Helper class for spanning rows

git-svn-id: https://svn.apache.org/repos/asf/xmlgraphics/fop/trunk@194334 13f79535-47bb-0310-9956-ffa450edef68

diff --git a/src/org/apache/fop/fo/flow/RowSpanMgr.java b/src/org/apache/fop/fo/flow/RowSpanMgr.java
new file mode 100644 (file)
index 0000000..9685330
--- /dev/null
+++ b/src/org/apache/fop/fo/flow/RowSpanMgr.java
@@ -0,0 +1,125 @@
+/*-- $Id$ --
+ * Copyright (C) 2001 The Apache Software Foundation. All rights reserved.
+ * For details on use and redistribution please refer to the
+ * LICENSE file included with these sources.
+ */
+
+package org.apache.fop.fo.flow;
+
+import org.apache.fop.layout.Area;
+import java.util.Enumeration;
+
+public class RowSpanMgr {
+    class SpanInfo {
+       int cellHeight;
+       int totalRowHeight;
+       int rowsRemaining;
+       //int numCols; // both V and H span
+       TableCell cell;
+        
+       SpanInfo(TableCell cell, int cellHeight, int rowsSpanned) {
+           this.cell = cell;
+           this.cellHeight = cellHeight;
+           this.totalRowHeight = 0;
+           this.rowsRemaining = rowsSpanned;
+       }
+
+       /**
+        * Return the height remaining in the span.
+        */
+       int heightRemaining() {
+           int hl = cellHeight - totalRowHeight;
+           return (hl>0)? hl : 0;
+       }
+
+       boolean isInLastRow() {
+           return (rowsRemaining == 1);
+       }
+
+       boolean finishRow(int rowHeight) {
+           totalRowHeight += rowHeight;
+           if (--rowsRemaining == 0) {
+               if (cell != null) {
+                   cell.setRowHeight(totalRowHeight);
+               }
+               return true;
+           }
+           else return false;
+       }
+    }
+
+    private SpanInfo spanInfo[];
+
+    public RowSpanMgr(int numCols) {
+       this.spanInfo = new SpanInfo[numCols];
+    }
+
+    public void addRowSpan(TableCell cell, int firstCol, int numCols,
+                        int cellHeight, int rowsSpanned) {
+       spanInfo[firstCol-1] = new SpanInfo(cell, cellHeight, rowsSpanned);
+       for (int i=0; i <numCols-1; i++) {
+           spanInfo[firstCol+i] =
+               new SpanInfo(null, cellHeight, rowsSpanned); // copy!
+       }
+    }
+
+    public boolean isSpanned(int colNum) {
+       return (spanInfo[colNum-1] != null);
+    }
+
+
+    public TableCell getSpanningCell(int colNum) {
+       if (spanInfo[colNum-1] != null) {
+           return spanInfo[colNum-1].cell;
+       }
+       else return null;
+    }
+
+
+    /** Return true if any column has an unfinished vertical span.
+     */
+    public boolean hasUnfinishedSpans() {
+       for (int i=0; i < spanInfo.length; i++) {
+           if (spanInfo[i] != null)
+               return true;
+       }
+       return false;
+    }
+
+       /** Done with a row.
+        * Any spans with only one row left are done
+        * This means that we can now set the total height for this cell box
+        * Loop over all cells with spans and find number of rows remaining
+        * if rows remaining  = 1, set the height on the cell area and
+        * then remove the cell from the list of spanned cells. For other
+        * spans, add the rowHeight to the spanHeight.
+        */
+    public void finishRow(int rowHeight) {
+       for (int i=0; i < spanInfo.length; i++) {
+           if (spanInfo[i] != null &&
+               spanInfo[i].finishRow(rowHeight))
+               spanInfo[i] = null;
+           }
+       }
+
+    /**
+     * If the cell in this column is in the last row of its vertical
+     * span, return the height left. If it's not in the last row, or if
+     * the content height <= the content height of the previous rows
+     * of the span, return 0.
+     */
+    public int getRemainingHeight(int colNum) {
+        if (spanInfo[colNum-1] != null) {
+           return spanInfo[colNum-1].heightRemaining();
+       }
+       else return 0;
+    }
+
+    public boolean isInLastRow(int colNum) {
+        if (spanInfo[colNum-1] != null) {
+           return spanInfo[colNum-1].isInLastRow();
+       }
+       else return false;
+    }
+
+}