Handle the case where dynamic content is in the middle of a page, selecting the first variant

Patch by Seifeddine Dridi, applied with some modifications


git-svn-id: https://svn.apache.org/repos/asf/xmlgraphics/fop/branches/Temp_WhitespaceManagement@1578270 13f79535-47bb-0310-9956-ffa450edef68

src/java/org/apache/fop/fo/flow/MultiCase.java

@@ -33,13 +33,11 @@ import org.apache.fop.fo.ValidationException;
  * TODO implement validateChildNode()
  */
 public class MultiCase extends FObj {
-    // The value of properties relevant for fo:multi-case.
+
+    // FO multi-case properties
     private int startingState;
     private String caseName;
     private String caseTitle;
-    private MultiCaseHandler multiCaseHandler;
-    // private ToBeImplementedProperty caseName;
-    // private ToBeImplementedProperty caseTitle;
     // Unused but valid items, commented out for performance:
     //     private CommonAccessibility commonAccessibility;
     // End of property values
@@ -59,12 +57,6 @@ public class MultiCase extends FObj {
         startingState = pList.get(PR_STARTING_STATE).getEnum();
         caseName = pList.get(PR_CASE_NAME).getString();
         caseTitle = pList.get(PR_CASE_TITLE).getString();
-        if (startingState == EN_SHOW) {
-            MultiSwitch multiSwitch = (MultiSwitch) parent;
-            if (multiSwitch.getCurrentlyVisibleNode() == null) {
-                multiSwitch.setCurrentlyVisibleNode(this);
-            }
-        }
     }
 
     /**
@@ -91,14 +83,6 @@ public class MultiCase extends FObj {
         }
     }
 
-    @Override
-    protected void addChildNode(FONode child) throws FOPException {
-        if (child instanceof MultiCaseHandler) {
-            multiCaseHandler = (MultiCaseHandler) child;
-        }
-        super.addChildNode(child);
-    }
-
     /** @return the "starting-state" property */
     public int getStartingState() {
         return startingState;
@@ -126,12 +110,4 @@ public class MultiCase extends FObj {
         return caseTitle;
     }
 
-    public boolean hasToggle() {
-        return multiCaseHandler != null;
-    }
-
-    MultiCaseHandler getHandler() {
-        return multiCaseHandler;
-    }
-
 }

src/java/org/apache/fop/fo/flow/MultiCaseHandler.java

@@ -1,38 +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.
- */
-
-package org.apache.fop.fo.flow;
-
-import org.apache.fop.apps.FOPException;
-
-/**
- * This interface is used in conjunction with {@link MultiSwitch}
- * to implement a callback system for handling fo:multi-case elements.
- */
-
-public interface MultiCaseHandler {
-
-    /**
-     * A filtering function used to select one or more fo:multi-case
-     * elements, children of {@link MultiSwitch}.
-     *
-     * @param multiSwitch parent of the fo:multi-case elements to filter
-     * @throws FOPException
-     */
-    void filter(MultiSwitch multiSwitch) throws FOPException;
-
-}

src/java/org/apache/fop/fo/flow/MultiSwitch.java

@@ -68,22 +68,6 @@ public class MultiSwitch extends FObj {
         super.endOfNode();
     }
 
-    @Override
-    public void finalizeNode() throws FOPException {
-        if (autoToggle.equals("best-fit")) {
-            // Nothing to do in this case
-            setCurrentlyVisibleNode(null);
-        } else {
-            FONodeIterator nodeIter = getChildNodes();
-            while (nodeIter.hasNext()) {
-                MultiCase multiCase = (MultiCase) nodeIter.next();
-                if (multiCase.hasToggle()) {
-                    multiCase.getHandler().filter(this);
-                }
-            }
-        }
-    }
-
     /**
      * {@inheritDoc}
      * <br>XSL Content Model: (multi-case+)

src/java/org/apache/fop/fo/flow/MultiToggle.java

@@ -33,7 +33,7 @@ import org.apache.fop.fo.properties.StringProperty;
  * Class modelling the <a href="http://www.w3.org/TR/xsl/#fo_multi-toggle">
  * <code>fo:multi-toggle<code></a> property.
  */
-public class MultiToggle extends FObj implements MultiCaseHandler {
+public class MultiToggle extends FObj {
     // The value of properties relevant for fo:multi-toggle (commented out for performance).
     //     private CommonAccessibility commonAccessibility;
      public StringProperty prSwitchTo;
@@ -92,39 +92,4 @@ public class MultiToggle extends FObj implements MultiCaseHandler {
         return FO_MULTI_TOGGLE;
     }
 
-    public void filter(MultiSwitch multiSwitch) throws FOPException {
-        if (multiSwitch.getCurrentlyVisibleNode() == null) {
-            multiSwitch.setCurrentlyVisibleNode(parent);
-        }
-
-        FONode currentlyVisibleMultiCase = multiSwitch.getCurrentlyVisibleNode();
-
-        if (prSwitchTo.getString().equals("xsl-any")) {
-//            NoOp
-        } else if (prSwitchTo.getString().equals("xsl-preceding")) {
-            FONodeIterator nodeIter = multiSwitch.getChildNodes(currentlyVisibleMultiCase);
-            if (nodeIter != null) {
-                if (!nodeIter.hasPrevious()) {
-                    currentlyVisibleMultiCase = nodeIter.lastNode();
-                } else {
-                    currentlyVisibleMultiCase = nodeIter.previousNode();
-                }
-            }
-        } else if (prSwitchTo.getString().equals("xsl-following")) {
-            FONodeIterator nodeIter = multiSwitch.getChildNodes(currentlyVisibleMultiCase);
-            if (nodeIter != null) {
-                //Ignore the first node
-                nodeIter.next();
-                if (!nodeIter.hasNext()) {
-                    currentlyVisibleMultiCase = nodeIter.firstNode();
-                } else {
-                    currentlyVisibleMultiCase = nodeIter.nextNode();
-                }
-            }
-        } else {
-            // Pick an fo:multi-case that matches a case-name...
-        }
-
-        multiSwitch.setCurrentlyVisibleNode(currentlyVisibleMultiCase);
-    }
 }

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

@@ -20,7 +20,10 @@ package org.apache.fop.layoutmgr;
 import java.util.LinkedList;
 import java.util.List;
 
-/*
+import org.apache.fop.fo.flow.MultiSwitch;
+import org.apache.fop.layoutmgr.BestFitPenalty.Variant;
+
+/**
  * Utility class used in {@link MultiSwitchLayoutManager}
  * to handle  the <i>best-fit</i> property value if specified in {@link MultiSwitch}
  */
@@ -30,32 +33,27 @@ public final class BestFitLayoutUtils {
 
     static class BestFitPosition extends Position {
 
-        public List<ListElement> knuthList;
+        private List<ListElement> knuthList;
 
         public BestFitPosition(LayoutManager lm) {
             super(lm);
         }
 
-        public BestFitPosition(LayoutManager lm, List<ListElement> knuthList) {
-            super(lm);
-            this.knuthList = knuthList;
-        }
-
         public List<Position> getPositionList() {
             List<Position> positions = new LinkedList<Position>();
             if (knuthList != null) {
                 SpaceResolver.performConditionalsNotification(knuthList, 0, knuthList.size() - 1, -1);
                 for (ListElement elem : knuthList) {
-                    if (elem.getPosition() != null && elem.getLayoutManager() != null) {
-                        positions.add(elem.getPosition());
-                    }
+                    positions.add(elem.getPosition());
                 }
             }
             return positions;
         }
+
         public void setKnuthList(List<ListElement> knuthList) {
             this.knuthList = knuthList;
         }
+
     }
 
     public static List<ListElement> getKnuthList(LayoutManager lm,
@@ -65,14 +63,23 @@ public final class BestFitLayoutUtils {
 
         BestFitPenalty bestFitPenalty = new BestFitPenalty(new BestFitPosition(lm));
         for (List<ListElement> childList : childrenLists) {
+            // TODO Doing space resolution here is not correct.
+            // Space elements will simply be nulled.
             SpaceResolver.resolveElementList(childList);
             int contentLength = ElementListUtils.calcContentLength(childList);
-            bestFitPenalty.addVariant(childList, contentLength);
+            bestFitPenalty.addVariant(new Variant(childList, contentLength));
         }
-        // TODO Adding the two enclosing boxes is definitely a dirty hack.
-        // Let's leave it like that for now, until I find a proper fix.
+        // TODO Adding two enclosing boxes is definitely a dirty hack.
+        // The first box forces the breaking algorithm to consider the penalty
+        // in case there are no elements preceding it
+        // and the last box prevents the glue and penalty from getting deleted
+        // when they are at the end of the Knuth list.
         knuthList.add(new KnuthBox(0, new Position(lm), false));
         knuthList.add(bestFitPenalty);
+        Variant firstVariant = bestFitPenalty.getVariants().get(0);
+        BestFitPosition pos = new BestFitPosition(lm);
+        pos.setKnuthList(firstVariant.knuthList);
+        knuthList.add(new KnuthGlue(firstVariant.width, 0, 0, pos, false));
         knuthList.add(new KnuthBox(0, new Position(lm), false));
         return knuthList;
     }
@@ -82,9 +89,8 @@ public final class BestFitLayoutUtils {
         // "unwrap" the NonLeafPositions stored in parentIter
         // and put them in a new list;
         LinkedList<Position> positionList = new LinkedList<Position>();
-        Position pos;
         while (posIter.hasNext()) {
-            pos = posIter.next();
+            Position pos = posIter.next();
             if (pos instanceof BestFitPosition) {
                 positionList.addAll(((BestFitPosition) pos).getPositionList());
             } else {

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

@@ -27,11 +27,11 @@ import org.apache.fop.layoutmgr.BestFitLayoutUtils.BestFitPosition;
 /**
  * A type of penalty used to specify a set of alternatives for the layout engine
  * to choose from. The chosen alternative must have an occupied size
- * that is less than the available BPD of the current page.
+ * less than the remaining BPD on the active page.
  */
 public class BestFitPenalty extends KnuthPenalty {
 
-    public class Variant {
+    public static class Variant {
 
         public final List<ListElement> knuthList;
         public final int width;
@@ -40,13 +40,14 @@ public class BestFitPenalty extends KnuthPenalty {
             this.knuthList = knuthList;
             this.width = width;
         }
+
         public KnuthElement toPenalty() {
             return new KnuthPenalty(width, 0, false, null, false);
         }
+
     }
 
     private final BestFitPosition bestFitPosition;
-
     private final List<Variant> variantList;
 
     public BestFitPenalty(BestFitPosition pos) {
@@ -55,15 +56,15 @@ public class BestFitPenalty extends KnuthPenalty {
         variantList = new ArrayList<Variant>();
     }
 
-    public void addVariant(List<ListElement> knuthList, int width) {
-        variantList.add(new Variant(knuthList, width));
+    public void addVariant(Variant variant) {
+        variantList.add(variant);
     }
 
-    public void activatePenalty(Variant bestVariant) {
+    public void setActiveVariant(Variant bestVariant) {
         bestFitPosition.setKnuthList(bestVariant.knuthList);
     }
 
-    public List<Variant> getVariantList() {
+    public List<Variant> getVariants() {
         return variantList;
     }
 

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

@@ -24,10 +24,7 @@ import java.util.List;
 import org.apache.fop.area.Area;
 import org.apache.fop.area.Block;
 import org.apache.fop.area.LineArea;
-import org.apache.fop.fo.FONode;
-import org.apache.fop.fo.FONode.FONodeIterator;
 import org.apache.fop.fo.FObj;
-import org.apache.fop.fo.flow.MultiSwitch;
 
 public class MultiSwitchLayoutManager extends BlockStackingLayoutManager {
 
@@ -41,7 +38,7 @@ public class MultiSwitchLayoutManager extends BlockStackingLayoutManager {
     public List<ListElement> getNextKnuthElements(LayoutContext context, int alignment) {
 
         referenceIPD = context.getRefIPD();
-        List<List<ListElement>> childrenLists = new LinkedList<List<ListElement>>();
+        List<List<ListElement>> childrenLists = new ArrayList<List<ListElement>>();
         LayoutManager childLM;
         while ((childLM = getChildLM()) != null) {
             if (!childLM.isFinished()) {
@@ -58,33 +55,6 @@ public class MultiSwitchLayoutManager extends BlockStackingLayoutManager {
         return BestFitLayoutUtils.getKnuthList(this, childrenLists);
     }
 
-    @Override
-    protected List<LayoutManager> createChildLMs(int size) {
-        MultiSwitch multiSwitch = (MultiSwitch) getFObj();
-        if (multiSwitch.getCurrentlyVisibleNode() != null) {
-            List<LayoutManager> newLMs = new ArrayList<LayoutManager>(size);
-            if (childLMs.size() == 0) {
-                createMultiCaseLM(multiSwitch.getCurrentlyVisibleNode());
-                return new ArrayList<LayoutManager>(size);
-            }
-            return newLMs;
-        } else {
-            return super.createChildLMs(size);
-        }
-    }
-
-    private void createMultiCaseLM(FONode multiCase) {
-        FONodeIterator childIter = multiCase.getChildNodes();
-        while (childIter.hasNext()) {
-            List<LayoutManager> newLMs = new ArrayList<LayoutManager>(1);
-            getPSLM().getLayoutManagerMaker()
-            .makeLayoutManagers((childIter.nextNode()), newLMs);
-            if (!newLMs.isEmpty()) {
-                this.getParent().addChildLM(newLMs.get(0));
-            }
-        }
-    }
-
     @Override
     public Keep getKeepTogether() {
         return Keep.KEEP_AUTO;
@@ -151,6 +121,8 @@ public class MultiSwitchLayoutManager extends BlockStackingLayoutManager {
 
         AreaAdditionUtil.addAreas(this, newPosIter, context);
         flush();
+        // TODO removing the following line forces the generated area
+        // to be rendered twice in some cases...
         curBlockArea = null;
     }
 

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

@@ -99,7 +99,7 @@ class PageBreakingAlgorithm extends BreakingAlgorithm {
     private int currentKeepContext = Constants.EN_AUTO;
     private KnuthNode lastBeforeKeepContextSwitch;
 
-    /** Holds the variant that should be assigned to the next node to be created */
+    /** Holds the variant of a dynamic content that must be attached to the next page node */
     private Variant variant;
 
     /**
@@ -458,7 +458,6 @@ class PageBreakingAlgorithm extends BreakingAlgorithm {
     /** {@inheritDoc} */
     @Override
     protected void considerLegalBreak(KnuthElement element, int elementIdx) {
-        variant = null;
         if (element.isPenalty()) {
             int breakClass = ((KnuthPenalty) element).getBreakClass();
             switch (breakClass) {
@@ -526,6 +525,7 @@ class PageBreakingAlgorithm extends BreakingAlgorithm {
         int actualWidth = totalWidth - pageNode.totalWidth;
         int footnoteSplit;
         boolean canDeferOldFN;
+        variant = null;
         if (element.isPenalty()) {
             if (element instanceof BestFitPenalty) {
                 actualWidth += handleBestFitPenalty(activeNode, (BestFitPenalty) element, elementIndex);
@@ -592,7 +592,7 @@ class PageBreakingAlgorithm extends BreakingAlgorithm {
     }
 
     private int handleBestFitPenalty(KnuthNode activeNode, BestFitPenalty penalty, int elementIndex) {
-        for (Variant var : penalty.getVariantList()) {
+        for (Variant var : penalty.getVariants()) {
             int difference = computeDifference(activeNode, var.toPenalty(), elementIndex);
             double r = computeAdjustmentRatio(activeNode, difference);
             if (r >= -1.0) {
@@ -1015,11 +1015,11 @@ class PageBreakingAlgorithm extends BreakingAlgorithm {
                             int total) {
         //int difference = (bestActiveNode.line < total)
         //      ? bestActiveNode.difference : bestActiveNode.difference + fillerMinWidth;
-        // Check if the given node has an attached dynamic content
+        // Check if the given node has an attached variant of a dynamic content
         KnuthPageNode pageNode = (KnuthPageNode) bestActiveNode;
         if (pageNode.variant != null) {
             BestFitPenalty penalty = (BestFitPenalty) par.get(pageNode.position);
-            penalty.activatePenalty(pageNode.variant);
+            penalty.setActiveVariant(pageNode.variant);
         }
         int difference = bestActiveNode.difference;
         if (difference + bestActiveNode.availableShrink < 0) {

test/layoutengine/standard-testcases/multi-switch_best-fit.xml

@@ -0,0 +1,51 @@
+<?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.
+-->
+<testcase>
+  <info>
+    <p>
+      Basic test for fo:multi-switch using the whitespace management extension.
+    </p>
+  </info>
+  <fo>
+    <fo:root xmlns:fo="http://www.w3.org/1999/XSL/Format" xmlns:fox="http://xmlgraphics.apache.org/fop/extensions">
+      <fo:layout-master-set>
+        <fo:simple-page-master master-name="page" page-height="70pt" page-width="120pt" 
+          margin="10pt">
+          <fo:region-body/>
+        </fo:simple-page-master>
+      </fo:layout-master-set>
+      <fo:page-sequence master-reference="page">
+        <fo:flow flow-name="xsl-region-body">
+          <fo:multi-switch fox:auto-toggle="best-fit">
+            <fo:multi-case>
+              <fo:block>First variant</fo:block>
+            </fo:multi-case>
+            <fo:multi-case>
+              <fo:block>Second variant</fo:block>
+            </fo:multi-case>
+          </fo:multi-switch>
+        </fo:flow>
+      </fo:page-sequence>
+    </fo:root>
+  </fo>
+  <checks>
+    <eval expected="1"       xpath="count(//flow/block)"/>
+    <eval expected="First variant" xpath="//flow/block"/>
+    <eval expected="14400"         xpath="//flow/block/@bpd"/>
+  </checks>
+</testcase>

test/layoutengine/standard-testcases/multi-switch_best-fit_middle-page.xml

@@ -0,0 +1,63 @@
+<?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.
+-->
+<testcase>
+  <info>
+    <p>
+      Dynamic content in the middle of a page: the first variant is selected.
+    </p>
+  </info>
+  <fo>
+    <fo:root xmlns:fo="http://www.w3.org/1999/XSL/Format" xmlns:fox="http://xmlgraphics.apache.org/fop/extensions">
+      <fo:layout-master-set>
+        <fo:simple-page-master master-name="page" page-height="70pt" page-width="120pt" 
+          margin="10pt">
+          <fo:region-body/>
+        </fo:simple-page-master>
+      </fo:layout-master-set>
+      <fo:page-sequence master-reference="page">
+        <fo:flow flow-name="xsl-region-body" font-size="8pt" line-height="10pt">
+          <fo:block>Before the multi-switch</fo:block>
+          <fo:multi-switch fox:auto-toggle="best-fit">
+            <fo:multi-case>
+              <fo:block>First variant</fo:block>
+            </fo:multi-case>
+            <fo:multi-case>
+              <fo:block>Second variant</fo:block>
+              <fo:block>Second variant</fo:block>
+            </fo:multi-case>
+          </fo:multi-switch>
+          <fo:block>After the multi-switch</fo:block>
+          <fo:block>Filler 1</fo:block>
+          <fo:block>Filler 2</fo:block>
+          <fo:block>This should be on page 2.</fo:block>
+        </fo:flow>
+      </fo:page-sequence>
+    </fo:root>
+  </fo>
+  <checks>
+    <eval expected="2"                   xpath="count(//pageViewport)"/>
+    <eval expected="5"                   xpath="count(//pageViewport[1]//flow/block)"/>
+    <eval expected="Before the multi-switch"   xpath="//pageViewport[1]//flow/block[1]"/>
+    <eval expected="First variant"             xpath="//pageViewport[1]//flow/block[2]"/>
+    <eval expected="After the multi-switch"    xpath="//pageViewport[1]//flow/block[3]"/>
+    <eval expected="Filler 1"                  xpath="//pageViewport[1]//flow/block[4]"/>
+    <eval expected="Filler 2"                  xpath="//pageViewport[1]//flow/block[5]"/>
+    <eval expected="1"                   xpath="count(//pageViewport[2]//flow/block)"/>
+    <eval expected="This should be on page 2." xpath="//pageViewport[2]//flow/block[1]"/>
+  </checks>
+</testcase>

test/layoutengine/standard-testcases/multi-switch_best-fit_multiple-variants.xml

@@ -0,0 +1,129 @@
+<?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.
+-->
+<testcase>
+  <info>
+    <p>
+      Check that the right variant is being selected (if any), depending on the space left on the 
+      page.
+    </p>
+  </info>
+  <fo>
+    <fo:root xmlns:fo="http://www.w3.org/1999/XSL/Format" 
+      xmlns:fox="http://xmlgraphics.apache.org/fop/extensions">
+      <fo:layout-master-set>
+        <fo:simple-page-master master-name="page"
+          page-height="70pt" page-width="220pt" margin="10pt">
+          <fo:region-body background-color="#F0F0F0"/>
+        </fo:simple-page-master>
+      </fo:layout-master-set>
+      <fo:page-sequence master-reference="page" font-size="8pt" line-height="10pt">
+        <fo:flow flow-name="xsl-region-body">
+          <fo:block>Page 1 line 1</fo:block>
+          <fo:block
+            space-before.minimum="15pt"
+            space-before.optimum="25pt"
+            space-before.maximum="30pt">Page 1 line 2</fo:block>
+          <fo:block>Page 1 line 3</fo:block>
+          <fo:block font-size="16pt" line-height="20pt">Filler</fo:block>
+          <fo:block>Before the multi-switch</fo:block>
+          <fo:multi-switch fox:auto-toggle="best-fit">
+            <fo:multi-case>
+              <fo:block>Variant 1 line 1</fo:block>
+              <fo:block>Variant 1 line 2</fo:block>
+            </fo:multi-case>
+            <fo:multi-case>
+              <fo:block>Variant 2 line 1</fo:block>
+            </fo:multi-case>
+          </fo:multi-switch>
+          <fo:block>This text should be on page 3.</fo:block>
+        </fo:flow>
+      </fo:page-sequence>
+
+      <fo:page-sequence master-reference="page" font-size="8pt" line-height="10pt">
+        <fo:flow flow-name="xsl-region-body">
+          <fo:block>Page 1 line 1</fo:block>
+          <fo:block
+            space-before.minimum="20pt"
+            space-before.optimum="25pt"
+            space-before.maximum="35pt">Page 1 line 2</fo:block>
+          <fo:block>Page 2 line 1</fo:block>
+          <fo:block font-size="16pt" line-height="20pt">Filler</fo:block>
+          <fo:block>Before the multi-switch</fo:block>
+          <fo:multi-switch fox:auto-toggle="best-fit">
+            <fo:multi-case>
+              <fo:block>Variant 1 line 1</fo:block>
+              <fo:block>Variant 1 line 2</fo:block>
+            </fo:multi-case>
+            <fo:multi-case>
+              <fo:block>Variant 2 line 1</fo:block>
+            </fo:multi-case>
+          </fo:multi-switch>
+          <fo:block>This text should be on page 3.</fo:block>
+        </fo:flow>
+      </fo:page-sequence>
+
+      <fo:page-sequence master-reference="page" font-size="8pt" line-height="10pt">
+        <fo:flow flow-name="xsl-region-body">
+          <fo:block>Page 1 line 1</fo:block>
+          <fo:block
+            space-before.minimum="20pt"
+            space-before.optimum="25pt"
+            space-before.maximum="35pt">Page 1 line 2</fo:block>
+          <fo:block>Page 2 line 1</fo:block>
+          <fo:block>Page 2 line 2</fo:block>
+          <fo:block font-size="16pt" line-height="20pt">Filler</fo:block>
+          <fo:block>Before the multi-switch</fo:block>
+          <fo:multi-switch fox:auto-toggle="best-fit">
+            <fo:multi-case>
+              <fo:block>Variant 1 line 1</fo:block>
+              <fo:block>Variant 1 line 2</fo:block>
+            </fo:multi-case>
+            <fo:multi-case>
+              <fo:block>Variant 2 line 1</fo:block>
+            </fo:multi-case>
+          </fo:multi-switch>
+          <fo:block>This text should be on page 3.</fo:block>
+        </fo:flow>
+      </fo:page-sequence>
+    </fo:root>
+  </fo>
+  <checks>
+    <!-- 1. First variant -->
+    <eval expected="3"                        xpath="count(//pageSequence[1]/pageViewport)"/>
+    <eval expected="Filler"                         xpath="//pageSequence[1]/pageViewport[2]//flow/block[1]"/>
+    <eval expected="Variant 1 line 1"               xpath="//pageSequence[1]/pageViewport[2]//flow/block[3]/block/block[1]"/>
+    <eval expected="This text should be on page 3." xpath="//pageSequence[1]/pageViewport[3]//flow/block[1]"/>
+
+    <!-- 2. Second variant -->
+    <eval expected="3"                        xpath="count(//pageSequence[2]/pageViewport)"/>
+    <eval expected="Page 2 line 1"                  xpath="//pageSequence[2]/pageViewport[2]//flow/block[1]"/>
+    <eval expected="Variant 2 line 1"               xpath="//pageSequence[2]/pageViewport[2]//flow/block[4]/block/block[1]"/>
+    <eval expected="This text should be on page 3." xpath="//pageSequence[2]/pageViewport[3]//flow/block[1]"/>
+
+    <!-- 3. No variant -->
+    <eval expected="3"                        xpath="count(//pageSequence[3]/pageViewport)"/>
+    <eval expected="4"                        xpath="count(//pageSequence[3]/pageViewport[2]//flow/block)"/>
+    <eval expected="Page 2 line 1"                  xpath="//pageSequence[3]/pageViewport[2]//flow/block[1]"/>
+    <eval expected="Page 2 line 2"                  xpath="//pageSequence[3]/pageViewport[2]//flow/block[2]"/>
+    <eval expected="Filler"                         xpath="//pageSequence[3]/pageViewport[2]//flow/block[3]"/>
+    <eval expected="Before the multi-switch"        xpath="//pageSequence[3]/pageViewport[2]//flow/block[4]"/>
+    <eval expected="2"                        xpath="count(//pageSequence[3]/pageViewport[3]//flow/block)"/>
+    <eval expected="Variant 1 line 1"               xpath="//pageSequence[3]/pageViewport[3]//flow/block[1]/block/block[1]"/>
+    <eval expected="This text should be on page 3." xpath="//pageSequence[3]/pageViewport[3]//flow/block[2]"/>
+  </checks>
+</testcase>