123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106 |
- /*
- * 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);
- }
-
- }
|