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
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
|
/*
* 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.area;
import org.apache.fop.area.inline.InlineArea;
import org.apache.fop.fo.Constants;
import java.io.Serializable;
import java.util.ArrayList;
import java.util.List;
/**
* The line area.
* This is a line area that contains inline areas.
*/
public class LineArea extends Area {
/**
* this class stores information about line width and potential adjustments
* that can be used in order to re-compute adjustement and / or indents when a
* page-number or a page-number-citation is resolved
*/
private class LineAdjustingInfo implements Serializable {
private int lineAlignment;
private int difference;
private int availableStretch;
private int availableShrink;
private double variationFactor;
private boolean bAddedToAreaTree;
private LineAdjustingInfo(int alignment, int diff,
int stretch, int shrink) {
lineAlignment = alignment;
difference = diff;
availableStretch = stretch;
availableShrink = shrink;
variationFactor = 1.0;
bAddedToAreaTree = false;
}
}
private LineAdjustingInfo adjustingInfo = null;
// this class can contain the dominant char styling info
// this means that many renderers can optimise a bit
private List inlineAreas = new ArrayList();
/**
* default constructor:
* nothing to do
*/
public LineArea() {
}
/**
* constructor with extra parameters:
* a new LineAdjustingInfo object is created
* @param alignment alignment of this line
* @param diff difference between content width and line width
* @param stretch the available stretch for any adjustments
* @param shrink the available shrink for any adjustments
*/
public LineArea(int alignment, int diff,
int stretch, int shrink) {
adjustingInfo = new LineAdjustingInfo(alignment, diff, stretch, shrink);
}
/**
* Add a child area to this line area.
*
* @param childArea the inline child area to add
*/
public void addChildArea(Area childArea) {
if (childArea instanceof InlineArea) {
addInlineArea((InlineArea)childArea);
// set the parent area for the child area
((InlineArea) childArea).setParentArea(this);
}
}
/**
* Add an inline child area to this line area.
*
* @param area the inline child area to add
*/
public void addInlineArea(InlineArea area) {
inlineAreas.add(area);
}
/**
* Get the inline child areas of this line area.
*
* @return the list of inline areas
*/
public List getInlineAreas() {
return inlineAreas;
}
/**
* Get the start indent of this line area.
* The start indent is used for offsetting the start of
* the inline areas for alignment or other indents.
*
* @return the start indent value
*/
public int getStartIndent() {
if (hasTrait(Trait.START_INDENT)) {
return getTraitAsInteger(Trait.START_INDENT);
} else {
return 0;
}
}
/**
* Updates the extents of the line area from its children.
*/
public void updateExtentsFromChildren() {
int ipd = 0;
int bpd = 0;
for (int i = 0, len = inlineAreas.size(); i < len; i++) {
ipd = Math.max(ipd, ((InlineArea)inlineAreas.get(i)).getAllocIPD());
bpd += ((InlineArea)inlineAreas.get(i)).getAllocBPD();
}
setIPD(ipd);
setBPD(bpd);
}
/**
* receive notification about the ipd variation of a descendant area
* and perform the needed adjustment, according to the alignment;
* in particular:
* <ul>
* <li>left-aligned text needs no adjustement;</li>
* <li>right-aligned text and centered text are handled locally,
* adjusting the indent of this LineArea;</li>
* <li>justified text requires a more complex adjustment, as the
* variation factor computed on the basis of the total
* stretch and shrink of the line must be applied in every
* descendant leaf areas (text areas and leader areas).</li>
* </ul>
* @param ipdVariation the difference between old and new ipd
*/
public void handleIPDVariation(int ipdVariation) {
switch (adjustingInfo.lineAlignment) {
case Constants.EN_START:
// nothing to do in this case
break;
case Constants.EN_CENTER:
// re-compute indent
addTrait(Trait.START_INDENT, new Integer(getStartIndent() - ipdVariation / 2));
break;
case Constants.EN_END:
// re-compute indent
addTrait(Trait.START_INDENT, new Integer(getStartIndent() - ipdVariation));
break;
case Constants.EN_JUSTIFY:
// compute variation factor
adjustingInfo.variationFactor *= (float) (adjustingInfo.difference - ipdVariation)
/ adjustingInfo.difference;
adjustingInfo.difference -= ipdVariation;
// if the LineArea has already been added to the area tree,
// call finalize(); otherwise, wait for the LineLM to call it
if (adjustingInfo.bAddedToAreaTree) {
finalise();
}
break;
default:
throw new RuntimeException();
}
}
/**
* apply the variation factor to all descendant areas
* and destroy the AdjustingInfo object if there are
* no UnresolvedAreas left
*/
public void finalise() {
if (adjustingInfo.lineAlignment == Constants.EN_JUSTIFY) {
// justified line: apply the variation factor
boolean bUnresolvedAreasPresent = false;
// recursively apply variation factor to descendant areas
for (int i = 0, len = inlineAreas.size(); i < len; i++) {
bUnresolvedAreasPresent |= ((InlineArea) inlineAreas.get(i))
.applyVariationFactor(adjustingInfo.variationFactor,
adjustingInfo.availableStretch,
adjustingInfo.availableShrink);
}
if (!bUnresolvedAreasPresent) {
// there are no more UnresolvedAreas:
// destroy the AdjustingInfo instance
adjustingInfo = null;
} else {
// this method will be called again later:
// the first time, it is called by the LineLM,
// afterwards it must be called by the LineArea itself
if (!adjustingInfo.bAddedToAreaTree) {
adjustingInfo.bAddedToAreaTree = true;
}
// reset the variation factor
adjustingInfo.variationFactor = 1.0;
}
} else {
// the line is not justified: the ipd variation has already
// been handled, modifying the line indent
}
}
}
|
