| /* |
| * 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.fo.flow.table; |
| |
| import java.util.BitSet; |
| import java.util.List; |
| |
| |
| |
| /** |
| * Helper class maintaining a record of occupied columns and an index to the next |
| * non-occupied column. |
| */ |
| public class ColumnNumberManager { |
| |
| private int columnNumber = 1; |
| |
| /** |
| * We use the term "index" instead of "number" because, unlike column numbers, it's |
| * 0-based. |
| */ |
| private BitSet usedColumnIndices = new BitSet(); |
| |
| /** |
| * Returns the number of the column that shall receive the next parsed cell. |
| * |
| * @return a column number, 1-based |
| */ |
| int getCurrentColumnNumber() { |
| return columnNumber; |
| } |
| |
| /** |
| * Flags columns <code>start</code> to <code>end</code> as occupied, |
| * and updates the number of the next available column. |
| * |
| * @param start start number, inclusive, 1-based |
| * @param end end number, inclusive |
| */ |
| void signalUsedColumnNumbers(int start, int end) { |
| for (int i = start - 1; i < end; i++) { |
| usedColumnIndices.set(i); |
| } |
| |
| columnNumber = end + 1; |
| while (usedColumnIndices.get(columnNumber - 1)) { |
| columnNumber++; |
| } |
| } |
| |
| /** |
| * Resets the record of occupied columns, taking into account columns already occupied |
| * by previous spanning cells, and computes the number of the first free column. |
| * |
| * @param pendingSpans List<PendingSpan> of possible spans over the next row |
| */ |
| void prepareForNextRow(List pendingSpans) { |
| usedColumnIndices.clear(); |
| PendingSpan pSpan; |
| for (int i = 0; i < pendingSpans.size(); i++) { |
| pSpan = (PendingSpan) pendingSpans.get(i); |
| if (pSpan != null) { |
| pSpan.rowsLeft--; |
| if (pSpan.rowsLeft == 0) { |
| pendingSpans.set(i, null); |
| } else { |
| usedColumnIndices.set(i); |
| } |
| } |
| } |
| // Set columnNumber to the first available column |
| columnNumber = 1; |
| while (usedColumnIndices.get(columnNumber - 1)) { |
| columnNumber++; |
| } |
| } |
| |
| /** |
| * Checks whether a given column-number is already in use |
| * for the current row. |
| * |
| * @param colNr the column-number to check |
| * @return true if column-number is already occupied |
| */ |
| public boolean isColumnNumberUsed(int colNr) { |
| return usedColumnIndices.get(colNr - 1); |
| } |
| |
| } |