
+        this.pendingKeepWithPrevious = Keep.KEEP_AUTO;
     }
 
     /**
@@ -263,18 +263,18 @@ public class LayoutContext {
 
     /**
      * Updates the currently pending keep-with-next strength.
-     * @param strength the new strength to consider
+     * @param keep the new strength to consider
      */
-    public void updateKeepWithNextPending(int strength) {
-        this.pendingKeepWithNext = Math.max(this.pendingKeepWithNext, strength);
+    public void updateKeepWithNextPending(Keep keep) {
+        this.pendingKeepWithNext = this.pendingKeepWithNext.compare(keep);
     }
 
     /**
      * Updates the currently pending keep-with-previous strength.
-     * @param strength the new strength to consider
+     * @param keep the new strength to consider
      */
-    public void updateKeepWithPreviousPending(int strength) {
-        this.pendingKeepWithPrevious = Math.max(this.pendingKeepWithPrevious, strength);
+    public void updateKeepWithPreviousPending(Keep keep) {
+        this.pendingKeepWithPrevious = this.pendingKeepWithPrevious.compare(keep);
     }
 
     /**
@@ -282,7 +282,7 @@ public class LayoutContext {
      * @return true if a keep-with-next constraint is pending
      */
     public boolean isKeepWithNextPending() {
-        return getKeepWithNextPending() != BlockLevelLayoutManager.KEEP_AUTO;
+        return !getKeepWithNextPending().isAuto();
     }
 
     /**
@@ -290,7 +290,7 @@ public class LayoutContext {
      * @return true if a keep-with-previous constraint is pending
      */
     public boolean isKeepWithPreviousPending() {
-        return getKeepWithPreviousPending() != BlockLevelLayoutManager.KEEP_AUTO;
+        return !getKeepWithPreviousPending().isAuto();
     }
 
     public void setLeadingSpace(SpaceSpecifier space) {
@@ -640,9 +640,8 @@ public class LayoutContext {
         + "\nStarts New Area: \t" + startsNewArea()
         + "\nIs Last Area: \t" + isLastArea()
         + "\nTry Hyphenate: \t" + tryHyphenate()
-        + "\nKeeps: \t[keep-with-next=" + KeepUtil.keepStrengthToString(getKeepWithNextPending())
-                + "][keep-with-previous="
-                + KeepUtil.keepStrengthToString(getKeepWithPreviousPending()) + "] pending"
+        + "\nKeeps: \t[keep-with-next=" + getKeepWithNextPending()
+                + "][keep-with-previous=" + getKeepWithPreviousPending() + "] pending"
         + "\nBreaks: \tforced [" + (breakBefore != Constants.EN_AUTO ? "break-before" : "") + "]["
         + (breakAfter != Constants.EN_AUTO ? "break-after" : "") + "]";
     }

src/java/org/apache/fop/layoutmgr/PageBreaker.java

@@ -451,9 +451,7 @@ public class PageBreaker extends AbstractBreaker {
         pslm.getCurrentPV().getCurrentSpan().notifyFlowsFinished();
     }
 
-    /**
-     * @return the current child flow layout manager
-     */
+    /** @return the current child flow layout manager */
     protected LayoutManager getCurrentChildLM() {
         return childFLM;
     }
@@ -472,44 +470,51 @@ public class PageBreaker extends AbstractBreaker {
      */
     private void handleBreakTrait(int breakVal) {
         Page curPage = pslm.getCurrentPage();
-        if (breakVal == Constants.EN_ALL) {
+        switch (breakVal) {
+        case Constants.EN_ALL:
             //break due to span change in multi-column layout
             curPage.getPageViewport().createSpan(true);
             return;
-        } else if (breakVal == Constants.EN_NONE) {
+        case Constants.EN_NONE:
             curPage.getPageViewport().createSpan(false);
             return;
-        } else if (breakVal == Constants.EN_COLUMN
-                || breakVal <= 0
-                || breakVal == Constants.EN_AUTO) {
+        case Constants.EN_COLUMN:
+        case Constants.EN_AUTO:
+        case Constants.EN_PAGE:
+        case -1:
             PageViewport pv = curPage.getPageViewport();
 
             //Check if previous page was spanned
             boolean forceNewPageWithSpan = false;
             RegionBody rb = (RegionBody)curPage.getSimplePageMaster().getRegion(
                     Constants.FO_REGION_BODY);
-            if (rb.getColumnCount() > 1
-                    && pv.getCurrentSpan().getColumnCount() == 1) {
-                forceNewPageWithSpan = true;
-            }
+            forceNewPageWithSpan
+                    = (rb.getColumnCount() > 1
+                        && pv.getCurrentSpan().getColumnCount() == 1);
 
             if (forceNewPageWithSpan) {
+                log.trace("Forcing new page with span");
                 curPage = pslm.makeNewPage(false, false);
                 curPage.getPageViewport().createSpan(true);
             } else if (pv.getCurrentSpan().hasMoreFlows()) {
+                log.trace("Moving to next flow");
                 pv.getCurrentSpan().moveToNextFlow();
             } else {
-                curPage = pslm.makeNewPage(false, false);
+                log.trace("Making new page");
+                /*curPage = */pslm.makeNewPage(false, false);
             }
             return;
-        }
-        log.debug("handling break-before after page " + pslm.getCurrentPageNum()
-            + " breakVal=" + getBreakClassName(breakVal));
-        if (needBlankPageBeforeNew(breakVal)) {
-            curPage = pslm.makeNewPage(true, false);
-        }
-        if (needNewPage(breakVal)) {
-            curPage = pslm.makeNewPage(false, false);
+        default:
+            log.debug("handling break-before after page " + pslm.getCurrentPageNum()
+                + " breakVal=" + getBreakClassName(breakVal));
+            if (needBlankPageBeforeNew(breakVal)) {
+                log.trace("Inserting blank page");
+                /*curPage = */pslm.makeNewPage(true, false);
+            }
+            if (needNewPage(breakVal)) {
+                log.trace("Making new page");
+                /*curPage = */pslm.makeNewPage(false, false);
+            }
         }
     }
 

src/java/org/apache/fop/layoutmgr/PageBreakingAlgorithm.java

@@ -96,6 +96,11 @@ class PageBreakingAlgorithm extends BreakingAlgorithm {
     //Controls whether a single part should be forced if possible (ex. block-container)
     private boolean favorSinglePart = false;
 
+    //Used to keep track of switches in keep-context
+    private int currentKeepContext = Constants.EN_AUTO;
+    private KnuthNode lastBeforeKeepContextSwitch;
+
+
     public PageBreakingAlgorithm(LayoutManager topLevelLM,
                                  PageProvider pageProvider,
                                  PageBreakingLayoutListener layoutListener,
@@ -190,6 +195,72 @@ class PageBreakingAlgorithm extends BreakingAlgorithm {
         footnoteElementIndex = -1;
     }
 
+    /**
+     * {@inheritDoc}
+     * Overridden to defer a part to the next page, if it
+     * must be kept within one page, but is too large to fit in
+     * the last column.
+     */
+    protected KnuthNode recoverFromTooLong(KnuthNode lastTooLong) {
+
+        if (log.isDebugEnabled()) {
+            log.debug("Recovering from too long: " + lastTooLong);
+            log.debug("\tlastTooShort = " + getLastTooShort());
+            log.debug("\tlastBeforeKeepContextSwitch = " + lastBeforeKeepContextSwitch);
+            log.debug("\tcurrentKeepContext = " + AbstractBreaker.getBreakClassName(currentKeepContext));
+        }
+
+        if (lastBeforeKeepContextSwitch == null
+                || currentKeepContext == Constants.EN_AUTO) {
+            return super.recoverFromTooLong(lastTooLong);
+        }
+
+        KnuthNode node = lastBeforeKeepContextSwitch;
+        lastBeforeKeepContextSwitch = null;
+        // content would overflow, insert empty page/column(s) and try again
+        while (!pageProvider.endPage(node.line - 1)) {
+            log.trace("Adding node for empty column");
+            node = createNode(
+                    node.position,
+                    node.line + 1, 1,
+                    0, 0, 0,
+                    0, 0, 0,
+                    0, 0, node);
+        }
+        return node;
+    }
+
+    /**
+     * Compare two KnuthNodes and return the node with the least demerit.
+     *
+     * @param node1 The first knuth node.
+     * @param node2 The other knuth node.
+     * @return the node with the least demerit.
+     */
+    protected KnuthNode compareNodes(KnuthNode node1, KnuthNode node2) {
+
+        /* if either node is null, return the other one */
+        if (node1 == null || node2 == null) {
+            return (node1 == null) ? node2 : node1;
+        }
+
+        /* if either one of the nodes corresponds to a mere column-break,
+         * and the other one corresponds to a page-break, return the page-break node
+         */
+        if (pageProvider != null) {
+            if (pageProvider.endPage(node1.line - 1)
+                    && !pageProvider.endPage(node2.line - 1)) {
+                return node1;
+            } else if (pageProvider.endPage(node2.line - 1)
+                    && !pageProvider.endPage(node1.line - 1)) {
+                return node2;
+            }
+        }
+
+        /* all other cases: use superclass implementation */
+        return super.compareNodes(node1, node2);
+    }
+
     /** {@inheritDoc} */
     protected KnuthNode createNode(int position, int line, int fitness,
                                    int totalWidth, int totalStretch, int totalShrink,
@@ -233,6 +304,28 @@ class PageBreakingAlgorithm extends BreakingAlgorithm {
         }
     }
 
+    /**
+     * {@inheritDoc}
+     * Overridden to consider penalties with value {@link KnuthElement#INFINITE}
+     * as legal break-points, if the current keep-context allows this
+     * (a keep-*.within-page="always" constraint still permits column-breaks)
+     */
+    protected void handlePenaltyAt(KnuthPenalty penalty, int position,
+                                   int allowedBreaks) {
+        super.handlePenaltyAt(penalty, position, allowedBreaks);
+        /* if the penalty had value INFINITE, default implementation
+         * will not have considered it a legal break, but it could still
+         * be one.
+         */
+        if (penalty.getP() == KnuthPenalty.INFINITE) {
+            int breakClass = penalty.getBreakClass();
+            if (breakClass == Constants.EN_PAGE
+                    || breakClass == Constants.EN_COLUMN) {
+                considerLegalBreak(penalty, position);
+            }
+        }
+    }
+
     /**
      * Handles the footnotes cited inside a block-level box. Updates footnotesList and the
      * value of totalFootnotesLength with the lengths of the given footnotes.
@@ -317,10 +410,66 @@ class PageBreakingAlgorithm extends BreakingAlgorithm {
 
     /** {@inheritDoc} */
     protected void considerLegalBreak(KnuthElement element, int elementIdx) {
+        if (element.isPenalty()) {
+            int breakClass = ((KnuthPenalty) element).getBreakClass();
+            switch (breakClass) {
+            case Constants.EN_PAGE:
+                if (this.currentKeepContext != breakClass) {
+                    this.lastBeforeKeepContextSwitch = getLastTooShort();
+                }
+                this.currentKeepContext = breakClass;
+                break;
+            case Constants.EN_COLUMN:
+                if (this.currentKeepContext != breakClass) {
+                    this.lastBeforeKeepContextSwitch = getLastTooShort();
+                }
+                this.currentKeepContext = breakClass;
+                break;
+            case Constants.EN_AUTO:
+                this.currentKeepContext = breakClass;
+                break;
+            default:
+                //nop
+            }
+        }
         super.considerLegalBreak(element, elementIdx);
         newFootnotes = false;
     }
 
+    /** {@inheritDoc} */
+    protected boolean elementCanEndLine(KnuthElement element, int line, int difference) {
+        if (!(element.isPenalty()) || pageProvider == null) {
+            return true;
+        } else {
+            KnuthPenalty p = (KnuthPenalty) element;
+            if (p.getP() <= 0) {
+                return true;
+            } else {
+                int context = p.getBreakClass();
+                switch (context) {
+                case Constants.EN_LINE:
+                case Constants.EN_COLUMN:
+                    return p.getP() < KnuthPenalty.INFINITE;
+                case Constants.EN_PAGE:
+                    return p.getP() < KnuthPenalty.INFINITE
+                            || !pageProvider.endPage(line - 1);
+                            //|| (deferPart && difference < 0);
+                case Constants.EN_AUTO:
+                    log.warn("keep is not auto but context is");
+                    return true;
+                default:
+                    if (p.getP() < KnuthPenalty.INFINITE) {
+                        log.warn("Non recognized keep context:" + context);
+                        return true;
+                    } else {
+                        return false;
+                    }
+                }
+            }
+        }
+    }
+
+    /** {@inheritDoc} */
     protected int computeDifference(KnuthNode activeNode, KnuthElement element,
                                     int elementIndex) {
         KnuthPageNode pageNode = (KnuthPageNode) activeNode;

src/java/org/apache/fop/layoutmgr/PageProvider.java

@@ -146,6 +146,49 @@ public class PageProvider implements Constants {
         return this.lastReportedBPD;
     }
 
+    // Wish there were a more elegant way to do this in Java
+    private int[] getColIndexAndColCount(int index) {
+        int columnCount = 0;
+        int colIndex = startColumnOfCurrentElementList + index;
+        int pageIndex = -1;
+        do {
+            colIndex -= columnCount;
+            pageIndex++;
+            Page page = getPage(false, pageIndex, RELTO_CURRENT_ELEMENT_LIST);
+            columnCount = page.getPageViewport().getCurrentSpan().getColumnCount();
+        } while (colIndex >= columnCount);
+        return new int[] {colIndex, columnCount};
+    }
+
+    /**
+     * Checks if a break at the passed index would start a new page
+     * @param index the index of the element before the break
+     * @return  {@code true} if the break starts a new page
+     */
+    boolean startPage(int index) {
+        return getColIndexAndColCount(index)[0] == 0;
+    }
+
+    /**
+     * Checks if a break at the passed index would end a page
+     * @param index the index of the element before the break
+     * @return  {@code true} if the break ends a page
+     */
+    boolean endPage(int index) {
+        int[] colIndexAndColCount = getColIndexAndColCount(index);
+        return colIndexAndColCount[0] == colIndexAndColCount[1] - 1;
+    }
+
+    /**
+     * Obtain the applicable column-count for the element at the
+     * passed index
+     * @param index the index of the element
+     * @return  the number of columns
+     */
+    int getColumnCount(int index) {
+        return getColIndexAndColCount(index)[1];
+    }
+
     /**
      * Returns the part index (0<x<partCount) which denotes the first part on the last page
      * generated by the current element list.
@@ -272,4 +315,4 @@ public class PageProvider implements Constants {
         return page;
     }
 
-}
+}

src/java/org/apache/fop/layoutmgr/StaticContentLayoutManager.java

@@ -314,18 +314,18 @@ public class StaticContentLayoutManager extends BlockStackingLayoutManager {
     }
 
     /** {@inheritDoc} */
-    public int getKeepTogetherStrength() {
-        return KEEP_AUTO;
+    public Keep getKeepTogether() {
+        return Keep.KEEP_AUTO;
     }
 
     /** {@inheritDoc} */
-    public int getKeepWithNextStrength() {
-        return KEEP_AUTO;
+    public Keep getKeepWithNext() {
+        return Keep.KEEP_AUTO;
     }
 
     /** {@inheritDoc} */
-    public int getKeepWithPreviousStrength() {
-        return KEEP_AUTO;
+    public Keep getKeepWithPrevious() {
+        return Keep.KEEP_AUTO;
     }
 
 }

src/java/org/apache/fop/layoutmgr/inline/LineLayoutManager.java

@@ -36,6 +36,7 @@ import org.apache.fop.datatypes.Numeric;
 import org.apache.fop.fo.Constants;
 import org.apache.fop.fo.flow.Block;
 import org.apache.fop.fo.properties.CommonHyphenation;
+import org.apache.fop.fo.properties.KeepProperty;
 import org.apache.fop.fonts.Font;
 import org.apache.fop.fonts.FontInfo;
 import org.apache.fop.fonts.FontTriplet;
@@ -46,7 +47,7 @@ import org.apache.fop.layoutmgr.BreakElement;
 import org.apache.fop.layoutmgr.BreakingAlgorithm;
 import org.apache.fop.layoutmgr.ElementListObserver;
 import org.apache.fop.layoutmgr.InlineKnuthSequence;
-import org.apache.fop.layoutmgr.KeepUtil;
+import org.apache.fop.layoutmgr.Keep;
 import org.apache.fop.layoutmgr.KnuthBlockBox;
 import org.apache.fop.layoutmgr.KnuthBox;
 import org.apache.fop.layoutmgr.KnuthElement;
@@ -876,12 +877,12 @@ public class LineLayoutManager extends InlineStackingLayoutManager
         for (int p = 0; p < knuthParagraphs.size(); p++) {
             // penalty between paragraphs
             if (p > 0) {
-                int strength = getKeepTogetherStrength();
-                int penalty = KeepUtil.getPenaltyForKeep(strength);
-                if (penalty < KnuthElement.INFINITE) {
-                    returnList.add(new BreakElement(
-                            new Position(this), penalty, context));
-                }
+                Keep keep = getKeepTogether();
+                returnList.add(new BreakElement(
+                            new Position(this),
+                            keep.getPenalty(),
+                            keep.getContext(),
+                            context));
             }
 
             LineLayoutPossibilities llPoss;
@@ -920,12 +921,12 @@ public class LineLayoutManager extends InlineStackingLayoutManager
                             && i >= fobj.getOrphans()
                             && i <= llPoss.getChosenLineCount() - fobj.getWidows()) {
                         // penalty allowing a page break between lines
-                        int strength = getKeepTogetherStrength();
-                        int penalty = KeepUtil.getPenaltyForKeep(strength);
-                        if (penalty < KnuthElement.INFINITE) {
-                            returnList.add(new BreakElement(
-                                    returnPosition, penalty, context));
-                        }
+                        Keep keep = getKeepTogether();
+                        returnList.add(new BreakElement(
+                                    new Position(this),
+                                    keep.getPenalty(),
+                                    keep.getContext(),
+                                    context));
                     }
                     int endIndex
                       = ((LineBreakPosition) llPoss.getChosenPosition(i)).getLeafPos();
@@ -1104,28 +1105,43 @@ public class LineLayoutManager extends InlineStackingLayoutManager
     }
 
     /** {@inheritDoc} */
-    public int getKeepTogetherStrength() {
-        return ((BlockLevelLayoutManager) getParent()).getKeepTogetherStrength();
+    public KeepProperty getKeepTogetherProperty() {
+        return ((BlockLevelLayoutManager) getParent()).getKeepTogetherProperty();
+    }
+
+    /** {@inheritDoc} */
+    public KeepProperty getKeepWithPreviousProperty() {
+        return ((BlockLevelLayoutManager) getParent()).getKeepWithPreviousProperty();
+    }
+
+    /** {@inheritDoc} */
+    public KeepProperty getKeepWithNextProperty() {
+        return ((BlockLevelLayoutManager) getParent()).getKeepWithNextProperty();
+    }
+
+    /** {@inheritDoc} */
+    public Keep getKeepTogether() {
+        return ((BlockLevelLayoutManager) getParent()).getKeepTogether();
     }
 
     /** {@inheritDoc} */
     public boolean mustKeepWithPrevious() {
-        return getKeepWithPreviousStrength() > KEEP_AUTO;
+        return !getKeepWithPrevious().isAuto();
     }
 
     /** {@inheritDoc} */
     public boolean mustKeepWithNext() {
-        return getKeepWithNextStrength() > KEEP_AUTO;
+        return !getKeepWithNext().isAuto();
     }
 
     /** {@inheritDoc} */
-    public int getKeepWithNextStrength() {
-        return KEEP_AUTO;
+    public Keep getKeepWithNext() {
+        return Keep.KEEP_AUTO;
     }
 
     /** {@inheritDoc} */
-    public int getKeepWithPreviousStrength() {
-        return KEEP_AUTO;
+    public Keep getKeepWithPrevious() {
+        return Keep.KEEP_AUTO;
     }
 
     /** {@inheritDoc} */
@@ -1230,6 +1246,7 @@ public class LineLayoutManager extends InlineStackingLayoutManager
                 break;
             }
             //TODO Something's not right here. See block_hyphenation_linefeed_preserve.xml
+            //for more info: see also https://issues.apache.org/bugzilla/show_bug.cgi?id=38264
 
             // collect word fragments, ignoring auxiliary elements;
             // each word fragment was created by a different TextLM

src/java/org/apache/fop/layoutmgr/list/ListBlockLayoutManager.java

@@ -29,10 +29,10 @@ import org.apache.commons.logging.LogFactory;
 import org.apache.fop.area.Area;
 import org.apache.fop.area.Block;
 import org.apache.fop.fo.flow.ListBlock;
+import org.apache.fop.fo.properties.KeepProperty;
 import org.apache.fop.layoutmgr.BlockStackingLayoutManager;
 import org.apache.fop.layoutmgr.ConditionalElementListener;
 import org.apache.fop.layoutmgr.ElementListUtils;
-import org.apache.fop.layoutmgr.KeepUtil;
 import org.apache.fop.layoutmgr.LayoutContext;
 import org.apache.fop.layoutmgr.LayoutManager;
 import org.apache.fop.layoutmgr.NonLeafPosition;
@@ -279,21 +279,18 @@ public class ListBlockLayoutManager extends BlockStackingLayoutManager
     }
 
     /** {@inheritDoc} */
-    public int getKeepTogetherStrength() {
-        int strength = KeepUtil.getCombinedBlockLevelKeepStrength(
-                getListBlockFO().getKeepTogether());
-        strength = Math.max(strength, getParentKeepTogetherStrength());
-        return strength;
+    public KeepProperty getKeepTogetherProperty() {
+        return getListBlockFO().getKeepTogether();
     }
 
     /** {@inheritDoc} */
-    public int getKeepWithNextStrength() {
-        return KeepUtil.getCombinedBlockLevelKeepStrength(getListBlockFO().getKeepWithNext());
+    public KeepProperty getKeepWithPreviousProperty() {
+        return getListBlockFO().getKeepWithPrevious();
     }
 
     /** {@inheritDoc} */
-    public int getKeepWithPreviousStrength() {
-        return KeepUtil.getCombinedBlockLevelKeepStrength(getListBlockFO().getKeepWithPrevious());
+    public KeepProperty getKeepWithNextProperty() {
+        return getListBlockFO().getKeepWithNext();
     }
 
     /** {@inheritDoc} */

src/java/org/apache/fop/layoutmgr/list/ListItemContentLayoutManager.java

@@ -28,8 +28,9 @@ import org.apache.fop.area.Block;
 import org.apache.fop.fo.flow.AbstractListItemPart;
 import org.apache.fop.fo.flow.ListItemBody;
 import org.apache.fop.fo.flow.ListItemLabel;
+import org.apache.fop.fo.properties.KeepProperty;
 import org.apache.fop.layoutmgr.BlockStackingLayoutManager;
-import org.apache.fop.layoutmgr.KeepUtil;
+import org.apache.fop.layoutmgr.Keep;
 import org.apache.fop.layoutmgr.LayoutContext;
 import org.apache.fop.layoutmgr.LayoutManager;
 import org.apache.fop.layoutmgr.NonLeafPosition;
@@ -221,20 +222,18 @@ public class ListItemContentLayoutManager extends BlockStackingLayoutManager {
     }
 
     /** {@inheritDoc} */
-    public int getKeepTogetherStrength() {
-        int strength = KeepUtil.getCombinedBlockLevelKeepStrength(getPartFO().getKeepTogether());
-        strength = Math.max(strength, getParentKeepTogetherStrength());
-        return strength;
+    public KeepProperty getKeepTogetherProperty() {
+        return getPartFO().getKeepTogether();
     }
 
     /** {@inheritDoc} */
-    public int getKeepWithNextStrength() {
-        return KEEP_AUTO;
+    public Keep getKeepWithNext() {
+        return Keep.KEEP_AUTO;
     }
 
     /** {@inheritDoc} */
-    public int getKeepWithPreviousStrength() {
-        return KEEP_AUTO;
+    public Keep getKeepWithPrevious() {
+        return Keep.KEEP_AUTO;
     }
 
 }

src/java/org/apache/fop/layoutmgr/list/ListItemLayoutManager.java

@@ -32,13 +32,13 @@ import org.apache.fop.area.Block;
 import org.apache.fop.fo.flow.ListItem;
 import org.apache.fop.fo.flow.ListItemBody;
 import org.apache.fop.fo.flow.ListItemLabel;
-import org.apache.fop.layoutmgr.BlockLevelLayoutManager;
+import org.apache.fop.fo.properties.KeepProperty;
 import org.apache.fop.layoutmgr.BlockStackingLayoutManager;
 import org.apache.fop.layoutmgr.BreakElement;
 import org.apache.fop.layoutmgr.ConditionalElementListener;
 import org.apache.fop.layoutmgr.ElementListObserver;
 import org.apache.fop.layoutmgr.ElementListUtils;
-import org.apache.fop.layoutmgr.KeepUtil;
+import org.apache.fop.layoutmgr.Keep;
 import org.apache.fop.layoutmgr.KnuthBlockBox;
 import org.apache.fop.layoutmgr.KnuthBox;
 import org.apache.fop.layoutmgr.KnuthElement;
@@ -83,8 +83,8 @@ public class ListItemLayoutManager extends BlockStackingLayoutManager
     private MinOptMax effSpaceBefore;
     private MinOptMax effSpaceAfter;
 
-    private int keepWithNextPendingOnLabel;
-    private int keepWithNextPendingOnBody;
+    private Keep keepWithNextPendingOnLabel;
+    private Keep keepWithNextPendingOnBody;
 
     private int listItemHeight;
 
@@ -254,8 +254,8 @@ public class ListItemLayoutManager extends BlockStackingLayoutManager
 
         context.updateKeepWithNextPending(this.keepWithNextPendingOnLabel);
         context.updateKeepWithNextPending(this.keepWithNextPendingOnBody);
-        context.updateKeepWithNextPending(getKeepWithNextStrength());
-        context.updateKeepWithPreviousPending(getKeepWithPreviousStrength());
+        context.updateKeepWithNextPending(getKeepWithNext());
+        context.updateKeepWithPreviousPending(getKeepWithPrevious());
 
         setFinished(true);
         resetSpaces();
@@ -276,16 +276,16 @@ public class ListItemLayoutManager extends BlockStackingLayoutManager
         int totalHeight = Math.max(fullHeights[0], fullHeights[1]);
         int step;
         int addedBoxHeight = 0;
-        int keepWithNextActive = BlockLevelLayoutManager.KEEP_AUTO;
+        Keep keepWithNextActive = Keep.KEEP_AUTO;
 
         LinkedList returnList = new LinkedList();
         while ((step = getNextStep(elementLists, start, end, partialHeights)) > 0) {
 
             if (end[0] + 1 == elementLists[0].size()) {
-                keepWithNextActive = Math.max(keepWithNextActive, keepWithNextPendingOnLabel);
+                keepWithNextActive = keepWithNextActive.compare(keepWithNextPendingOnLabel);
             }
             if (end[1] + 1 == elementLists[1].size()) {
-                keepWithNextActive = Math.max(keepWithNextActive, keepWithNextPendingOnBody);
+                keepWithNextActive = keepWithNextActive.compare(keepWithNextPendingOnBody);
             }
 
             // compute penalty height and box height
@@ -339,14 +339,13 @@ public class ListItemLayoutManager extends BlockStackingLayoutManager
             }
 
             if (addedBoxHeight < totalHeight) {
-                int strength = BlockLevelLayoutManager.KEEP_AUTO;
-                strength = Math.max(strength, keepWithNextActive);
-                strength = Math.max(strength, getKeepTogetherStrength());
+                Keep keep = keepWithNextActive.compare(getKeepTogether());
                 int p = stepPenalty;
                 if (p > -KnuthElement.INFINITE) {
-                    p = Math.max(p, KeepUtil.getPenaltyForKeep(strength));
+                    p = Math.max(p, keep.getPenalty());
                 }
-                returnList.add(new BreakElement(stepPosition, penaltyHeight, p, -1, context));
+                returnList.add(new BreakElement(stepPosition, penaltyHeight, p, keep.getContext(),
+                        context));
             }
         }
 
@@ -644,21 +643,18 @@ public class ListItemLayoutManager extends BlockStackingLayoutManager
     }
 
     /** {@inheritDoc} */
-    public int getKeepTogetherStrength() {
-        int strength = KeepUtil.getCombinedBlockLevelKeepStrength(
-                getListItemFO().getKeepTogether());
-        strength = Math.max(strength, getParentKeepTogetherStrength());
-        return strength;
+    public KeepProperty getKeepTogetherProperty() {
+        return getListItemFO().getKeepTogether();
     }
 
     /** {@inheritDoc} */
-    public int getKeepWithNextStrength() {
-        return KeepUtil.getCombinedBlockLevelKeepStrength(getListItemFO().getKeepWithNext());
+    public KeepProperty getKeepWithPreviousProperty() {
+        return getListItemFO().getKeepWithPrevious();
     }
 
     /** {@inheritDoc} */
-    public int getKeepWithPreviousStrength() {
-        return KeepUtil.getCombinedBlockLevelKeepStrength(getListItemFO().getKeepWithPrevious());
+    public KeepProperty getKeepWithNextProperty() {
+        return getListItemFO().getKeepWithNext();
     }
 
     /** {@inheritDoc} */

src/java/org/apache/fop/layoutmgr/table/ActiveCell.java

@@ -32,8 +32,8 @@ import org.apache.fop.fo.flow.table.ConditionalBorder;
 import org.apache.fop.fo.flow.table.EffRow;
 import org.apache.fop.fo.flow.table.PrimaryGridUnit;
 import org.apache.fop.fo.properties.CommonBorderPaddingBackground;
-import org.apache.fop.layoutmgr.BlockLevelLayoutManager;
 import org.apache.fop.layoutmgr.ElementListUtils;
+import org.apache.fop.layoutmgr.Keep;
 import org.apache.fop.layoutmgr.KnuthBlockBox;
 import org.apache.fop.layoutmgr.KnuthBox;
 import org.apache.fop.layoutmgr.KnuthElement;
@@ -75,7 +75,7 @@ class ActiveCell {
     /** True if the next CellPart that will be created will be the last one for this cell. */
     private boolean lastCellPart;
 
-    private int keepWithNextStrength;
+    private Keep keepWithNext;
 
     private int spanIndex = 0;
 
@@ -218,7 +218,7 @@ class ActiveCell {
         includedLength = -1;  // Avoid troubles with cells having content of zero length
         totalLength = previousRowsLength + ElementListUtils.calcContentLength(elementList);
         endRowIndex = rowIndex + pgu.getCell().getNumberRowsSpanned() - 1;
-        keepWithNextStrength = BlockLevelLayoutManager.KEEP_AUTO;
+        keepWithNext = Keep.KEEP_AUTO;
         remainingLength = totalLength - previousRowsLength;
 
         afterNextStep = new Step(previousRowsLength);
@@ -314,7 +314,11 @@ class ActiveCell {
             KnuthElement el = (KnuthElement) knuthIter.next();
             if (el.isPenalty()) {
                 prevIsBox = false;
-                if (el.getP() < KnuthElement.INFINITE) {
+                if (el.getP() < KnuthElement.INFINITE
+                        || ((KnuthPenalty) el).getBreakClass() == Constants.EN_PAGE) {
+                    // TODO too much is being done in that test, only to handle
+                    // keep.within-column properly.
+
                     // First legal break point
                     breakFound = true;
                     KnuthPenalty p = (KnuthPenalty) el;
@@ -533,7 +537,7 @@ class ActiveCell {
      */
     CellPart createCellPart() {
         if (nextStep.end + 1 == elementList.size()) {
-            keepWithNextStrength = pgu.getKeepWithNextStrength();
+            keepWithNext = pgu.getKeepWithNext();
             // TODO if keep-with-next is set on the row, must every cell of the row
             // contribute some content from children blocks?
             // see http://mail-archives.apache.org/mod_mbox/xmlgraphics-fop-dev/200802.mbox/
@@ -576,8 +580,8 @@ class ActiveCell {
         }
     }
 
-    int getKeepWithNextStrength() {
-        return keepWithNextStrength;
+    Keep getKeepWithNext() {
+        return keepWithNext;
     }
 
     int getPenaltyValue() {

src/java/org/apache/fop/layoutmgr/table/RowGroupLayoutManager.java

@@ -60,8 +60,8 @@ class RowGroupLayoutManager {
         LinkedList returnList = new LinkedList();
         createElementsForRowGroup(context, alignment, bodyType, returnList);
 
-        context.updateKeepWithPreviousPending(rowGroup[0].getKeepWithPreviousStrength());
-        context.updateKeepWithNextPending(rowGroup[rowGroup.length - 1].getKeepWithNextStrength());
+        context.updateKeepWithPreviousPending(rowGroup[0].getKeepWithPrevious());
+        context.updateKeepWithNextPending(rowGroup[rowGroup.length - 1].getKeepWithNext());
 
         int breakBefore = Constants.EN_AUTO;
         TableRow firstRow = rowGroup[0].getTableRow();

src/java/org/apache/fop/layoutmgr/table/TableAndCaptionLayoutManager.java

@@ -23,6 +23,7 @@ import org.apache.fop.area.Area;
 import org.apache.fop.area.Block;
 import org.apache.fop.fo.flow.table.TableAndCaption;
 import org.apache.fop.layoutmgr.BlockStackingLayoutManager;
+import org.apache.fop.layoutmgr.Keep;
 import org.apache.fop.layoutmgr.LayoutContext;
 import org.apache.fop.layoutmgr.PositionIterator;
 
@@ -201,19 +202,8 @@ public class TableAndCaptionLayoutManager extends BlockStackingLayoutManager {
     }
 
     /** {@inheritDoc} */
-    public int getKeepTogetherStrength() {
-        int strength = KEEP_AUTO;
-        /* TODO Complete me!
-        int strength = KeepUtil.getCombinedBlockLevelKeepStrength(
-                getTableAndCaptionFO().getKeepTogether());
-        */
-        strength = Math.max(strength, getParentKeepTogetherStrength());
-        return strength;
-    }
-
-    /** {@inheritDoc} */
-    public int getKeepWithNextStrength() {
-        return KEEP_AUTO;
+    public Keep getKeepWithNext() {
+        return Keep.KEEP_AUTO;
         /* TODO Complete me!
         return KeepUtil.getCombinedBlockLevelKeepStrength(
                 getTableAndCaptionFO().getKeepWithNext());
@@ -221,12 +211,12 @@ public class TableAndCaptionLayoutManager extends BlockStackingLayoutManager {
     }
 
     /** {@inheritDoc} */
-    public int getKeepWithPreviousStrength() {
-        return KEEP_AUTO;
+    public Keep getKeepWithPrevious() {
+        return Keep.KEEP_AUTO;
         /* TODO Complete me!
         return KeepUtil.getCombinedBlockLevelKeepStrength(
                 getTableAndCaptionFO().getKeepWithPrevious());
         */
     }
 
-}
+}

src/java/org/apache/fop/layoutmgr/table/TableCaptionLayoutManager.java

@@ -23,6 +23,7 @@ import org.apache.fop.area.Area;
 import org.apache.fop.area.Block;
 import org.apache.fop.fo.flow.table.TableCaption;
 import org.apache.fop.layoutmgr.BlockStackingLayoutManager;
+import org.apache.fop.layoutmgr.Keep;
 import org.apache.fop.layoutmgr.LayoutContext;
 import org.apache.fop.layoutmgr.PositionIterator;
 
@@ -197,21 +198,8 @@ public class TableCaptionLayoutManager extends BlockStackingLayoutManager {
     }
 
     /** {@inheritDoc} */
-    public int getKeepTogetherStrength() {
-        int strength = KEEP_AUTO;
-        /* TODO Complete me!
-        strength = Math.max(strength, KeepUtil.getKeepStrength(
-                getTableCaptionFO().getKeepTogether().getWithinPage()));
-        strength = Math.max(strength, KeepUtil.getKeepStrength(
-                getTableCaptionFO().getKeepTogether().getWithinColumn()));
-        */
-        strength = Math.max(strength, getParentKeepTogetherStrength());
-        return strength;
-    }
-
-    /** {@inheritDoc} */
-    public int getKeepWithNextStrength() {
-        return KEEP_AUTO;
+    public Keep getKeepWithNext() {
+        return Keep.KEEP_AUTO;
         /* TODO Complete me!
         return KeepUtil.getCombinedBlockLevelKeepStrength(
                 getTableCaptionFO().getKeepWithNext());
@@ -219,8 +207,8 @@ public class TableCaptionLayoutManager extends BlockStackingLayoutManager {
     }
 
     /** {@inheritDoc} */
-    public int getKeepWithPreviousStrength() {
-        return KEEP_AUTO;
+    public Keep getKeepWithPrevious() {
+        return Keep.KEEP_AUTO;
         /* TODO Complete me!
         return KeepUtil.getCombinedBlockLevelKeepStrength(
                 getTableCaptionFO().getKeepWithPrevious());

src/java/org/apache/fop/layoutmgr/table/TableCellLayoutManager.java

@@ -24,6 +24,7 @@ import java.util.List;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
+
 import org.apache.fop.area.Area;
 import org.apache.fop.area.Block;
 import org.apache.fop.area.Trait;
@@ -31,21 +32,23 @@ import org.apache.fop.fo.flow.table.ConditionalBorder;
 import org.apache.fop.fo.flow.table.GridUnit;
 import org.apache.fop.fo.flow.table.PrimaryGridUnit;
 import org.apache.fop.fo.flow.table.Table;
-import org.apache.fop.fo.flow.table.TablePart;
 import org.apache.fop.fo.flow.table.TableCell;
 import org.apache.fop.fo.flow.table.TableColumn;
+import org.apache.fop.fo.flow.table.TablePart;
 import org.apache.fop.fo.flow.table.TableRow;
 import org.apache.fop.fo.properties.CommonBorderPaddingBackground;
 import org.apache.fop.fo.properties.CommonBorderPaddingBackground.BorderInfo;
 import org.apache.fop.layoutmgr.AreaAdditionUtil;
 import org.apache.fop.layoutmgr.BlockLevelLayoutManager;
 import org.apache.fop.layoutmgr.BlockStackingLayoutManager;
-import org.apache.fop.layoutmgr.KeepUtil;
+import org.apache.fop.layoutmgr.ElementListUtils;
+import org.apache.fop.layoutmgr.Keep;
 import org.apache.fop.layoutmgr.KnuthBox;
 import org.apache.fop.layoutmgr.KnuthElement;
 import org.apache.fop.layoutmgr.KnuthGlue;
 import org.apache.fop.layoutmgr.KnuthPenalty;
 import org.apache.fop.layoutmgr.LayoutContext;
+import org.apache.fop.layoutmgr.LayoutManager;
 import org.apache.fop.layoutmgr.Position;
 import org.apache.fop.layoutmgr.PositionIterator;
 import org.apache.fop.layoutmgr.SpaceResolver;
@@ -138,9 +141,9 @@ public class TableCellLayoutManager extends BlockStackingLayoutManager
         List contentList = new LinkedList();
         List returnList = new LinkedList();
 
-        BlockLevelLayoutManager curLM; // currently active LM
-        BlockLevelLayoutManager prevLM = null; // previously active LM
-        while ((curLM = (BlockLevelLayoutManager) getChildLM()) != null) {
+        LayoutManager curLM; // currently active LM
+        LayoutManager prevLM = null; // previously active LM
+        while ((curLM = getChildLM()) != null) {
             LayoutContext childLC = new LayoutContext(0);
             // curLM is a ?
             childLC.setStackLimitBP(MinOptMax.subtract(context
@@ -153,11 +156,12 @@ public class TableCellLayoutManager extends BlockStackingLayoutManager
                 log.debug("child LM signals pending keep with next");
             }
             if (contentList.isEmpty() && childLC.isKeepWithPreviousPending()) {
-                primaryGridUnit.setKeepWithPreviousStrength(childLC.getKeepWithPreviousPending());
+                primaryGridUnit.setKeepWithPrevious(childLC.getKeepWithPreviousPending());
                 childLC.clearKeepWithPreviousPending();
             }
 
-            if (prevLM != null) {
+            if (prevLM != null
+                    && !ElementListUtils.endsWithForcedBreak(contentList)) {
                 // there is a block handled by prevLM
                 // before the one handled by curLM
                 addInBetweenBreak(contentList, context, childLC);
@@ -174,7 +178,7 @@ public class TableCellLayoutManager extends BlockStackingLayoutManager
             }
             prevLM = curLM;
         }
-        primaryGridUnit.setKeepWithNextStrength(context.getKeepWithNextPending());
+        primaryGridUnit.setKeepWithNext(context.getKeepWithNextPending());
 
         returnedList = new LinkedList();
         if (!contentList.isEmpty()) {
@@ -195,7 +199,7 @@ public class TableCellLayoutManager extends BlockStackingLayoutManager
         }
         final KnuthElement lastItem = (KnuthElement) ListUtil
                 .getLast(returnList);
-        if (((KnuthElement) lastItem).isForcedBreak()) {
+        if (lastItem.isForcedBreak()) {
             KnuthPenalty p = (KnuthPenalty) lastItem;
             primaryGridUnit.setBreakAfter(p.getBreakClass());
             p.setP(0);
@@ -556,26 +560,23 @@ public class TableCellLayoutManager extends BlockStackingLayoutManager
     }
 
     /** {@inheritDoc} */
-    public int getKeepTogetherStrength() {
-        int strength = KEEP_AUTO;
+    public Keep getKeepTogether() {
+        Keep keep = Keep.KEEP_AUTO;
         if (primaryGridUnit.getRow() != null) {
-            strength = Math.max(strength, KeepUtil.getKeepStrength(
-                    primaryGridUnit.getRow().getKeepTogether().getWithinPage()));
-            strength = Math.max(strength, KeepUtil.getKeepStrength(
-                    primaryGridUnit.getRow().getKeepTogether().getWithinColumn()));
+            keep = Keep.getKeep(primaryGridUnit.getRow().getKeepTogether());
         }
-        strength = Math.max(strength, getParentKeepTogetherStrength());
-        return strength;
+        keep = keep.compare(getParentKeepTogether());
+        return keep;
     }
 
     /** {@inheritDoc} */
-    public int getKeepWithNextStrength() {
-        return KEEP_AUTO; //TODO FIX ME (table-cell has no keep-with-next!)
+    public Keep getKeepWithNext() {
+        return Keep.KEEP_AUTO; //TODO FIX ME (table-cell has no keep-with-next!)
     }
 
     /** {@inheritDoc} */
-    public int getKeepWithPreviousStrength() {
-        return KEEP_AUTO; //TODO FIX ME (table-cell has no keep-with-previous!)
+    public Keep getKeepWithPrevious() {
+        return Keep.KEEP_AUTO; //TODO FIX ME (table-cell has no keep-with-previous!)
     }
 
     // --------- Property Resolution related functions --------- //

src/java/org/apache/fop/layoutmgr/table/TableContentLayoutManager.java

@@ -35,10 +35,9 @@ import org.apache.fop.fo.flow.table.EffRow;
 import org.apache.fop.fo.flow.table.PrimaryGridUnit;
 import org.apache.fop.fo.flow.table.Table;
 import org.apache.fop.fo.flow.table.TablePart;
-import org.apache.fop.layoutmgr.BlockLevelLayoutManager;
 import org.apache.fop.layoutmgr.BreakElement;
 import org.apache.fop.layoutmgr.ElementListUtils;
-import org.apache.fop.layoutmgr.KeepUtil;
+import org.apache.fop.layoutmgr.Keep;
 import org.apache.fop.layoutmgr.KnuthBox;
 import org.apache.fop.layoutmgr.KnuthElement;
 import org.apache.fop.layoutmgr.KnuthGlue;
@@ -213,13 +212,13 @@ public class TableContentLayoutManager implements PercentBaseContext {
         context.clearKeepsPending();
         context.setBreakBefore(Constants.EN_AUTO);
         context.setBreakAfter(Constants.EN_AUTO);
-        int keepWithPrevious = BlockLevelLayoutManager.KEEP_AUTO;
+        Keep keepWithPrevious = Keep.KEEP_AUTO;
         int breakBefore = Constants.EN_AUTO;
         if (rowGroup != null) {
             RowGroupLayoutManager rowGroupLM = new RowGroupLayoutManager(getTableLM(), rowGroup,
                     stepper);
             List nextRowGroupElems = rowGroupLM.getNextKnuthElements(context, alignment, bodyType);
-            keepWithPrevious = Math.max(keepWithPrevious, context.getKeepWithPreviousPending());
+            keepWithPrevious = keepWithPrevious.compare(context.getKeepWithPreviousPending());
             breakBefore = context.getBreakBefore();
             int breakBetween = context.getBreakAfter();
             returnList.addAll(nextRowGroupElems);
@@ -228,7 +227,7 @@ public class TableContentLayoutManager implements PercentBaseContext {
 
                 //Note previous pending keep-with-next and clear the strength
                 //(as the layout context is reused)
-                int keepWithNextPending = context.getKeepWithNextPending();
+                Keep keepWithNextPending = context.getKeepWithNextPending();
                 context.clearKeepWithNextPending();
 
                 //Get elements for next row group
@@ -246,17 +245,17 @@ public class TableContentLayoutManager implements PercentBaseContext {
                  */
 
                 //Determine keep constraints
-                int penaltyStrength = BlockLevelLayoutManager.KEEP_AUTO;
-                penaltyStrength = Math.max(penaltyStrength, keepWithNextPending);
-                penaltyStrength = Math.max(penaltyStrength, context.getKeepWithPreviousPending());
+                Keep keep = keepWithNextPending.compare(context.getKeepWithPreviousPending());
                 context.clearKeepWithPreviousPending();
-                penaltyStrength = Math.max(penaltyStrength, getTableLM().getKeepTogetherStrength());
-                int penaltyValue = KeepUtil.getPenaltyForKeep(penaltyStrength);
+                keep = keep.compare(getTableLM().getKeepTogether());
+                int penaltyValue = keep.getPenalty();
+                int breakClass = keep.getContext();
 
                 breakBetween = BreakUtil.compareBreakClasses(breakBetween,
                         context.getBreakBefore());
                 if (breakBetween != Constants.EN_AUTO) {
                     penaltyValue = -KnuthElement.INFINITE;
+                    breakClass = breakBetween;
                 }
                 BreakElement breakElement;
                 ListIterator elemIter = returnList.listIterator(returnList.size());
@@ -267,7 +266,7 @@ public class TableContentLayoutManager implements PercentBaseContext {
                     breakElement = (BreakElement) elem;
                 }
                 breakElement.setPenaltyValue(penaltyValue);
-                breakElement.setBreakClass(breakBetween);
+                breakElement.setBreakClass(breakClass);
                 returnList.addAll(nextRowGroupElems);
                 breakBetween = context.getBreakAfter();
             }

src/java/org/apache/fop/layoutmgr/table/TableLayoutManager.java

@@ -35,11 +35,11 @@ import org.apache.fop.fo.FONode;
 import org.apache.fop.fo.FObj;
 import org.apache.fop.fo.flow.table.Table;
 import org.apache.fop.fo.flow.table.TableColumn;
+import org.apache.fop.fo.properties.KeepProperty;
 import org.apache.fop.layoutmgr.BlockLevelEventProducer;
 import org.apache.fop.layoutmgr.BlockStackingLayoutManager;
 import org.apache.fop.layoutmgr.BreakElement;
 import org.apache.fop.layoutmgr.ConditionalElementListener;
-import org.apache.fop.layoutmgr.KeepUtil;
 import org.apache.fop.layoutmgr.KnuthElement;
 import org.apache.fop.layoutmgr.KnuthGlue;
 import org.apache.fop.layoutmgr.LayoutContext;
@@ -256,10 +256,10 @@ public class TableLayoutManager extends BlockStackingLayoutManager
         log.debug(contentKnuthElements);
         wrapPositionElements(contentKnuthElements, returnList);
 
-        context.updateKeepWithPreviousPending(getKeepWithPreviousStrength());
+        context.updateKeepWithPreviousPending(getKeepWithPrevious());
         context.updateKeepWithPreviousPending(childLC.getKeepWithPreviousPending());
 
-        context.updateKeepWithNextPending(getKeepWithNextStrength());
+        context.updateKeepWithNextPending(getKeepWithNext());
         context.updateKeepWithNextPending(childLC.getKeepWithNextPending());
 
         if (getTable().isSeparateBorderModel()) {
@@ -448,20 +448,18 @@ public class TableLayoutManager extends BlockStackingLayoutManager
     }
 
     /** {@inheritDoc} */
-    public int getKeepTogetherStrength() {
-        int strength = KeepUtil.getCombinedBlockLevelKeepStrength(getTable().getKeepTogether());
-        strength = Math.max(strength, getParentKeepTogetherStrength());
-        return strength;
+    public KeepProperty getKeepTogetherProperty() {
+        return getTable().getKeepTogether();
     }
 
     /** {@inheritDoc} */
-    public int getKeepWithNextStrength() {
-        return KeepUtil.getCombinedBlockLevelKeepStrength(getTable().getKeepWithNext());
+    public KeepProperty getKeepWithPreviousProperty() {
+        return getTable().getKeepWithPrevious();
     }
 
     /** {@inheritDoc} */
-    public int getKeepWithPreviousStrength() {
-        return KeepUtil.getCombinedBlockLevelKeepStrength(getTable().getKeepWithPrevious());
+    public KeepProperty getKeepWithNextProperty() {
+        return getTable().getKeepWithNext();
     }
 
     // --------- Property Resolution related functions --------- //

src/java/org/apache/fop/layoutmgr/table/TableStepper.java

@@ -30,12 +30,10 @@ import org.apache.fop.fo.Constants;
 import org.apache.fop.fo.flow.table.EffRow;
 import org.apache.fop.fo.flow.table.GridUnit;
 import org.apache.fop.fo.flow.table.PrimaryGridUnit;
-import org.apache.fop.layoutmgr.BlockLevelLayoutManager;
 import org.apache.fop.layoutmgr.BreakElement;
-import org.apache.fop.layoutmgr.KeepUtil;
+import org.apache.fop.layoutmgr.Keep;
 import org.apache.fop.layoutmgr.KnuthBlockBox;
 import org.apache.fop.layoutmgr.KnuthBox;
-import org.apache.fop.layoutmgr.KnuthElement;
 import org.apache.fop.layoutmgr.KnuthGlue;
 import org.apache.fop.layoutmgr.KnuthPenalty;
 import org.apache.fop.layoutmgr.LayoutContext;
@@ -241,40 +239,38 @@ public class TableStepper {
                 }
             }
 
-            int strength = BlockLevelLayoutManager.KEEP_AUTO;
+            Keep keep = Keep.KEEP_AUTO;
             int stepPenalty = 0;
             for (Iterator iter = activeCells.iterator(); iter.hasNext();) {
                 ActiveCell activeCell = (ActiveCell) iter.next();
-                strength = Math.max(strength, activeCell.getKeepWithNextStrength());
+                keep = keep.compare(activeCell.getKeepWithNext());
                 stepPenalty = Math.max(stepPenalty, activeCell.getPenaltyValue());
             }
             if (!rowFinished) {
-                strength = Math.max(strength, rowGroup[activeRowIndex].getKeepTogetherStrength());
+                keep = keep.compare(rowGroup[activeRowIndex].getKeepTogether());
                 //The above call doesn't take the penalty from the table into account, so...
-                strength = Math.max(strength, getTableLM().getKeepTogetherStrength());
+                keep = keep.compare(getTableLM().getKeepTogether());
             } else if (activeRowIndex < rowGroup.length - 1) {
-                strength = Math.max(strength,
-                        rowGroup[activeRowIndex].getKeepWithNextStrength());
-                strength = Math.max(strength,
-                        rowGroup[activeRowIndex + 1].getKeepWithPreviousStrength());
+                keep = keep.compare(rowGroup[activeRowIndex].getKeepWithNext());
+                keep = keep.compare(rowGroup[activeRowIndex + 1].getKeepWithPrevious());
                 nextBreakClass = BreakUtil.compareBreakClasses(nextBreakClass,
                         rowGroup[activeRowIndex].getBreakAfter());
                 nextBreakClass = BreakUtil.compareBreakClasses(nextBreakClass,
                         rowGroup[activeRowIndex + 1].getBreakBefore());
             }
-            int p = KeepUtil.getPenaltyForKeep(strength);
+            int p = keep.getPenalty();
             if (rowHeightSmallerThanFirstStep) {
                 rowHeightSmallerThanFirstStep = false;
                 p = KnuthPenalty.INFINITE;
             }
-            if (p > -KnuthElement.INFINITE) {
-                p = Math.max(p, stepPenalty);
-            }
+            p = Math.max(p, stepPenalty);
+            int breakClass = keep.getContext();
             if (nextBreakClass != Constants.EN_AUTO) {
                 log.trace("Forced break encountered");
                 p = -KnuthPenalty.INFINITE; //Overrides any keeps (see 4.8 in XSL 1.0)
+                breakClass = nextBreakClass;
             }
-            returnList.add(new BreakElement(penaltyPos, effPenaltyLen, p, nextBreakClass, context));
+            returnList.add(new BreakElement(penaltyPos, effPenaltyLen, p, breakClass, context));
             if (penaltyOrGlueLen < 0) {
                 returnList.add(new KnuthGlue(-penaltyOrGlueLen, 0, 0, new Position(null), true));
             }

status.xml

@@ -58,6 +58,9 @@
       documents. Example: the fix of marks layering will be such a case when it's done.
     -->
     <release version="FOP Trunk" date="TBD">
+      <action context="Renderers" dev="AD" type="add" fixes-bug="46905">
+        Added basic implementation for column-keeps.
+      </action>
       <action context="Renderers" dev="AD" type="fix" fixes-bug="46883">
         Hotspot in AbstractGraphicsDrawingOrderContainer. Reduced time spent in the method
         by introducing a member variable to hold the data-length.

test/layoutengine/disabled-testcases.xml

@@ -216,4 +216,10 @@
     <description>A soft hyphen should be a preferred as break compared to a
     normal hyphenation point but is not.</description>
   </testcase>
+  <testcase>
+    <name>Page-keep not respected in multi-column layout</name>
+    <file>keep_within-page_multi-column_overflow.xml</file>
+    <description>The block should cause overflow in the
+    last column on the page, rather than be broken.</description>
+  </testcase>
 </disabled-testcases>

test/layoutengine/standard-testcases/inline_block_nested_6.xml

@@ -52,16 +52,15 @@
       <skip>5</skip>
       <!-- penalty between blocks b11 and b12, set by InlineLM in b1 -->
       <penalty w="0" p="0"/>
-      <skip>6</skip>
+      <skip>5</skip>
       <!-- penalty between blocks b21 and b22, set by InlineLM in b2 -->
       <!-- keep-together.within-page="always" -->
       <penalty w="0" p="1000"/>
-      <skip>6</skip>
+      <skip>3</skip>
       <!-- penalty between blocks b31 and b32, set by InlineLM in b3 -->
       <!-- keep-with-next.within-page="always" -->
       <penalty w="0" p="1000"/>
-      <skip>5</skip>
-      <skip>3</skip>
+      <skip>14</skip>
     </element-list>
   </checks>
 </testcase>			          

test/layoutengine/standard-testcases/keep_within-column_basic.xml

@@ -0,0 +1,155 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+  Licensed to the Apache Software Foundation (ASF) under one or more
+  contributor license agreements.  See the NOTICE file distributed with
+  this work for additional information regarding copyright ownership.
+  The ASF licenses this file to You under the Apache License, Version 2.0
+  (the "License"); you may not use this file except in compliance with
+  the License.  You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+-->
+<!-- $Id$ -->
+<testcase>
+  <info>
+    <p>
+      This test checks whether keeps within-column are respected.
+    </p>
+  </info>
+  <fo>
+    <fo:root xmlns:fo="http://www.w3.org/1999/XSL/Format">
+      <fo:layout-master-set>
+        <fo:simple-page-master master-name="page" page-width="400pt" page-height="70pt">
+          <fo:region-body column-count="5" />
+        </fo:simple-page-master>
+      </fo:layout-master-set>
+      <fo:page-sequence master-reference="page" font-size="10pt">
+        <fo:flow flow-name="xsl-region-body">
+          <fo:block break-before="page">
+            <!-- simple test: keep the second block together within
+                 one column, breaking the preceding block early 
+                 if necessary -->
+            <fo:block id="block-1">
+              [BOB-1] foo bar foo bar foo bar foo bar foo bar
+              foo bar foo bar foo bar foo bar foo bar foo bar
+              foo bar foo bar foo bar foo bar foo bar foo bar
+              foo bar foo bar foo bar foo bar foo bar [EOB-1]
+            </fo:block>
+            <fo:block id="block-2" keep-together.within-column="always">
+              [BOB-2] foo bar foo bar foo bar foo bar foo [EOB-2]
+            </fo:block>
+          </fo:block>
+          <fo:block break-before="page">
+            <!-- same as the first, but now a nested block
+                 with a higher integer value, and some content
+                 following -->
+            <fo:block id="block-3" keep-together.within-column="5">
+              [BOB-3] foo bar foo bar foo bar foo bar foo bar
+              foo bar foo bar foo bar foo bar foo bar foo bar
+              foo bar foo bar foo bar foo bar foo bar foo bar
+              foo bar foo bar foo bar foo bar foo bar foo bar
+              foo bar foo bar foo bar foo bar foo bar foo bar
+              <fo:block font-weight="bold" id="block-3a" keep-together.within-column="always">
+                [BOB-3a] foo bar foo bar foo bar foo bar foo [EOB-3a]
+              </fo:block>
+              foo bar foo bar foo bar foo bar foo bar foo bar
+              foo bar foo bar foo bar foo bar foo bar foo bar
+              foo bar foo bar foo bar foo bar foo bar [EOB-3]
+            </fo:block>
+          </fo:block>
+          <fo:block break-before="page">
+            <!-- nested block must be kept together within the same
+                 page, while the outer block may be broken, if necessary -->
+            <fo:block font-style="italic" id="block-4" keep-together.within-column="5">
+              [BOB-4] foo bar foo bar foo bar foo bar foo bar
+              foo bar foo bar foo bar foo bar foo bar foo bar
+              foo bar foo bar foo bar foo bar foo bar foo bar
+              foo bar foo bar foo bar foo bar foo bar foo bar
+              foo bar foo bar foo bar foo bar foo bar foo bar
+              foo bar foo bar foo bar foo bar foo bar foo bar
+              <fo:block id="block-4a" keep-together.within-page="always">
+                [BOB-4a] foo bar foo bar foo bar foo bar foo bar
+                foo bar foo bar foo bar foo bar foo bar foo bar
+                foo bar foo bar foo bar foo bar foo bar foo bar
+                foo bar foo bar foo bar foo bar foo bar foo bar
+                foo bar foo bar foo bar foo bar foo bar foo bar
+                foo bar foo bar foo bar foo bar foo bar foo bar
+                foo bar foo bar foo bar foo bar foo bar foo bar
+                foo bar foo bar foo bar foo bar foo bar [EOB-4a]
+              </fo:block>
+              foo bar foo bar foo bar foo bar foo bar foo bar
+              foo bar foo bar foo bar foo bar foo bar foo bar
+              foo bar foo bar foo bar foo bar foo bar [EOB-4]
+            </fo:block>
+          </fo:block>
+          <fo:block break-before="page">
+            <!-- test keep-with-next in conjunction with keep-together
+                 respecting the default value for widows/orphans -->
+            <fo:block id="block-5">
+              <fo:block id="block-5a">
+              [BOB-5a] foo bar foo bar foo bar foo bar foo bar
+              foo bar foo bar foo bar foo bar foo bar foo bar
+              foo bar foo bar foo bar foo bar foo bar foo bar
+              foo bar foo bar foo bar foo bar foo bar foo bar
+              foo bar foo bar foo bar foo bar foo bar foo bar
+              foo bar foo bar foo bar foo bar foo bar [EOB-5a]
+              </fo:block>
+              <fo:block id="block-5b" keep-with-next.within-column="always">
+              [BOB-5b] foo bar foo bar foo bar foo bar foo bar
+              foo bar foo bar foo bar foo bar foo bar [EOB-5b]
+              </fo:block>
+              <fo:block id="block-5c" keep-together.within-column="always">
+              [BOB-5c] foo bar foo bar foo bar foo bar foo bar
+              foo bar foo bar foo bar foo bar foo bar [EOB-5c]
+              </fo:block>
+            </fo:block>
+          </fo:block>
+          <fo:block break-before="page">
+            <!-- test keep-together in conjunction with keep-with-previous -->
+            <fo:block id="block-6">
+              <fo:block id="block-6a">
+              [BOB-6a] foo bar foo bar foo bar foo bar foo bar
+              foo bar foo bar foo bar foo bar foo bar foo bar
+              foo bar foo bar foo bar foo bar foo bar foo bar
+              foo bar foo bar foo bar foo bar foo bar foo bar
+              foo bar foo bar foo bar foo bar foo bar [EOB-6a]
+              </fo:block>
+              <fo:block id="block-6b" keep-together.within-column="always">
+              [BOB-6b] foo bar foo bar foo bar foo bar foo bar [EOB-6b]
+              </fo:block>
+              <fo:block id="block-6c" keep-with-previous.within-column="always">
+              [BOB-6c] foo bar foo bar foo bar foo bar foo bar
+              foo bar foo bar foo bar foo bar foo bar [EOB-6c]
+              </fo:block>
+            </fo:block>
+          </fo:block>
+        </fo:flow>
+      </fo:page-sequence>
+    </fo:root>
+  </fo>
+  <checks>
+    <!-- check total page-count -->
+    <eval expected="10" xpath="count(//page)" />
+    <!-- block-2 should end up in its own column, column 4 -->
+    <eval expected="1" xpath="count(//block[@prod-id='block-2']/ancestor::flow)" />
+    <eval expected="3" xpath="count(//block[@prod-id='block-2']/ancestor::flow/preceding-sibling::flow)" />
+    <!-- block-3a should end up in its own column, column 5 -->
+    <eval expected="1" xpath="count(//block[@prod-id='block-3a']/ancestor::flow)" />
+    <eval expected="4" xpath="count(//block[@prod-id='block-3a']/ancestor::flow/preceding-sibling::flow)" />
+    <!-- block-4a should end up in its own page -->
+    <eval expected="1" xpath="count(//block[@prod-id='block-4a']/ancestor::page)" />
+    <!-- block 5c should end up in its own column, with two preceding lines from block 5b -->
+    <eval expected="1" xpath="count(//block[@prod-id='block-5c']/ancestor::flow)" />
+    <eval expected="2" xpath="count(//block[@prod-id='block-5c']/preceding-sibling::block/lineArea)" />
+    <!-- block 6b should end up in its own column, with two following lines from block 6c -->
+    <eval expected="1" xpath="count(//block[@prod-id='block-6b']/ancestor::flow)" />
+    <eval expected="2" xpath="count(//block[@prod-id='block-6b']/following-sibling::block/lineArea)" />
+  </checks>
+</testcase>
+

test/layoutengine/standard-testcases/keep_within-page_multi-column_overflow.xml

@@ -0,0 +1,58 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+  Licensed to the Apache Software Foundation (ASF) under one or more
+  contributor license agreements.  See the NOTICE file distributed with
+  this work for additional information regarding copyright ownership.
+  The ASF licenses this file to You under the Apache License, Version 2.0
+  (the "License"); you may not use this file except in compliance with
+  the License.  You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+-->
+<!-- $Id$ -->
+<testcase>
+  <info>
+    <p>This test checks for a remaining issue after adding support
+      for keep-*.within column (see Bugzilla 46905). 
+      keep-together.within-page does not work as expected in multi-column
+      layout. If the part does not fit into one page, it will ultimately
+      still be broken.
+    </p>
+  </info>
+  <fo>
+    <fo:root xmlns:fo="http://www.w3.org/1999/XSL/Format">
+      <fo:layout-master-set>
+        <fo:simple-page-master master-name="page" page-width="400pt" page-height="70pt">
+          <fo:region-body column-count="5" />
+        </fo:simple-page-master>
+      </fo:layout-master-set>
+      <fo:page-sequence master-reference="page" font-size="10pt">
+        <fo:flow flow-name="xsl-region-body">
+          <!-- block must be kept together within the same page -->
+          <fo:block id="block-4a" keep-together.within-page="always">
+            [BOB-4a] foo bar foo bar foo bar foo bar foo bar
+            foo bar foo bar foo bar foo bar foo bar foo bar
+            foo bar foo bar foo bar foo bar foo bar foo bar
+            foo bar foo bar foo bar foo bar foo bar foo bar
+            foo bar foo bar foo bar foo bar foo bar foo bar
+            foo bar foo bar foo bar foo bar foo bar foo bar
+            foo bar foo bar foo bar foo bar foo bar foo bar
+            foo bar foo bar foo bar foo bar foo bar foo bar
+            foo bar foo bar foo bar foo bar foo bar foo bar
+            foo bar foo bar foo bar foo bar foo bar foo bar
+            foo bar foo bar foo bar foo bar foo bar [EOB-4a]
+          </fo:block>
+        </fo:flow>
+      </fo:page-sequence>
+    </fo:root>
+  </fo>
+  <checks>
+    <eval expected="1" xpath="count(//pageViewport)" />
+  </checks>
+</testcase>

test/layoutengine/standard-testcases/table-row_keep-together.xml

@@ -64,10 +64,10 @@
     <element-list category="breaker" index="0">
       <box w="14400"/>
       <penalty w="0" p="0"/>
-      <box w="28800"/>
-      <penalty w="0" p="0"/>
       <box w="14400"/>
-      <skip>3</skip>
+      <penalty w="0" p="INF"/>
+      <box w="14400"/>
+      <skip>5</skip>
     </element-list>
   </checks>
 </testcase>

test/layoutengine/standard-testcases/table_keep-together.xml

@@ -101,7 +101,9 @@
     <element-list category="breaker" index="0">
       <box w="14400"/>
       <penalty w="0" p="0"/>
-      <box w="28800"/>
+      <box w="14400"/>
+      <penalty w="0" p="INF"/>
+      <box w="14400"/>
       <penalty w="0" p="INF"/>
       <box w="14400"/>
       <penalty w="0" p="0"/>