aboutsummaryrefslogtreecommitdiffstats
path: root/src/java/org/apache/fop/layoutmgr/KeepUtil.java
blob: 1fd595ae0524f58d6027ef05a7ce6c9507a80d4c (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
/*
 * 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.layoutmgr;

import org.apache.fop.fo.Constants;
import org.apache.fop.fo.properties.Property;

/**
 * Utility class for working with keeps.
 */
public class KeepUtil {

    /**
     * Converts a keep property into an integer value.
     * <p>
     * Note: The conversion restricts the effectively available integer range by two values.
     * Integer.MIN_VALUE is used to represent the value "auto" and
     * Integer.MAX_VALUE is used to represebt the value "always".
     * @param keep the keep property
     * @return the keep value as an integer
     */
    public static int getKeepStrength(Property keep) {
        if (keep.isAuto()) {
            return BlockLevelLayoutManager.KEEP_AUTO;
        } else if (keep.getEnum() == Constants.EN_ALWAYS) {
            return BlockLevelLayoutManager.KEEP_ALWAYS;
        } else {
            return keep.getNumber().intValue();
        }
    }
    
    /**
     * Returns the penalty value to be used for a certain keep strength.
     * <ul>
     *   <li>"auto": returns 0</li>
     *   <li>"always": returns KnuthElement.INFINITE</li>
     *   <li>otherwise: returns KnuthElement.INFINITE - 1</li>
     * </ul>
     * @param keepStrength the keep strength
     * @return the penalty value
     */
    public static int getPenaltyForKeep(int keepStrength) {
        if (keepStrength == BlockLevelLayoutManager.KEEP_AUTO) {
            return 0;
        }
        int penalty = KnuthElement.INFINITE;
        if (keepStrength < BlockLevelLayoutManager.KEEP_ALWAYS) {
            penalty--;
        }
        return penalty;
    }
    
}