fixed a looping problem, added more comments

git-svn-id: https://svn.apache.org/repos/asf/xmlgraphics/fop/trunk@195369 13f79535-47bb-0310-9956-ffa450edef68

1 files changed, 73 insertions, 9 deletions

diff --git a/src/org/apache/fop/layoutmgr/LineLayoutManager.java b/src/org/apache/fop/layoutmgr/LineLayoutManager.java
index 445ce66cb..ad79b552f 100644
--- a/src/org/apache/fop/layoutmgr/LineLayoutManager.java
+++ b/src/org/apache/fop/layoutmgr/LineLayoutManager.java
@@ -36,6 +36,13 @@ import java.util.ArrayList;
 /**
  * LayoutManager for lines. It builds one or more lines containing
  * inline areas generated by its sub layout managers.
+ * A break is found for each line which may contain one of more
+ * breaks from the child layout managers.
+ * Once a break is found then it is return for the parent layout
+ * manager to handle.
+ * When the areas are being added to the page this manager
+ * creates a line area to contain the inline areas added by the
+ * child layout managers.
  */
 public class LineLayoutManager extends InlineStackingLayoutManager {
 
@@ -44,7 +51,6 @@ public class LineLayoutManager extends InlineStackingLayoutManager {
      * Each value holds the start and end indexes into a List of
      * inline break positions.
      */
-    // private static class LineBreakPosition implements Position {
     private static class LineBreakPosition extends LeafPosition {
         // int m_iPos;
         double m_dAdjust; // Percentage to adjust (stretch or shrink)
@@ -82,8 +88,18 @@ public class LineLayoutManager extends InlineStackingLayoutManager {
     // inline start pos when adding areas
     int iStartPos = 0;    
 
+    /**
+     * Create a new Line Layout Manager.
+     * This is used by the block layout manager to create
+     * line managers for handling inline areas flowing into line areas.
+     *
+     * @param fobj the block the is creating the lines
+     * @param lms the list of layout managers that will add inline areas
+     * @param lh the default line height
+     * @param l the default lead, from top to baseline
+     * @param f the default follow, from baseline to bottom
+     */
     public LineLayoutManager(FObj fobj, List lms, int lh, int l, int f) {
-        //super(fobj, lms.listIterator(), lh, l, f);
         super(fobj, lms.listIterator());
         lineHeight = lh;
         lead = l;
@@ -91,6 +107,10 @@ public class LineLayoutManager extends InlineStackingLayoutManager {
         init(); // Normally done when started by parent!
     }
 
+    /**
+     * Initialize the properties for this layout manager.
+     * The properties are from the block area.
+     */
     protected void initProperties(PropertyManager propMgr) {
         MarginProps marginProps = propMgr.getMarginProps();
         m_iIndents = marginProps.startIndent + marginProps.endIndent;
@@ -103,7 +123,9 @@ public class LineLayoutManager extends InlineStackingLayoutManager {
     /**
      * Call child layout managers to generate content.
      * This gets the next break which is a full line.
-     * 
+     *
+     * @param context the layout context for finding breaks
+     * @return the next break position
      */
     public BreakPoss getNextBreakPoss(LayoutContext context) {
         // Get a break from currently active child LM
@@ -126,6 +148,8 @@ public class LineLayoutManager extends InlineStackingLayoutManager {
         clearPrevIPD();
         int iPrevLineEnd = m_vecInlineBreaks.size();
 
+        m_prevBP = null;
+
         while ((curLM = getChildLM()) != null) {
             // INITIALIZE LAYOUT CONTEXT FOR CALL TO CHILD LM
             // First break for the child LM in each of its areas
@@ -302,8 +326,6 @@ public class LineLayoutManager extends InlineStackingLayoutManager {
         }
     }
 
-
-
     private BreakPoss getBestBP(ArrayList vecPossEnd) {
         if (vecPossEnd.size() == 1) {
             return ((BreakCost) vecPossEnd.get(0)).getBP();
@@ -389,7 +411,16 @@ public class LineLayoutManager extends InlineStackingLayoutManager {
         }
     }
 
-
+    /**
+     * Make a line break for returning as the next break.
+     * This makes the line break and calculates the height and
+     * ipd adjustment factors.
+     *
+     * @param prevLineEnd previous line break index
+     * @param target the target ipd value
+     * @param textalign the text align in operation for this line
+     * @return the line break position
+     */
     private BreakPoss makeLineBreak(int prevLineEnd, MinOptMax target,
                                     int textalign) {
         // make a new BP
@@ -509,6 +540,11 @@ public class LineLayoutManager extends InlineStackingLayoutManager {
         return curLineBP;
     }
 
+    /**
+     * Reset the positions to the given position.
+     *
+     * @param resetPos the position to reset to
+     */
     public void resetPosition(Position resetPos) {
         if (resetPos == null) {
             iStartPos = 0;
@@ -525,6 +561,12 @@ public class LineLayoutManager extends InlineStackingLayoutManager {
         }
     }
 
+    /**
+     * Add the areas with the break points.
+     *
+     * @param parentIter the iterator of break positions
+     * @param context the context for adding areas
+     */
     public void addAreas(PositionIterator parentIter,
                          LayoutContext context) {
         addAreas(parentIter, 0.0);
@@ -536,8 +578,14 @@ public class LineLayoutManager extends InlineStackingLayoutManager {
     // Generate and add areas to parent area
     // Set size etc
     // dSpaceAdjust should reference extra space in the BPD
+    /**
+     * Add the areas with the associated space adjustment.
+     *
+     * @param parentIter the iterator of breaks positions
+     * @param dSpaceAdjust the space adjustment
+     */
     public void addAreas(PositionIterator parentIter, double dSpaceAdjust) {
-        LayoutManager childLM ;
+        LayoutManager childLM;
         //int iStartPos = 0;
         LayoutContext lc = new LayoutContext(0);
         while (parentIter.hasNext()) {
@@ -563,13 +611,29 @@ public class LineLayoutManager extends InlineStackingLayoutManager {
                 lc.setLeadingSpace(lc.getTrailingSpace());
                 lc.setTrailingSpace(new SpaceSpecifier(false));
             }
-            addSpace(lineArea, lc.getTrailingSpace().resolve(true),
-                     lc.getSpaceAdjust());
+            // when can this be null?
+            if(lc.getTrailingSpace() != null) {
+                addSpace(lineArea, lc.getTrailingSpace().resolve(true),
+                         lc.getSpaceAdjust());
+            }
             parentLM.addChild(lineArea);
         }
         setCurrentArea(null); // ?? necessary
     }
 
+    /**
+     * Add an unresolved area.
+     * If a child layout manager needs to add an unresolved area
+     * for page reference or linking then this intercepts it for
+     * line area handling.
+     * A line area may need to have the inline areas adjusted
+     * to properly fill the line area. This adds a resolver that
+     * resolves the inline area and can do the necessary
+     * adjustments to the line and inline areas.
+     *
+     * @param id the id reference of the resolveable
+     * @param res the resolveable object
+     */
     public void addUnresolvedArea(String id, Resolveable res) {
         // create a resolveable class that handles ipd
         // adjustment for the current line